NY Times: Best & Worst Cases
Over the weekend, the NY Times published a piece by Curt Stager — a professor of natural sciences at Paul Smith’s College.
Prof. Stager’s opening salvo:
The cleanup (of the carbon already in the atmosphere) will take tens of thousands of years even if we switch quickly to renewable energy sources.
When the Earth’s slow cyclic tilting and wobbling along its eccentric orbital path once again leads to a major cooling period some 50,000 years from now, enough of our heat-trapping carbon emissions will still remain in the atmosphere to warm the planet just enough to weaken that chill.
Holy Smokes, Batman … 50,000 years
But, not to worry, Prof. Stager serves up a best case scenario…
Based on past history, here’s what Prof. Stager says is the best that we can expect:
If we switch quickly from fossil fuels, climates might come to resemble those of the interglacial warm periods that punctuated ice ages of the last two million years.
During the last interglacial, which began 130,000 years ago and lasted about 13,000 to 15,000 years, global average temperatures were 2 to 5 degrees Fahrenheit higher than today.
Enough of the ice in Greenland and Antarctica melted to lift sea levels by about 20 feet, but most polar ice survived.
Many species and ecosystems adapted to the changes that didn’t suit them by simply migrating toward the poles.
Polar bears survived, presumably because they found enough icy refuges in the high Arctic to keep them going.
The warmth hippos, elephants and other typically African animals north through Europe.
OK, I think I understand.
Go back a couple hundred thousand (or a couple of million) years, and we’ve seen this play before … and it’s not pretty.
Water levels rise, people and animals drift to the North & South Poles, and it takes 13,000 to 15,000 years for things to get right again.
Oh me, oh my.
And that’s the best case.
Prof. Stager also presents a more likely, worst case scenario:
If we burn all remaining coal, oil and gas reserves within the next century or two, we could introduce a more extreme, longer-lasting hothouse much like one that occurred about 56 million years ago: the Paleocene-Eocene Thermal Maximum, or PETM.
Global average temperatures climbed 10 degrees or more, erasing cold-loving species and habitats from the planet.
With atmospheric carbon dioxide concentrations several times higher than today, a combination of warming and carbonic acid buildups in the oceans exterminated many deep-sea creatures and dissolved limy minerals and shells from the ocean floor.
The spectacular rise of the PETM lasted several thousand years.
If we were to de-ice the planet in similar fashion again, global mean sea level would rise well over 200 vertical feet.
OK, if we reach back a little further in history … say, 50 or 60 million years … then we can get our arms around this one.
Temps go up by 10 degrees and all hell breaks loose.
Which begs a question: were there carbon-spewing cars back then?
I thought Fred Flintstone had to foot-peddle his way to work.
I guess Prof. Stager has better sources than I do.
Finally, Prof. Stager’s conclusion:
A switch from finite fossil energy to cleaner, renewable energy sources is inevitable: We are only deciding how and when to do it.
That is what world leaders and policy makers will be grappling with at the United Nations Conference on Climate Change in Paris.
Here’s the rub …
According to several news outlets:
The United Nations Conference on Climate Change is expected to produce a landmark agreement during the next two weeks.
But it remains to be seen whether the gathering of 150 world leaders near Paris will achieve the target of limiting rising global temperatures to no more than 2 degrees Celsius above pre-industrial levels this century.
English translation: no deal.
Let’s hope for Prof. Stager’best case, right?