One was a farm boy from Ontario, the other the son of itinerant Iowa farmers. Both are now world-renowned scientists and activists with the attention of global leaders. However, the public only listens to one of them. The wrong one.
Commander Chris Hadfield has expanded our horizons, making the International Space Station an accessible place to virtually visit, and giving us wonderful views of our planet photographed from space. When the Canadian astronaut recorded a version of David Bowie's Space Oddity for his departure from the ISS, it was played on national news broadcasts across the globe and has been viewed more than 12 million times on YouTube.
It's a stark contrast with the stern-faced Iowan caution of James Hansen. The world's most renowned climate scientist has little joy to bring. Instead of heart-warming photos of electric lights blazing from the surface of Earth, he has dull graphs showing the slow, steady advance of the global warming apocalypse – ironically, caused in part by the electric lights that have made Hadfield's pictures so popular. Hansen doesn't have a song.
He doesn't even have a particularly motivating speaking style. You'd be forgiven for thinking that Hansen was a firebrand. He gets arrested in protests over environment-damaging mining practices and the construction of a pipeline that will bring the world's dirtiest oil to market. NASA has tried to gag him – and he gathered evidence of this and then took it to the New York Times. He has lobbied national leaders the world over. But Hansen is a fact-driven, cautious speaker who is careful not to get emotional over his message.
That is probably why it hasn't made any headway. If you heard the sound of weeping and gnashing of teeth in central London last night [16 May], it was because Hansen was giving a talk. The howling from the LSE lecture hall wasn't outrage over climate change - everyone in the building already appreciated those facts. What became increasingly clear as Hansen spoke was that there is no way to make anyone in power do anything about them.
Being informed is not enough. In April, Hansen retired from his position as director of NASA's Institute of Space Studies in order to be able to sue the federal government (government employees are not allowed to sue their employer) over their lack of action on climate change. The federal government's defence is likely to be, "well, it was all so dull, James."
By Hansen's own admission, the whole subject is "too technical for the public". He has tried to soften the message by framing the issue in terms of the world that we are bequeathing to his descendants. In his book Storms of my Grandchildren, Hansen allowed himself "one graph per chapter" he said last night. It was still too much: the book was dismissed as dry. He is currently forcing his message downwards in complexity by working on another book that is composed of a series of letters to his first grandchild, called Sophie's Planet. He's not confident it will make any difference at all. An audience member asked how he would reach the people who mattered: the ones who didn't fancy coming to hear him speak. "I don't really have a good answer to that," he said.
It would be interesting to know what Hadfield's answer would be - if he were allowed to speak. Hansen was in Europe to give testimony to the European Parliament about the folly of using oil from the Canadian tar sands. This is not something a Canadian scientist can do: if they receive government money, they are not allowed to talk about environmental issues without government permission, which is rarely forthcoming. Coverage of government-funded climate change research has dropped by 80 per cent in Canadian media because reporters can't access the researchers.
By now, however, Hadfield surely has the global currency to take off the gag without fear of reprisals from the Harper government. Perhaps he could even write the protest song that Hansen so desperately needs. At the end of the 1960s, the Apollo astronauts' experience and photography of Earth from space kick-started the modern environmental movement: their photographs made us fall in love with Earth. Hadfield has successfully repeated the trick for the age of social media – now he should use his power for good. If he were to join forces with Hansen, it's conceivable that two farm boys might just save the world.