A warming of two degrees Celsius above pre-industrial temperatures is frequently cited as the limit beyond which the world will face “dangerous” climate change.
Beyond this level, continents would cease to absorb more carbon dioxide than they produced.The analysis showed that as the tundra and other regions of permafrost starts thawing, they would spew more gas into the atmosphere, adding to the warming effect of human emissions.
The end result would be dramatic ecological changes, including widespread coastal flooding, reduced food production, and widespread species extinction, the study said.
Andrew Weaver and colleagues at the University of Victoria in Canada used a computer model to determine how much emissions must be limited in order to avoid exceeding a two degrees Celsius increase.
The model is an established tool for analysing future climate change and was used in studies cited in the IPCC's reports on climate change.
They modelled the reduction of industrial emissions below 2006 levels by between 20 and 100 percent by 2050.
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A 100 percent reduction of emissions saw temperature change stabilise at 1.5°C above the pre-industrial figure. With a 90 percent reduction by 2050, Weaver's model predicted that temperature change would eventually exceed two degrees Celsius compared to pre-industrial temperatures but then plateau.
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Governments should now consider reducing emissions to 90 percent below current levels and remove what is left in the atmosphere by capturing and storing carbon, he said.
The study appears in the journal Geophysical Research Letters, reports New Scientist magazine
Source-ANI
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