This piece is designed to help politicians (primarily right-wingers) understand climate change.
With that aim in mind, I’ve kept it simple.
A reduction in greenhouse gas emissions of up to 28 per cent (as proposed by the Australian government) would not be good, it would be bad.
That’s because it would mean we were still emitting 72 per cent of what we had been.
That means emissions would still be massive (really high).
Carbon dioxide (CO2) takes hundreds of years to break down.
That means that a lot of what we emitted a long time ago is still up there.
And what we emit now is added to it.
It’s the concentration of greenhouse gases that determines how much heat is trapped. (We can’t argue with the laws of physics, but let’s not get into that.)
CO2 concentrations have increased really fast over the past 100 years.
They’re now way over what we’ve previously seen in the 300,000 years of human existence (and a long time before that).
We’ve been lucky to have had “Goldilocks” conditions over the 10,000 years of so-called human “civilisation”.
Concentrations of methane (CH4) and nitrous oxide (N2O) have also increased.
Sorry about the funny words and symbols in that last point.
Heating creates feedbacks in the climate system, which cause more heating.
That process continues and accelerates (goes faster).
That means it might get out of control (if it’s not already).
We would call that “runaway” climate change.
That would be really, really bad.
sdecoret, “View of blue planet Earth in space with her atmosphere Europe continent 3D rendering elements of this image furnished by NASA – Illustration”, ID 1016700121, Shutterstock