The main difference is that one is a factual claim (which is also visible), while the other one is a complex prediction of the future. I could be mistaken and

The main difference is that one is a factual claim (which is also visible), while the other one is a complex prediction of the future. I could be mistaken and don't have sources (I'm sure easily searchable though), but I think the arctic glaciers should have already been melted by now, by some predictions. So some of the climate science has already made incorrect predictions, and I don't think it is 'settled'. Even if everyone agrees it is happening and how, the details are extremely important if we then want to extrapolate to political action. I still support renewables and businesses going green, but that could happen even if climate change isn't a looming threat because there are other benefits like having less pollution in cities, or preserving the natural habitats etc.