A much younger, far more reckless version of me liked to take a bicycle to places no sane person would voluntarily pedal toward. Once, I left Vienna with nothing more than stubbornness and a questionable sense of adventure, and three months later I rolled into Khartoum like some sunburned lunatic who’d taken a wrong turn at the Danube.
I slept in the desert more times than I can count—usually in a hammock, suspended above the ground like some wary piece of laundry, just to keep the local fauna from nibbling on me during the night. The amusing part was this: when I slept rough in Greece or along the Turkish coast, I barely needed a blanket; the nights were warm, soft, almost indulgent. Yet farther south—Egypt, Sudan—the desert turned vicious after sunset. I’d be shivering in places where the thermometer had flirted with the low fifties just hours earlier.
The reason was embarrassingly simple. The air down there was bone-dry, utterly incapable of holding onto the day’s furnace-like heat. Up north, along the coasts, the nights stayed warm because the air was loaded with water vapor. And water vapor, unlike most of the climate fairy tales we’re fed, actually retains heat. Compared to that, the other supposed “effects” are so minuscule one might reasonably conclude they barely exist at all.