It’s too late chaps, we’re toast!

In January 2008 Joseph Romm said Quote:

The nation?s top climate scientist, NASA?s James Hansen, apparently now believes ?the safe upper limit for atmospheric CO2 is no more than?350?ppm,? according to an?op-ed?by the great environmental writer Bill McKibben. Yet while preindustrial levels were 280, we?re now already at?more than 380 and rising 2 ppm a year!

Like many people, in the 1990s I believed 550 was the target needed to avoid climate catastrophe ? but now it?s clear that:

  1. 550 ppm would lead to the greatest disaster ever experienced by human civilization ? returning us to temperatures last seen when sea levels were some 80 feet higher. This is especially true because ?
  2. long before we hit 550, major carbon cycle feedbacks ? the loss of carbon from the tundra and the Amazon, the saturation of the ocean sink (already beginning) would almost certainly kick into high gear, inevitably pushing us to much, much higher CO2 levels.

Exactly when those feedbacks seriously kick in is the rub. No one knows for sure, but based on my review of the literature and interviews of leading climate scientists, somewhere between 400 and 500 ppm seems most likely. It could be lower, but it probably couldn?t be much higher.

So I, like the Center for American Progress and the?world?s top climate scientists, now believe 450 ppm is the upper bound. […] End of quote.

Unfortunately, all the earlier doom and gloom predicted for 350 ppm did not read the script and show up as planned, so we simply redefine the ‘limit’ to be 400 or 500 or, when we get to 450, to 600. (Rinse and repeat)

We have just whistled past 410 ppm and it appears 450 ppm is less than 16 years away according to the report from CNN Quote:

Carbon dioxide (CO2), the No. 1 greenhouse gas leading to man-made global warming, has reached a dubious new milestone.

The level of the gas in the atmosphere, which is measured by instruments on top of Hawaii’s Mauna Loa Observatory,?topped 410 parts per million (ppm) for the month of April.

This is the highest concentration of the heat-trapping gas ever recorded at the Observatory, where direct measurements have been taking place for more than 60 years, giving us the longest detailed record.

The Keeling Curve.

Passing 410 ppm “is important because it punctuates another milestone in the upwards march of CO2,” according to Ralph Keeling, head of the Scripps CO2 program at Scripps Institution of Oceanography in California.

“At the recent pace, we’ll hit 450 ppm in a mere 16 years, and 500 ppm 20 years after that. That’s well within dangerous territory for the climate system,” Keeling added.? End of quote.

However, I have just looked out the window and the world is still there, ticking along merrily, not getting rapidly hotter, possibly getting colder, sea levels are rising at 1 or 2 mm per year as per usual, storms come and go, climate refugees don’t seem to be a problem, ocean acidification isn’t acidifying …

…. but we are collecting billions in carbon payments; millions in grant funding; and first class flights to conferences all around the world, so it’s all going to plan.