The testimony of Professor William H. Calvin at the EPA Endangerment Hearing in Seattle, May 22, 2009
I am William H. Calvin, a Seattle author, lecturer, and professor emeritus at the University of Washington School of Medicine now affiliated with our Program on Climate Change. In 1958 when I was an undergraduate physics major, I saw a short movie where the climate scientists of the day were predicting global warming (you can now find it on YouTube). The science was good enough for an endangerment ruling back in the EPA’s first year, 1971.
We have squandered the fifty-year lead time that early climate science provided us. We now have a climate problem so big that CO2 emission reductions, even to zero, won’t be a climate fix. If we were removing CO2 in a big way, countering ongoing emissions and drawing down the 38% excess CO2, then emission reductions would speed the day and reduce the needed sequestration capacity. But without a program to quickly clean up the CO2 excess, emission reductions will not even buy us some time before we reach the overwhelming levels of climate change-and because of abrupt climate shifts, that could happen well before mid-century.
For methane, the second largest greenhouse gas problem, natural drawdown mechanisms get rid of half within ten years. That’s in contrast to CO2, where it takes centuries and, in the process, acidifies the oceans. Because of this timing difference, methane emission reductions can make a substantial difference within a decade. The major U.S. sources of methane are not cows in Iowa feedlots or leaking pipelines in Texas but rather mining in Appalachia. Mine gas is mostly methane, as is natural gas, and mining regions around the world appear as hot spots on a methane map.
We can do something about that, stopping mountain-top removal and sealing old mines. But the other big methane source is melting permafrost. It is melting because the Arctic regions are warming so fast that we will lose one-third of the permafrost in the next several decades. This source of global warming must instead be countered, by taking carbon out of circulation somewhere else.
Treating our climate ills is analogous to treating cancer. We are familiar with surgery for removing the tumor, followed by chemotherapy to clean up the remaining bits. Chemotherapy alone cannot clean up most tumors, but it is still valuable in combination with surgery. For chemo, read emission reductions; for surgery, read carbon removal.
Not only must carbon removal be big enough but it and emissions reduction must together be fast enough to remove us from the danger zones for abrupt climate shifts before something big happens. A serious jolt would cause catastrophic crop failures and food riots within a year, creating global waves of climate refugees with the attendant famine, pestilence, war, and genocide.
I’d say that we must clean up CO2 by 2030. Acquiescing in a slower approach is like playing Russian roulette with the climate gun. Our climate fix must be big and quick.
Professor Calvin is a Member of the West Coast Climate Equity Advisory Board.