The IPCC and the future state of glaciers
The IPCC is the Intergovernmental Panel on Climate Change, and it was established in 1988 by the United Nations Environment Programme and the World Meteorological Organisation.
The objective of the IPCC is to provide governments with scientific information that they can use to develop climate policies. The IPCC generates very extensive reports every few years, considering the state of our climate and attempting to predict future impacts on all aspects of the earth, including glaciers and ice sheets. It utilises a series of emission scenarios (i.e. a range of possible futures based on the amount of greenhouse gases that are generated, the mitigation strategies put in place, and thus the severity of climate change impacts) and predicts the consequences of these different scenarios on the earth’s ice bodies. Ideally, these scenarios should then be used by governments to manage their behaviour and activities. The reports are the work of many scientists from across the globe, are exceptionally extensive and are free to be read by all. However, here we summarise briefly the key predicted findings in relation to glaciers, ice sheets and the implications for sea level rise.
The IPCC splits up the earth’s ice masses into Antarctica, Greenland and glaciers throughout the world beyond these main ice bodies. The most recent report, referred to as ‘The Ocean and Cryosphere in a Changing Climate’ (which was published in 2019), has the following key messages:
- Loss of glacier mass, along with declining snow cover, is projected to continue as a result of increasing surface temperatures, with ‘unavoidable consequences for river runoff and local hazards’. Most starkly, in regions dominated by smaller glaciers (e.g. the Andes, Scandinavia, Central Europe), under the higher emissions scenario, more than 80% of all glaciers are predicted to disappear by 2100, and more frighteningly, under any emissions scenario, many glaciers will disappear because of changes that have already occurred to our climate.
- Both the ice sheets of Antarctica and Greenland are projected to lose mass at an increasing rate throughout the 21st century and beyond that. These changes are set to increase in both rate and magnitude in the latter part of the 21st century in a scenario of high greenhouse gas emissions, but if these are reduced substantially, then changes in mass loss will be reduced.
- Sea level will continue to rise at an increasing rate. Future projections of sea level rise vary, depending on the emissions pathway followed. For a high emissions scenario, the role of melt contributions from Antarctica will be particularly significant. In the coming centuries, under the worse-case emissions scenarios, there will be annual sea level rises of several cm per year resulting in a rise of several metres. This can be limited to approximately 1 m in 2300 if emissions are at their lowest. As a result, there will of course be increasing coastal hazards, which of course is of concern for the countless millions of people who live in coastal villages, towns and cities.
The IPCC provide huge amounts of detail, and the points above provide only a very brief summary of predicted future behaviour. As you will see though, precisely what happens to the world’s glaciers and ice sheets, and also to sea levels and water supplies in the future is strongly determined by the amount of greenhouse gases that we, as the world’s population, generate, and the impacts these have on global temperatures. Attempting to minimise our greenhouse gas emissions and the consequences of that are of the utmost importance.
Click here to access the most recent IPCC report ‘The Ocean and Cryosphere in a Changing Climate’.
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