The first Arctic summer with ice-free waters must be around 2050. Columbia University reports.
In 1985, scientists discovered a hole in the ozone layer over Antarctica, increasing the effect of ultraviolet radiation on the climate. For this reason, the Montreal Protocol on the Protection of the Ozone Layer was signed in 1987, in which almost all countries of the world joined.
Lorenzo Polvani and colleagues examined the measures taken at the time and concluded that they could delay the onset of the “ice-free Arctic summer” by about 15 years. “The first ice-free Arctic summer – when there is almost no sea ice in the Arctic Ocean – will be an important milestone in the climate change process, and our findings [о его наступлении] it was a surprise for us,” the authors write. According to older climate estimates, the first such summer should have occurred around 2035. The updated models show that we are now talking about 2050, and these changes are primarily related to the Montreal Protocol. Calculations show that had it not been adopted, the estimated global mean surface temperature would have been about 0.5 degrees warmer, and the Arctic polar cap would have been 1 degree warmer by 2050.
This is because substances that deplete the ozone layer, such as freon and carbon tetrachloride, are also greenhouse gases. Now that governments have drastically reduced their emissions, the pace of global warming has slowed. According to the authors, this proves that climate policy can be effective within a single generation.
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