Funny You Should Ask

The QI elves are a team of writers and comedians who find the answers to impossible questions, doing the research for the long-running QI TV series, podcasts and spin-off books. For the next little while, we’ll be running some of their finest findings: the weird, wonderful, witty and wise, from their latest book, Funny You Should Ask ... Again.

How do we know that greenhouse gases warm the Earth?

In 1824, mathematician Joseph Fourier worked out that the Earth should be a lot colder than it is, given the amount of heat that comes from the Sun. He calculated that we’re kept warmer by our atmosphere acting like a blanket, which traps heat close to the ground. The eccentric Frenchman was obsessed with heat and would keep his rooms uncomfortably hot for visitors, while wearing a heavy coat himself.

Just over 30 years later, in 1856, American scientist and inventor Eunice Newton Foote collected an air pump, two glass cylinders and four thermometers and set about working out how this effect varied for different elements and molecules. She filled the tubes with gases, heated them up in the sunshine, and then timed how long it took for them to cool, eventually discovering that carbon dioxide was one of the very best gases at trapping heat. She wrote the first paper that suggested that the more greenhouse gases there were in the atmosphere, the more the planet would heat up.

By rights, Foote should be a household name, but she had three things working against her. She was an amateur, so her work was seen as less trustworthy. She was American, at a time when Europe was the centre of scientific discovery. And most importantly, she was a woman making groundbreaking discoveries in a man’s world. So, most of the credit went to an Irish physicist, John Tyndall, who came to the same conclusion three years later.

Extracted from Funny You Should Ask … Again, by the QI Elves (Faber, $27.99), which is out now.