It's been many years since I have thought about climate change in this amount of detail. I'd forgotten how complex and overwhelming it can be once you start digging a bit deeper. But following these recent threads, I've got a better appreciation now of why lots of people still don't accept it fully, and that has been really interesting. I don't mean because they are correct. Just that it can be extremely difficult to get your head around it all, and I can see how easy it is to go down the wrong path into denial, but still with the best of intentions. I also have even greater respect for climate scientists. It's a common denier meme to denigrate climate science. But it's actually really tricky and multi faceted, combining several disciplines as varied as geology, meteorology and physics.
I believe the obvious starting point for everyone who still has doubts, should be whether they accept the basic physics, established almost two hundred years ago, that certain gases absorb infra red radiation and heat up. Everything else follows from that.
Next, do they accept that greenhouse gases naturally keep the earth warm, and that without them the earth would be a giant ball of ice. Then following on from this, if they accept a certain amount of greenhouse gases keep the earth warm, do they accept that adding more greenhouse gases will make the earth even warmer.
The trickiest part, perhaps, is accepting the reason that the earth's temperature has been so incredibly stable for almost ten thousand years, and has allowed humans to flourish. This is because of two very complex systems, which have both been in almost perfect equilibrium. One is the earth's carbon cycle and the other is the earth's energy balance. Burning fossil fuels and other human activity has changed both. Although the human impacts may be quite small compared with the natural forces, it is enough to throw out these perfect equilibriums. That might be the hardest bit of all to understand and accept.