Sometimes our inner-Cassandra gets the better part of us, I suppose. We may read the latest report, couple it with the veritable mountain of reports that proceeded it and upon which it usually builds, and then step well back from writing what it seems, to us, to mean. Who wants to scream, "aaarh, you're all gonna die"? No one wants to say that. No one wants to think that.
Gwynne Dyer doesn't seem to have many reservations on that score. Writing about last week's paper published in the Proceedings of the National Academy of Sciences, says we have passed the point of no return. Here is Dyer's recent column, almost in its entirety:
The article has the usual low-key scientific title: Trajectories of the Earth System in the Anthropocene. The authors never raise their voices, but they point out the likeliest of those trajectories – the one we will stay on even if all the promises in the 2015 Paris Accord on climate change are kept – runs right off a cliff.
Hothouse Earth is not very hospitable to human life. Hundreds of millions or even a billion or two would probably survive, but the damage to agricultural systems would be so extreme that billions more would die. (The authors don’t say this, of course, but the people who have to think about these contingencies, like the military in the developed countries, know it very well.) What the authors are saying is that global warming driven directly by human emissions of greenhouse gases is only smaller part of the problem. The real threat is the unstoppable natural feedbacks, triggered by the warming that we have caused, that will take us up to the killing temperatures.
They list 10 of them, the biggest being loss of Arctic sea-ice, melting of the permafrost zone, dieback in the boreal and the Amazon forests and changes driven by warming in the ocean circulation system. Just triggering one or two of these feedbacks could cause enough additional warming to set off others, like a row of toppling dominoes.
Yet the role of these feedbacks was not discussed in the scientific journals, not included in the predictions of future warming issued every four or five years by the Intergovernmental Panel on Climate Change (IPCC), and definitely not part of the public debate. Why not?
When you make a statement in science, you have to be able to prove it, generally with hard numbers and testable predictions. The hard numbers weren’t available.
So the climate scientists didn’t make grand assertions – but they did manage to get the threshold of two degrees Celsius higher global temperature adopted as the never-exceed target for the IPCC’s efforts to get the warming under control. (Nobody said publicly how they arrived at that number, but it was because the scientists thought that it was about where the feedbacks would start kicking in.) The scale and trigger-points of the feedbacks have finally been calculated, more or less, and the news is as bad as the scientists feared. We have passed the point where a return to the stable climate of the past 14,000 years is possible, and we are on course for Hothouse Earth.
The best we can do is try to stabilize the warming at or just below plus two degrees, and that will not be possible without major human interventions in the climate system. It would require “deep cuts in greenhouse gas emissions, protection and enhancement of biosphere carbon sinks, efforts to remove CO2 from the atmosphere, (and) possibly solar radiation management. . . .”
...As Jim Lovelock, the creator of earth system science, wrote 39 years ago, we may “wake up one day to find that (we have) the permanent lifelong job of planetary maintenance engineer.”
I haven’t bothered to ask Lovelock if we are there yet. Of course we are.You may have read the latest controversy that also came out this week concerning the first parts of the world that will become uninhabitable - lethal to human life. The first region identified is China's densely populated agricultural belt. Temperatures there will first hit "wet bulb 35," a combination of heat and humidity so intense that the human body can't cool itself and bakes from the inside out. Even a young, healthy and fit person at rest in the shade would survive for six hours max.
Another area in line for wet bulb 35 is the Persian Gulf region - Iran, Iraq, the Gulf States, Saudi Arabia - all the places where we've wasted treasure and lives for the best part of the last 20 years in a vain effort to achieve something or other.
Parts of the Caribbean and Central America are expected to become at least seasonally uninhabitable - if you can call the loss of your growing season a seasonal problem.
And, as for us, we're not going to escape unscathed. With any luck we'll be in the "least and last" impacted club but even that is going to be a tough ride. And I'm sure our government is going to get right on that, just as soon as they've got their armada of bitumen supertankers up and running. Right? Yeah, right.