Photo: / Christopher Michel CC BY

1 tonne of CO2 melts 3 m2 of Arctic ice

Study argues that Arctic summer sea ice can survive only if global warming is kept below 1.5°C.

Noting that Arctic ice cover for summer has already shrunk by more than half in the past 40 years, the climate scientists predicted that the remaining ice will disappear by the middle of the century. Published in Science, the study evaluates the future of the Arctic summer sea ice on the basis of observational data obtained between 1953 and 2015. Making a linear connection between carbon dioxide emissions and Arctic summer sea ice, the study led by lead author Dirk Notz from the Max Planck Institute for Meteorology in Hamburg, Germany, commented that the observed numbers are very simple. “For each ton of carbon dioxide that a person emits anywhere on this planet, 3 m2 (± 0.1m2) of Arctic summer sea ice disappears,” he noted.

The study argues that Arctic summer sea ice can survive only if global warming is kept below 1.5°C. by reducing greenhouse gas emissions including carbon dioxide. “The internationally agreed 2°C global warming target is not sufficient to allow Arctic summer sea ice to survive,” noted Notz.

The study traces a robust linear relationship between monthly mean September sea ice area and total CO2 emissions based on the observational record. The methodology addresses the disparity problem that long plagued climate-model simulations regarding the sea-ice loss. According to the study, the linear relationship makes it clear that a loss of 3 ± 0.3 m2 of September sea ice area per metric ton of CO2 emission is really happening. The damage wrought by carbon dioxide as a greenhouse gas is that it keeps the heat retained in the Earth’s atmosphere and escalates the global temperature more and more.



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