Record Sea Ice Losses at BOTH Poles: This is What it Means

We've just hit the winter solstice - the first day of winter. And that means sea ice extent in the Arctic is going through its annual period of increase, which generally reaches a maximum around February before beginning its annual melting. And we are seeing an increase. But that increase is setting a record that we wish we weren't seeing because so far it's a record low.


Last year (that is, around February of 2016) we recorded the lowest Arctic sea ice extent in history. This year so far we're seeing that record low being broken. Now it's still early in the growth season so it might recover. Or it might not. Clearly the dropping sea ice extent in the Arctic continues the trend we've been seeing for decades. The ice is melting more than usual in the summer and its not growing back as much in the winter.

[See larger here]

As bad as that is - and it is very bad indeed - we're seeing an even worse result right now in the Antarctic. Because the Antarctic is at the southern pole, the area is now going into summer. As of early December Antarctic sea ice extent was the lowest on record.

It is highly unusual to see record low sea ice extents at both poles at the same time. Of course, these early indicators could reverse as the seasons (freezing in Arctic, melting in Antarctic) continue over the next two or three months, but the overall trends are not giving us much hope for correction.

To make matters worse, the Arctic is seeing its warmest temperatures for this time of year ever. And not just a little warmer; temperatures are heating up to unbelievable levels that have climate scientists startled - at least 20 degrees Celsius warmer than normal. Temperatures have actually been above the freezing point. This is causing melting during a part of the year where the ice should be freezing.

Part of the reason in the Arctic is because this past year set a record low total ice extent for the year (a combination of the record low maximum and near-record low minimum). With warmer waters in the summer and early fall the ice growth never got a good start in the late fall and now winter. If the low ice extent maximum trend continues it creates a vicious cycle of conditions that will lead to acceleration of the downward spiral we've been witnessing for years.

Total Polar Sea Ice Extent:

The reasons for the low ice extent in Antarctica are harder to explain. It may be related to weakening of westerly winds that generally insulate the Antarctic from the effects of global warming. Or it might be related to the ozone layer. Or just dumb luck. Unlike the Arctic, the Antarctic is harder to define. One thing is clear, however, and that is that the Antarctic should be the last place we would see the effects of climate change. The fact that we are seeing them (e.g., destruction of west Antarctic ice shelf and more rapid movement of glaciers in the east Antarctic) suggests we may have reached a tipping point. The ramifications of any sudden melting of land-based Antarctic ice (along with melting of Greenland) will be dramatic, to put it mildly.

The ramifications of Arctic melting are already being experienced - great warming, more melting, national defense issues, rising sea levels (from land-based melting), dramatic changes in weather patterns and jet streams, and much more.

We'll have to watch what happens over the next few months - melting in the Antarctic and freezing in the Arctic - to see if these record lows continue. If you're not sure how to read the graphs, check out this quick primer. For the basics on how the Arctic and Antarctic are different, read here.

Climate Wars - Arctic vs Antarctic Ice Melt

Arctic sea ice is melting. This is one of the most common points made whenever climate change is discussed (in addition to the obvious point that the climate is heating up). But Antarctic sea ice is growing, so it's a wash, right?

No. No. No.

This time of year climate scientists (and the informed public) spend a lot of time tracking the annual melting of sea ice in the Arctic. Climate deniers counter by exclaiming: "but the ice is growing in Antarctica." Deniers cry that the overall global sea ice total is the most important number and that Antarctica makes up for the ice lost in the Arctic.

Again. Emphatically. No. No. No.

This idea is akin to saying that a person making a billion dollars a year and a person making minimum wage (about $15,000/year) are equitable because the average income between the two is over $500 million.

In other words, it's silly.

To begin with, over the last 40 years the Arctic has lost about 21,000 square miles of sea ice per year. During that same time the Antarctic has gained only about 7,300 square miles per year. So even if "total global sea ice" was a valid measurement (which it isn't), it would show a net loss of nearly 14,000 square miles per year. That's hardly a winning argument.

The fact is that the Arctic and Antarctic are completely different systems and not directly comparable in any way. To help people understand the difference between the two poles, let's take a look at the main processes of both. 


The most obvious difference is that the Arctic is an ocean surrounded by land and the Antarctic is continental land surrounded by ocean. This difference has a profound affect on how and when ice is formed, not to mention what happens when it melts.

Arctic

Every summer sea ice shrinks in the Arctic, and every winter it grows. To track these patterns we rely on several measurements, one of which is sea ice extent (others are ice volume and ice age). Sea ice extent is defined as an area of ocean covered by at least 15% sea ice.* Two key numbers are the maximum ice extent (the greatest ice extent of any given year, usually in February) and the minimum ice extent (the least ice extent of any given year, usually in September). Generally the melting in the summer is not complete, that is, there is still sea ice even at the minimum. This, however, could change as various feedback effects tend to increase melting (e.g,. more open water means more warming, which means faster and greater melting). It is expected that at some point we'll see an ice free Arctic for some period of time during the summer. For a variety of reasons, that's not a good thing at all.

Both the minimum and maximum indicators have been showing an overall decrease in sea ice extent in the Arctic. For example, the following chart shows ice extent for March 1979-2016. As can be seen, some years are worse than others, but the general trend is clearly loss of ice over time. The same pattern applies to every single month. Feel free to look at other examples on the National Snow & Ice Data Center website.

Because of short-term variations in weather, the year to year values vary, but the trend is clear - the Arctic is losing ice. [See here for a video explanation of trend and variation] By the way, when deniers claim "Arctic ice has recovered," they are falsely cherry picking one of those little peaks and dishonestly ignoring the clear overall trend to fabricate their entirely - and obviously - false conclusions. [This intentional deception is why we know that deniers are being dishonest, not merely ignorant]

Antarctic

While the Arctic is frozen ocean, the Antarctic is frozen land. While the sea ice in the Arctic grows out into the ocean and is constrained by the land, the sea ice in the Antarctic grows out from the land, basically surrounding the continent and expanding without much resistance as far as the cold water and winds can take it. Remember that sea ice extent is defined as "at least 15% coverage of a unit area," so it doesn't necessarily mean the entire area is covered with ice, but with that much unhindered space to grow, it can go a long way.

Scientists have a very good understanding of the processes driving ice gain and loss in the Arctic; for the Antarctic there is greater uncertainty. What we do know from measurements is that, like the Arctic, the sea ice in the Antarctic grows in the winter and shrinks in the summer. Unlike the Arctic, the sea ice shrinks almost completely away each year in the Antarctic. In recent years there has been a pattern of increasing sea ice extent in the Antarctic, the opposite pattern of what we're seeing in the Arctic. The reasons for this are still a point of discussion, but new data have helped clarify the reasons for the trend.


One important factor is that greater melting of land-based glaciers and ice sheets has put more freshwater into the ocean surrounding Antarctica. Since the water is so cold, and because the freshwater tends to float on top of the denser saltwater of the ocean, you see rapid freezing of this new surface water. Another factor is the wind. Unlike the land-constrained Arctic, the winds have virtually limitless ability to push any forming sea ice floes further out to sea, where the cold temperatures tend to fill in the spaces and increase sea ice extent. Studies have also shown greater and faster movement of Antarctic glaciers toward the coasts, which helps push more ice offshore. In addition, the west Antarctic ice shelf** has been collapsing, and will continue to do so irreversibly.

The graphic above comes from NASA's GRACE satellite. It shows that despite the annual winter increase (and annual summer loss) of sea ice in the Antarctic, the overall ice mass of the continent itself has been dropping. Ice mass on Greenland shows the same pattern, only worse.

All of this information tells us that while we may see short-term increases in the Antarctic annual sea ice extent, continued warming of the climate will inevitably result in a much rapider overall ice loss as the glaciers continue to move to the coast and the west Antarctic ice shelves disappear.

So we can see that the two poles are completely different in every aspect, which makes any adding of their ice masses meaningless. All the factors in the Arctic point to continued and rapid ice losses by every measurement (sea ice extent, ice mass, ice age, ice thickness, ice volume). The increased open water results in even faster warming and melting, with these effects getting worse as additional feedback mechanisms kick in. Antarctica is showing a very different pattern but one no less of concern. Sure, the sea ice extent is increasing, but the reasons for it all point to major long term problems in Antarctica that will eventually have global ramifications even coming from such a remote continent. Continued overall ice loss from the land will contribute, along with ice melting on Greenland, to rapid sea level rise. Some recent studies have suggested that we could reach a  threshold that would cause a catastrophic melting of the two ice sheets, thus resulting in huge increases in sea level in a matter of decades rather than centuries. That may not happen, but then again, it might.

As mentioned earlier, climate deniers like to talk about the Antarctic whenever the discussion is about the Arctic (especially given it is the winter growth period in the south while we're watching the summer melting in the north). But adding the two together to get some sort of "total sea ice" value is both meaningless and dishonest. The two areas work independently, both in how they are impacted by man-made climate change and how they contribute to it.

By no honest analysis can anyone say the trends are good.


Notes from text:

*The 15% threshold is a bit confusing because it doesn't mean the entire area is covered with ice or that any given area is exactly 15% - the area could have anywhere from 15% to 100% sea ice. Obviously, an area that is 100% packed with ice would have more ice than an area only 15% covered by ice, yet they would both be counted as being the same sea ice extent. This is why we also look at ice volume, ice age, and thickness.

** Ice shelves are floating ice still connected to the land. Sea ice is that which has broken off and is floating. Ice sheets are the massive layers of ice that cover huge areas of land - Greenland and Antarctica carry the two remaining large ice sheets. Glaciers can be thought of as mini ice sheets flowing down mountains.

Antarctica is Melting and Attorneys General are Going After ExxonMobil

Two major stories rise to the surface this week in climate news. A new study warns that melting in Antarctica could raise sea levels substantially more and faster than previously thought. And the Attorneys General from several states band together to investigate "what Exxon knew" about climate change...and when.

Antarctica

Antarctica (i.e., the South Pole) is a favorite of climate deniers because it serves as a convenient counterpoint whenever the Arctic (i.e., the North Pole) sea ice extent is reaching another record low. The denier position, like all denier positions, is both wrong and intentionally fraudulent for a variety of reasons. And now it's getting even worse.

A new study published in the scientific journal Nature suggests that previous sea level rise estimates could be vast underestimated. The last IPCC report in late 2013 estimated a mean sea level rise of between about 1.5 to over 3 feet by the end of the this century. The new study suggests the reality might be more like 5 feet in that time, double or even triple the previous estimates.

This new study comes is independent of another recent study published by James Hansen and 18 co-authors also warning of catastrophic sea level rise due to melting of Antarctic and Greenland ice sheets.

It actually gets worse, so read up on this issue here, and here, here, and here. The full peer-reviewed paper in Nature can be downloaded for free here.

ExxonMobil

It came as no shock to most insiders when it was recently made public Exxon knew that fossil fuel consumption was warming the climate. They've known it for decades and their own internal scientists were the ones telling them. Like most big corporations, Exxon (and the combined ExxonMobil, as well as all the other big fossil fuel companies) has many scientists on staff. Some focus on resource development (e.g., finding new oil, gas, and coal reserves) while others focus on a wide range of testing, both to develop new products and to comply with health and safety regulations. Scientists at these companies are often the cream of the crop, that is, they are very good scientists. It is these scientists who long ago informed Exxon (and other companies through the American Petroleum Institute, the primary trade association/lobbying firm for the fossil fuel industry) that the vastly increased carbon emissions from their products were causing dramatic and dangerous warming the climate system.

The problem is what Exxon and others did with this knowledge and the best comparison is to the actions of the tobacco industry. In both cases the industry dealt with the knowledge of harm by suppressing it. On top of this they funded front groups and consultants to create doubt about the science.

After this "revelation" of suppression of knowledge became public recently, public pressure helped initiate investigations by a now growing body of state Attorneys General. A federal Justice Department investigation is also either underway or contemplated. Support for investigations has reached at least 15 Attorneys General, with more likely in the future.

While independent, these two issues are helping to push man-made climate change to the forefront again. A recent poll showed the highest public concern about climate change in a long time. In addition, the Arctic has just set the lowest annual maximum on record, not a good start to the annual meltdown that threatens to produce an ice-free Arctic Ocean for periods of the summer sometime in the future.

As noted previously, 2016 could surpass 2015 as the hottest year ever, continuing a trend of a warming climate. This could very well be a critical year in climate policy action.

How Climate Deniers Take Advantage of Science to Lie About Science

It's a recurring practice. A new climate study comes out and suddenly the internet is saturated with "reinterpretations" by climate deniers of what the study says. This is how climate denier lobbyists misrepresent, aka lie, about the science. The most recent is how they have lied about a new study released by NASA regarding mass gains in Antarctica.

Keep in mind that science is incremental. One study generally isn't meaningful by itself. Science is the compendium of all related studies. For example, one study may suggest that (under the conditions of the study) Antarctica is gaining more ice than it is losing while other studies show that West Antarctica may have gone into a state of irreversible retreat. That doesn't make any one study right or wrong, merely additional data points in the total understanding of the science. It's how science works.

A summary of this particular study being misrepresented can be found in NASA's press release. You can download the full study as a PDF file from this journal site. I highly recommend anyone wanting to understand the study read the actual paper because press releases often do a lousy job of communicating the science. Yes, I know, communicating the science is what press releases are designed to do, but my experience tells me that they  introduce confusion as often as they inform, in part because they report single studies and not the total science. I'll tackle that topic in another post.

The inadequacy of press releases for studies and the very nature of how science works results in opportunities for climate denier lobbyists to exploit uncertainties. And that is exactly what they do.

In this case we have information that may (or may not) contradict other information and the lobbyists pounced on it. As is their standard tactic, deniers take one point from the paper, fabricate an entire story line that fits their narrative, and put the false story line out on their paid lobbyist blog and media outlets. These lobbyists know that their false story will be plagiarized and repeated on every conspiracy and political blog by ideologues until the blogosphere is saturated with the false interpretation. That's how climate denial lobbyists work.

Greg Laden, a scientist who writes on Science Blogs, explains how the NASA study has been "misunderstood." [I think Greg is giving the blogosphere too much benefit of the doubt by using the term "misunderstood;" as the recent revelations about Exxon's knowledge decades ago that fossil fuels were causing climate change show, climate denial lobbyists know they are misrepresenting (i.e., lying about) the science. It's intentional.] That said, Greg notes that to begin with, the study may not be correct. While touted as "recent data" the data set used actually ended in 2008 so would miss the rapid ice loss of the last seven years. As Greg notes:

The last decade of research on Antarctica have shown, in many studies using a variety of techniques, that Antarctica is contributing to sea level rise. They have also shown that the rate of melting in Antarctic is probably increasing. Even more importantly, they have indicated that certain areas of Antarctic are current in a state of instability, suggesting that the rate of contribution of the southern continent’s ice mass to sea level rise may increase abruptly in the near future.

So the study, like all studies, needs to be placed into context with the state of the science. Deniers never do that; they cherry pick what they like and make believe all the rest of the science doesn't exist. This tactic is so prevalent in climate denial that the lead scientist of the study even predicted that climate deniers would misrepresent his work, which is exactly what they did, as reported in the above linked article:

"I know some of the climate deniers will jump on this," but "it should not take away from the concern about climate warming."

The first lesson here is that it isn't appropriate to take one study and assume it represents the total state of the science. Science is the sum total of all the relevant studies. The second lesson is that the climate denial lobbyists knowingly and willfully misrepresent single studies and then draw global "state of the science" conclusions that are inconsistent with the sum total of all the science.