Commentary Throughout the midsection of the United States in February, record frigid temperatures were inconvenient for those politicians who call global warming an “existential threat.” Global warming is already here, we are told. However, it didn’t feel like it if you lived in Bismarck, North Dakota, where temperatures fell to decades-low numbers, or in Chicago, Oklahoma City, Dallas, or Houston. San Antonio had snow for the first time in recent memory. The environmental apocalyptics say this doesn’t prove anything about what is happening with the planet’s climate. And you know what? They are 100 percent correct. But last summer, when hundreds of thousands of acres burned in California, that event was prima-facie evidence of global warming, and if you challenged that premise, you faced ridicule as a “denier.” About 10 years ago, when Barack Obama was president, his scientists put out a silly report on climate change, showing that the …