Can Paris avert climate threat to cryosphere?
Meltpool on the Greenland ice sheet (Pic: I.Quaile)
To those of us who work on polar subjects, there is no question about the relevance of the cryosphere to the annual UN climate negotiations. But in the run-up to the annual mega-event – especially in a year dubbed by some to be the “last chance” for climate – it was not easy to get attention for the Arctic, Antarctic and high-altitude peaks and glaciers of the world.
I had a discussion with some of my colleagues who focus on Africa and Asia. With problems like political unrest, wars, famine and drought to cope with, the fate of polar bears, one told me, is completely irrelevant.
You could say this colleague is suffering from a kind of tunnel vision. But it also prompts me to wonder whether the way we communicate the threat of climate change is partly to blame.
Not just polar bears
Earlier this week I read about a study indicating that people were more likely to donate to campaigns which focus on people, on social injustice rather than on conservation and environmental degradation. Somehow, we journalists have to make the connection between the two. When you remind people that increasing sea levels caused to a large extent by changes in our ice sheets pose a huge threat not only to small island states but to many of the world’s megacities, the cryosphere takes on a new relevance. Not to mention the fact that the ice, snow and permafrost covered regions of our planet play a major role in regulating the world’s climate and water supplies.
Ice off Svalbard (Pic I.Quaile)
One organization that works to bring the attention of delegates at the UN climate talks to our icy regions is the International Cryosphere Climate Initiative, ICCI. In time for this year’s COP21, it commissioned a report from leading scientists: “Thresholds and closing windows. Risks of irreversible cryosphere climate change”. The report summarizes the levels of risk in five key areas: ice sheets loss and related sea-level rise, polar ocean acidification, land glacier loss, permafrost melt, and the loss of Arctic summer sea ice. The report is based on the last IPCC assessment plus literature published in the three years since.
Bringing the ice closer
Pam Pearson is the director and founder of ICCI. I have interviewed her on various occasions, including during visits she made to Bonn, the home of the UNFCCC, to brief delegates. This time we were not able to meet in person, but we have been in Email contact. I asked her how difficult it was to arouse interest within the negotiations at the moment, with so much going on. She told me it was difficult mainly because very few people globally actually live near cryosphere.
“Yet we are all deeply connected to these regions, because of their role in the Earth climate system — especially through sea-level rise, water resources from land glaciers, and permafrost release that will make it harder to meet carbon budgets. “
The Arctic, parts of Antarctica and many mountain regions have already warmed two to three times faster than the rest of the planet, between 2 and 3.5 degrees Celsius up on pre-industrial levels. Climate change is also affecting high altitude areas such as the Himalayas and the Andes, where seasonal glacier melt provides water for drinking and irrigation, especially in dry periods.
When the outside risk becomes the norm
The changes are far more extreme than those forecast in even the most pessimistic scenarios of a few years ago. In the IPCC’s 2007 Fourth Assessment, the outer extreme estimate for sea level rise (mostly from glacier ice melt) was about one meter by the end of this century. Today, the experts say even if we could halt warming now, it would be impossible to avoid sea-level rise of one meter from glaciers, ice sheets and the natural expansion of warming waters, within the next two hundred years. Most scientists also agree that the West Antarctic ice sheet has already been destabilized by warming to the extent where this probably cannot be halted, which will increase sea level further.
Pam Pearson, Director of ICCI. (Pic: I.Quaile)
Pearson used to be a climate negotiator herself, so she knows the pressures and constraints. She told me that while participants in the climate conferences were broadly aware of issues like ice melt at the poles and on high-altitude glaciers, they tended to lack awareness of two key aspects:
“First, that we have already passed, or are close to passing temperature levels that will cause certain processes to begin; and second, that some of these processes cannot be stopped once they get started.”
She says a “sense of urgency” is lacking, and stresses that although some of the most damaging consequences will only occur in hundreds or even thousands of years, they will be determined by our actions or inactions in the coming few decades. That includes the 2020-30 commitment period that is the focus of the agreement being worked on in Paris Pearson stresses.
The cryosphere needs more ambitious targets
The report analyses the implications of the INDCs, or current pledges put on the table by the countries of the world for the Paris climate talks. The scientists come to the conclusion that these will not be enough to prevent the onset of many irreversible cryosphere processes.
Even the two-degree pathway agreed by the international community translates into a peak cryosphere temperature of between 4 and 7 degrees above pre-industrial levels, according to the ice experts. Yet the UN and others say current commitments would lead to global temperatures 2.7 to 3.5 degrees Celsius above pre-industrial levels by 2100, rising later to between 3.4 and 4.2 degrees. The peak in global carbon emissions would occur well after 2050. The associated temperatures would trigger permanent changes in our ice and snow that cannot be reversed, including the complete loss of most mountain glaciers, the complete loss of portions of West Antarctica’s Ice Sheets and parts of Greenland. This would ultimately equate to an unstoppable sea level rise of a minimum four to ten meters, the scientists find.
Greenland’s glaciers are already discharging huge amounts of ice into the ocean (I.Quaile)
In addition, the increase of CO2 being absorbed in the Southern Ocean around Antarctica and the Arctic Ocean is turning the water more acidic and so threatening fisheries, marine ecosystems and species.
Another of the key issues which is often neglected is that of permafrost. About a quarter of the Northern Hemisphere’s land area contains ground that remains frozen throughout the year. This holds vast amounts of ancient organic carbon. So when it thaws, carbon dioxide and methane are released, which fuel further warming. Even a temperature rise of 1.5 degrees could result in a 30% loss of near-surface permafrost. This would mean 50 Gigatonnes of additional carbon emissions by 2100. Given that the total carbon budget allocated to a two-degree temperature rise is only 275 Gigatonnes, that would be a huge factor. The ICCI experts say this thaw would not be reversible, except on geological time scales.
Dwindling Arctic sea ice
Arctic summer sea ice has declined rapidly, especially since 2000. Only about half the sea ice survives the summer today compared to 1950. This is “both a result and a cause of overall Arctic and global warming”, according to the ICCI report. White ice reflects heat into space. When it melts, it is replaced by dark water, which absorbs the heat, exacerbating warming further.
The Arctic sea ice has a tempering effect on global temperatures and weather patterns. It would only be possible to reverse the disappearance of the ice in summer with a return to regular global temperatures of 1 to 2 degrees above pre-industrial times, according to the report.
Andes and Himalayas
Receding mountain glaciers in the European Alps, American Rockies, Andes and East Africa were among the first identified, visible impacts of climate change, originally from natural factors. Sometime in the past 50 years, anthropogenic climate change surpassed natural warming as the main driver of retreat, and caused about two-thirds of glacier melt between 1991 and 2010, according to the ICCI report.
Glaciers – beautiful but highly endangered, like this one I visit regularly in the Swiss alps. (Pic. I.Quaile)
Glaciers are important to nearby communities as a source of water for drinking or irrigation. Some are especially important in dry seasons, heat waves and droughts. Melting glaciers provide an increase in water for a limited time. But ultimately, the lack of water could make traditional agriculture impossible in some regions of the Himalayas or the Andes.
So unless governments in Paris move fast to increase their commitments and bring the deadlines for emissions reductions forward, the windows to prevent some of these irreversible impacts on the polar and high mountain regions may close during the 2020-2030 commitment period.
It is not too late
However, the scientists stress that it is still possible to reduce emissions to the required level, if the political will becomes strong enough. Pam Pearson says the world has to get onto the path towards the two-degree goal now. Like many experts, she says this in itself is risky enough for the cryosphere, and a 1.5 degree pathway would be safer:
“So if countries indeed agree with UNFCCC chief Christiana Figueres’ proposal to meet every five years to strengthen INDCs, moving onto these lower-temperature pathways should be a concrete goal. Perhaps even more important, I understand the French COP presidency may be aiming at strengthening actions PRIOR to 2020, in the 2015-2020 period. This kind of earlier action is really vital, and will make the job of keeping temperatures as low as possible easier”
Without much more ambitious targets, the ICCI study concludes it will be “close to impossible” to avoid rapid deterioration of our snow and ice regions.
The challenge is to make the delegates in Paris understand that that does not just mean cosmetic changes to distant parts of the globe, but that it would also destabilize the global climate, displace millions of people and endanger food and water supplies in many parts of the world.
