Could China alone add 2.7 degrees by 2050?


in Economics, Politics, Science, The environment


I would like to see the climatic model that David Sandalow, the Assistant Secretary of State for Energy in the US, used to project a 2.7°C degree temperature rise by 2050 as the result of business-as-usual emissions in China and an 80% cut elsewhere. Firstly, it seems like too early a date to see such a big rise. Lags in the climate system mean that decades pass before the full effects of emissions are felt. If we saw an increase of 2.7°C by 2050, there would presumably be a great deal more warming in the pipeline. That would probably mean hugely catastrophic impacts by 2100. Secondly, while China is important, it is still only about 20-25% of global emissions. If emissions by every other state fell by 80%, China’s would need to grow massively to compensate.

If you believe that climate sensitivity is very high it is indeed possible that such a rise could occur that quickly, and primarily as the result of emissions from one very large state. That being said, Sandalow’s analysis would be much more convincing if he provided the details on the simulation he used to get the 2.7°C figure. What does he think China’s business-as-usual emissions pathway will be? How quickly does he assume that other states will cut by 80%? What does he think the sensitivity of the climate to greenhouse gasses really is?

If the climate really is so sensitive that China alone could push us into seriously dangerous territory by 2050, then we have all the more reason to be deeply concerned about rising global emissions and the ineffective efforts that have been made so far to reduce them. That being said, a lot more details of Sandalow’s methodology would be necessary, before we can accept the validity of his claim.

{ 2 comments… read them below or add one }

. August 3, 2009 at 7:46 pm

China shows every sign of changing its high-carbon ways, if the west accepts responsibility for its past

Protest over the closure of the Vestas plant in Britain contrasts with China’s commitment to a low-carbon future

This week, Vestas, one of the world’s biggest manufacturers of wind turbines, went to court to try to take possession of its Isle of Wight offices after it announced closure of its factory there because of lack of demand in Britain. In the same week, Greenpeace reported that China’s big power companies emit as much CO2 in a year as the whole of the UK.

What conclusions should we draw from these two events? The least useful response is the clichéd rhetorical question: “Why should I bother to change my light bulbs if China is building coal-fired power stations?” The impact of changing the light bulbs in any given household may be puny, but it saves money and it makes an easy, if small contribution to cutting emissions. Even with every light bulb changed, the average UK citizen still emits five times — and average US citizen 10 times — as much carbon as the average Chinese citizen. Changing the light bulbs is just the beginning.

China’s overall carbon numbers look big because, as Charles de Gaulle remarked, “China is a very big country and a lot of people live there.” China has one-fifth of the world’s population but it is only in the last couple of years that China’s global emissions have overtaken those of the US, a country with a fifth of China’s population and the resources and the technology to take the lead in cutting emissions. Historically, the developed world put most of the carbon dioxide in the atmosphere. Between 1850 and 2005, 27% of the carbon emitted came from the US, Russia and China accounted for 8% each, Germany 7%, the UK 6%, Japan 4% and India 2%.

. August 3, 2009 at 7:52 pm

China begins transition to a clean-energy economy
June 8, 2009





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