While Nicholas Stern, the world’s top climate economist, recently endorsed 350 ppm as “a very sensible long-term target,” he laid out two blunt messages about our current do-nothing strategy in a talk to students in Beijing’s People’s University:
Stern warned that if the world continued to emit around the same levels of greenhouse gases every year, there was a 50 percent chance temperatures would rise more than five degrees Celsius (nine degrees Fahrenheit) within 100 years.
Stern knows the scientific literature (see “M.I.T. doubles its projection of global warming by 2100 to 5.1°C” and Hadley Center warns of “catastrophic” 5-7°C warming by 2100 on current emissions path“).
A rise of “five degrees Celsius has not been seen on this planet for 30 million years — we as humans have been here for only 200,000 years,” he said.
“This type of temperature change involves radical dislocation, it involves re-writing where people can live, it would involve the movement of hundreds of millions, probably billions, of people.”
“This would result in extended, serious global conflict.”
It would result in Hell and High Water.
The second message was aimed at China, and equally blunt. As Treehugger put it:
China is the world’s leading CO2 polluter but it often relies on per capita emissions data to show that its footprint — and thus its responsibility to manage climate change — is much lighter than that of developed countries.
Not so fast, says Stern. As AFP reported, he said that
… 13 Chinese provinces, regions and cities had higher per capita emissions than France. Six also overtook Britain.
“There are many parts of China where emissions intensity and emissions per capita are looking much like some of the richer countries in Europe,” he said in a speech that laid out his predictions on global warming.
China and other developing nations are opposed to any compulsory cuts in emissions, saying their per capita emissions are low and the responsibility for solving the problem rests with developed countries that have polluted longer.
Based on Stern’s calculations, emissions per person worldwide would have to fall to two tonnes by 2050 to minimise the risk of a dangerous rise in temperature.
Currently, according to Stern, China emits six tonnes per person, the European Union emits an average of 12, and the United States 25.
Stern, a noted economist, said he was confident China would lead on climate change action.
And all evidence suggests China will lead (see “Peaking Duck: Beijing’s Growing Appetite for Climate Action“) — if the Congress passes a climate bill (see “ ‘China will sign’ global treaty if U.S. passes climate bill, E.U. leader says“).
For the record, Stern’s analysis would seem to derive in part from the recent Proceedings of the National Academy of Sciences paper, “Sharing Global CO2 Emission Reductions Among One Billion High Emitters“:
We present a framework for allocating a global carbon reduction target among nations, in which the concept of “common but differentiated responsibilities” refers to the emissions of individuals instead of nations. We use the income distribution of a country to estimate how its fossil fuel CO2 emissions are distributed among its citizens, from which we build up a global CO2 distribution. We then propose a simple rule to derive a universal cap on global individual emissions and find corresponding limits on national aggregate emissions from this cap. All of the world’s high CO2-emitting individuals are treated the same, regardless of where they live. Any future global emission goal (target and time frame) can be converted into national reduction targets, which are determined by “Business as Usual” projections of national carbon emissions and in-country income distributions. For example, reducing projected global emissions in 2030 by 13 GtCO2 would require the engagement of 1.13 billion high emitters, roughly equally distributed in 4 regions: the U.S., the OECD minus the U.S., China, and the non-OECD minus China. We also modify our methodology to place a floor on emissions of the world’s lowest CO2 emitters and demonstrate that climate mitigation and alleviation of extreme poverty are largely decoupled.