The CO2
emissions as per the USA, China, and EU stated goals have been estimated to
yield a 0.2 degree C temperature reduction by 2050. This figure was estimated
assuming all other nations followed either the USA or the Chinese commitments (I
assumed the EU commitment is too stupid to be copied by other nations).
The USA China agreement is soft, Obama celebrated the deal with Chinese President Xi Jinping last week. He seemed really happy he got the Chinese to stop growing their emissions after 2030.
Obama toasts the big deal with Xi Jingping
If we follow my method then we have three sets of CO2 emissions commitments:
i. EU commitment, 40 % reduction by
2030.
ii. USA commitment, 28 % reduction by
2025.
iii. China commitment, continued growth
and no more increases beyond 2030.
Given the
lack of stated commitments by other nations, I used my judgment and placed them
in one of the three groups above. I also extrapolated these commitments
assuming all nations except for Africa would continue reducing their CO2 emissions
by 2.1 % per year. This happens to be the reduction the USA has to use to
achieve Obama´s pledge to the Chinese.
The Chinese
and other Asian nations (except Japan and South Korea) are the gorillas in the CO2 emissions
scenarios. Because they, as well as minor players (Latin America, former Soviet
Union, and so on) do not reduce emissions growth until 2030 the total world´s
emissions will continue to rise and peak at 20 % above today´s level, as shown
in this graph:
CO2
emissions if all nations participate
in CO2 reduction efforts in three classes…
However, if
we assume 50 % of the CO2 emissions do not stay in the atmosphere (this is
roughly what happened over the last century), then CO2 concentrations reach 493
ppm by 2050 (versus 536 ppm if we use my estimate of fossil fuel burn rate,
documented in a previous post).