Nothing in that post explains why Thiel is a climate change denier. The only thing I see that could be construed that way is that he said it hasn't gotten warme

Nothing in that post explains why Thiel is a climate change denier. The only thing I see that could be construed that way is that he said it hasn't gotten warmer the last 15 years. It depends on when Thiel made that statement whether it was true or not at the time. The warming that occurred over the last year meant that there was statistically significant warming, but before about February the warming over the last 15 years was not statistically significant. At worst getting the facts wrong by a few months doesn't make Thiel a climate change denier.