re: #39 robdouth

As with most (all?) things in science, future predictions are subject to some degree of uncertainty. And your degree of confidence in the answer depends on the question you’re asking. If the question is a Yes/No one, such as: “Is there evidence that global warming is happening, and that human beings have had a contribution?”, then there is more than enough evidence to confidently assert that the answer is “Yes”. But if you instead ask: “How much will the climate change in the next 20 years if we maintain our current pace of emissions?”, there is (legitimate) scientific disagreement about what the answer is. Since policy requires us to tackle the latter question, the waters get muddy very quickly.