To: John Kerry, Secretary of State, John Holdren, Assistant to the President for Science and Technology, President Donald Trump, Rep. Ted Lieu (CA-33), Rep. Katherine Clark (MA-5), Sen. Dianne Feinstein (CA-1), Sen. Kamala Harris (CA-2), Sen...

CO2 is up to 400: Methane must come down to 1250

While society is struggling to control CO2 emissions, it must immediately and deeply cut methane and black carbon to help preserve the near-term global climate and help prevent growing risks of catastrophic and irreversible changes in the arctic.

We implore our leaders to immediately set more ambitious targets for methane and black carbon. Methane could be brought down globally to 1250ppb in two decades. This could probably be achieved without any U.S. legislation at all, but with a large-scale effort, under U.S. leadership, to restructure, expedite and greatly strengthen already existing programs initiated by the U.S. government and now part of UNEP (United Nations Environment Programme).

Why is this important?

In the world of climate, what goes up doesn’t always easily come back down. That’s true of atmospheric CO2 levels, and while we are struggling to control CO2, we must also immediately cut methane and black carbon to help preserve the climate we have for the coming decades. As James Hansen, perhaps the world’s most famous climate scientist, has said, “Expected difficulties in slowing the growth rate of CO2 and eventually stabilizing atmospheric CO2 amount make the non-CO2 (climate factors) all the more important.”

We agree, and we implore our leaders to immediately set more ambitious targets for methane and black carbon. Methane could be brought down globally to 1250ppb in two decades. This could probably be achieved without any U.S. legislation at all, but with a global effort, under U.S. leadership, to restructure, expedite and greatly strengthen already existing programs at UNEP (United Nations Environment Programme) and elsewhere.