1. While it mentions projections in air-pollution related deaths, it doesn't say whether increased air-pollution deaths due to warming was considered. There's a well-established connection between heat and air pollution, especially ground level ozone and smog.

2. You can't generalize from one country to the entire world, especially from a relatively cold country. I agree that in northern Alaska and southern Chile, cold kills more people than heat. What about India? (Yes, sometimes it gets cold in India too, but try and tell me that's worse than the heat. I've been there.)

Futhermore, the air pollution problems exacerbated by heat are probably less in the UK, which is gets much more wind and rain than places with dry seasons.