Tag Archives: Global Warming

How warm was 2015, how warm will 2016 be?

January 4, 2016Uncategorized2016, Climate Change, Climate Change, El Nino, Global Warming, Global Warming, Warmest YearGreg Laden

The year that just finished, 2015, was the warmest year recorded in the instrumental record. The actual data for December is not officially available yet, but my friend and colleague John Abraham keeps track of the global surface temperature daily and has done an amazing job at estimating the final temperature anomaly value that is eventually reported in each of several databases. He has provided a graph using his estimated value, above.

There are two major contributing factors, maybe three depending on how you count everything, to 2015 being the warmest year. The main factor is, of course, global warming. The Earth’s surface temperature is going up because of the Greenhouse Effect, and along with that, we are seeing remarkable climate disruption, including floods, other inclement weather, and a host of problems. On top of this, the last part of 2015 saw a strong El Niño, the strongest recorded in historic documents. This weather event, which involves the departure of ocean-stored heat in the Pacific into the atmosphere, is continuing, though it will likely peak soon and begin to decline (but see below). That is all we need, really, to explain 2015, but there may be a third factor that overlaps with those two worth singling out. Some areas of the world’s oceans, including parts of the Atlantic and the Pacific (outside the usual Pacific El Niño warming effect), have been exceptionally warm on the surface. This is really just part of the whole anthropogenic global warming thing, but seems more extreme this year. In other words, it seems as though the ocean is putting more stored heat into the atmosphere than just that part that El Niño contributes, and the surface temperature measurements include sea surface temperature.

How warm will 2016 be? Playing the odds, it would always be a good bet that the next year will be warmer than the current year, on average, because global warming continues. However, even as the surface temperature trends upwards over time, the actual measurements from year to year wiggle up and down a fair amount owing to a number of factors. So, on average, if you bet on warming for each subsequent year you would overall win, but you might lose that bet during some years. (In fact, you could lose your shirt if warming happens to occur with infrequent large spikes interspersed among years that see modest cooling, so be careful!)

However, 2016 is actually more than 50-something percent likely to be warm compared to 2015. One reason is that El Nino will continue for the first part of 2016, and the effect that El Niño has on surface temperature is delayed. The peak effect occurs several months after the peak of the El Niño itself. So, if El Niño peaks in February, for example, we will have global warming + El Niño enhancement through early summer. So at least half of the months of 2016 will be very warm. There is a very good chance, then, that 2016 will be warmer even than 2015.

Mark Boslough, a physicist who writes quite a bit about Global Warming, has made a bet along these lines. He is not betting that 2016 will be warmer than 2015, but he is betting on the long term upward trend of the Earth’s surface temperatures. He’s really putting his money where his mouth is, by the way, to the tune of 25,000 US dollars. The details of his bet are here. So far, as far as I know, none of those in the climate science denial world have taken him up.

Michael Mann on El Niño, COP15, Future Climate Change

January 1, 2016UncategorizedClimate Change, Climate Change, El Nino, Global Warming, Severe weatherGreg Laden

Despite the devastating storms across the country the last few weeks, NASA is forecasting the worst is yet to come. Michael Mann, author of “Dire Predictions: Understanding Climate Change” joins to discuss.

Climate change: up close and personal in Missouri

December 31, 2015UncategorizedClimate Change, Climate Change, Floods, Global Warming, Global Warming, Guest Post, Missouri Flooding, Severe weather, weather whiplashGreg Laden

This is a guest post by Larry Lazar.

If you have had the news on the last day or two you may have seen stories and images about the Missouri floods. Many of those images are from Eureka (where we live), Pacific (where my wife Kellie works) and Valley Park (which is on my commute to work). That picture of the submerged McDonald’s you may have seen on the news is in Union, Missouri, about 20 miles to the southwest of Eureka

We are dry, mostly, and doing okay. The basement was flooded during the initial 3 day rain event due to a failed sump pump and a couple downspouts that came unattached from the drain pipes during the heavy downfall. The hydrostatic pressure of the ground water on the foundation was simply too much to hold back. We fixed the drain spouts and had a new sump pump installed on Sunday and that stopped any more water from coming in. We are fortunate that we returned home from visiting my family in Michigan on Saturday instead of Sunday or the water would have been much higher.

Unfortunately it doesn’t take much water to ruin carpet pads and drywall. My son and I were able to get the carpets up and the pads out the back of the house with a lot of labor but not too much trouble. There are now 14 high powered and very noisy blowers and a super-sized dehumidifier running non-stop in the basement at a cost of $30 per day per machine (disaster capitalism is quite profitable). We are told everything will be dried out in 2 to 3 days.

We have learned a painful and expensive lesson about not having a sump pump rider on our home insurance. The rider would have covered damages from the failed pump. We also would have been covered if our dishwasher had overflowed but not from ground water. Fortunately, because we acted quickly, we didn’t have any significant content damage so the only costs will be drying the place out and installing new pads under the salvaged carpets. Kellie thinks she is getting some new furniture out of the deal. I have no idea how less fortunate folks that have far more damage are going to get through this financially.

Flood lessons to pass along: check your sump pump, downspouts and your insurance policy. Keep important stuff up off the basement floor. Purchase a generator to keep the sump pump running when the power fails.

Downtown Eureka is a true disaster. The sand bagging effort was futile against the record water levels as most of the businesses downtown have water over their front doors. O’Dell’s, our favorite Irish pub, will be out of commission for a long time so now we have to go across the freeway to have good beer from the tap. The businesses Eureka residents depend on will be out of commission for many months.

Many homes along the river have been lost and are now downstream. These homes are built on stilts and have survived many flood events in the past but stilts can only go so high. We can no longer use the climate of the past to guide our decisions on the future. The rules for the game of life have changed and we must adapt to those rules.

Eureka has now had two 500 year floods in the last 22 years. The increasing frequency of these “500 year” (or more) type events really brings home what James Hansen wrote about in “Storms of my Grandchildren”. I’m pretty sure these frequency estimates will be a meaningless descriptor in the future. It will be interesting to see what the spring brings as the climate change fueled El Nino really kicks in.

All the roads out of Eureka were closed except for one and that one was a parking lot most of the time. Semi tractors on curvy and hilly two lane roads are not a good combination. Many subdivisions in the area have been isolated for a couple days now. The river crested around 6 last night so water levels, and media coverage, are quickly receding and moving downriver. We are looking forward to returning to some type of normalcy, and increased urgency for action on climate change, in the New Year.

If you want to help the best thing to do is to demand increased action on climate change from your political leaders.

We will need a price on carbon (see Citizen’s Climate Lobby), increased investment in energy efficiency, renewables and nuclear, and adaptation plans for the climate changes that are unavoidable. The American Red Cross is doing great work in helping people get through these disasters. I’m sure they could use your support.

Highlights of Climate Change Research in 2015

December 29, 2015Uncategorized2015, Climate Change, climate change research, Global Warming, Global Warming, year in reviewGreg Laden

The following is a list of posts on this blog that report new climate change research, usually but not always from the peer reviewed literature, or posts that are longer essays intended to give context to ongoing climate change research. The first few posts are from December 2014, which addresses the fact that “year end summaries” tend to be written during December, or even before, so December of any given year gets the shaft.

December 2014 – How scientists unraveled the El Niño mystery
December 2014 – New Research on Tree Rings as Indicators of Past Climate
December 2014 – Global Temperature A Century Ago Vs. Today
01–15 Lots of new climate change science stuff
01–22 Global warming’s effects are coming on faster than previously thought.
01–26 The Great Blizzard of 2015: Fair to say it is AGW amplified.
01–28 What happened to the Blizzard of 2015?
02–23 Global Warming Changing Weather in the US Northeast
02–26New Research Suggests Global Warming Is About To Heat Up
03–01 New Research Demonstrates Link Between Greenhouse Gas Pollution and Global Warming
03–03 The Hydraulic Hypothesis and the End of Civilization
03–12 New Study On How Global Warming Changes The Weather
03–23 Drought in California and Climate Change: They are linked
03–23 New Research Shows Exceptional Slowdown In Major Atlantic Ocean Currents (UPDATED)
03–26 Antarctic Ice Shelves Melting at Accelerating Rate
03–30 Pine Beetle-Caused Forest Death, And Climate Change
03–31 How Sea Floor Ecosystems Are Damaged By, And Recover From, Abrupt Climate Change
03–31 With Global Warming, Will Cold Outbreaks Be Less Common?
04–20 An Improved Classification And Explanation For El Nino (New Research)
04–24 Comparing models and empirical estimates of noise in the climate system
04–29 Comparing models and empirical estimates Part II: interview with Brown
05–14 A Global Warming Expectation Confirmed: Upper Troposphere Warming
05–15 Seepage: Climate change denial and its effect on the scientific community
05–21 New Research: Antarctic Glaciers Destabilized
05–21 The risk of hot and cold weather
05–22 California Drought Caused By Climate Change
05–26 Heat And Death In India: Global Warming’s Direct Effect
06–02 Bad Climate Science Debunked
06–03 Does global warming destroy your house in a flood?
06–04 New Research On Global Warming Hiatus
06–07 What does “Global Warming” mean?
07–07 Global Warming: Earth, Wind, Fire, and Ice
07–27 Catastrophic Sea Level Rise: More and sooner
08–04 The alleged hiatus in global warming didn’t happen, new research shows.
08–14 Update on climate models and heat waves
08–25 Scientific Consensus On Climate Change
09–01 Anthropogenic Global Warming Causes Significant Changes in Climate Zones
09–02 The outlook for Hawaiian coral is bleak
09–18 Once Again, The #FauxPause Is Killed By Actual Research
10–05 Arctic Sea Ice in 2015
10–08 NOAA declares third ever global coral bleaching event
11–1- Rates Of Climate Change Potentially Very High
11–03 Evidence of high climate sensitivity
11–03 NASA Study of Antarctic Ice Melt Misunderstood
11–16 NASA Reports Astonishing Uptick In Surface Temperature
11–17 Yet another way climate change will affect birds
11–18 New Antarctic Glacial Melt Study Slightly Increases IPCC Rate Estimate
11–22 Antarctic Ice Sheet Deterioration Study Left Out Important Factors
11–22 Antarctic Ice Sheet Deterioration Study Left Out Important Factors
11–25 WMO: 2011–2015 is the warmest five year period on record
11–26 Global Warming Did Not Pause
11–30 Matt Ridley and Benny Peiser’s Misleading Guide to the Climate Debate
12–02 Global Warming Could Make Peat Bogs Less Of A Carbon Sink
12–04 Incredibly important finding on renewable energy
12–15 Antarctic Ice Melting: Tamsin Edwards Responds to Richard Alley
12–15 Antarctic Ice Melting: Tamsin Edwards Responds to Richard Alley

Weather, Climate Change, and Related Matters in 2015

December 28, 2015Uncategorized2015 in review, Arctic Sea Ice, Climate and weather, Climate Change, fire, flood, Global Warming, heat, Hurricane, Severe weather, storms, Tropical storms, weather whiplashGreg Laden

I had considered writing an accounting of all the outlandish weather events of 2015, but that project quickly became a tl:dr list of untoward happenings which is both alarming and a bit boring, since it is so long. So, I decided to generate something less comprehensive, focusing more on the context and meaning of the diverse and impressive set of outcomes of anthropogenic global warming, an historically strong El Niño, and, well, weather which is already a pretty whacky thing.

See: Highlights of Climate Change Research in 2015

It should be noted right away that 2015 is the last year in which any human alive will see CO2 levels dip below 400 parts per million.

What is the biggest single weather related news of 2015?

Floods, probably. Around the world, there were a lot of floods, and a lot of them were very damaging and deadly. Also, many of these floods appeared with little warning, even in places like Texas, where the meteorology is pretty good. Those Texas floods were of special note, as were the floods in the Carolinas. But outside the US there were major floods in Asia, especially Vietnam and Myanmar, as well as Yemen. Alaska, Oklahoma, Atacama in South America, also saw severe floods.

Why were there so many floods?

I’m pretty sure it is accurate to say that there was more flooding, and more severe flooding, than typical for, say, 20th century climatology. We had many 1,000 year flood events, too many to assume that these events remain as 1,000 year events.

See: Global Warming Changing Weather in the US Northeast

There are probably two or three reasons for increased flooding, which of course is caused by increased and concentrated rainfall along with other factors such as land use changes that cause rainfall to result in more flooding. One is the simple fact that a warmer atmosphere, due to global warming, contains more water, and thus, we get more rain. How much more? Not a lot, but enough to make a difference. If you put together a bunch of weather data and plot the annual precipitation rate over the last century or so, and fit a line to the data, the line will look flat. It isn’t really flat, and in fact, a properly fitted line on good data will show a statistically significant upslope. But still, the total amount of extra precipitation is a small percentage of the usual amount of precipitation, so the slope is not impressive unless you draw it out using heavy-handed graphing methods.

_____________________
A few other places are doing end of year reviews. Inside Climate is doing a series of 2015 retrospectives. Skeptical Science has an overview of the year. Environmental health news has a wish list pivoting on 2015 and a year in review. And Then There’s Physics summarizes 2015. Critical Angle takes a critical look at 2015 here. If you see any more out there in the wild, let me know. Media Matters has “The 15 Most Ridiculous Things Conservative Media Said About Climate Change In 2015.” Media Matters also has 5 New Year’s Resolutions For Reporting On Climate Change. HotWhopper has The Fake Sceptic Awards for 2015 here.
_____________________

A second factor is a set of changes in how, when, and where the rain falls. Normally, in the temperate regions, rain storms move along with trade winds, guided or influenced by jet streams, fairly quickly. But if the jet streams slow down, the storms slow down, so we may see 4 inches of rain fall in one place that normally would have been spread out over a larger area, never exceeding half (or less) of that amount in any given area. The jet streams have slowed down and also become curvier, which both increases the amount of rain that falls in a give area but also may transfer moisture from and to places that are normally not involved as much in such a process. For example, the storm we are expecting today in the upper Midwest and Plains is not a typical Canadian Clipper, but rather a Gulf Coast storm related to the deadly blizzards and tornado swarms we’ve seen over the last few days to the south.

See: Does global warming destroy your house in a flood?

This clumping of rain in smaller areas also means that other areas that would normally have received some rain don’t, causing what my colleague Paul Douglas refers to as “flash droughts.” These are dry periods that don’t last long enough, and are not severe enough, to register on any official drought-o-meter, but nonetheless stress local water systems (such as farming) enough to be a nuisance.

A third factor is sea surface temperature. This really relates to, and is probably one of the main causes, of the first factor (increased precip overall), and feeds into the second factor (clumping of rain) but deserves its own consideration. Elevated sea surface temperatures in the Atlantic off the US coast last winter caused a lot more moisture than normal to feed into nor’easter storms, which in turn have become more common (because of increased sea surface temperatures and other factors), thus dumping large quantities of snow in the US Northeast. The same thing dumped lots of extra snow in a region that normally gets very little snow, the US Southeast, the winter before.

See: A selection of books on climate change

These changes have been happening for decades, and are due to global warming. The warming caused by the human release of extra greenhouse gasses, and other human effects, increase the warmth, thus the evaporation, thus the precipitation. Part of this warming trend involved increasing the warmth of the Arctic at a much higher rate than most of the rest of the planet. This, in turn, seems to have caused the jet stream to become wavy and slow down. The jet streams and trade winds are ultimately caused and controlled by the Earth spinning, which has not changed, and the temperature differential between the warm equator and the cold poles, which has changed quite a bit.

See: Weather Whiplash Is Like My Old Broken Sprinkler

But what about El Niño?

Didn’t El Niño cause these changes, and thus, aren’t these weather events unrelated to global warming?

No, and for two reasons.

First, many of these events happened during the first half of the year, before the start of the current El Niño, which is in fact the strongest El Niño so far observed directly, and possibly the strongest El Niño in millennia.

The second reason is that the heat released by the El Niño (the release of heat stored in the Pacific Ocean is what an El Niño is, in functional terms) is added to an already warmed world. It may even be that the extra severity of this year’s El Niño is upscaled by anthropogenic global warming. In any event, any records we set during the current El Niño exceed earlier El Niño years because the El Niños we experience are shorter term warming events on top of a steadily increasing global warming phenomenon.

We had a lot of fires

Last year and this year, or really, the last few years, have seen excessive, above normal rates of forest and brush fires in various regions. We have seen major fires in Australia, North America, and Southeast Asia during this period, with North America breaking several recent records this year.

See: Forest fires in Indonesia choke much of south-east Asia

These fires are caused by a combination of factors, but ultimately heat increasing evaporation, prior rainy years increasing available fuel, and warm winters increasing tree death to parasites (thus increasing fuel), all have contributed.

North America, in the old days, had much more fire-heavy years than anything recent because we were busy cutting down the forest, piling up “slash” (left over tree parts) and running sparky old fashioned coal-driven railroad engines up and down between the slash piles, catching them on fire. In addition, just burning the slash on purpose contributed to the overall amount of fire, especially when the slash fires got out of control.

We also saw some pretty impressive fires a couple of decades ago because of what we now know were bad fire management practices, which had actually grown out of those earlier decades of logging related fires. In other words, the frequency and distribution of forest and brush fires is complex. During aridification, probably global warming related, in Africa during the 70s and 80s, vast areas started to burn more regularly than usual. In those days, I would fly at night over Libya, Chad and the Sudan a couple of times a year, and could observe the entire region was burning all the time, easily visible from 26,000 feet.

The bottom line: The frequency and extent of fires is variable and chaotic, but anthropogenic global warming seems to have contributed significantly to us having more of them.

Were there more storms in 2015?

Record breaking tropical storms occurred in 2015. All of the tropical cyclone/hurricane basins saw interesting activity, with the Atlantic being the most quiet, and the Eastern Pacific, possibly, being the strangest.

There were 22 Category 4 or 5 storms this year in the Northern Hemisphere, a record number. The last record year was recent, 2004. Studies have shown overall that the total energy that forms up in tropical cyclones has increased with global warming, though the actual total number of storms is highly variable.

It is reasonable to expect an increase in the frequency and severity of tropical storms with global warming, while at the same time, in some areas, smaller storms may become less common. This is partly because smaller storms are more readily abated by some of the global-warming related changes in weather systems such as increased wind shear and increased dust in the tropical atmosphere. At the same time, extremely high sea surface temperatures, and also, high water temperatures as depth (100–200 meters) increase the potential strength of storms that do get past that initial formation.

Hurricane Patricia, in the Eastern Pacific (landfall in Mexico) was an especially important storm. It was a physically small storm, but had more powerful winds than ever seen in a tropical storm. The storm went from nothing to a full hurricane in several hours (instead of several days).

The significance of this can not be underestimated. We have a situation where the conditions that might cause a hurricane to form are extreme, because of global warming (and this year, more so because of El Niño). So, when when these conditions are in place, a hurricane can form faster, and get more powerful, than normal. Consider the prospect of a land falling Category 5+ storm forming offshore from an area with low lying terrain (not like where Patricia struck land) with a high population density (not like where Patricia struck land) and moving on shore immediately. Like for instance, an Atlantic or Gulf of Mexico version of Patricia making landfall near Miami or NOLA.

Most of the really large hurricanes of this year were in the Pacific basin, distributed across the entire region, but Hurricane Joaquin, which was a very large and powerful storm in the Atlantic, did have us on the edge of our seats for a while when some of the better weather predicting models suggested it might make landfall. Also, nearly unprecedented tropical storms formed near the Arabian Pennensula.

This was a hot year

Other than February, which was merely hot rather than really hot, globally, every month so far this year has broken or nearly broken one or more records, depending on which database one uses. The running 12-month average of surface temperatures started to break records before El Niño kicked in, and continued to do so since. This will continue for several more months, even if the El Niño phenomenon itself stops soon, because it takes several months for surface temperatures to show the El Niño effect.

More specifically, there were killer heat waves in the Western Cape of South Africa, South Asia, and the Middle East. Australia recorded its hottest day ever. North America experienced numerous record breaking days, in the US and Canada. Cherry trees thought it was spring and bloomed last week in Washington. I saw birds building a nest outside my house in Minnesota two weeks ago, and our lawn was green(ish) through last weekend.

Ocean Oddness and Other Events

Let us not forget the Great Blob of Hot Water in the northern Pacific. This non El Niño phenomenon, which has been going for a couple of years no, has had El Niño like effects in the region, and probably relates to the non normal weather in along the western coast of North America, including record breaking heat in Alaska, major storms in or near Alaska, and of course, the California Drought.

A Haboob-Nado in China involved some of the strongest winds ever seen in the region, and may have, very unusually, contained an embedded tornado. We had a mild tornado season in the US, in Tornado Alley, until a few days ago when a not-very-seasonal tornado season sprung up and killed close to 50 people in just a few days. The American southeast does get winter tornadoes, but Michigan does not. But this year, there was a first ever recorded December tornado in that state.

The Arctic Sea ice has been diminishing in its minimum extent for a few decades now, and this year we saw the third lowest amount. The volume of Arctic sea ice continues to shrink.

You all know about the Syrian Refugee crisis. This is the latest chapter in the collapse of the Syrian state, which in turn happened because of long term drought in that country killing off the agricultural system and forcing farmers into the cities, where many became involved in the Syrian Civil War, which opened up the opportunity for the Islamic State to take a large amount of territory in the region. And so on. The Syrian refugee crisis is likely to be an early version of more of the same to come over future decades. And, I quickly point out, this is not likely to have been the first climate refugee situation, just much worse than prior events related to the spread of deserts in North Africa and drying out in West Asia.

Research on Climate Change

This year saw some interesting research in climate change.

One team studies major oscillations in climate that relate to oceans (of which El Niño is a shorter-term smaller part). This research suggests that the last couple of decades have seen less warming than we might expect over the long term, and further suggests that an uptick in the rate of warming is in our medium term future.

Related research also shows that accelerated melting of northern glaciers, especially Greenland, could alter Atlantic currents, so while the Earth generally warms due to increased greenhouse gasses, weather may change to a colder regime in Europe, some time over the next few dedades.

We are seeing an increased rate at which climate and weather experts are attributing bad weather to global warming. This is partly a shift in thinking and methods among the experts, and partly because of an actual increase in such events.

There has been interesting research in the Antarctic. We are seeing increased concern about, and evidence for, destabilization of huge inland glaciers that could start to fall apart and contribute to sea level rise at any time in the next several years. At the same time we saw one study that seemed to suggest that Antarctic is gaining ice, rather than losing it. If that is true, than recent decades of sea level rise are partly unexplained. Alternatively, the research, which has some known flaws, may simply be wrong. Look for some interesting results related to Antarctic glacier during 2016.

The famous #FauxPause in global warming, claimed by many climate change deniers to be a real thing (no warming in X years, etc.) was already known to be Faux, but this year saw several independent nails being driven into that coffin. Rather than a pause that disproves global warming, we have a better understood series of changed in the long term warming in the planet’s surface temperature.

See: In a blind test, economists reject the notion of a global warming pause

Sea floor biotic diversity was shown to be threatened by warming, coral bleaching is more likely and in fact happening at a higher rate, and probably mostly due to El Niño, there has been some odd ocean animal migrations.

The planting zones, the gardening and agricultural zones we use to decide which crops to plant and when, have over the last several years shifted in most places in North America by one or two zones. This year, the people who make the zone maps came out with a new one.

Sea levels continue to rise, and the rate of rise is rising. Rare nuisance flooding in coastal areas, most famously but not only Miami, have become regular events. Sales in waterproof shoes are expected to increase.

Communication and Politics

Across meteorology we see the graph and chart makers scrambling to find new colors for their maps showing heat. Y-axes are being stretched everywhere. We seem to be stuck with a five level category system for tropical cyclones/hurricanes, but we are seeing so many storms that are way stronger, bigger, more destructive than earlier Category 5 storms that talk of adding a category is no longer being responded to with angry mobs of pitchfork wielding weather forecasters who came of age with the older system.

See: How to not look like an idiot

There has been a great deal of significant climate change related activism, and COP happened, with a strong message to address the human causes of climate change sooner than later. Climate change has actually become an issue in US elections. For the first time a major world leader, President Obama, has faced off with the deniers and told them to STFU. Major news outlets such as the Washington Post and the Guardian have started to take climate change seriously. The idea that reporters must give equal weight to the “two sides of the story” (science is real, vs. science is not real) is disappearing.

Denial of climate change and climate change science reached its high water mark over the last 12 months. It will now fade away.

And that is a short and incomplete summary of weather and climate in 2015.

A note for my regular readers: Yes, I chose the burning Earth graphic to annoy the denialist. Check the comments below to see if that annoyed anyone.

Antarctic Ice Melting: Tamsin Edwards Responds to Richard Alley

December 15, 2015UncategorizedAntarctic Glacier, Climate Change, Climate Change, Glacier Melt, Global Warming, Global Warming, Richard Alley, Tamsin EdwardsGreg Laden

In November, I wrote a post describing research on Antarctic glacial melting by Catherine Ritz, Tamsin Edwards, Gaël Durand, Antony Payne, Vincent Peyaud, and Richard Hindmarsh (“Potential sea-level rise from Antarctic ice-sheet instability constrained by observations”). I had asked one of the authors, Tamsin Edwards, to address a few questions about the study. I also asked glacier expert Richard Alley a few questions. Alley got back to me right away, but Edwards was unable to do so, so I wrote up Alley’s commentary here, with the intention of covering Edwards’ response at a later time. Over the weekend, Edwards responded to my questions as well as many of Alley’s comments, and thus, this post.

In my original post, I wrote,

The study asked how much Antarctic ice sheets might contribute to global sea level by 2100 and 2200 AD. The results contradicted some earlier estimates which are on the high end, but conformed very closely to the current IPCC estimate, raising that number by a negligible amount.

To this, Edwards responds,

Our likely range (central two thirds of the distribution: 4–21 cm by 2100) is a few centimetres higher than the IPCC’s estimates of the likely range for A1B. Our extremely unlikely threshold (1 in 20 chance of exceeding 30 cm) is lower than some previous estimates of the upper bound and is also at the low end of the IPCC’s estimate of “not more than several tenths of a metre”.

I asked Edwards if it was correct to cay that the study’s results conform to expectations based on the prior summary of research from the IPCC (with a minor adjustment), but that the results also contradict some earlier higher-end estimates of Antarctic contribution to sea level rise. Her response was that it would be correct “…to conclude that our results do not contradict estimates of large potential sea level rise from instability in the long-term. Palaeodata provide information on millennial timescales about how much ice is potentially unstable, while our study focuses on how quickly that ice can be lost over the next 200 years. For example, we say, “These constraints are not absolute bounds—greater deglaciation has occurred in the past over longer time scales—but appear to limit the amount of ice that can be lost in two centuries.”

I also asked about the interplay between ice melting vs. falling off (as ice bergs, etc.) into the sea. She told me that, “this can only be evaluated with a process-based model, of course, so this is one of the strengths of our work over previous papers that extrapolated from past observations (and therefore could not account for this). Our results are also consistent with high resolution models that represent these processes in more detail.”

In my previous post I quoted Richard Alley as noting that not all of these non-melting mechanisms were accounted for. Alley had told me,

…the model does not allow loss of any ice shelves, does not allow grounding-line retreat from calving of icebergs following ice-shelf loss, and does not allow faster retreat from breakage of cliffs higher than those observed today, especially if aided by meltwater wedging in crevasses. The model restricts grounding-line retreat to the rate given by thinning of ice during viscous flow of an unbuttressed but still-present ice shelf, with a specified upper limit enforced on the rate of that retreat.

Edwards responded,

Fundamentally our study aims to represent the aggregate effects of multiple mechanisms, not to simulate each of the individual mechanisms themselves. We then use a wide range of possible representations to sample the uncertainties.

For example, regions predicted (by other studies) to be vulnerable to ice shelf collapse are given a “MISI onset” date, after which the grounding line is forced to retreat. This means the actual ice shelves in the model are, essentially, irrelevant: removing them has little effect because it is “over-ridden” by the forced retreat. The same applies to iceberg calving – we represent its effects in moving the grounding line.

Alley had said, “the model also does not allow retreat up a sloping bed under forcing.” To which, Edwards replied, “We do allow retreat along regions of up-sloping bed. I’m not sure how long a distance Richard would think was sufficient. Also, our aim was to estimate sea level rise due to MISI (a hypothesis specifically about down-sloping beds).”

Alley also noted that the model used in the study had an enforced upper limit that would not allow a very rapid retreat. To this, Edwards provided this response:

We used grounding line retreat rates of up to 3 km per year everywhere in Antarctica and tested rates up to 5 km per year – much higher than observed in the Amundsen Sea Embayment. Our projected ice losses were somewhat restricted by the limit on unbuttressed thinning (and also, in the ensemble, by testing with observations). When we turned this limit off in two of the ensemble members with the highest sea level rise, the results were only 15 cm higher at 2100; when we turned off the observational testing, we predicted the chance of exceeding half a metre increased to only 2%.

Edwards notes that cliff failure may produce higher rates of ice loss, and

by hacking ice off even faster and without the theoretical and observational constraints we used. But it was described by the authors – Dave Pollard, Rob DeConto and Richard himself – as “somewhat speculative”. There are no observations that confirm or quantify it, so we don’t think there is yet sufficient evidence to override the information we do know. It’s also not included in state-of-the-art models (with which, as I said, our results are consistent), such as the high resolution BISICLES: to my knowledge people do not see this as a limitation.

Edwards pointed out to me that the use the term “implausible,” meaning unlikely, but not impossible, and that unexpected processes may at some point emerge.

She notes,

We look forward to further papers that either confirm our results or else provide strong evidence that faster ice losses are likely over the next two centuries: for example, moving cliff failure from “somewhat speculative” into “current understanding” and estimating the probability of such an “ice swan” occurring over substantial regions on this time scale.

On a finer point of detail, Edwards took the opportunity to clarify what might seem a fine point, but one that is very important, in the research. She notes that the Guardian writeup noted that the study involved 3000 slightly different versions of the model. However, the total range of the variables were wide, but with individual similar models being only a little different from each other.

I’m not entirely sure how to interpret these apparent differences. I strongly suspect, as I wrote here, that a full understanding of the mechanisms of non-melting deterioration of ice sheets will result in higher rates of contribution to sea level rise (which is probably the main variable of concern here). And, I think Alley agrees with this. But Edwards is making the case that these factors have essentially been covered in the reported results, though allowing for the possibility that there are processes that may surprise us. I used the analogy (to which Edwards refers) of an ice sculpture swan falling apart. We can hope that the swan is understood, and that future melting of major ice sheets do not turn out to be a black swan rather than a mere ice swan.

Global Warming In November

December 15, 2015UncategorizedClimate Change, Climate Change, El Nino, Global Warming, Global Warming, November 2016Greg Laden

The NASA GISS global temperature anomaly for November has been published.

October’s value was originally reported as 104, but has been corrected (it is normal to have small corrections on an ongoing basis) to 106. November’s value, just out, is 105.

This is hundreds of a degree C anomaly, the standard number used to report, off of a baseline. The baseline in the case of NASA GISS is 1951-1980, which does not represent pre-industrial levels.

The huge uptick we saw during the last part of the current year is the result of global warming, which has been pushing temperatures up, and the current El Nino, which probably started to affect these measurements in late September. Over the next few months or so, El Nino proper will start to decline, but the surface temperatures will remain elevated by El Nino (there is a lag). After that, we should see monthly temperature readings being to drop, but the overall trend is likely to continue.

The graphic at the top of the page is the 12 month moving average from the NASA GISS data base, up through November. Notice that since the 1960s there has been a very steady upward trend, with some variation. Most of the big upward spikes you see are El Nino years, and the lower troughs are typically periods with one or more La Nina events. These variations reflect the interaction between surface (air and sea surface) and the ocean, mainly the Pacific.

2015 is currently the warmest year on record, and 2014 is the second warmest year. It is virtually impossible for 2015 to drop below warmest once December values are added in. Likely, the spread between warmest and second warmest year will increase.

November 2015 is the second warmest month-by-anomaly (not actual temperature, but relative to other instances of the same month) and November 2015 is the second warmest. All the other warmest months in the top 10 are from the 90s or 80s, found during El Nino years.

As the effects of the current El Nino peak and decline, we will see the “warmest month” thing fade away until the next El Nino, but the 12 month moving average will continue to rise for quite some time, then level off, then likely decline somewhat. But overall, the trend is expected to be on average upward because, ladies and gentlemen, anthropogenic global warming is real and is happening now.

Attacking Climate Science and Scientists

December 10, 2015Climate Change, UncategorizedClimate Change, Global Warming, Lemar Smith, McCarthyism, Michael Mann, Uncategorized, War On ScienceGreg Laden

You are a scientists and you are doing two things.

First, you have finished a preliminary study and submitted a grant proposal based on your evolving idea about something, and you have just submitted a related paper to a peer reviewed journal. Well, OK, that’s a bunch of things, but they are all related to the temporal stream of the research you are expected to do as a member of the academic community.

Second, you are having conversations with your mentor, your colleagues, others, about this research in which you are traveling up and down various alleyways searching for answers to outstanding questions, ways to refine your methodology, approaches to explaining complex things. Most of the time, just when you think you might have cornered an answer, it turns out to be just another question briefly disguised as a result. But, the whole time, you are having this conversation and it is fruitful and productive, and helps your research move forward.

Suddenly, Nefarious Guy, who is the antagonist in this story, appears on the scene. The first thing Nefarious Guy does is to force you to release the data from your preliminary study, and to put a copy of the peer reviewed paper you’ve submitted on the internet. The result? Some bogus dood at another institution gets hold of your preliminary study, publishes the result under his own name. Meanwhile, the journal contacts you and says they are rejecting your paper. They want new, as yet undistributed results taking up the precious pages of their journal, and your paper is no longer new, since it is all over the internet. The last four years of work is now severely damaged. Your tenure committee is not impressed with your excuses. Your career is damaged. Later, when you give a talk to some high school kids on what is like to be a scientist, a youngster asks, “What advice would you give to someone like me, who really wants to be a scientist?” You are compelled, ethically, to tell her to start off by making friends with a lawyer and not having very high expectations for her career.

But Nefarious Guy did not end his antics there. He also got hold of many of those conversations you’ve been having with your colleagues. You see, those conversations, in conformity with the way the modern world works, have largely been via email, and these emails have been acquired and made public. Now, Nefarious Guy and his minions have been mining these emails and putting bits and pieces of them out there, stripped of their actual context and embedded in a stream of lies about how the research was done and what the motivations of the researcher “really” are.

This dishonest misrepresentation of the honest conversations you’ve had does not damage your career, because all the other scientists and academics, including the granting agencies, can see right through Nefarious Guy’s exploits. But his actions do something worse. They damage science itself, because they become part of the public discourse, and the public is generally gullible, often looking for a reason to complain anyway, and do not understand the nature of what has happened.

Nefarious Guy is a stand in for any number of politically motivated science deniers who wish to damage the scientific process, discredit the widely held scientific consensus on climate change, and punish individual scientists for being honest and truthful.

One such individual is Congressman Lemar Smith of Texas. Michael Mann, a climate scientist who has been subjected to some of this sort of nefarious activity, recently wrote an Op Ed in the New York Times that talks about Smith’s assault on climate science.

Mann notes that Smith “has long disputed the overwhelming scientific evidence that carbon dioxide emissions from burning fossil fuels are changing the climate. Now he is using his committee chairmanship to go after the government’s own climate scientists, whose latest study is an inconvenience to his views.”

Last month, Smith subpoenaed climate scientist Kathryn Sullivan of NOAA demanding the release of those honest convo emails and other similar documents pertaining to climate change related research published in Science. The study produced results most inconvenient. Essentially, it was a detailed look at the data showing that the famous #FauxPause in the rise of global surface temperatures was indeed faux.

NOAA told Smith to take a hike. Smith doubled down. More than once. It is important to note that no one is denying access to data, methods, or results. The entire scientific community is appalled at Congressman Smith’s requests and his implications that these scientists are up to something. The information Smith needs to prove himself wrong are available. This is nothing but an expeditionary move to damage science and some of the scientists who do that science.

Mann notes that Smith has tried to do this sort of damage before, sometimes with success.

Mann concludes,

While there is no doubt climate change is real and caused by humans, there is absolutely a debate to be had about the details of climate policy, and there are prominent Republicans participating constructively in that discourse. Let’s hear more from these sensible voices. And let’s end the McCarthy-like assault on science led by the Lamar Smiths of the world. Our nation is better than that.

The New York Times gave Smith right of reply, in which he doubles down yet again, asserting that “federal employees at the National Oceanic and Atmospheric Administration have altered temperature data to try to refute an 18-year plateau in global temperatures…” He insists that satellite data refute the idea that warming has continued. That satellite data to which he refers is the cooked up unpublished and unreviewed, known-to-be-faulty bogus result of a couple of science deniers. Well, it is published, in a blog post, but not in the peer reviewed literature.

No wonder so many Americans distrust Congress. Both houses.

Global Warming Could Make Peat Bogs Less Of A Carbon Sink

December 2, 2015UncategorizedAccelerating Feedback, Amoeba, Carbon Sink, Climate Change, Global Warming, Global Warming, Mixotroph, Peat Bog, Positive Feedback, SphagnumGreg Laden

A new study, “An unexpected role for mixotrophs in the response of peatland carbon cycling to climate warming” by Vincent Jassey and others, just came out in Scientific Reports. The study is fairly preliminary, but fascinating, and unfortunately may signal that yet another effect of global warming that would result in more global warming.

What makes this study interesting is that it examines the detailed ecological relationships between several different kinds of organisms in both field and lab settings, in order to get a handle on what they do when conditions warm. Mixotrophs are organisms that mix up their role in the trophic web, shifting between being producers (using sunlight to make carbohydrates) or consumers (eating either producers or consumers). Several different mixotrophs that photosynthesize can be found in aquatic and semi aquatic ecosystems, but in this study only mixotrophic amoebae were considered. But before revealing what these shape shifting strategy shifters are up to, a word about the carbon cycle.

See: What does “Global Warming” mean?

About 770 gigatons of Carbon Dioxide (note: Not Carbon, but the gas CO2) are added to the atmosphere every year from natural sources. About 780 gigatons are taken in by those same systems. This is today; At various times in the past this has been different. Anyway, about 10 gigatons are removed, on average, per year over time. Human activities, including burning fossil fuel and other factors, add about 30 gigatons a year, for an imbalance of +20 gigatons. This has caused the concentration of the greenhouse gas CO2 in the atmosphere to go from somewhere south of 280ppm (parts per million) to just north of 400ppm since the beginning of the Industrial Era. This has caused global warming.

Adding CO2, and thus retaining more heat on the surface of the planet, could increase biological activity in such a way that natural ecosystems absorb more Carbon, thus offsetting the human contribution. Also, CO2 is plant food. So, with more CO2, and a longer growing season, plants could bulk up and take in more CO2 than normally, offsetting the human-caused imbalance. Unfortunately, this does not happen.

Well, plants may well take in a bit more CO2 and convert it to plant tissues, but other things happen as well. For example, expanding the growing season also means melting permafrost in northern climates. There, huge amounts of Carbon sequestered long term is released (as CO2 or methane, which is also a greenhouse gas and eventually converts to CO2). So warming caused by adding CO2 to the atmosphere has an amplifying effect, causing even more warming, and more amplification, and so on. We refer to this as a positive feedback cycle, but it is not positive at all from the perspective of planetary health.

See this for more information about a negative feedback involving plants that turns out to not be a negative feedback.

Of all that CO2 moving in and out of the natural system, about 890 gigatons is interchanging on the land (soils, vegetation, freshwater ecosystems, etc.) while about 670 gigatons interact with the ocean. This means that a good amount more than half of the carbon cycle happens over land. Of that, several percent (estimates vary) happens in relation to peat bogs. Here the numbers can get a bit misleading. The normal amount of Carbon that goes into, or comes out of, the world’s peat bogs over a period of time under normal conditions may be very small compared to the total amount of carbon stored in those bogs, which might be rapidly released as CO2 or methane if certain things happen. For example, peat is a fuel source, and has been widely mined for many years. In other areas, bogs are drained or covered over. Here in the Twin Cities, vast bogs are now Urban Saint Paul (covered over) or farms growing turf or corn (drained) so whatever they were doing in the early 19th century as part of the natural system, they are not doing that any more. The peat that is burned for fuel or used in smelting operations, etc., adds most of its Carbon to the atmosphere all at once, and thereafter contributes nothing to sequestering carbon.

See: How do human CO2 emissions compare to natural CO2 emissions?

For all these reasons, what happens in peat bogs does not stay in peat bogs. Changes to peat bogs that cause changes in their role in the Carbon cycle may be very important under global warming.

Now, think about this for a second. If you have an organism that can either sequester carbon by acting like a plant, or release carbon (as CO2) by acting as an animal (though it is neither), then what that animal is doing matters to the Carbon cycle. Also, if the organism can either grow and reproduce using mainly sunlight, or consume other organisms at a higher rate, that strategy shifting may influence the entire ecosystem. The new research project looks at all of this, and seems to show that on balance, warming up the ecosystem significantly changes the amounts of Carbon released vs. retained in many peat bogs.

From the Abstract:

…little is known about the responses of peatland mixotrophs to climate change and the potential consequences for the peatland C cycle. With a combination of field and microcosm experiments, we show that mixotrophs in the Sphagnum bryosphere play an important role in modulating peatland C cycle responses to experimental warming. We found that five years of consecutive summer warming with peaks of +2 to +8°C led to a 50% reduction in the biomass of the dominant mixotrophs, the mixotrophic testate amoebae (MTA). The biomass of other microbial groups (including decomposers) did not change, suggesting MTA to be particularly sensitive to temperature. In a microcosm experiment under controlled conditions, we then manipulated the abundance of MTA, and showed that the reported 50% reduction of MTA biomass in the field was linked to a significant reduction of net C uptake (–13%) of the entire Sphagnum bryosphere. Our findings suggest that reduced abundance of MTA with climate warming could lead to reduced peatland C fixation.

The way in which MTA biomass reduction reduces peatland Carbon fixation is not entirely clear. I asked Vincent Jassey, the study’s lead author, how the reduction in biomass of the dominant mixotrophs in the Sphagnum bryosphere reduces overall photosynthesis. He told me that what is measured is the overall rate of photosynthesis of the entire ecosystem, and that further research would be needed to assess exactly what is happening. “MTA are living within/between Sphagnum leaves. So, when we measure photosynthesis on Sphagnum, it takes into account the photosynthesis made by MTA as well,” he said. “This is the first time a paper outlines the potential role of MTA in overall Carbon fixation of bryosphere, showing its potential importance for peatlands…we showed that a decrease of MTA abundance/biomass is linked to a decrease of Sphagnum bryosphere photosynthesis. [So far] we made indirect measurements and this needs to be verified in future research.”

The next step, then, is to how MTA benefits the moss. So far, “…these links are largely unknown. This is something I’m working on. We want to quantify more precisely the contribution of MTA photosynthesis to bryosphere photosynthesis in the field in our future research and see if its response to warming will be significant in term of C loss in peatlands.”

I think this research is important for several reasons. One is that this is a step towards understanding a complex ecological system that makes up a significant percentage of terrestrial ecosystems, which may involve inter-species symbiosis or other important interaction. The other is that this system appears to represent yet another case of amplifying feedback in global warming, where more warming ultimately leads to more warming. Decades ago, many scientists hoped or assumed that the anthropogenic greenhouse effect would be at least partly attenuated by negative feedback systems, where more Carbon is sequestered as a result of warming, but we now know that while this does happen, it is more common to find amplifying feedbacks. This, of course, relates to the question of climate sensitivity. Many factors will determine where the global surface temperatures will equilibrate with a doubling of pre-Industrial CO2 levels in the atmosphere, and how organisms or ecological systems respond to warming is part of that.

See: Books on Climate Change: Great ideas for holiday gifts!

I will speculate further and suggest that this is important in relation to the question of carbon sequestering through geo-engineering. It has been suggested that preserving or expanding peat bogs, like growing more trees or similar measures, would help sequester more carbon. But the carbon-sequestering value one places per unit area on various kinds of peat bogs or other wetlands has to be correctly measured and understood. If these values are going to change in a warming world, we need to know this.

Matt Ridley and Benny Peiser’s Misleading Guide to the Climate Debate

November 30, 2015UncategorizedBenny Peiser, Climate Change, Climate Change, Global Warming, Global Warming, Matt Ridley, Paris TalksGreg Laden

This post was written by Peter Sinclair and Greg Laden in response to a recent Wall Street Journal Op Ed piece by Matt Ridley and Benny Peiser.

In a recent Wall Street Journal commentary, “Your Complete Guide to the Climate Debate,”
Matt Ridley and Benny Peiser ask what might make world leaders concerned about the security impacts of climate change. One answer might be the US Department of Defense.

In its 2010 Quadrennial Defense review, Pentagon experts wrote:

“…climate change could have significant geopolitical impacts around the world, contributing to poverty, environmental degradation, and the further weakening of fragile governments. Climate change will contribute to food and water scarcity, will increase the spread of disease, and may spur or exacerbate mass migration.”

If that sounds familiar, it’s because it’s today’s front page news. A 2014 Defense Department document underlined the message, calling climate warming “a threat multiplier.”

Ridley and Peiser ridicule President Obama over his “careless” statement that climate change is a greater threat than terrorism. Indeed, recent research indicates that the current Syrian refugee crisis is at least partly a result of climate change enhanced drought in the region.

Ridley and Peiser claim that global temperatures have risen only slowly. This is simply untrue. The upward march of global surface temperatures varies, as expected for any natural system such as this, but continues on an upward trend. Contrarian claims of an extended pause in global warming have been debunked over recent months by at least a half dozen studies. (See: this, this, this, this, and this.)

Ridley and Peiser also suggest that surface temperatures have risen less than earlier climate modeling had projected. This is simply untrue. Global surface temperatures have risen at a pace of about 0.15 degrees C per decade since 1990, which is within the range of earlier IPCC projections.

Ridley/Peiser suggest that current record smashing weather events are due to El Nino, not climate change.

Wrong for two reasons.

First, many of the record breaking events we have experienced over recent years happened when there was no El Nino.

Second, records that are set during an El Nino period are, obviously, compared to all other prior El Nino periods as well. This year’s El Nino is exceeding earlier El Nino years in heat and tropical storm activities precisely because of a continued rise in planetary heat.

Ridley and Peiser claim that it has been warmer at times during the last 10,000 years. This statement is not supportable. While scientists know that orbitally caused warming occurred some 8000 years ago, the most current research suggests that today’s surface temperature exceed those values, or will shortly under current trends.

It is incorrect to assert that there have been no changes in extreme storms, or flooding. In the past week we have seen a new annual northern hemisphere record in major hurricanes, with 30 storms category 3 and above this year, literally blowing away the old record of 23, with the season not yet over.

Every year for the last three years, careful and conservative researchers publishing in the Bulletin of the American Meteorological Society have studied the contribution of global warming to major weather events around the world, the papers collected in an annual volume “Explaining Extreme Events … from a Climate Perspective.” Every year the number of events attributed to global warming goes up. (See these three reports.)

The US Global Change Research Program has documented the increase in extreme precipitation events across the country, and in recent weeks, the east and gulf coast of the US have been inundated by a “1000 year rain event”, as well as a new phenomenon, coastal flooding not associated with any storm, merely the regular pull of the tides, on an ocean that has risen several inches since 1950.

Miami taxpayers are currently spending 500 million dollars on pumps and other infrastructure to remedy the flooding Peiser and Ridley say does not exist.

Ridley and Peiser make the claim that tropical storms can’t be as much of a problem now as they were in the past because the number of deaths attributed to natural disasters is reduced. The irony of this statement is stunning. The reason there are fewer deaths due to weather related natural disasters is precisely because climate science and meteorology have developed methods and models to predict and warn. That very same science is telling us about the recent, ongoing, and future changes in climate due to the burning of coal, oil, and natural gas.

Ridley and Peiser seek to confuse by conflating Arctic and Antarctic sea ice, without mentioning that the small increase in Antarctic sea ice, along with the large loss of Arctic ice, is predicted from our understanding of the global warming process, and that, globally, sea ice area is clearly in a multi-decadal decline, the very reason that our giant oil companies are lobbying so intensely for access to polar regions they know are thawing.

Similarly deceptive is the claim that “Antarctica is gaining land based ice”. Here they cite a one-off outlier study, not the other dozen studies completed since 2012 by groups from NASA, the European Space Agency and others, most using more recent data than the cited piece, and all of which show overall Antarctic land ice loss. Moreover, the author of the study cited has said that
if the sea level rise does not come from Antarctica, it obviously must be undercounted elsewhere, such as Alpine glaciers, Greenland, or thermal expansion of the oceans – since observed sea level rise is unequivocal.

That sea level rise is also the most unambiguous indicator of a warming planet. The relentless and accelerating observed rise of the seas supports the half dozen recent studies showing that global warming has not halted or paused, and continues apace.

Ridley and Peiser claim that research is increasingly showing climate sensitivity to be low. This is entirely the opposite of what has been happening. The most likely range of values of climate sensitivity (the amount of increase in surface temperature that eventually occurs as a result of the doubling of CO2 in the atmosphere) was established over a century ago. Recently revealed documents show that Exxon Mobil Corporation itself studied climate science as early as the late 70’s, and its findings were in clear agreement with the National Academy of Science 1979 report, which estimated a climate sensitivity of 3°C, plus or minus 1.5° C. Tables in Exxon’s 1982 Climate Change “Primer” for executives show predictions for 2015 markedly similar to contemporary estimates by NASA, and NOAA.

Meanwhile, the solutions for climate change are at hand.

Solar and wind energy have grown faster, and costs have plummeted further, than even most fervent supporters would have predicted a few years ago. Wind and solar are now out-competing coal and nuclear everywhere, and even gas in many markets. Recent volatility in oil and gas prices make the predictable zero cost of renewables all the more attractive, as more and more major corporations are signing power purchase agreements for renewable energy, based on markets, not political correctness.

In a recent article in Scientific American, Engineers Mark Jacobsen and Mark Deluchi have shown how 139 countries can generate their total energy needs by 2050 from wind, solar, and water technologies.

Today’s average cost of large-scale solar in the U.S. is 5 cents/kWh. The installed cost of solar is down by half since 2009. The cost of wind in the U.S. is 2.5 cents per kWh, and efficiency is about the same, and sometimes below 1 cent/kWh. (See this.)

Denmark, Scotland, Spain, and Portugal are now producing more than half their electricity from renewable sources, Germany is close to a third – and the German grid is 10 times more reliable than the US grid.(See this)

In 20 US states, contractors will put solar panels on your roof for free – and in San Antonio Texas, the utility will pay you for the privilege of putting those panels on, and lowering your utility bill. (See this and this)

It’s a business model that will spread, sooner than coal barons like Matt Ridley would like you to believe.

Polling shows again and again that large majorities of Americans across all demographics favor rapid development of renewable energy, and tough regulations for greenhouse gases.

In addition, most importantly, a large majority of Americans now believe that climate change is a moral issue that obligates government officials, and private citizens, to take action.

The tactics of confusion and distortion are losing their effectiveness, as more and more Americans experience the effects of a climate altered world first hand. It’s time to stop denying the science, and begin discussing the solutions.

Global Warming Did Not Pause

November 26, 2015Uncategorized#FauxPause, Climate Change, Climate Change, Global Warming, Global Warming, Hiatus, PauseGreg Laden

You’ve heard much about the so-called “pause” or “hiatus” in global warming.

One of the implications of a multi-year “pause” in global warming is that the science of global warming must be somehow wrong, because with CO2 rising in atmosphere, due to human activity, how can the surface not warm? However, surface temperatures have been rising, but at a somewhat slower rate than at some other times.

The truth is that there is a lot of variation in that upward trending surface temperature value, measured as an anomaly above expected temperatures. Sometimes the variation pushes the rate of warming up, sometimes it pushes the rate of warming down. This has always happened, and will always happen.

So there was something of a lowering of rate of surface warming, but at the same time, no such reduction in rate of ocean warming. Most of the heat from global warming is added to the ocean, not the surface. So, the reality is, global warming has been continuing apace.

One of the factors involved in a slowdown is probably the fact that the Pacific Ocean has been absorbing more heat, for a longer period, relatively uninterrupted by large El Ninos (which reverse that trend), for longer than usual. This year’s El Nino is returning some of that heat to the atmosphere. But even before El Nino kicked in, we were having month after month of record breaking heat (with the very rare month not being a record breaker) for a long time.

Anyway, a couple of papers have recently been published that look once more at the “pause” and I wanted to point them out. The best way to get at these papers is to read the guest commentary by tephan Lewandowsky, James Risbey, and Naomi Oreskes on RealClimate.org: Hiatus or Bye-atus?

The idea that global warming has “stopped” has long been a contrarian talking point. This framing has found entry into the scientific literature and there are now numerous articles that address a presumed recent “pause” or “hiatus” in global warming. Moreover, the “hiatus” also featured as an accepted fact in the latest IPCC report (AR5). Notwithstanding its widespread use in public and apparent acceptance in the scientific community, there are reasons to be skeptical of the existence of a “hiatus” or “pause” in global warming …. We have examined this issue in a series of three recent papers, which have converged on the conclusion that there is not now, and there never has been, a hiatus or pause in global warming.

Just go and read the post, and if you like, the links therein.

WMO: 2011-2015 is the warmest five year period on record

November 25, 2015UncategorizedClimate Change, Climate Change Graphics, El Nino, Global Warming, Global Warming, ocean, surface temperature, Warmest Year, WMOGreg Laden

The World Meteorological Organization has announced that they expect 2015 to be the warmest year on record, and that we are in the warmest five year period on record. We are speaking here of global surface temperatures, though similar descriptions probably apply to the upper 2000 meters or so of the ocean as well.

The global average surface temperature in 2015 is likely to be the warmest on record and to reach the symbolic and significant milestone of 1° Celsius above the pre-industrial era. This is due to a combination of a strong El Niño and human-induced global warming, according to the World Meteorological Organization (WMO).

The years 2011-2015 have been the warmest five-year period on record, with many extreme weather events – especially heatwaves – influenced by climate change, according to a WMO five-year analysis.

“The state of the global climate in 2015 will make history as for a number of reasons,” said WMO Secretary-General Michel Jarraud. “Levels of greenhouse gases in the atmosphere reached new highs and in the Northern hemisphere spring 2015 the three-month global average concentration of CO2 crossed the 400 parts per million barrier for the first time. 2015 is likely to be the hottest year on record, with ocean surface temperatures at the highest level since measurements began. It is probable that the 1°C Celsius threshold will be crossed,” said Mr Jarraud. “This is all bad news for the planet.”

Greenhouse gas emissions, which are causing climate change, can be controlled. We have the knowledge and the tools to act. We have a choice. Future generations will not.”

They have some nice graphics:

Global annual average temperatures anomalies (relative to 1961-1990) based on an average of three global temperature data sets (HadCRUT.4.4.0.0, GISTEMP and NOAAGlobalTemp) from 1950 to 2014. The 2015 average is based on data from January to October. Bars are coloured according to whether the year was classified as an El Niño year (red), a La Niña year (blue) or an ENSO-neutral year (grey).Note uncertainty ranges are not shown, but are around 0.1°C.

Ocean heat content down to a depth 2000m. Three-month (red), annual (black) and 5-year (blue) averages are shown. Source: NOAA NCEI

Caption for the graphic at the top of the post:

Global annual average near-surface temperature anomalies from HadCRUT4.4.0.0 (Black line and grey area indicating the 95% uncertainty range), GISTEMP (blue) and NOAAGlobalTemp (orange). The average for 2015 is a provisional figure based on the months January to October 2015. Source: Met Office Hadley Centre.

Antarctic Ice Sheet Deterioration Study Left Out Important Factors

November 22, 2015UncategorizedAntarctic Ice Sheet, Climate Change, Climate Change, Global Warming, Global WarmingGreg Laden

A few days ago a team of climate scientists (Catherine Ritz, Tamsin Edwards, Gaël Durand, Antony Payne, Vincent Peyaud, and Richard Hindmarsh) published a study of “Potential sea-level rise from Antarctic ice-sheet instability constrained by observations.”

The study asked how much Antarctic ice sheets might contribute to global sea level by 2100 and 2200 AD. The results contradicted some earlier estimates which are on the high end, but conformed very closely to the current IPCC estimate, raising that number by a negligible amount.

The authors note that rising seas due to global warming is a significant problem. In other words, this research could be good news on one way, in that the highest estimates were not supported. But it is bad news in another way, in that the Antarctic ice sheet will contribute enough that when added to other sources of sea level rise, coastal regions will be seriously affected.

One of the study’s authors, Tamsin Edwards, wrote a summary of the paper in The Guardian. That essay provides a useful summary of the history of Antarctic ice-sheet research, and places the new research in perspective. In particular, Edwards notes,

We’re not the first to predict the consequences of Antarctic instability. So what’s new? We are the first to use all three elements I think are essential for climate predictions: physics, observations, and statistics.

I’m not sure if this is the first study to use data, physics, and statistics, but if it is, wow. However, there may be one very important thing missing from Ritz and Edwards Et Al: A full consideration of the factors involved in ice sheets turning into ocean because of global warming.

The study involved developing a computer model simulating the behavior of the ice sheet. This model was refined by comparing results of different runs, each using slightly different values for the relevant variables, with observations, in order to weight the model variants to get a more plausible set of results. Several thousand runs of the model were evaluated in this way.

My impression of the study, which I partially wrote up here, was that there were two possible problems. One derives from those earlier higher-end estimates that the new study contradicts. Some of those estimates are based on paleo data, which attempt to link either CO2 levels or global temperatures with known sea levels contemporary with those values. Looking at sea level from a paleo perspective, one could argue that current levels of atmospheric CO2 should be associated with much higher sea levels than we have today. Since added CO2 takes decades to be realized as surface warming, and surface warming takes, we assume, considerable time to be manifest as polar ice sheet melting or deterioration, the timing of sea level rise is very much an open question. In other words, a paleo-based estimate of many feet of sea level rise does not necessarily conflict with the results of this paper, which predict “that the Antarctic ice sheet will contribute up to 30 cm sea-level equivalent by 2100 and 72 cm by 2200.” Both could be right, because it may simply take several hundred years for sea levels to reach an equilibrium consistent with between 400 and 500 or so parts per million of CO2 in the atmosphere.

The second problem concerned me a bit more. This is the idea embodied in the “Ice swan analogy” I outlined in my post. The transformation of a continental ice sheet (and its nearby sea-situated parts) into ocean water could be somewhat over simply characterized as having two parts. One is simply the melt of ice being greater than the replacement of ice from precipitation and cold conditions. The other is the physical collapse of parts of the glaciers, causing large amounts of ice to slough off into the sea where they will quickly melt and contribute to sea level rise. It is likely that the latter would affect the former, so melting would increase because of changes to the structure and position of ice after physical collapse of large parts of it. Removing the distal part of a glacier’s tongue may unplug upstream sources of meltwater, and cause further rapid deterioration by destabilizing the ice sheet’s structure.

If the catastrophic deterioration of parts of the ice sheet (catastrophic in the sense that nothing happens, then more of nothing, then still more, then suddenly a threshold is reached huge chunks fall of for a time, then back to nothing again) is not accounted for, or insufficiently accounted for, in a model, then the model may be underestimating total ice sheet contribution to sea level rise, and the rate at which that may happen.

The possibility that large scale or at least rapid deterioration of parts of the ice sheet could happen has potentially important consequences. First, if such a thing does occur in large scale, the rate of sea level rise could be very rapid for a period of years. A sea level that goes up a few millimeters a year is potentially different, as a problem to which we must adapt, than one that rises in fits and starts. Second, the total contribution of Antarctic ice sheets to sea level rise may be both larger, and less predictable.

Richard Alley is a climate scientist at Penn State who studies ice, glaciers, sea level change, and abrupt climate change. I asked him for his opinion on the Ritz, Edwards, et al. paper. I am happy-sad to say that many of his remarks mirrored my own thoughts. Happy because it is always nice to have one’s ideas about complex science confirmed by an expert to not be completely wrong. Sad, because the Ritz, Edwards et al paper does look like it may be underestimating the total amount and rate of Antarctic ice sheet contribution to sea level rise.

Alley is concerned about the lack of attention in the Ritz, Edwards et al study to important relevant mechanisms.

Alley told me that among the many factors that contribute to sea level rise (melting of mountain glaciers transferring water from the land to the ocean, expansion of ocean water as it warms, possibly from mining of groundwater exceeding water trapping from dams and other human activities) that “the largest uncertainties are attached to the ice sheets. For the 20 years leading up to the IPCC Fifth Assessment Report, the Shepherd et al. IMBIE assessment (Science, 2012) found an accelerating contribution to sea-level rise from the ice sheets, but with an average of only ~0.6 mm/yr out of the ~3 mm/yr total. At that rate, loss of all the ice sheets would require just over 100,000 years; the rate of loss of 0.001%/yr is equivalent to me as a professor losing 1/3 of one potato chip per year on a diet. Both I and the ice sheets could lose weight more rapidly; we generally would consider my weight loss to be good and that of the ice sheets to be bad.”

Alley notes that the projections made by the IPCC are a good starting point for understanding sea level rise, but that work done since the IPCC projections were solidified for the most recent report tend to indicate slightly higher rates. As with other features of climate change such as climate sensitivity, the distribution of possible sea level rise rates has a long tail at the high end. This means that rates below the average estimate are highly unlikely, but higher rates are not as unlikely, and there is a small possibility of much higher rates. The tail at the high end of the distribution is lengthened primarily by uncertainty with what will happen in Antarctica. This problem is central to current research on the contribution of Antarctica to sea level rise.

Alley notes, “Because the ongoing changes are relatively slow in their contribution to global sea-level rise, and based on other research showing how some of the processes involved in ice-sheet shrinkage cannot accelerate hugely, there has been some optimism that the long tail won’t be realized. However, a small but growing body of scientific literature has looked at the possibility that fracturing could greatly speed shrinkage; meltwater can wedge open crevasses on ice shelves or non-floating ice near the coast, thinning beyond some threshold tends to lead to complete ice-shelf loss, giant icebergs calving off the resulting ice cliffs can move the grounding line back rapidly especially if aided by meltwater wedging, and theoretically estimated limits on cliff heights suggest that much faster iceberg loss and cliff retreat are possible.”

Alley was co-author of a review here that addresses this topic. Here’s the abstract from that paper:

Ocean-ice interactions have exerted primary control on the Antarctic Ice Sheet and parts of the Greenland Ice Sheet, and will continue to do so in the near future, especially through melting of ice shelves and calving cliffs. Retreat in response to increasing marine melting typically exhibits threshold behavior, with little change for forcing below the threshold but a rapid, possibly delayed shift to a reduced state once the threshold is exceeded. For Thwaites Glacier, West Antarctica, the threshold may already have been exceeded, although rapid change may be delayed by centuries, and the reduced state will likely involve loss of most of the West Antarctic Ice Sheet, causing >3 m of sea-level rise. Because of shortcomings in physical understanding and available data, uncertainty persists about this threshold and the subsequent rate of change. Although sea-level histories and physical understanding allow the possibility that ice-sheet response could be quite fast, no strong constraints are yet available on the worst-case scenario. Recent work also suggests that the Greenland and East Antarctic Ice Sheets share some of the same vulnerabilities to shrinkage from marine influence.

Alley lauds the Ritz, Edwards, et al paper as representing “a great amount of careful work, and provid[ing] a particularly broad exploration of some of the poorly known parameters that control the ice sheet.” However, he finds that the study did not address some important mechanisms.

…the model does not allow loss of any ice shelves, does not allow grounding-line retreat from calving of icebergs following ice-shelf loss, and does not allow faster retreat from breakage of cliffs higher than those observed today, especially if aided by meltwater wedging in crevasses. The model restricts grounding-line retreat to the rate given by thinning of ice during viscous flow of an unbuttressed but still-present ice shelf, with a specified upper limit enforced on the rate of that retreat. The model also does not allow retreat up a sloping bed under forcing, something that is widely observed. The Supplementary Information includes discussion of checks that the authors did to assess the importance of these assumptions, which the authors argue justify omitting the mechanisms. However, it remains that with the model not allowing very rapid retreat, not allowing ice-cliff crumbling after ice-shelf loss, and not allowing retreat up sloping beds, the model cannot exhibit some possible behaviors that could cause rapid ice-sheet shrinkage.

So, I view this as an important step forward for the scientific community, but the qualification in the last sentence of the paper leads to additional information showing that we cannot yet confidently place quantitatively reliable limits on the possible sea-level rise from the Antarctic ice sheet. I personally hope that the new paper is right, but I will continue research on this topic in the hope of providing improved estimates. Until such work is successful, I do not believe we can exclude the possibility of faster sea-level rise than suggested in the new paper.

I did ask Edwards questions about these missing elements, but have not heard back yet. If I do, I’ll either post her response as a separate item or add them here, as seems appropriate.

Record Highs Beating Record Lows 2:1 With Global Warming

November 19, 2015UncategorizedClimate Change, Climate Change, Global Warming, Global Warming, Record High Temperatures, Record Low TemperaturesGreg Laden

Record daily high and low temperatures happen now and then at a give weather station. In a normal, stable climate the number of record highs and record lows should be about even. But with human-caused global warming, record highs are expected to be more common than record lows. And they are.

Climate Nexus has this handy dandy widget to track record highs and record lows over the previous year.

Click to see the 1950s, when global warming was not as severe at it is today. Then look at the 1990s when things were starting to take off. Then look at the last year.

Here is NCAR’s Gerry Meehl talking about the record record highs.

Thanks to Climate Nexus for putting this together.

Atmospheric temperatures still swing between “cold” and “hot” years, even as they now trend warmer on average. This is because of natural variation in the climate system, as heat cycles between the atmosphere and the ocean through phenomena such as El Niño. Heat records are more likely to be broken when natural variation runs in the same direction as global warming. When the two are out of sync, it is more likely that temperatures will be average or even a little below average. Therefore, the rising trend in the ratio of record highs to record lows is clearest when looking over decades.

The image at the top of the post is from UCAR.

NOAA: October Warmest On Record

November 18, 2015UncategorizedClimate Change, Climate Change, Global Warming, Global Warming, NOAA, October, Warmest MonthGreg Laden

NOAA has just followed JMA and NASA in reporting on October’s average global surface temperature. The surface temperature is the combination of thermometer-at-head-height data and sea surface temperatures, averaged out for the planet. Several groups track this data, and though there is much overlap in the instruments used, each group has its own way of processing the data to eliminate errors and biases, and to adjust for missing information (such as large regions with little data).

NOAA points out that October had the greatest above-average departure from average for any month. Also, NOAA confirms that the year to date temperature is the highest in their data set, which goes back to the 19th century.

Other highlights from the NOAA web page:

The October average temperature across global land and ocean surfaces was 1.76°F (0.98°C) above the 20^th century average. This was the highest for October on record, surpassing the previous record set last year by 0.36°F (0.20°C), and marked the sixth consecutive month a monthly global temperature record has been broken. This record departure from average was also the highest on record for any month, surpassing the previous record set last month by 0.13°F (0.07°C).

The October globally-averaged land surface temperature was 2.39°F (1.33°C) above the 20^th century average. This was the highest for October in the 1880–2015 record, surpassing the previous record set in October 2011 by 0.31°F (0.17°C).

The October globally-averaged sea surface temperature was 1.53°F (0.85°C) above the 20^th century average. This was the highest temperature for October in the 1880–2015 record surpassing the previous record set last year by 0.27°F (0.15°C). This was also the highest departure from average for any of the 1630 months of recordkeeping, surpassing the previous record set last month by 0.07°F (0.04°C).

The average Arctic sea ice extent for October 2015 was 460,000 square miles (13.4 percent) below the 1981–2010 average. This was the sixth smallest October extent since records began in 1979, according to analysis by the National Snow and Ice Data Center using data from NOAA and NASA.

Antarctic sea ice extent during October 2015 was 90,000 square miles (1.3 percent) below the 1981–2010 average. This was the 14^th largest Antarctic sea ice extent on record. On October 6^th, the Antarctic sea ice extent reached its annual maximum extent at 7.24 million square miles, slightly above average and in contrast to the past three years when record large maximum sea ice extents were observed.

According to data from NOAA analyzed by the Rutgers Global Snow Lab, the Northern Hemisphere snow cover extent during October was 1.49 million square miles above the 1981–2010 average and the seventh largest in the 48-year period of record. Eurasia had its sixth largest October snow cover extent, while North America had its 11^th largest.

The year-to-date temperature across global land and ocean surfaces was 1.55°F (0.86°C) above the 20^th century average. This was the highest for January–October in the 1880–2015 record, surpassing the previous record set in 2014 by 0.22°F (0.12°C). Eight of the first ten months in 2015 have been record warm for their respective months.

The year-to-date globally-averaged land surface temperature was also the highest for January–October in the 1880–2015 record at 2.30°F (1.28°C) above the 20^th century average. This value surpassed the previous record of 2007 by 0.31°F (0.17°C).

The year-to-date globally-averaged sea surface temperature was 1.28°F (0.71°C) above the 20^th century average and the highest for January–October in the 1880–2015 record. This value surpassed the previous record of 2014 by +0.14°F (+0.08°C).

The full report for October is here.

I put NOAA’s graphic of land and ocean temperature for the year to date at the top of the post. There are three things to note here.

First, the vast majority of the planet’s surface is above average for the year so far. Second, huge areas of the land and sea are record warm for the year so far. Third, that blue patch in the North Atlantic is still there. This is a region that has been anomalously cool for several years now, and is of significant concern because changes in atmospheric and ocean conditions in that region may cause a shift in the major Atlantic sea currents that control a lot of weather in the Northern Hemisphere, especially in northern and western Eurasia.

Here’s a graphic of specific anomalies of note for October 2015 (original here):