Tag Archives: Antarctic Sea Ice

Climate change is real, it is a problem, and it is getting worse

February 5, 2017UncategorizedAntarctic Sea Ice, Arctic Sea Ice, Climate and weather, Climate Change, Climate Change, Destruction of farmland, Global Warming, Increasing temperature, Sea Level Rise, Severe weather, Warmest YearGreg Laden

The year 2016 was messy and expensive and full of climate change enhanced weather disasters. There were, according to Jeff Masters and Bob Henson, over 30 billion dollar disasters last year.

This is the fourth-largest number on record going back to 1990, said insurance broker Aon Benfield in their Annual Global Climate and Catastrophe Report issued January 17 (updated January 23 to include a 31st billion-dollar disaster, the Gatlinburg, Tennessee fire.) The average from 1990 – 2016 was 22 billion-dollar weather disasters; the highest number since 1990 was 41, in 2013.

The frequency of flood disasters in Europe have doubled over 35 years.

The number of devastating floods that trigger insurance payouts has more than doubled in Europe since 1980, according to new research by Munich Re, the world’s largest reinsurance company.

The firm’s latest data shows there were 30 flood events requiring insurance payouts in Europe last year – up from just 12 in 1980 – and the trend is set to accelerate as warming temperatures drive up atmospheric moisture levels.

Globally, 2016 saw 384 flood disasters, compared with 58 in 1980, although the greater proportional increase probably reflects poorer flood protections and lower building standards in the developing world

As I’m sure you’ve heard, he year 2016 was the hottest year on record, and 2017 is also going to be hot. (I personally doubt 2017 will be hotter, but then again, I was thinking that 2016 might not break the 2015 record.)

Mark Bgoslough as an interesting piece here on how global temperature records are made, analyses, and reported. I recommend reading that. Here, I want to use a graphic he made for that item to point something outI’ve added the green lines. I’ll just leave it here without comment.

People in the northeastern US should be about 50% more concerned about global warming than everyone else, because new research suggests that this region will warm about 50% faster than the globe in coming years.

The fastest warming region in the contiguous US is the Northeast, which is projected to warm by 3°C when global warming reaches 2°C. The signal-to-noise ratio calculations indicate that the regional warming estimates remain outside the envelope of uncertainty throughout the twenty-first century, making them potentially useful to planners. The regional precipitation projections for global warming of 1.5°C and 2°C are uncertain, but the eastern US is projected to experience wetter winters and the Great Plains and the Northwest US are projected to experience drier summers in the future.

John Abraham summarizes and interprets the results here.

Regardless of the so-called temperature target, what this study shows is that even if we do keep the globe as a whole to a 2°C temperature increase, some regions, like the Northeast United States will far exceed this threshold. So, what is “safe” for the world is unsafe for certain regions.

A recent poll tells us that 90% of rural Australians are concerned about the impacts of climate change. Most were concerned about drought and flooding. Fewer than half this coal fire power stations should be phased out.

I think that if you did a similar poll in the US, you would find that most rural Americans don’t are about climate change, and even fewer think coal should be phased out. Since all rural people, Australians or Americans and everyone else, have already been affected to at least some degree by climate change, and since the science strongly suggests that things will get much worse for them in the future, all of these folks should be concerned and all of them should be for doing something about it. The good news is that the cognitive dissonance we see in the Australia between climate change and concern may be a harbinger for future changes in American attitudes. Australia has probably been affected by severe weather caused or enhanced by climate change to a much larger degree than has Rural America. In short, I expect disdain for coal to catch up to concern about climate change in Oz, while in America, eventually, people will get more and more on board with both.

Americans are more concerned about not offending farmers than they are about saving them. In American farmlands, we expect climate change to reduce staple crop production substantially by the end of the century. The farmers need to get on board more quickly if they want their grandchildren to be able to be farmers too.

A question on everyone’s mind: “Is the California Drought over and what does this mean?”

It looks over. Reservoirs are filling, snow is piling up in the mountains, everything is wet.

However, there are several things still to consider. For one, the recharging of water supplies is not complete, and if near-zero-rain conditions return right away, the drought will slowly return. This is of course always a concern, but right now we have a slightly different question to ask for California. Is it the case that the conditions that led to the California drought are the “new normal” (a phrase I’m not really happy with) I the sense that from now on, there will be less snow pack, less rainfall, etc. In other words, is it the case that the future of California is generally much dryer all the time with the occasional drenching rainy season, because of climate change?

We don’t know yet, but there is one fairly obvious area of concern: Snow pack. Snow pack plays a role in watering California. Snow pack forms during the rainy winter, and slowly melts thereafter. If that precipitation wasn’t temporarily stored up as snow, the winter rains would be more flooding, and there would be less water retained in the system for the rest of the year. Increasing warmth, due to global warming, has caused more of the precipitation that falls in the mountains to be rain rather than snow, and it has caused the snow to melt more quickly.

Warmer temperatures also mean more evaporation, so getting everything all wet and squishy for a few months during the Winter may mean less a few months later when a warm and dry atmosphere starts to drunk the moisture out of the ground and off the reservoir’s surfaces at an accelerated rate.

This piece by Andrea Thompson at Climate Central does a great job of summarizing the current situation in California.

I have been noting for years (well, for a couple of years) that the best available paleo data suggest that the current levels of CO2 and/or temperature, protracted over a reasonable amount of time, should be associated with sea levels of about 8 meters. In other words, if you are worried about sea level rise, and you should be, the amount of sea level rise that we are currently locked into is enough to inundate much of Southeast Asia’s rice growing land, large parts of various US states such as Louisiana and Florida, and to cause retreat from many of the world’s most densely settled cities.

Over recent months the interface between the scientific research and journalism has started to squeeze out the occasional example of this startling fact, one we’ve known for years but have been afraid to say about else we be considered non reputable. From the Independent:

The last time ocean temperatures were this warm, sea levels were up to nine metres higher than they are today, according to the findings of a new study, which were described as “extremely worrying” by one expert.

The researchers took samples of sediment from 83 different sites around the world, and these “natural thermometers” enabled them to work out what the sea surface temperature had been more than 125,000 years ago.

How long will this take? Nobody knows. This depends on how fast the major glaciers melt.

Carlos Gimenez, mayor of Miami, is already rolling up his pants:

“Let’s be clear, sea-level rise is a very serious concern for Miami-Dade County and all of South Florida,” Mayor Carlos Gimenez told the crowd Wednesday morning at the South Miami-Dade Cultural Arts Center during his annual State of the County address. “It’s not a theory. It’s a fact. We live it every day.”

Arctic Sea Ice in 2015

October 5, 2015UncategorizedAntarctic Sea Ice, Antarctic Sea Ice, Arctic Sea Ice, Arctic Sea Ice Extent, Arctic Sea Ice Volume, Climate Change, Climate Change, Climate Change Graphics, Global Warming, Global WarmingGreg Laden

Every year the sea ice that covers the northern part of the Earth expands and contracts though the winter and the summer. The minimum extent of the sea ice is usually reached some time in September, after which it starts to reform.

Human caused greenhouse gas pollution has increased the surface temperatures of the earth, as measured on the land at about heat height with thermometers, and on the sea at the surface, mainly with satellites. Warming of the surface has continued apace for several decades, though with some expected squiggling up and down in how fast that is happening.

Greenhouse gas, mainly CO2, causes warming because of its heat trapping properties, and this warming (and the CO2 itself) set in motion a number of feedback systems that either push against warming or increase warming. Most of these feedback systems, unfortunately, are what we call “positive” feedbacks, though they are not “positive” in a good way. They are effects that increase the amount of warming beyond what would happen from just the CO2. One of the biggest global effects is an increase in the amount of water vapor carried by the atmosphere. Since water vapor is also a greenhouse gas, more CO2 -> more greenhouse effect -> more water vapor -> more greenhouse effect.

One of the bad effects of greenhouse warming is the melting of more ice in the Arctic during the summer. On average, less and less ice is left by the end of the melt season in September. Again, this amount squiggles up and down a bit, but it is a persistent downward trend. Since ice reflects sunlight away from the earth, a decrease in ice cover in the Arctic means more warming. This has both regional effects (such as an increase in melting of land-based Greenland glaciers) and a global effect. The regional effect is very important, because this has resulted in a phenomenon known as Arctic Amplification. This refers to the fact that of all the different regions of the earth, the Arctic is warming more than most other regions. The large scale systems of air movement that make up much of our climate, and thus control much of our weather, are shaped and driven in large part by the redistribution of heat form tropical areas (where the sun has a stronger warming effect) outward towards the poles. This redistribution shapes trade wind patterns and determines the location and strength of the jet streams. The relatively warmer Arctic has changed the basic shape and pattern of these major climatic features in ways that have caused significant changes in weather. The drought in California is caused in part by the persistence of a large jet stream meander caused, almost certainly, by Arctic Amplification and other changes in heat distribution in the northern latitudes. Another change is the increase in large scale precipitation events. Here in the twin cities, for example, the frequency of 3″ plus rainstorm over the year has changed from about one every two years to one every year, on average. Rainfall events of between 1 and 2 inches, and between 2 and 3 inches, have also increased.

There are two major properties of Arctic ice that should be considered. One, just discussed, is extent. Extent matters because of its direct effect on albedo, the reflection of sunlight back into space. Less ice extent, caused by warming, means even more warming. The other property is ice volume. Ice volume builds up over time. Thick ice includes ice from previous years that didn’t melt. The system is complex and dynamic, but a healthy Arctic ice ecosystem has a good amount of thick high-volume ice that persists through the melt season and forms the anchor against which annually re-freezing surface ice forms. The less ice volume, the less stable the Arctic Sea ice is, and the more difficult it becomes to reform. Exactly how this effect works depends on exactly which part of the Arctic one is in.

Over the last several decades, the volume of Arctic Sea ice has reduced by something like 80%. This is not good.

Andy Lee Robinson has made an amazing and highly instructive graphic showing the decline in Arctic Sea ice volume over the years. Here is the most updated version showing data up through this year, based on these data:

From Andy’s YouTube page:

Published on Oct 4, 2015

This is an animated visualization of the startling decline of Arctic Sea Ice, showing the minimum volume reached every September since 1979, set on a map of New York with a 10km grid to give an idea of scale. It is clear that the trend of Arctic sea ice decline indicates that it’ll be ice-free for an increasingly large part of the year, with consequences for the climate.

The rate of ice loss in the Arctic is staggering. Since 1979, the volume of Summer Arctic sea ice has declined by more than 80% and accelerating faster than scientists believed it would, or even could melt.

Based on the rate of change of volume over the last 30 years, I expect the first ice-free summer day in the Arctic Ocean (defined as having less than 1 million km² of sea ice) to happen between 2016 and 2022, and thereafter occur more regularly with the trend of ice-free duration extending into August and October.

(The music for the graphic was also composed and played by Andy.)

By the way, those interested in computer technology will note that Andy’s graphic is produced on the most powerful and stable operating system, Linux, using OpenSource tools.

I produced the animation using hand-written perl and php code to create povray scripts, and scheduling task distribution using MySQL between 7 linux servers working in parallel to render 810 frames at 1920 x 1080 resolution. The “farm” renders 22 frames simultaneously taking between 1-2 hours per frame. On completion, ffmpeg combines the individual frames and music into a high quality mp4 video.

So, that’s cool.

Anyway, Andy has also created the now famous Sea Ice Death Spiral graphic, showing Arctic Sea ice volume since 1979, in a particularly helpful graphic style. Notice that the sea ice volume is fairly stable for several years, then starts to decline rapidly and continues to do so thereafter.

Sea ice extent has followed a similar pattern. Let’s have a look at this year in relation to the last several decades. First, this graphic made using the interactive graphing tool at the National Snow and Ice Data Center shows this year’s ice in relation to the average and standard deviation since 1979. Here we see that the ice extent has been following the lowest end of the two standard deviation spread. The lowest extent shown here is the fourth lowest since records began:

To add even more perspective, the next to graphics show the first ten years in the NSIDC data set, followed by the last ten years. In both cases, the thick black line is the average for the entire data set. This comparison clearly indicates that things have changed in the Arctic:

One of the things that people who wish to deny climate science usually start whinging about at this point in the discussion is that the Antarctic has had an increase in sea ice, and that somehow this all evens out. Let me briefly explain why this is incorrect.

There has been an increase in the extent of sea ice in the Antarctic, but there are at least two (maybe three) reasons for this. First, there has been a major increase in winds in the southern hemisphere caused by climate change. This includes winds coming off the Antarctic continent. These winds break up the sea ice and blow it around, opening areas between blocks of floating ice, which then freeze quickly. This causes an increase in extent of the ice. The other is the increase in fresh water entering the sea around Antarctic because the glaciers are melting. This fresh water allows the sea to freeze at a higher temperature, causing more ice. There may be other reasons having to do with currents of both air and water, and rainfall, also caused by climate change. So, climate change causes these changes in sea ice at both poles.

The increase in maximum sea ice in the Antarctic does not increase albedo because it happens in the dark. So the decreased global albedo in the Arctic is not offset by changes in the Antarctic. All of the regional ecological changes affecting sea life and so on can not be offset between the Arctic and Antarctic, because they are on opposite ends of the planet. Also, note, that this year we did not see an increase in Antarctic sea ice. Overall it is expected that global warming will turn around the Antarctic sea ice amount, and also, we are expecting Antarctic glaciers to begin melting at a higher rate over the next decade or so. It will be interesting to see what eventually happens. In any event, keep in mind that the Arctic and Antarctic are very different geographical regions. The Arctic is a sea surrounded by continents. The Antarctic is a continent surrounded by sea. We could not possibly expect the same things to happen in these two areas. The comparison often made by climate science contrarians is absurd.

Antarctic Sea Ice and Global Warming

October 9, 2014UncategorizedAntarctic Sea Ice, Antarctic Sea Ice, Climate and weather, Climate Change, Climate Change, Global Warming, Global WarmingGreg Laden

Did you ever leave your freezer door slightly open on a humid day only to find chunks of new ice formed at the gap? When that happens, did you conclude “Oh, my freezer is colder than usual, I wonder how that happened?” No. You concluded that you had left the door slightly open, some cold got out, and vapor froze on your gasket.

Sea ice is hard to make. The sea is salt water, so it has a lower freezing point than fresh water. The sea has potentially large waves and lots of currents. This is just not a situation where ice can easily form. Yet, it does form on the oceans near the Earth’s poles because it is really cold there. But even within that context, more or less ice can form because of important details like how much fresh water is mixing in with the cold salt water, and exactly where currents of warmer or colder water are going. The formation of sea ice at the ends of the Earth is probably somewhat more complicated than the formation of frost and rind on your refrigerator.

(A quick note: Sea ice is ice that sits on, and therefore, essentially, in the sea. It is not glacial ice. Those are two very different things. I’m sure you knew that but just in case this is a good moment to point it out.)

In recent years, the amount of sea ice forming around Antarctica has bee going up. Global warming causes local warming but it also causes local cooling (like when the Arctic Vortex got knocked off center last winter and visited the middle of North America, an event that still causes a sense of fear and loathing among those of us who experienced it). So when we hear about expanding sea ice in the Antarctic, knowing that anthropogenic global warming is a real thing, we might assume that this is just one of those phenomena that runs counter to expectations but that is still part of the overall process of warming-driving climate change resulting from the addition of greenhouse gasses to the atmosphere.

And that is essentially correct, though the reasons may be a bit unclear and require further study.

So, thinking about our freezer, and the overall problem of making sea ice, there seem to be three things that can cause more of this ice. One might be the addition of fresh water to the system. That seems likely if the Antarctic glaciers are melting (which they are). Depending on where the fresh water goes, that could allow the formation of sea ice. Also, if precipitation increased in the area, that would add fresh water.

Second, the area where the sea ice is forming could be colder. That seems backwards in on a warming planet, but actually, that can happen too. Antarctica is, to a larger extent than the Arctic, a semi-closed system of air and sea currents, because it is a roundish continent surrounded by sea at one end of the planet. This means that cold air might be retained over the continent rather coherently. At the North Pole, “Winter (January) temperatures … can range from about ?43 °C (?45 °F) to ?26 °C (?15 °F), perhaps averaging around ?34 °C (?29 °F),” while at the South Pole, “In winter, the average temperature remains steady at around ?58 °C (?72 °F).” (source: Google). The north pole is sea, the south pole is land, and the south pole is at a higher elevation, but those differences are partly why the south pole is colder. Anyway, with all this cold air on the Southern Continent, perhaps one only needs to have air currents change a little to move that cold air over the sea a bit more to add to the chances of freezing water and making sea ice.

Third is the possibility that the disruptive effects of storms, waves, or surface currents could change, making for a calmer environment, allowing more ice formation.

Have any of these things happened?

Yes. Yes, they have.

Joe Romm has a writeup on some recent research that helps to explain the increase in Antarctic Sea ice (NOAA: Record Antarctic Sea Ice Growth Linked To Its Staggering Loss Of Land Ice).

The National Snow and Ice Data Center notes:

…sea ice surrounding the Antarctic continent reached its maximum extent on September 22 at 20.11 million square kilometers (7.76 million square miles). This is 1.54 million square kilometers (595,000 square miles) above the 1981 to 2010 average extent, which is nearly four standard deviations above average. Antarctic sea ice averaged 20.0 million square kilometers (7.72 million square miles) for the month of September. This new record extent follows consecutive record winter maximum extents in 2012 and 2013. The reasons for this recent rapid growth are not clear. Sea ice in Antarctica has remained at satellite-era record high daily levels for most of 2014.

“What we’re learning is, we have more to learn,” said Ted Scambos, lead scientist at NSIDC.

The unusual sea ice growth in Antarctica might be caused by changing wind patterns or recent ice sheet melt from warmer, deep ocean water reaching the coastline, according to scientists at NSIDC. The melt water freshens and cools the deep ocean layer, and it contributes to a cold surface layer surrounding Antarctica, creating conditions that favor ice growth.

From Skeptical Science:

The most common misconception regarding Antarctic sea ice is that sea ice is increasing because it’s cooling around Antarctica. The reality is the Southern Ocean surrounding Antarctica has shown strong warming over the same period that sea ice has been increasing. Globally from 1955 to 1995, oceans have been warming at 0.1°C per decade. In contrast, the Southern Ocean (specifically the region where Antarctic sea ice forms) has been warming at 0.17°C per decade. Not only is the Southern Ocean warming, it’s warming faster than the global trend. This warming trend is apparent in satellite measurements of temperature trends over Antarctica…

And, from NOAA:

Much of this year’s sea ice growth occurred late in the winter season, and weather records indicate that strong southerly winds blew over the Weddell Sea in mid-September 2014. Antarctica is a continent surrounded by open ocean. So unlike the Arctic, where surrounding landmasses constrain how much sea ice can expand, Antarctic sea ice can spread out over a bigger area. Winds blowing from the land toward the ocean encourage ice growth in the waters north of the continent.

Winds probably did not act alone to spur so much sea ice growth; melting land ice may have played a role. Most of Antarctica’s ice lies in the ice sheets that cover the continent, and in recent decades, that ice has been melting. Along the coastline, ice shelves float on the ocean surface, and much of the recent melt may be driven by warm water from the deep ocean rising and making contact with ice shelf undersides.

How does the melting of land ice matter to sea ice formation? The resulting meltwater is fresher than the seawater. As it mixes with the seawater, the meltwater makes the nearby seawater slightly less dense, and slightly closer to the freezing point than the ocean water below. This less dense seawater spreads out across the ocean surface surrounding the continent, forming a stable pool of surface water that is close to the freezing point, and close to the ice onto which it could freeze.

Added cold seems to be a factor. Added fresh water seems to be a factor. Changes in where cold air and relatively fresh water goes seems to be a factor. I don’t know about storminess and currents at the outer edge of ice formation.

The dramatic and steady increase in Antarctic Sea Ice is yet another example of the effects of climate change.