Understanding global warming intellectually is not the same as feeling its presence in your daily life—or seeing photos of a 50-foot wall of fire. …Britain’s homes and office spaces weren’t designed with high temperatures in mind; unlike in the Mediterranean and other hot climates, our buildings aren’t typically made with thick walls and shutters to keep out sunlight. Mechanical air-conditioning is unusual in private homes because we already have air-conditioning. We call it rain. Britain might be a rich, developed country, but that doesn’t make it ready for climate change. …“Environmentalism” sounded woolly and tree-hugging when I read it or wrote it. “Climate change” sounded antiseptic and bloodless. “Look at that 50-foot wall of fire” might just do the trick. …The first thing to do is let the fear in, without letting it paralyze us. This isn’t fine. So what do we do next?