Melting in the North Pole, South Pole and Third Pole?

ID-10050797So often we hear about the melting of the ice at the North and South Poles. Their rapid decline is a dire warning of further changes to our ecosystems a warming climate might bring as well as a wake-up call that climate change is happening right now. But if a shrinking Arctic and Antarctic aren’t enough to convince you, perhaps a shrinking third pole will.

A recent article in the Economist explores the third largest area of ice on our planet. 46,000 glaciers cover 100,000 square kilometres in Tibet’s plateau and surrounding mountains. While it is only 6% the size of Greenland’s ice cap, another 1.7m square kilometres is permafrost, equivalent to 7% of the permafrost of the Arctic. But the third pole’s significance is its direct relation to people. It is the source of Asia’s 10 biggest rivers, the basins of which are home to about 1.5 billion people, in 12 countries. If this pole were to melt you can imagine that would be a lot of water to deal with, water that would no longer be available year on year.

Despite its social importance, the Tibetan plateau glaciers have yet to be comprehensively studied and, on the nature of their decline, there is conflicting information. In 2007 the Intergovernmental Panel on Climate Change declared that the Himalaya’s glaciers could disappear by 2035, a figure later strongly contested. Reversely a study published in Nature in 2012 showed that glaciers on the Tibetan plateau were indeed growing. But again these figures were criticised not least for relying on satellite imagery  unable to distinguish between frozen glaciers and glacial lakes. So what is the situation, are Himalayan glaciers advancing or retreating? Well scientists, Dr Yao Tandong of the Institute of Tibetan Plateau Research, in Beijing, Dr Lonnie Thompson of Ohio State University and Dr Tobias Bolch of the University of Zurich agree that some glaciers are growing, such as those in the west of the region while those in the eastern Himalayas and east of the Tibetan plateau are rapidly declining. Those in the central regions are also decreasing in size but at a less rapid pace. [Read more…]

Where are we on climate change?

ID-100103034 (2)Professor Sir Brian Hoskins, Director of the Grantham Institute for Climate Change and advisor to the UK government through the Committee on Climate Change, recently gave a talk at Imperial College London on the latest research and actions around climate change.

Global CO2 levels are currently at 397ppm (parts per million), a level not seen for 4.5 million years. We have increased CO2 levels in the atmosphere by 40% since the Industrial Revolution. While there has been a clear and significant increase in global temperatures since 1850, we have seen a hiatus on temperature rises in the last decade. While sceptics may use this as evidence to support their claims, a decade of cooler temperatures is not outside the range of predictions from climate models.

Global sea levels are rising 3mm per year. While the melting of the Western Antarctic and Greenland ice sheets is contributing around 1mm of this increase, it is unknown how likely this is to accelerate if we reach a threshold point of destabilisation. In the Arctic, recent pictures of the ice cap in mid-September (when it is at its minimum size) show it is half the average size it was in the last century. By 2050-2060 we would expect the arctic ice cap to have vanished come September.

We have seen some significant heat extremes in the past decade: the 2003 European heatwave, 2010 Russian heatwave and more recently the 2012 US drought. Work by NASA scientists Dr James Hansen and colleagues indicates a shift to more frequent and severe bouts of high temperatures. But it is not just heat extremes, as the climate changes we are also seeing cold extremes in certain locations despite remarkable warmth elsewhere. This indicates our ability to predict regional trends is much more limited than our ability to predict global averages and while we may, in the past have viewed climate change as a warming of the planet, now we are trying to understand it as a disruption of our climate systems, one that will have severe and varied results. [Read more…]