The US Is a Net CO2 Sink

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.

Objection:

The United States actually absorbs more CO2 into the land than it emits into the air. The world should be grateful.

Answer:

As often is the case, at the heart of this talking point is a grain of truth, though it is no longer equivalent to what it has been forcibly grown into. According to the US Department of Energy the land use changes taking place in the United States between 1952 and 1992 have resulted in a net absorption of CO2, but only of natural CO2. That is, in the natural fluxes of CO2 into and out of forests and peat bogs and soil, there is more carbon being absorbed than there is being emitted. This also includes carbon that has been sequestered as lumber and other wood products. (These fluxes are actually much larger than anthropogenic emissions, but they go both ways, whereas fossil fuel burning only emits carbon).

This net sink of natural carbon has only been sufficient to offset around 25% of the industrial and domestic fossil fuel carbon such as from automobile exhaust and coal-fired power plants. In Chapter 7 of this 1996 report, the DoE notes:

For purposes of comparison, this estimated amount of sequestered carbon offset approximately 17 percent of the 1,381 million metric tons of carbon (or 5,068 million metric tons of carbon dioxide) emitted in the United States in 1992 from the burning of fossil fuels.

So, at least for 1992, that leaves 83% of fossil fuel burning emissions that are left in the atmosphere to spread throughout the globe or to be absorbed into the oceans. In the 2003 report, this has increased to 88.1% that is not sequestered on American lands:

The U.S. Environmental Protection Agency (EPA) estimates annual U.S. carbon sequestration in 2003, based on data generated by the U.S. Department of agriculture (USDA), at 828.0 million metric tons carbon dioxide equivalent (MMTCO2e), a decline of approximately 21 percent from the 1,042.1 MMTCO2e sequestered in 1990 (Table 33). Land use, land-use change, and forestry practices offset approximately 16.9 percent of total U.S. anthropogenic carbon dioxide emissions in 1990 and 11.9 percent in 2003.

(page 75-76)

With a starting per capita emissions level five times greater than that of the global average, that leaves alot that the world does not have to thank the US for.

This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.

"The US Is a Net CO2 Sink" was first published here, where you can still find the original comment thread. This updated version is also posted on the Grist website, where additional comments can be found, though the author, Coby Beck, does not monitor or respond there.