Amplification of climate change in the Arctic

In contrast to multi-year old ice, first-year old ice—ice that formed only since the last melt season—is thinner, saltier, and much more prone to melt.

Over the years, the loss of sea ice has become especially manifest in the older ice, as illustrated by the image below.

Salt content and hardness play a part in multi-year ice’s resistance to melt, explains a recent NOAA article, but the main characteristic that allows the ice to survive the melt season is thickness.

Screenshots from: PIOMAS Arctic Sea Ice Thickness Simulation 1978-2011

The decline in thickness over the years goes a long way to explain the self-reinforcing character of sea ice decline in the Arctic.

As another recent NOAA article describes, there is “something extra” behind the record ice retreats of the past 6 years: each June, the prevailing winds shifted from their normal west-to-east direction and instead blew strongly from the south across the Bering and Chuchki Seas (left on the image below), over the North Pole, and out toward Fram Strait. (The length of the lines is qualitative: longer lines mean stronger winds.)

Average June wind vectors in 2007-2012 (orange) compared to 1981-2010 average (white) based on NCEP reanalysis data provided by Physical Sciences Division at NOAA ESRL. Map by Dan Pisut, NOAA Environmental Visualization Lab.

The image below shows the unusual air pressure patterns that gave rise to the wind shift. Air pressure across the Arctic in Junes from 2007-2012 was completely lopsided, with two pockets of higher-than-average pressure sprawled across the North American Arctic and Greenland. These areas of high pressure act like boulders in a river. They slow and disrupt the normal westerly flow of the wind, forcing it to make, large, meandering detours to the north or south.

Average geopotential height anomaly at 700 millibar pressure level in Junes from 2007-2012 compared to the long-term average (1981-2010) based on NCEP reanalysis data provided by PSD at NOAA ESRL. Orange colors are higher-than-average pressure; blue is lower-than-average pressure.     Map by Dan Pisut, NOAA Environmental Visualization Lab.

Arctic oceanographer and his NOAA colleagues think these “blocking highs” on the North American side of the Arctic created the unusually strong southerly flow that brought warm air into the central Arctic and over Greenland. The persistent southerly winds would help explain both the record low sea ice extent in summer 2012, as well as the island-wide melting of the surface of the Greenland Ice Sheet, which satellites detected in July 2012.

“This story started with us trying to figure out why the sea ice extents of the past 6 years or so have been so much lower than we would expect based on the long-term warming trend alone,” says Overland, “and we think this unusual circulation of the Arctic atmosphere is major part of it.”

Why, asks Overland, have these high pressure patterns have been forming so consistently each June for the past six years? The repeated appearance of these atmospheric features each June is so unusual that it’s the equivalent of a 1-in-a-1000 event. Can this be attributed to natural variability?

Instead, Overland’s hunch is that the cause is a change in the atmosphere that is itself connected to climate change in some way, possibly linked to record and near-record low June snow cover in the Canadian Arctic in recent years. “We don’t know that part of the story yet,” he says, “but this would certainly be the type of amplification of climate change [warming triggers changes that lead to more warming] we have been expecting to see in the Arctic.”

References

- Arctic Sea Ice Getting Thinner, Younger
http://www.climatewatch.noaa.gov/article/2012/arctic-sea-ice-getting-thinner-younger

- June wind shift a little something extra behind recent Arctic ice losses
http://www.climatewatch.noaa.gov/article/2012/june-wind-shift-a-little-something-extra-behind-recent-arctic-ice-losses

- Poles apart: A record-breaking summer and winter
http://nsidc.org/arcticseaicenews/2012/10/poles-apart-a-record-breaking-summer-and-winter/

- PIOMAS Arctic Sea Ice Thickness Simulation 1978-2011, published Sep 14, 2012 by ArctischePinguin

https://www.youtube.com/watch?v=G1TLzgSlGtQ

Related

- Arctic summer wind shift
http://arctic-news.blogspot.com/2012/10/arctic-summer-wind-shift.html

- The recent shift in early summer Arctic atmospheric circulation
http://www.agu.org/pubs/crossref/2012/2012GL053268.shtml

- Presentation by Dr. Jennifer Francis, Rutgers University
https://www.youtube.com/watch?v=RtRvcXUIyZg
http://marine.rutgers.edu/~francis/pres/Francis_Vavrus_2012GL051000_pub.pdf

- Accelerated Warming in the Arctic
http://arctic-news.blogspot.com/2012/09/accelerated-warming-in-the-arctic.html

- Changes to Polar Vortex affect mile-deep ocean circulation patterns
http://arctic-news.blogspot.com/2012/09/changes-to-polar-vortex-affect-mile-deep-ocean-circulation-patterns.html

- Diagram of Doom
http://arctic-news.blogspot.com/2012/08/diagram-of-doom.html

- Opening further Doorways to Doom
http://arctic-news.blogspot.com/2012/08/opening-further-doorways-to-doom.html

- Opening the Doorways to Doom
http://arctic-news.blogspot.com/2012/08/opening-the-doorways-to-doom.html

- How extreme will it get?
http://arctic-news.blogspot.com/2012/07/how-extreme-will-it-get.html

Saving the Arctic Ice (#2)

By Nathan Currier Greenpeace, Greenwashing and Geoengineering

Nathan Currier, senior climate advisor for Public Policy Virginia

I've been discussing the Greenpeace "Save the Arctic" campaign in light of the reality there, where we will likely reach near-zero summer arctic sea ice in just the next few years. Before exploring, in the next post, direct climate interventions that could really help save the arctic, we now must look at all our other options -- just as, in a medical crisis, one eliminates other options before opting for surgery.

Of course, one option is to blithely say, "Look, the ice can come back later," and therefore do nothing to impede the arrival of an ice-free arctic ocean. At the recent Greenpeace New York meeting, this seemed to be the tacitly assumed option. Now, I am quite aware of modeling studies demonstrating sea ice loss itself to be readily reversible. Andrew Revkin of the New York Times asked James Hansen at the meeting about the Eemian interglacial (~130,000-115,000 yrs ago), its ice loss and recovery -- seemingly keen to highlight this comforting reversibility. But this reversibility depends on environmental conditions. One minor detail that wasn't mentioned was that CO2 was then around pre-industrial levels (280ppm), hardly soaring up around 400ppm as now, a level possibly not seen on Earth for 15 million years, so one should hardly expect the planet to give an Eemian-style response now, either in the long-term or next year (for a variety of reasons aside from CO2 levels, in fact).

What about green energy, solar panels and the like, the kinds of things proposed at the Greenpeace meeting? Anyone contemplating emissions strategy ought to keep the UNEP graph (Shindell et al, 2011) in my first post up on their walls: Even pretty large CO2 source reductions won't bring relief from warming until about 2040 (and could bring near-term warming). By that time, the increased insolation to the arctic ocean might have gone so far as to give an ice-free arctic for a considerably larger chunk of the year, with really drastic effects. Is that a plan for "saving" the arctic?

The only way through emissions to have an impact on what is going on there right now is through non-CO2 reductions like black carbon and methane. And aside from that, there's nothing left except direct intervention -- which could cover a wide variety of options, some of them being what I'll call "localized geoengineering," and will discuss next time.

Now, Hansen has been the primary advocate of the concept of using non-CO2 reductions to help bridge the time gap of getting reduced warming from CO2 reductions, so my one question for Hansen at the meeting was whether he thought that could still be used alone to confront the arctic crisis. Hansen's answer was frank and accurate. As Hansen said, and I hope Greenpeace, Bill McKibben and all the others present heard, "If you need a rescue package, to some degree it inherently is geoengineering."

He didn't say that non-CO2 reductions wouldn't still be helpful (they are 100 percent necessary right away, just as massive CO2 reductions to near-zero by mid-century are necessary), but he certainly didn't say that they could halt the loss of the sea ice now alone, either -- indeed, I believe that the numbers show that they can't. It has now become clear that emissions reductions alone can no longer save the arctic ice. This is a big deal, and it needs to sink in.

Greenpeace's campaign aims to make the arctic a sanctuary, by which they primarily mean keeping out the fossil industry. Hansen himself has many papers stating that easily recoverable fossil sources inevitably will get used. The arctic's resources are obviously getting more easily recoverable by the season. Keeping the fossil industry away without cooling it is probably impossible -- and, at a certain level, might even be destructive. What if Greenpeace succeeded, but the arctic were left to melt? Picture some natural disaster, akin to the Macando well disaster, but happening all on its own. No, I don't mean an oil spill -- I mean a bunch of methane bubbling up from the seabed and reaching the atmosphere in large ongoing belches. This kind of thing is likely to start at some point if we let the sea ice disappear, as Hansen himself discussed at the meeting -- and it won't stop like an oil spill, but rather will likely become an ongoing process. Then we will actually need the fossil industry's expertise to go in there and help trap as much as possible. Believe me, I am not saying this to invite the fossil industry in. I am saying this because we must somehow keep the arctic cool. Lastly, ships and refineries both emit black carbon, which has an extremely strong but complex to quantify effect on local warming, and ice and snow-covered places are the most vulnerable to its effects because it settles on them and changes their reflectivity. So, even without fossil extraction, just if arctic ship traffic picks up dramatically, this could greatly accelerate ice (and snow) losses, helping ensure that this theoretical reversibility remains just that, something we'll never see. I'm sure Greenpeace means well, but currently their campaign most resembles those full-page greenwashing fantasies from Shell and PB, "Creating Your Clean Energy Future," and so on. At present, it's a sham.

The unquestioned reliance upon ice loss reversibility at the Greenpeace meeting might have been correct from a purely physical viewpoint alone, but was highly pernicious all the same, because it masks that we are about to quietly walk through the most monumental climate threshold we have yet crossed, and will then almost certainly discover, for a whole array of reasons -- all those minor physical mechanisms I elaborated last time, or the issues regarding the fossil industry I have just mentioned -- that it's difficult to turn around. Folks, what I am trying to say is: You can't let this happen, and yet you definitely can no longer prevent this happening just through emissions alone. That means that some form of direct climate intervention will be necessary there.

The clincher is this: When Hansen mentioned at the meeting that we could reverse ice loss, he also added, "And the truth is, we have to do that."

That is, he said, in order to avoid other major tipping points that clearly aren't reversible (ice sheets, methane hydrates). So the only remaining question is precisely when it must be reversed. London-based group AMEG, of which I am a member, takes the position: right away. Think of what this all means: It's completely impossible to achieve that reversal through emissions for many decades, even in the most optimistic scenario for large-scale emissions reductions -- and it would be far too dangerous to leave this unattended for that amount of time. So you will end up needing geoengineering in any case, just to achieve the reversal. Now, if you will quickly need to undo something that's about to happen, and potentially you might have great trouble undoing it at all later -- and the means will need to be the same in each instance -- then, isn't it far, far better to prevent that thing from happening, rather than trying to reverse it later?

Bill McKibben spoke with mild resignation about losing the sea ice, as though it were a pity, adding that we might "learn from it." But he's been profoundly ill-advised on the science, I'm afraid. If we don't fight this, we'll be "learning" like players of Russian roulette learn. And each decade left untreated might be like adding a bullet to the round.

Instead, we urgently need for Bill to understand this situation, and to start a "1250.org" (a 1250ppb target for methane) right away to complement his 350.org (Hansen's CO2 ppm target), and get his people back in the streets. Greenpeace must meet again with those scientists -- many more of them -- but with "time translators" present, so that Director Naidoo understands why Jim Hansen calls geoengineering a rescue package.

Trying to save the arctic is currently the most vital thing in the world, the front lines of the climate war, so let's all applaud Greenpeace for taking up the cause. Now they just have to bite the bullet, and recognize it's a fantasy unless two things happen right away, together at once:

1. A number of complementary direct arctic interventions (I'll discuss these soon).

2. Complete restructuring of the programs designed to reduce non-CO2 emissions (a long list of acronym-laden things like the M2M, GMF, GMI, CCAC), so that they really work -- and make this a public rallying cry, a global "1250" movement to help save ourselves.

[First posted at the Huffington Post; posted with author's permission]

State of Climate Change October 2012

A video featuring Paul Beckwith, climate scientist at University of Ottawa, who gives an update on the state of climate change, October 2012.

Paul adds that it was off the cuff and unscripted. "I wandered by Parliament Hill to see the people who were doing a climate change fast and ended up talking about the Arctic with them."

Here is a link to their website and protest:
http://www.facebook.com/CLIMATEFAST

Lethally Hot Temperatures During the Early Triassic Greenhouse

Paleogeographic reconstruction of the Early Triassic world (Smithian substage) around 250 million years ago, with
a ‘dead zone’ in the tropics. Presence of marine reptiles (ichthyosaurs), terrestrial tetrapods and fish was almost exclusively in higher latitudes (>30 °N and >40 °S) with rare exceptions. Credit: Yadong Sun, University of Leeds

The end-Permian mass extinction, which occurred around 250 million years ago, wiped out nearly all the world's species. Typically, a mass extinction is followed by a 'dead zone' during which new species are not seen for tens of thousands of years. In this case, the dead zone, during the Early Triassic period which followed, lasted for five million years.

A study jointly led by the University of Leeds and China University of Geosciences (Wuhan), in collaboration with the University of Erlangen-Nurnburg (Germany), shows the cause of this lengthy devastation was a temperature rise to lethal levels in the tropics: around 50-60°C (122-140°F) on land, and 40°C  (104°F) at the sea-surface.

Lead author Yadong Sun, who is based in Leeds while completing a joint PhD in geology, says: “Global warming has long been linked to the end-Permian mass extinction, but this study is the first to show extreme temperatures kept life from re-starting in Equatorial latitudes for millions of years.”

The dead zone would have been a strange world – very wet in the tropics but with almost nothing growing. No forests grew, only shrubs and ferns. No fish or marine reptiles were to be found in the tropics, only shellfish, and virtually no land animals existed because their high metabolic rate made it impossible to deal with the extreme temperatures. Only the polar regions provided a refuge from the baking heat.

Before the end-Permian mass extinction the Earth had teemed with plants and animals including primitive reptiles and amphibians, and a wide variety of sea creatures including coral and sea lillies.

This broken world scenario was caused by a breakdown in global carbon cycling. In normal circumstances, plants help regulate temperature by absorbing carbon dioxide and burying it as dead plant matter. Without plants, levels of carbon dioxide can rise unchecked, which causes temperatures to increase.

Professor Paul Wignall from the School of Earth and Environment at the University of Leeds, one of the study's co-authors, said: “Nobody has ever dared say that past climates attained these levels of heat. Hopefully future global warming won't get anywhere near temperatures of 250 million years ago, but if it does we have shown that it may take millions of years to recover.”

References

- Lethally Hot Temperatures During the Early Triassic Greenhouse
http://www.sciencemag.org/content/338/6105/366.abstract

- Tropical collapse caused by lethal heat
http://www.eurekalert.org/pub_releases/2012-10/uol-tcc101712.php

Related

- How extreme will it get?
http://arctic-news.blogspot.com/2012/07/how-extreme-will-it-get.html

- The potential impact of large abrupt release of methane in the Arctic
http://arcticmethane.blogspot.com/2012/05/potential-impact-of-large-abrupt.html

- Methane in the Arctic
http://arctic-news.blogspot.com/2012/05/video-and-poster-methane-in-arctic.html