Reducing pollution: Why the big rush?

Why are those concerned about climate change impatient to reduce carbon pollution? It may seem that an increase of 3-5 degrees F would hardly be noticeable, but 5 degrees F separates the average annual temperature of Albuquerque from Seattle.

Yes, a new paper in Science finds that, as deniers remind us, temperatures have indeed been as warm in the past as they are now. Sea surface temperatures were similar to those of today’s warmed world 120,000 years ago, but sea level was 20-30 feet higher than now.

Carbon dioxide we put into the atmosphere today will still be there after we die because it takes decades for CO2 to leave the atmosphere. Warming we see now results from carbon emitted years ago; even if we could stop now, our grandchildren would suffer the disruptions we’ve bequeathed them. We’re also close to a tipping point when warming will generate additional warming even without our nudging it along. Melting Arctic ice causes more warming because dark land and water absorb more solar radiation than ice (think hot black asphalt in on a hot summer day). With heat comes additional evaporation, and water vapor itself traps more heat. Soils in the arctic also contain huge stores of carbon, frozen in permafrost. As these soils melt, that carbon is released, amplifying warming, which melts yet more permafrost in a self-reinforcing feedback.

It’s frightening, but we can still blunt the worst effects if we act effectively and soon. Tell your representatives to support common-sense policies to limit climate change.

This story was originally published March 14, 2017 at 6:04 PM with the headline "Reducing pollution: Why the big rush?."