Melting snow and ice. A call for action

Snow and ice are melting far above normal seasonal changes, and the changes are occurring at an accelerating pace. We see this happening in all snow- and ice-covered regions: Antarctica, the Arctic, Greenland, the “third pole” of the Himalayas, and other glaciated areas throughout the world.

The consequences for the regions affected are already considerable and more are expected. However, the melting is not only an issue for the areas where it occurs. Snow and ice are important components of the Earth’s climate system. Melting will be felt in all regions of the world through increased global warming and rising sea levels. Moreover, the loss of summer ice cover on the Arctic Ocean is leading to greater absorption of heat from the Sun. This is thawing the permafrost surrounding the Arctic and threatening the release of very large quantities of additional carbon dioxide and methane to the atmosphere.

In April 2009, climate scientists and foreign ministers from states affected by melting snow and ice brought the attention of the globe to the plight of the cryosphere in their conference Melting Ice: Regional Dramas, Global Wake-Up Call. As co-chairs of the conference we charged a group of leading scientists to summarize what we know about how fast this melting is occurring, and how it will affect the Earth and its climate.

Those scientists have now completed their work: and as bad as things looked last spring, today’s reality turns out to be even worse. Melting to a degree thought physically impossible, from the Himalayas to the Arctic and even in Antarctica, is occurring now. Arctic sea ice has been shown to be more endangered, Greenland runoff has risen to unprecedented rates, and glaciers continue to shrink and disappear. Such changes already have begun to seriously impact water supplies, the pace of sea level rise, and the global climate system itself.

We strongly urge that political action be taken to ensure a globally responsible policy to substantially reduce the emission of greenhouse gases. We are not helpless against this threat. Indeed there is much that we as nations and as peoples can do, whether we are living in the realms of snow and ice or are affected by its melting in other parts of the globe.

The first is by now apparent and widely recognized internationally: deep cuts in global greenhouse gas emissions. No other remedy we know can ensure that we avoid dangerous man-made climate change and that we preserve the polar and alpine environments as we know them today.

However, even if we manage to turn the rising curve of global greenhouse gas emissions in the coming years, the reduction will not occur quickly enough to preserve the polar and alpine environments as we know them today.

Increasing concentrations of black carbon at mid-latitudes could be responsible for a significant fraction of the rapid Arctic warming observed over the last decades. That leads us to a second way to respond: take action that will make a real impact in the near future, and most especially, address short-lived climate pollutants such as black carbon, methane and tropospheric ozone.

Our third point is a more somber one: despite all our efforts, we likely cannot prevent some changes in the Arctic and glacier environments. Adaptation is inevitable. Many peoples affected cannot cope with the challenges alone. Industrialized nations must assist by becoming part of the solution, not least because they bear the main responsibility for the man-made climate change we have seen so far.

Our fourth and final point is the need to base political action on scientific findings – and to ensure that science is steadily improved and updated. There are uncertainties with respect to how snow and ice will continue to respond to a changing climate, as well as with regard to how these changes will affect natural and social systems. Reducing these uncertainties through scientific research is critical for making sustainable mitigation and adaptation strategies.

However, let there be no doubt: we know enough to act now. We need early action on short-lived forcers like black carbon, and we need more effective assistance to those affected across the world by these unprecedented rates of melting. But first and foremost, we need a strong international commitment to reduce greenhouse gas emissions.