Peak warming will be proportional to cumulative CO2 emissions, but the rate and velocity of climate change may be very different under different emissions pathways, even when cumulative emissions are equal. Thus, the ability of ecosystems to adapt or migrate is sensitive to the pathway of emissions.
Several thousand measurements of Chinese coal and clinker indicate that CO2 emissions in China have been overestimated by 14% in recent years, or about 2.5 billion tons of CO2 per year. This is a very large revision with important implications for international climate negotiations and assessments of the global carbon cycle.
US CO2 emissions dropped 11% between 2007-2013; a trend has been widely attributed to the increased use of natural gas over coal. We decompose the drivers of the decline and show that the recent economic downturn and not the gas boom deserves most of the credit for the decrease in emissions.
Worldwide, existing power plants represent roughly 300 billion tons of future CO2 emissions if all plants operate for 40 years, and these "committed emissions" in the power sector have been growing at a rate of ~4% per year. This paper proposes tracking these commitments to quantify future emissions implied by current investments.