@Olivier5,
Olivier5 wrote:
Quote:What they haven't defined yet is what proportion of the warming is due to human activity and what proportion is purely natural.
Not really. Climate change appears entirely due to human causes.
The climate has been changing ever since this planet formed and it will always change. More specifically, the climate has been warming and cooling in a steady cycle for hundreds of thousands of years. This is well documented. We are currently in one of those warming trends, which started well before humanity could do anything more than make a campfire.
Human activity is contributing to climate change, of that there can be little doubt. Just how much it's contributing is not yet clear.