This is the sum of all fears. From the article in The Nation:

"We as a species have never experienced 400 parts per million of carbon dioxide in the atmosphere," Guy McPherson, professor emeritus of evolutionary biology, natural resources, and ecology at the University of Arizona and a climate change expert of twenty-five years, told me. "We've never been on a planet with no Arctic ice, and we will hit the average of 400 ppm...within the next couple of years. At that time, we'll also see the loss of Arctic ice in the summers.... This planet has not experienced an ice-free Arctic for at least the last three million years."

As an alumnus of the University of Arizona let me tell you how radical that university is NOT. Note that McPherson is an emeritus.

* October 2009: The Hadley Centre for Meteorological Research releases an updated prediction, suggesting a 4C temperature increase by 2060.

• November 2009: The Global Carbon Project, which monitors the global carbon cycle, and the Copenhagen Diagnosis, a climate science report, predict 6C and 7C temperature increases, respectively, by 2100.

• December 2010: The UN Environment Programme predicts up to a 5C increase by 2050.

• 2012: The conservative International Energy Agency's World Energy Outlook report for that year states that we are on track to reach a 2C increase by 2017.

• November 2013: The International Energy Agency predicts a 3.5C increase by 2035.

A briefing provided to the failed UN Conference of the Parties in Copenhagen in 2009 provided this summary: "The long-term sea level that corresponds to current CO2 concentration is about 23 meters above today's levels, and the temperatures will be 6 degrees C or more higher. These estimates are based on real long-term climate records, not on models."

And this rapid fall back is in spite of the 'deny and delay' tactics employed so effectively by corporations whose interests would be harmed by effective action. Yet they are being routed by reality. Politicians may have to listen to powerful incumbent interests, but the rest of us don't. Though any action may be too little and too late, we have a duty to act as though our actions could matter.

There is no word for actions causing the extinction of 90% of all living species, even inadvertently. Ecocide does not do the possibility/probability justice. Any suggestions?

"It is not necessary to have hope in order to persevere."