The Arctic Ocean is facing the ominous threat of going ice free in the not so distant future unless carbon dioxide emissions are controlled.
This was warned in a new study, which said 3 square meters of Arctic summer sea ice is vanishing for every single ton of carbon dioxide produced in any part of the planet.
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 will disappear by the middle of the century.
Published in Science, the study evaluates the future of the Arctic Summer Sea 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, 3m2 (± 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 degrees Celsius by reducing greenhouse gas emissions including carbon dioxide.
Global Warming Target Insufficient
"The internationally agreed 2°C global warming target is not sufficient to allow Arctic summer sea ice to survive," noted Notz.
Hinting the inadequacy of global pacts on carbon emission, the lead author said the Paris accord on climate change seeks to seal carbon dioxide emissions at 1 trillion metric tons so that global temperature rise can be capped to 2 degrees Celsius.
"We might be able to keep global warming below two degrees, but Arctic sea ice will go," Notz said.
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.
Further, CO2 emissions acidify the world's oceans and make life harder for creatures in the sea. The fossil fuels burned up by humans further add to the release of carbon dioxide.
Ocean Warming Hazard
In the case of sea ice, an annual cycle goes on in terms of the growth of ice in the winter and its melting by summer.
If global warming continues at this rate, the summer sea ice of the Arctic will melt completely and add more to the rise of global temperatures, says Cecilia Bitz, a scientist at the University of Washington, who is not part of the study.
This is because sea ice reflects sunlight and ocean absorbs the energy from sunlight. With sparse sea ice protecting the Earth's surface, the ocean will end up taking more energy and sea water will grow extremely warmer.