How much emissions do we have to reduce to limit climate change to acceptable levels? It’s a slippery slope – the Kyoto Protocal calls for a mere 6-8% reduction, but it’s widely acknowledged that they need to be reduced by 80% or more. Last week we reported that even the 10 year window scientists gave us before climate change “really kicks in” has closed 8 years early because of rapid growth in China and India. (See No 10 Year Window – Greenhouse Gases Have Hit Danger Mark: http://www.sustainablebusiness.com/news/sbnews.cfm?id=14411)
The scientific concensus seems to be that we must limit climate change to a two degrees rise in temperature in the next century. Above that, we face “dangerous” climate change. A new computer analysis shows that the only way to do that is to TOTALLY eliminate industrial emissions.
Beyond a two degree rise, continents would no longer absorb more CO2 than they produce. Tundra and other areas of permafrost would thaw and produce more gas, adding to emissions. The result would be widespread flooding, reduced food production and widespread species extinction.
The computer model used was the same as that used in the Intergovernmental Panel on Climate Change (IPCC) reports on climate change. According the University of Victoria in Canada, where the study was conducted, although they tested the effect of reduced industrial emissions from 20-100% below 2006 levels, only the 100% elimination held the temperature rise below 2 degrees Celsius.
The report strongly urges governments to reduce emissions to 90% below current levels and remove the rest from the atmosphere by capturing and storing carbon.
“There is a disconnect between the European Union arguing for a 2°C threshold and calling for 50% cuts at 2050 – you can’t have it both ways,” says Andrew Weaver, who headed the research. “If you’re going to talk about 2°C you have got to be talking 90% emissions cuts.”
Even if emissions are cut by 50%, CO2 will continue to build up in the atmosphere and temperatures will rise. The only way to reliably stabilize the temperature is to make sure that industrial emissions do not exceed what can be absorbed by vegetation, soil and oceans.
The study appears in the journal, Geophysical Research Letters.
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