20151206 - climate change

Why are we being such idiots about climate change?

John Carey

Veteran environment writer John Carey looks at the reasons we don’t seem to make meaningful progress on climate change — and issues a rousing call to arms for us all to step up and play our part.

When I started covering climate change more than thirty years ago, the underlying science was already clear. Heat from the sun warms the Earth. Gases like carbon dioxide in the atmosphere then act like a snuggly blanket or greenhouse to trap much of that warmth, keeping much of the heat from radiating back out to space.
For humans, this greenhouse effect is a vital — and fortuitous — physical phenomenon. Without it, the Earth would be in a deep freeze. Life as we know it couldn’t exist. We would have no mighty civilizations, no vast fields covered with amber waves of grain. No smart phones or keeping up with the Kardashians.
But like most good things, we can have too much of this greenhouse effect. Spew extra carbon dioxide, methane and other heat-trapping gases into the atmosphere by burning fossil fuels and cutting down forests, as humans have been doing since the dawn of the Industrial Age, and it’s like pulling an extra cozy comforter over the planet. We get warmer. Ice sheets and glaciers melt. Sea levels rise. The extra energy in the atmosphere means more powerful and extreme storms, bringing tempests that wash away Vermont towns and send walls of water into subway tunnels in Manhattan. “Suddenly, climate change isn’t about the polar bears or the distant Maldives Islands anymore,” a Nashville, TN, flood victim told me for a story I wrote for Scientific American on the growing number of droughts, floods and other extreme weather events, “It’s about the mold on your baby’s crib.”
And get ready for much worse. In the 1950s, a pioneering scientist named Charles David Keeling realized the importance of measuring CO₂ in the atmosphere, and wangled funding for instruments on the lonely peak of Hawaii’s Mauna Loa. Those measurements, which continue today, show that CO₂ levels have risen dramatically from 316 parts per million in 1958 to 400 ppm now — a rate ten times faster than the Earth has experienced in hundreds of millions of years. And we know from the paleontological record that the past variations in greenhouse gas concentrations are associated with dramatic swings in climate. One of my favorite cautionary tales is the Paleocene-Eocene Thermal Maximum of 55 million years ago, when crocodiles cavorted off of a steamy Greenland and the tropics may have been too hot for life. Keep burning coal, oil and gas, and that’s exactly where we headed. Good for crocodiles, maybe, but not for modern civilization.
Climate change deniers say nothing is certain. True, we don’t know if the planet will be two degrees or ten degrees warmer in 2100. But I fault both the scientific community and the press for not explaining that uncertainty cuts both ways — and that the future could be far more threatening than the current scientific consensus estimates.

I fault both the scientific community and the press for not explaining that uncertainty cuts both ways.

I even scared myself by writing a recent story in Scientific American that was prompted by the worries of a few activist scientists, like NASA’s James Hansen, that climate change could happen way faster than anyone had expected. I was convinced that it could. The key evidence comes from the past. Small wobbles and other changes in the Earth’s orbit move the planet closer or farther from the sun over periods of hundreds of thousands of years. As a result, slightly more or less heat from the sun reaches the Earth. Evidence from ice cores shows us that the wobbles can have a huge effect on climate, causing mighty ice sheets to wax and wane, and temperatures to plunge or soar.
Yet the changes in solar heat reaching the Earth have been far too small to cause such huge changes in climate by themselves.
What’s happening, paleoclimatologists have figured out, is that the tiny changes trigger feedbacks that greatly amplify the small initial “push.” Add just enough heat to melt a bit of permafrost, for instance, and the thawing tundra sends enough methane and carbon dioxide into the air to create a stronger greenhouse effect. That, in turn, speeds the melting and causes the release of yet more greenhouse gases, thus accelerating the warming like a runaway train.
Now, by burning fossils fuels, we’re adding 12 times more heat per square foot of the Earth’s surface than those natural wobbles ever did. It’s crazy not to expect that the effects will be even more dramatic than the past wild swings in climate. Scientists tell me about their own nightmare scenarios, in which today’s modest increase in planetary temperatures triggers feedbacks that accelerate the warming enough to bring widespread crop failures and climate catastrophe in our lifetimes.
The sobering truth is that the planet has already been responding faster than expected. Sophisticated climate models have been enormously valuable in predicting what might happen as greenhouse gas concentrations climb. But they are telling us only part of the story. No climate models predicted the extraordinary decline of Arctic sea ice, for example, for reasons that are not well understood. So what other nasty surprises may await us?

 http://ideas.ted.com/why-are-we-being-such-idiots-about-climate-change/
 http://www.borgenmagazine.com/climate-change-need-global-adaption/