Sometimes it鈥檚 good to over-reach 鈥� particularly when it comes to stopping climate change. New evidence comparing the impacts of 1.5掳C and 2掳C rises in temperature reveal the unprecedented food shortages, economic inequality and species loss that will occur if we don鈥檛 aim for the more ambitious target.
In 2015, global leaders signed up to the : a commitment to keep global warming under 2掳C and possibly even limit it to 1.5掳C.
Comparisons between the two targets show they have dramatically different impacts. For example, several regions are predicted to reach unprecedented levels of food insecurity, due to increased flooding and drought as a consequence of global warming. For three-quarters of the countries assessed, this increase is larger at 2掳C than 1.5掳C. The most vulnerable regions are sub-Saharan Africa and South Asia.
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Meanwhile, the global average GDP per capita is projected to be 5 per cent lower at the end of the century under 2掳C warming relative to 1.5掳C, and 13 per cent lower than under no additional warming. This economic loss will be felt most strongly by low-income countries, creating greater global inequality.
A degree of difference
However, a rise of 1.5掳C compared with 2掳C would see an additional 5.5 per cent of the globe able to act as a 鈥渃limate refuge鈥� for plants and animals.
Finally, keeping to 1.5掳C would reduce the loss of Arctic sea ice, which has shrunk by about 40 per cent since 1979. A major concern is that Septembers in the Arctic could soon be entirely ice-free. Two studies suggest that this will only happen about once every 40 years in a world that keeps warming to 1.5掳C, compared with every three to five years under 2掳C conditions.
Philosophical Transactions of the Royal Society A
Nature Climate Change
Nature Climate Change
