How Ambitious is China's Proposal to Peak CO2 Emissions by 2030?

A few days ago China and the US jointly announced emissions targets for 2030. China proposes that their carbon emissions will peak by not later than 2030. How ambitious is this goal? In our 2010 paper in Energy Policy, Frank Jotzo and I asked how ambitious China's 2020 target to reduce emission intensity by 40-45% between 2005 and 2020 was. We concluded that it represented significant effort beyond expected intensity reductions under business as usual.

In a recent paper Xiliang Zhang and coauthors project Chinese emissions under three scenarios. Under a no policy scenario, emissions rise to 16.5 billion tonnes (Gt) in 2030 and continue to rise throughout the century. Under their "continued effort" scenario where current policy initiatives are continued, emissions rise to 11.8 Gt in 2030 and peak in 2045. Finally, under their accelerated effort scenario, emissions rise to 10.2 Gt in 2030 where they peak. So, on this basis, China's proposal does constitute a new accelerated effort.

Another way of looking at these scenarios is in terms of the rate of reduction in emissions intensity in 2030. The rates are -1.9%, -3.4%, and -4.1% respectively. China's 2020 emissions intensity target represents a 3.6% annual rate of reduction in emissions intensity from 2005 to 2020. So, by this metric the new target represents an increase in effort over the current policies.