Now that Presidents Obama and Xi Jinping are congratulating each other at the G20 summit that they both agree with the Paris Climate Agreement, it’s as well to remind ourselves that neither party has made any significant decision to show that they take it seriously. I thought I’d remind myself just where I am.
It’s a nonsense to say that we know what drives the global warming that’s been going on for about 150 years. The current orthodox belief is that the additional man-made CO2 in the atmosphere traps infra-red heart that that usually leaves the planet on a cloudless night — thus driving the temperature upwards.
But what about the other possible driver? This is that if the earth was getting warmer anyway for natural reasons — as it has done many times in the past — then the additional temperature releases CO2 from the oceans.
Both drives can be tested scientifically in laboratory conditions but their relative strengths can’t be compared within the setting of the earth’s surface itself and its cloud cover. It’s far too complex to control for all the variable factors that might be contributing to the second of the two drives above.
Until then I prefer to believe in the validity of the Vostok ice core sample — that, in the last 400,000 years, changing global temperatures precede, not follow, changing CO2 content in the atmosphere.