Scientists have repeatedly stated the 2020 target must be 25 to 40 percent emission reductions from the 1990 emission baseline. (dotearth.blogs.nytimes.com)
Plugging in 100 percent emission reductions by industrialized nations by 2100 while postulating maximum climate sensitivity yields a temperature reduction of 4 / 10ths of a degree celsius (rounded up). (niskanencenter.org)
It included a strong editorial, Going Green, stating that in order to reach the «necessarily ambitious goal: 80 percent emission reduction in carbon emissions from their 1990 levels by 2050: (carbontax.org)