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The UN Intergovernmental Panel on Climate Change (IPCC) report released today (Monday 8 Oct 2018) calls for urgent and unprecedented actions to reach the Paris agreement pledge to keep temperatures between 1.5°C and 2°C.

The report highlights a number of climate change impacts that could be avoided by limiting global warming to 1.5°C compared to 2°C, or more.  For instance, by 2100, global sea level rise would be 10 cm lower with global warming of 1.5°C compared with 2°C.  The likelihood of an Arctic Ocean free of sea ice in summer would be once per century with global warming of 1.5°C, compared with at least once per decade with 2°C.

At its meeting in Incheon, Republic of Korea the IPCC said that limiting global warming to 1.5°C would require rapid, far-reaching and unprecedented changes in all aspects of society.  With clear benefits to people and natural ecosystems, limiting global warming to 1.5°C compared to 2°C could go hand in hand with ensuring a more sustainable and equitable society.

The Special Report on Global Warming of 1.5°C was approved by the IPCC on Saturday.  It will be a key scientific input into the Katowice Climate Change Conference in Poland in December, when governments review the Paris Agreement to tackle climate change.

Expert comment from British Antarctic Survey

Dr Emily Shuckburgh, Deputy Head of Polar Oceans at the British Antarctic Survey, said:

“This report presents two starkly different futures. It methodically articulates how the risks of extreme weather and sea level rise, of species loss and extinction, and of a deterioration in many dimensions of human wellbeing increase substantially from 1.5°C to 2°C of warming. The report also warns, for instance, that catastrophic loss of ice sheets in Greenland and Antarctica, which would eventually result in many metres of sea level rise, could be triggered at around 1.5°C to 2°C of global warming.

“Everyone should take careful note: governments, businesses and individuals. Today we are on a pathway to reach 3°C by the end of the century. The report makes clear that decisions made across society over the next few years will make a radical difference to our future climate and will determine the fate of future generations.”

 Dr Robert Larter, Deputy Science Leader of Palaeo Environments, Ice Sheets and Climate Change at British Antarctic Survey, said:

“During the last interglacial period (~125,000 years ago) average global temperatures reached about 2C above pre-industrial and associated peak global mean sea levels were between 6 and 9 m above modern. Therefore, if we get near to 2C we can expect that we will be committing to substantial sea-level rise.

“A further concern is that as ice sheets melted after the last glacial period there were times when sea level rose at a rate of more than 3 m per century, which is an order of magnitude faster than the current rate. This implies that there are situations in which ice sheets can melt much more rapidly than they have over the period we have been observing them. Therefore, we should be very cautious about disturbing these sleeping giants.”

More information

The Summary for Policymakers of the Special Report on Global Warming of 1.5°C (SR15) is available at https://www.ipcc.ch/report/sr15 or www.ipcc.ch.