The problem I have is the idea that scientists are deliberately lying and – as you point out – the uncritical acceptance of any suggestion that climate change either isn’t happening or is nothing to do with us (in fact the very things that the conspiracy theorists accuse the scientists of doing).

Someone can say they don’t think the present climate variations are man-made. That’s fine. They can point to past climate events or the solar activity ideas and we can discuss those (the solar activity theory was interesting, it looked good for a while and raising it was scientifically valid, but the flaws in it have now been established).

Yep – most areas of science are full of uncertainties (otherwise we wouldn’t need to do science any more). Newton was wrong – though his theories are a good enough approximation that we can use them every day – and one or other or both of relativity and quantum mechanics look like they will probably have to be adjusted to make them consistent, but we don’t have legions of people accusing Einstein of being a fraud.

The root of the problem lies with people (specially in the USA, but also elsewhere) not knowing what the scientific method is all about. They think that because a particular branch of science has uncertainties, or described laws that were later rebutted (physics and ether, for example), one is entitled to “doubt” their conclusions. They will believe what any charlatan has to say against climate science no matter if it is all lies, it only needs to sound “reasonable”. The “sceptics” industry often succeeds in making people believe there is debate among scientists. BIg news: debate is common and necessary in science, but there is also a wide consensus.

Climate science has big uncertainties, but it is the best understanding we humans have about that matter. On another level (because you can prove things more often than in climate science), it is the same with physics or any other science. We may be deluding ourselves about relativity and quantum physics and the world is really resting on the back of a giant turtle. But is IS the best understanding we as a species have right now about the problem. So you better pay heed to it.

Not familiar with the other source, but in the few minutes before I got bored I didn’t hear a lot of actual scientific evidence.