Tag Archives: Climate Change

Climate change: up close and personal in Missouri

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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

IMG_0563We 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.

IMG_0560Flood 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.

IMG_0559All 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

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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.

Antarctic Ice Melting: Tamsin Edwards Responds to Richard Alley

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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

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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.

My impressions of the Ted Cruz Climate Denial Circus

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I watched most of yesterday’s Senate hearings live (ironically titled Data or Dogma? Promoting Open Inquiry in the Debate over the Magnitude of Human Impact on Earth’s Climate), and what I missed, I sampled via the magic of recorded video. I considered fisking the hearings, in particular, the closing statement by Senator Ted Cruz (and his next-day interview on NPR). But I was distracted by work on Ikonokast, a new podcast Mike Haubrich and I are starting up (our first guest, taped yesterday, is Shawn Otto). And, many others had responses out on the internet quickly enough that my contribution was clearly not necessary (I’ve got some links below pointing to some of those commentaries).

More on Ted Cruz here, at Ikonokast Episode One

But even after that I’m left with a few impressions worth noting.

Obviously this was a partisan hearing designed to insert a bunch of climate science denial into the Congressional Record. One part of the hearing, though, failed in that respect, because minority members are allowed to invite a witness or two. The minority wisely chose Admiral David Titley, a climate scientists and meteorologist and an excellent communicator. To give a flavor of Admiral Titley’s contribution, check out this segment in which he discusses satellite data collection and interpretation:

That video is embedded and discussed in this post by Peter Sinclair, which you should check out as it covers other important things.

Cruz’s closing statement and interview were astonishing to me, rather unexpected. Every point he tried to make was out of the denialist playbook. That might seem to make sense. But the key points in the denialist playbook are old, tired, discredited, debunked, so easily dismissed that they can’t possibly be taken seriously any more. One would have thought he would have come up with something more effective. But he didn’t. Possibly because there isn’t anything.

Which brings us to this not-to-miss segment of the hearing, a statement by Senator Ed Markey and the denier’s (Curry and Steyn) reactions to that statement. Senator Markey made the poignant and relevant point that the empaneled witnesses represent the last redoubt of climate denialism, a strong contrast with the fact that every country in the world was at the same time busy in Paris trying to address climate change on the assumption that the world’s scientists have made a clear and honest case that global warming is the existential issue of the day. Watch the clip. The whole clip. Interesting things happen. If by the end of it you don’t want to have Senator Markeys baby, you might be a climate science denialist.

Note the contemptuous last stand of Mark Steyn and Judith Curry (starting about 8:20). I didn’t know it was OK to talk to Senators that way during a hearing. I also didn’t know it was OK to lie to Congress.

I said several months ago that we were at or near Peak Denial. Peter Dykstra seems to feel the same way (Commentary: Will we reach peak denial soon?). That was a somewhat risky statement at the time. It no longer is.

Check out these reactions to the hearings:

Everything Senator Ted Cruz said about climate change in this NPR interview was wrong.

Most Hated Senator Shows Why in Denial Circus Hearing
Ted Cruz’ Groovy Climate Expert

Deniers Debunked, Corrected, Chastised, Exposed

Ted Cruz’s Disturbing Views on Climate Change (and Other Things)

Today’s Climate Change Congressional Hearings

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This afternoon in Washington DC, Texas Republican Ted Cruz, who does not believe in global warming yet is chairman of the Senate Subcommittee on Space, Science, and Competitiveness, will convene a hearing called “Data or Dogma? Promoting Open Inquiry in the Debate over the Magnitude of Human Impact on Earth’s Climate.” The purpose of the hearing appears to be to reify the false debate of the reality and importance of anthropogenic global warming, and is yet another step in the current McCarthyesque attack on legitimate climate scientists and their research.

This is an important moment in the history of bullshit.

Among the “experts” giving testimony will be the Canadian conservative shock jock Mark Steyn. Steyn’s relationship to global warming is similar to, say, Rush Limbaugh’s relationship to women’s rights. He is a bloviating ignoramus who treats the truth like so much dog poo on the bottom of his shoe. If he actually knows anything about climate science, he is doing a very good job of hiding it. His major contribution to the discussion is a continuous attack on climate scientists based mostly on cherry picked quotes. In fact, he recently self published a book made up, apparently, of cherry picked quotes and related material in an effort to discredit top climate scientists. For a flavor for what he has done, check out this analysis of the quotes he used of several established climate scientists.

I have a copy of Steyn’s testimony. Steyn is being sued for defamation by scientist Michael Mann. I won’t go into the details of that suit, but a very large part of Steyn’s testimony before the Senate is about that law suit or related issues. It appears that the Republicans on the Senate science subcommittee are allowing an anti-science Canadian citizen to use the Senate hearing room to argue his side of a civil law suit. (Part of his argument, by the way, is to say several insulting things about the judicial branch hearing this case, and the judge. Entering these comments into the congressional record.)

One of the interesting things Steyn does is to define a set of “experts” whom he claims make the case against global warming, and whose work has been either ignored or discredited by mainstream climate science. This set includes the recently turned Judith Curry; John Christy, one of the only climate scientists to believe that the Earth’s system is relatively insensitive to increases in greenhouse gas concentration; Meteorologist Lennart Bengtsson, famous for briefly joining the science denier organization “Global Warming Policy Foundation,” only to quit a short time later in what seemed to be a ploy to accuse mainstream science as being McCarthyistic (so yes, there will be irony in Washington DC today); Lord Nigel Lawson, a blue-blood non-scientist science denier which I’m pretty sure is a category (including Lord Christopher Monckton and coal baron Lord Viscount Matt Ridley); the economist Roger Pielke Junior, who is famous for being drummed out of the statistico-rationalist site FiveThirtyEight after he represented his research attempting to show that hurricanes aren’t really a problem, but accidentally let a bunch of actual statistics experts see what he was up to; and the recently discredited Harvard-Smithsonian not-a-professor soft money guy Willie “The Sun Did It” Soon.

Roger is a real life academic who has climate change impacts wrong, in my opinion (and I’m not alone) and has stepped into a fight he was regrettably unprepared for. But otherwise he’s just some guy with a faculty job. Until now. Now, according to Congressional Testimony, he is part of a set that includes a handful of crazy anti-science rantologists. John Cristy and Judith Curry are both testifying today, along with Steyn. Curry was a legit climate scientists who, much to the horror and chagrin of her colleagues, has slid farther and farther into the anti-science abyss, who rarely makes sense any more, and who is probably the last established academic anyone would want to give testimony about such an important issue. But she is apparently very excited about giving this testimony.

The point of these associations? Mark Steyn, who is a spiritual leader of the anti-science movement, has placed a couple of people who might not have wanted to be classified with discredited scientists and ranting yahoos into the same boat with said individuals. Maybe fairly, maybe not. I wonder how they feel about this.

Now, to be fair, Steyn’s testimony, which is mostly him pleading his side of the law suit, is not entirely inappropriate for this particular hearing. The hearing is about the meta-context in which the science is being done, and the law suit is about nefarious accusations made by a guy who looks a lot like a bought and paid for science denier against Michael Mann. Steyn isn’t so much the problem here, but rather, the hearing itself, and the subcommittee, is the problem. Steyn is merely the poster boy.

For those just tuning in, one of the things Steyn will yammer on about today (or at least, enter into the record) is this deal about Michael Mann and the Nobel Prize. According to Nobel, “The Nobel Peace Prize 2007 was awarded jointly to Intergovernmental Panel on Climate Change (IPCC) and Albert Arnold (Al) Gore Jr. for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change.” Mike Mann and others who were on that panel rightfully were credited, thusly, with winning the Nobel Prize. And they did. But technically, the Nobel Committee does not actually use that nomenclature. They say that the panel, not the people on it, won the prize. Once this semantic detail was made clear, the people on the IPCC appropriately adjusted their language to reflect the Nobel construction of things. But Steyn has been yammering about this since, claiming that his arch nemesis, the actual scientist Mann, claimed something that was not true. Apparently Steyn will continue this yammering this afternoon for the benefit of our Senate, and we the taxpayers will be paying for this.

The highlight, I say non-sardonically, of the hearings may be the testimony of Rear Admiral David Titley, a PhD in Meteorology who has made significant contributions to understanding and communicating about climate change. I assume he was invited by the minority party. If you haven’t seen Rear Admiral Ditley’s TEDx Talk, you should. He was a climate skeptic, then he looked into it, and realized that climate change is one of the most important issues of the day. He is a great communicator and an honest interlocutor. He’ll be swabbing the deck with the likes of Steyn and Curry.

Steyn’s testimony has the climate science wrong. I am pretty sure the minority members of the committee will be aware of this, and will address these issues in a well informed manner. But the truth is, with Republicans in control in the Senate, and with the current McCarthyesque attack on climate scientists well under way, this hearing will largely be a circus.

In my opinion, the following statement by Steyn, from his written testimony, should be first, because it is the most important thing he has to say:

In that respect, let me close by turning to my area of expertise. I am not a climate scientist, but I am an acknowledged expert in the field of musical theatre

In response, the chair of the subcommittee would appropriately say, “Oh, excuse me, then, Mr. Steyn, we obviously invited you by accident. You may now return to Canada. Thank you for your time.”

Photograph from here, “Protesters gather near the office of [Florida] Senator Marco Rubio to ask him to take action to address climate change. Photograph: Joe Raedle/Getty Images”

Incredibly important finding on renewable energy

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The big complaint people have about renewable energy, or at least, the big complaint that has some merit, is that renewables, such as wind and solar, are intermittent and to varying degrees, unpredictably intermittent. This makes it hard to match demand for electricity to supply. Some aspects of this argument are overstated. For example, a steady supply (the same potential power all the time, every minute of the day) can be a bug as well as a feature. If every electron of electricity we used came from nuclear power plants, there would be a problem because our demand fluctuates and you can’t vary the output of a nuclear plant. Some of the arguments are inaccurate. For example, it is not true that a nuclear power plant produces the same exact amount of electricity all the time. Nuke plants often reduce production unexpectedly. If there is some sort of problem, they partly shut down. And, of course, the shut down for refueling. So they are not perfect.

The problem if intermittent and less than ideally predictable supply can be addressed a number of ways. One is big huge batteries, which are costly and otherwise problematic. There are various other storage methods using water and air and things that can hold heat or “hold cold.” And so on. Then, of course, there is the grid. If it is sunny one place and cloudy a different place, electricity can be shunted between.

Still, we often see arguments suggesting that these methods of matching supply and demand of electricity are problematic in one way or another.

A new research project, just out in the Proceedings of the National Academy of Sciences, addresses these issues and gives great hope to the use of 100% non-nuclear renewables to meet energy demands. The paper is by Mark Jacobson, Mark Delucchi, Mary Cameron, and Bethany Frew, and is titled “Low-cost solution to the grid reliability problem with 100% penetration of intermittent wind, water, and solar for all purposes.”

Here is the abstract and the statement of significance from the paper:

Screen Shot 2015-12-04 at 11.58.07 AM

This study addresses the greatest concern facing the large-scale integration of wind, water, and solar (WWS) into a power grid: the high cost of avoiding load loss caused by WWS variability and uncertainty. It uses a new grid integration model and finds low-cost, no-load-loss, nonunique solutions to this problem on electrification of all US energy sectors (electricity, transportation, heating/cooling, and industry) while accounting for wind and solar time series data from a 3D global weather model that simulates extreme events and competition among wind turbines for available kinetic energy. So- lutions are obtained by prioritizing storage for heat (in soil and water); cold (in ice and water); and electricity (in phase-change materials, pumped hydro, hydropower, and hydrogen), and using demand response. No natural gas, biofuels, nuclear power, or sta- tionary batteries are needed. The resulting 2050–2055 US electricity social cost for a full system is much less than for fossil fuels. These results hold for many conditions, suggesting that low-cost, reliable 100% WWS systems should work many places worldwide.

The large-scale conversion to 100% wind, water, and solar (WWS) power for all purposes (electricity, transportation, heating/cooling, and industry) is currently inhibited by a fear of grid instability and high cost due to the variability and un- certainty of wind and solar. This paper couples numerical simu- lation of time- and space-dependent weather with simulation of time-dependent power demand, storage, and demand response to provide low-cost solutions to the grid reliability problem with 100% penetration of WWS across all energy sectors in the con- tinental United States between 2050 and 2055. Solutions are obtained without higher-cost stationary battery storage by pri- oritizing storage of heat in soil and water; cold in water and ice; and electricity in phase-change materials, pumped hydro, hy- dropower, and hydrogen.

I’m still absorbing the paper. I’m informed that the authors of this paper know what they are talking about. People I know in the clean energy biz have been saying for some time that they are pretty sure we can do this, and this study seems to support the idea. Even if this is not perfect, it seems that we can be close to using primarily renewables with some contribution from nuclear, and some adjustments in how we use energy. The key message of this work: It is not hopeless, we can save the world! Will we?

Global Warming Could Make Peat Bogs Less Of A Carbon Sink

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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

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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

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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

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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.
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
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

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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

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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

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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 20th 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 20th 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 20th 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 14th largest Antarctic sea ice extent on record. On October 6th, 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 11th largest.
  • The year-to-date temperature across global land and ocean surfaces was 1.55°F (0.86°C) above the 20th 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 20th 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 20th 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):

    201510

    Low Hanging Fruit: A Very Healthy Diet for The Planet Earth

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    Michael Mann has an editorial on Scientific American’s site putting the well known 2.0C limit in perspective for the upcoming climate talks in Paris.

    Mann makes a number of important points in his essay (read it here: Meeting a Global Carbon Limit Is Cheaper Than Avoiding One) but there is one point that I want to underscore.

    The key factor is that there are technological innovations and economies of scale that emerge only in the course of actually doing something.

    Here’s the thing. Let’s say you were suddenly in charge of one trillion dollars of money that could be used to address climate change. What would you spend the money on? Here are some suggestions.

    1) Build machines that take CO2 out of the air.

    2) Invest in the “next generation” of nuclear reactors.

    3) Purchase a huge amount of deforested land and re-forest it.

    4) Divide the money up among numerous research groups to develop as yet unknown clean energy technologies that may save us.

    All those things are potentially good ideas, and we should probably think about doing all of them at some level. But that is not how you should spend your trillion dollars. The way you should spend your trillion dollars is to underwrite the cost of converting as many homes and businesses as you can to using passive geothermal heating and cooling, and to install photovoltaic on the roofs. Some of the money could also be used to switch internal combustion engines over to electric. Why do these things first? Because they are low hanging fruit. The results would be immediate. A home that uses passive geothermal will use about half, or less, of the fossil carbon for that purpose. A home that has fully deployed PV panels on the roof can cover the electricity for all of that home’s commuting costs and run the heating and cooling system, and a few other things, for much of the year. And so on. As long as our landscape is characterized by buildings with roofs that serve mainly to convert sunlight into heat, we can buy out that sunlight, harness it, and move towards a greater percentage of clean energy very very quickly.

    At the same time, of course, we do want to do research on new technologies, perhaps even carbon capture (though I think that should be way down on the list). But there is so much we can do with existing technologies addressing existing needs. As Mann put it, “The obstacle is not a physical one—it is one of political and societal will.”