Planet in peril

The Need for Urgent Action “Climate is nearing dangerous tipping points. Elements of a “perfect storm,” a global cataclysm, are assembled. – James Hansen, Director of NASA’s Goddard Institute for Space Studies.

1. We have released so much carbon dioxide (CO2) from burning fossil fuels, deforestation and bad agricultural practices that atmospheric CO2 is now at 385 parts per million (ppm), 67% above the average of the past 800.000 years (covering many glacial/interglacial cycles), and 29% above the maximum of the same period. The rate of increase is 2.2ppm/year and getting faster. From radioisotope fingerprinting of atmospheric CO2 we know that the current excess of CO2 in the air is from fossil fuel burning, not from natural causes, so humans are certainly responsible.

2. Due to planetary inertia, the full extent of warming from the CO2 currently already in the air will not fully materialize until many years later. Two powerful positive feedback mechanisms are already underway: ice-albedo (melting of ice-sheets reduces sunlight deflection by ice, ocean absorbs more heat than ice, hastening warming), and the release of green house gases by warmer ocean, soil and biosphere.

3. In September 2008, one of the most feared manifestations of this feedback effect is confirmed in the Arctic: massive deposits of sub-sea methane are bubbling to the surface via “methane chimneys” as ice and permafrost (which serves as a “lid” to the methane) melts. Methane is a green house gas at least 25 times stronger than CO2, and its deposits under the permafrost and the ocean floor are bigger than all the oil that was ever burnt and that could ever be extracted! The Intergovernmental Panel on Climate Change (IPCC) did NOT take the effect of methane hydrate release into their calculations when they set 450ppm CO2 as the “do-not-exceed” line, for averting the worst catastrophes.

4. When atmospheric CO2 was above 450 ppm in the earth’s history, the planet was completely ice-free, and sea level was 75 meters higher than today, according to paleoclimate records.

5. NASA’s top climatologists tell us that the safe upper limit of atmospheric CO2 that we should aim to stay below is probably between 300-350 ppm. We have already overshot it. The longer we stay above that, the less likely we could still turn back the long term climate change that we have set in motion, which will eventually proceed way beyond human control.

6. Sudden warmings of a few degrees in the past have triggered mass extinctions. Current species extinction rate is estimated at 100 to 1000 times “background” or average extinction rates in the evolutionary time scale of planet Earth. A mass extinction is underway and we have to reverse course quickly enough to prevent the worst.

7. The solutions to climate crisis by switching to renewable energies and a green economy also represent an unprecedented economic and job-creating opportunity, and all the necessary technologies are already here, but development of some of them for large scale deployment is urgently needed.

For more details illuminating how this is such an urgent issue, please visit the website of CSGF board member Maggie Zhou.