The Arctic is melting: 18 reasons to care

Arctic sea ice has once again smashed all kinds of records - for extent, area and volume. Every year a huge amount of ice melts in summer and refreezes in winter, but the trend over the last few decades has been strongly downwards, especially during the summer months. In fact, this year, the extent of ocean with at least 15% sea ice cover declined to a level less than half of what it used to average just twenty years or so ago. Through it is harder to measure, the volume of summer sea ice is down by about three quarters from what it used to be. I posted an introduction to sea ice area, extent and volume back here.

When compared to our best reconstructions of the history of Arctic sea ice over the last 1450 years, the last few decades are, well, unusual. The graph above, which shows the ups and downs of summer sea ice extent over the years gives a sense of just how staggeringly quickly this part of the world is changing. Indeed, the collapse in sea ice is so rapid that it continues to stun even the scientists who have been watching it closely for decades. Back in 2007, the IPCC Fourth Assessment Report said that it was unlikely the Arctic would be seasonally free until after 2100.* Now, the UK Met Office says it is likely sometime between 2040 and 2060, most other Arctic organisations speak about sometime around 2030, while a handful of individual experts warn that, depending on weather conditions, it could be as early as the next Olympics in Rio. There is almost no evidence that this has occurred for at least the last few hundred thousand years (estimates range from 700,000 to 4 million years). *There are different definitions for what "ice-free" means. The most common is when extent drops below one million square kilometres, meaning that there might still be some ice clinging on around the north Greenland coast or in bays and inlets in the high Canadian Arctic, but effectively, the main ocean is free of ice.

Whatever the precise timing, why do we care? So what if some polar bears drown? Why does it matter to me what is happening thousands of miles away in the middle of an ocean amidst a deserted wilderness? Because the Arctic is closer than you think. The effects of declining summer sea ice are many. Here are eighteen reasons to care about the likelihood of a seasonally ice-free Arctic Ocean in the coming years. Only one is polar bears:

1. Polar bears: And walruses, seals and all the other unique Arctic wildlife that depend on sea ice. Seasonal sea ice loss threatens the unique and endemic Arctic biota. The polar bear is an photogenic icon, and as the largest terrestrial predator it instantly commands widespread respect and attention, but there is so much more at stake than simply polar bears.

2. Cultural loss. The loss of sea ice undermines the way of life of various indigenous groups in the Arctic, who rely on hunting and the ice for their livelihood and culture.

3. Infrastructure damage: As the Arctic region is warming, the permafrost that covers the land is both melting and being rapidly eroded. There are many structures and roads built on the permafrost that are already suffering severe damage.

4. Albedo change: Less floating white ice means more exposed dark water, which absorbs more solar radiation, increasing the total incoming heat flux of the planet, and specifically of the Arctic Ocean. The reflectivity of the planet's surface is called its albedo, and the decrease in albedo caused by loss of Arctic ice during the period when it is receiving 24 hours of sunlight is considered by many scientists to be the greatest single threat on this list.

5. Permafrost methane: A warming Arctic Ocean and atmosphere speeds the melt of permafrost in Canada, Siberia and Alaska, not only threatening infrastructure (see #3), but also releasing stored methane (CH₄), a highly potent greenhouse gas that degrades into carbon dioxide, making it both a short term climate nasty and a long term headache. The total amount of frozen methane is vast and although it unlikely to all melt quickly, it is soon likely to become a significant and sustained drag on efforts to cut emissions. More emissions from thawing permafrost means less room and time for us to make our own transition away from carbon-intensive energy systems.

6. Submarine methane: Warmer waters increase the rate at which vast submarine deposits of methane clathrates found along the Siberian continental shelf destabilise and are released to the atmosphere, giving a further kick to warming. Some observers are petrified this "clathrate gun" could end basically all life on earth in matter of years through a catastrophic self-perpetuating release. As I've noted previously, scientists are yet to see a convincing geophysical mechanism for this being a sudden and catastrophic release (with consequent spike in global CH₄) rather than a progressive leak resulting in an elevation of CH₄ with rising CO₂. This represents further drain on our carbon budgets, though the precise scale and timing of these emissions are less understood than those from terrestrial thawing.

7. More available heat: To convert ice at 0ºC to water at 0ºC takes energy, even though the temperature has not changed. The considerable energy involved in this phase change is called latent heat. Without ice in the ocean sucking up extra energy during summer, the solar energy that previous went into melting ice can go into the oceans (and later be released to the atmosphere). This is like removing a handbrake, though my back of the envelope attempts to quantify it suggest it will be significantly smaller effect than albedo change (#4). I'd like to see these calculations made by someone who knows what they are doing.

8. Wacky weather: This is something of a wild card and could prove to be the biggest danger to human society. Losing the ice is already changing wind patterns around the Arctic, which in turn affect the weather throughout the northern hemisphere. There is some evidence that more exposed water in the Arctic and a decreased temperature difference between the equator and pole (since the Arctic region is warming much faster than further south) is increasing the amplitude of the meanders in the jet stream. In turn, this slows down progression of the meanders, leading to "blocking patterns", where one region gets "stuck" in a certain weather pattern, whether heatwave, drought or flood. The 2010 Moscow heatwave that killed 11,000 people and sent the price of wheat skyrocketing (in turn helping to spark the Arab Spring), the 2010 Pakistan floods that displaced 20 million people, the 2010/11 record cold winters in Europe and parts of the US and the 2012 US heatwave and drought have all been linked to unusually persistent blocking patterns. Losing the ice may mean we see more of these kinds of things. The jury is still out on this theory, but if not precisely like this, the loss of Arctic sea ice will almost certainly affect wind circulation patterns and so weather both regionally and hemispherically.

9. Greenland melt: Over the long term, this may be the biggest change. The warmer the Arctic Ocean gets, the warmer Greenland is likely to get, and the faster its glaciers slide and melt into the sea. While floating sea ice doesn't affect sea levels (and there's relatively little of it anyway), there's enough ice on top of Greenland to raise sea levels by 7.2 metres (on average). As I read it, glacial draining and calving of the ice sheet is a larger sea level rise contributor than straight melting (thus the recent fracas over dramatic surface melt may not be the key issue for Greenland - remember, this recent melt event cut centimetres off a sheet that averages over two kilometres thick). The real danger is the acceleration of ice flow dynamics (i.e. the ice cube is more likely to slide off the table before it has finished melting). And the largest boost to glacier acceleration is from warming oceans meeting marine terminating glaciers. No one is entirely sure how long this will take, but it is a process that once it is underway in earnest, is likely to have a momentum of its own, meaning that our descendants will be committed to ever rising sea levels for centuries to come. The somewhat good news is that it is also a process that (on present understandings) is assumed to have some physical constraints due to friction (i.e. there are speed limits for glaciers, even in very warm conditions). The West Antarctic ice sheet, being largely grounded on bedrock well below sea level is actually more plausibly in danger of catastrophically sudden break-up, though warming in the Antarctic is currently only a fraction of what is being observed in the Arctic.

10. Resource conflict: An increasingly ice-free Arctic opens up a geopolitical minefield as nations scramble to take advantage of the resources previously locked away under the ice. The starter's gun for this race has well and truly fired, with various oil companies sending rigs to begin drilling for oil and gas this season. As one signal of the seriousness with which this is now taken, meetings of the Arctic council (comprised of nations bordering the Arctic) now attract Hillary Clinton rather than a minor government official.

11. More oil: The presence of significant amounts of oil and gas under the Arctic Ocean has been suspected and known for some time. Less ice means that fossil hydrocarbons that were previously off limits now become economically viable to extract, thus increasing the pool of available carbon reserves and so worsening the challenge of keeping most of them underground.

12. Fishing: Another resource now increasingly able to be exploited due to the loss of seasonal sea ice. Pristine (or somewhat pristine) marine ecosystems are thus exposed to greater exploitation (and noise pollution).

13. Shipping lanes: The fabled North West passage through the remote islands of Canada has been open to commercial shipping without icebreakers only four times in recorded history: 2011, 2010, 2008, 2007. The North East passage has also been open in recent years. These previously inaccessible Arctic shipping routes reduce fuel needs of global shipping by cutting distances (a negative feedback) but also brings more diesel fuel into the Arctic region, leaving black soot on glaciers (a positive feedback). I'm not sure which is the larger effect overall.

14. Toxin release: For various reasons, certain toxins and heavy metals from human pollution seem to accumulate in Arctic sea ice. As it melts, they are being released once more into the environment.

15. Invasive species: Melting ice reconnects marine ecosystems that were previously separated by ice, enabling migration of species into new regions, with unpredictable ecosystem changes as a result. This is already occurring.

16. Ocean circulation? These last three points are more speculative and I'm yet to see studies on them. But loss of sea ice could well change the patterns of ocean currents in the great global conveyor belt known as thermohaline circulation. This drives weather patterns throughout the entire globe.

17. Acidification acceleration? By increasing the open ocean surface area for atmosphere-ocean gas exchange, the rate of ocean acidification could slightly increase. Would this make any difference to ocean capacity to act as CO₂ sink or rate of acidification? This could well be irrelevant, but it is a question I have.

18 Political tipping point? The loss of virtually all perennial Arctic sea ice would be a highly visual and difficult to dispute sign of rapid and alarming climate change, representing a potential tipping point in public awareness and concern. If we are waiting for that, however, before we make any serious efforts to slash emissions (especially if it doesn't occur until 2030 or later), we'll already have so much warming committed that we'll pretty much be toast. At best, therefore, this point might consolidate public support for massive rapid emissions reductions already underway. These eighteen reasons can be summarised in five broad headings:

1. Direct effects upon local wildlife, human communities and infrastructure (1, 2, 3, 12, 14, 15);
2. Positive feedback affects that accelerate the warming process (4, 5, 6, 7, 11);
3. Changes to human economic and political systems through the opening up of previous inaccessible resources and routes (10, 13, 18);
4. Disruptions to the great atmospheric and oceanic circulation patterns that shape the experience of billions of people directly (8, 16);
5. Acceleration of long term threats (9, 17).

The loss of Arctic sea ice will not suddenly be the end of the world, but it represents a major milestone on the path to self-destruction along which we are currently hurtling with accelerating speed.

UPDATE: My opening graph needs some important further clarification. The unamended graph is a 40 year smoothed average, while the additional material displays year-on-year changes and so is not comparing apples to apples. However, using only 40 year averages to capture the dramatic changes of the last few years is also likely misleading. There is further discussion of this image here, here and here.

Does nature have a price? and other stories

Pricing nature: George Monbiot highlights the myopia of attempting to include "ecosystem services" within mainstream neoliberal economic thought. The initial government report noted that some of the services provided by natural ecosystems "may in fact be infinite in value". You don't say.

Ten Billion: A "play", reviewed here and here, in which noted Cambridge scientist Stephen Emmott plays noted Cambridge scientist Stephen Emmott. The only set is a recreation of his messy Cambridge office and the drama is Emmott delivering a lecture on our current predicament. describes himself as a "rational pessimist" and lays out the daunting, perhaps impossible, task before us in the coming decades where we face multiple converging crises. He concludes that the only rational way forward is radical cultural change with widespread embrace of lower consumption and fewer children (this is pretty close to what I think, with nuances regarding children), but thinks it is not going to happen (this is also basically what I think, though with all kinds of reasons why it is still worth trying). Given that those who will hear this are those willing to pay through the nose for a night of "theatre" more disturbingly horrifying than any fictional film, it's probably better to avoid reading too much into fact that all performances are sold out. Attempts such as this to piece together the various disparate pieces of information that float around the internet and scientific journals are to be valued. That people come away terrified ought to be entirely unsurprising. What is needed is a moral vision capable of surveying such a situation and finding reasons to throw ourselves "once more unto the breach, dear friends, once more".

Australian coal: A victory as one proposed coal plant is shelved.

Hunger games: Coming soon to a future near you. Future heat, drought, food costs and global unrest. I have long been saying that such secondary and tertiary effects of climate change are at least as dangerous as any direct physical effects, though they may not generate headlines that mention climate.

Planetary boundaries: "Approaching a state shift in Earth's biosphere", a recent paper in Nature includes this in its abstract: "Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence."

Solastalgia: The word is a neologism coined by psychologist Glenn Albrecht in 2003 and is gaining some recognition. It refers to nostalgia one feels for a place being lost even while you're still there, a homesickness while you're still at home, but home is becoming less hospitable. In Albrecht's own words, it is "emplaced or existential melancholia experienced with the negative transformation (desolation) of a loved home environment". I think it is a useful concept, even if I'm not convinced by the etymology.

Extreme weather: Extreme heat events experienced in many places in recent years are very, very unlikely to be unrelated to climate change. A new study by James Hansen on the attribution of extreme weather events does not use models, but is a statistical study based on observed changes that argues that the increase in what used to be extreme events (three standard deviations above the 1950-80 average) to now cover something like 10% of the globe's surface at any given time (rather than about 0.1% during 1950-80), is strong evidence that such events are vanishingly unlikely to not be related to climate change.

Overheated economy: Temperature rises correlate with declines in economic indicators and political stability, at least in developing nations. Good thing we're not expecting any discernable pattern in global temperatures over the next few decades and centuries then.

The West in Flames: The US West and Southwest is projected by most climate models to get hotter and drier. This has all kinds of implications, but this article by the author of A Great Aridness summarises the implications for trees and wildfire. It's not pretty.

400ppm CO2: Last time CO2 levels were this high. A study investigating conditions 15 million years ago found that "The last time carbon dioxide levels were apparently as high as they are today — and were sustained at those levels — global temperatures were 5 to 10 degrees Fahrenheit (2.8-5.6ºC) higher than they are today, the sea level was approximately 75 to 120 feet (22.9-36.6m) higher than today, there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland".

The Other Arab Spring, and other stories

Tom Friedman (NYT): The Other Arab Spring: "All these tensions over land, water and food are telling us something: The Arab awakening was driven not only by political and economic stresses, but, less visibly, by environmental, population and climate stresses as well."

SMH: Coal seam gas is no climate saviour. On the contrary, exploiting alternative fossil fuels only increases the total available pool of carbon that can be transferred from safely underground into the atmosphere and oceans. Indeed, the benefits of gas over coal are frequently overstated. Natural gas is a bridge to nowhere, in the absence of major improvements to leaking. Leaks throughout the supply chain mean that, from a climate perspective, natural gas is at best only slight better than coal (and may actually be worse) over a twenty year timeframe, since methane, while relatively short-lived, is far more potent at warming the planet than carbon dioxide. According to another new study, the benefits of even a massive switch from coal to gas would be relatively minor and would not be seen until late this century.

The Conversation: Medium density is the future.

Yahoo: Beyond 2ºC. Former UNFCCC chief admits we're not going to hold warming to two degrees, long agreed as an international target. Anyone reading the literature would have known this for some time (we're on track for four degrees. Or more), but that someone with so much invested in the international negotiations to admit this publicly is a big step, largely ignored in the media. H/T Lou.

TAE: The nature of tipping points. Some clarity on a commonly misunderstood and misused phrase. Some of the final comments about CO₂ are a little overstated, but it's a useful summary.

The Atlantic: Physiological limits of adapting to warming. A summary of this 2010 PNAS paper by Sherwood and Huber, in which they point out that there are certain climatic conditions above which humans simply cannot survive.

CC: Fascinating new study on the effect of a melting Arctic on northern hemisphere weather. The basic idea is that as the Arctic warms faster than the rest of the globe, the temperature difference between the Arctic and the equator drops, which results in a slowing down of the jet stream, which in turn results in slower-moving weather patterns, which exacerbates extreme weather by making dry or wet, hot or cold spells all longer and so more intense. This is yet another study contributing to the growing body of evidence that the extreme cold UK winters of 2009/10 and 2010/11 may well have been linked to changes in the Arctic. More of these studies are linked in the comments back here.

Bill McKibben: How we subsidise our own destruction. McKibben offers five pieces of simple and straightforward advice on distinguishing good from bad subsidies.

Guardian: Lloyd's of London warns against Arctic drilling. No one really knows how we would clean up an oil spill in the Arctic, which in icy waters would not break down at anything like the pace of the BP Gulf of Mexico disaster. But even if all the oil is safely delivered from under the Arctic to the atmosphere, via a brief sojourn in our cars, it will still spell the end for Arctic ecosystems. And much else besides.

The point of no return was passed some time ago

"I believe we will see increasing nihilism. I think also there is a very big chance that if the science starts telling us we are beyond the point of no return, I think we could open up the box for a whole range of utterly aberrant responses. Some of which might be utter despair and a kind of last minute self-seeking behaviour. Some of which might go in who knows what direction in terms of aggressive scapegoating, projection, pushing this onto to other people, other issues that have nothing to do with climate change."

- George Marshall, "The Ingenious Ways We Avoid Believing in Climate Change".

This whole lecture (in three parts: one, two, three) is worth watching for many insights into the psychology of responding to the threat of climate change. These comments come towards the end of the presentation and concern the situation that I am particularly interested in: the perception that we are "too late" to avoid some really horrible outcomes. For many people, such a scenario may well lead to the kinds of reactions that Marshall mentions, and things could turn very ugly. The 2006 film Children of Men depicted a world a in 2027 where hope for the future has been lost and the social backdrop is not a pretty one.

The point of no return in terms of avoiding some seriously bad outcomes was passed some time ago. That doesn't justify inaction or "let us eat, drink and be merry, for tomorrow we die", since (a) negative effects won't hit all at once tomorrow, or even The Day After Tomorrow, but will build over years, decades and centuries, (b) our current actions can still avoid even worse outcomes than are already "in the pipeline" and (c) because of the resurrection, in the Lord our labour is not in vain (1 Corinthians 15.58). No act of love, however apparently futile, is wasted, since love is the future.

"The most exciting decade in the history of the planet"

"The climate challenge is the easy one [...]. Incremental change is not an option."

Rockström was lead author on last year’s Nature paper on planetary boundaries and this video is an excellent 20 minute summary of the shift from the Holocene to the Anthropocene, of the multiple "hockey stick" graphs we face, of the non-linear behaviour of earth systems and of the nine planetary boundaries we've transgressed or are in danger of passing soon.

We are in an ecologically novel situation. Never before have we been so close to self-destruction on such a scale.

A fun little animation

Wake Up, Freak Out - then Get a Grip from Leo Murray on Vimeo.
What effect ought potential catastrophes have on our collective moral deliberations and resolutions? This short film is one example of a discourse pattern that seems quite common. How valid are its moves? I am not here asking about the validity of its empirical claims about the present state or causes of climate change,* but the rhetorical and ethical resources this kind of discourse marshals to shape collective deliberations.
For the animator's own discussion and disclaimers on this topic, see here.