- This is part two of a two-part post. Read part one here.
On the wall of Wally Broecker’s building at the Lamont-Doherty Earth Observatory hangs a 16-foot long terry-cloth snake, blue with pink spots, that he calls the ‘climate beast’. Left in his office as a surprise by his workmates, its name refers to one of Wally’s most powerful quotes about the climate: “If you’re living with an angry beast, you shouldn’t poke it with a sharp stick.”
Today, the sharp stick is the CO2 we’re emitting by burning fossil fuels, which Wally was warning about by 1975. By that time he had also helped confirm that throughout history, changes in Earth’s orbit have given the climate beast regular kicks, triggering rapid exits from ice ages. He became obsessed with the idea that climate had changed abruptly in the past, and the idea we could provoke the ‘angry beast’ into doing it again.
Among the many samples that Wally was carbon dating, from the late 1950s onwards he was getting treasure from the oceans. Pouring sulphuric acid into seawater, he could convert dissolved carbonate back into CO2 gas that he could then carbon date. And though nuclear weapon tests had previously messed with Wally’s results, they actually turned out to help improved our knowledge of the oceans. The H-bomb tests produced more of the radioactive carbon-14 his technique counts, and as that spike moved through the oceans, Wally could track how fast they absorbed that CO2.
In the 1970s, as Wally and a large team of other scientists sailed on RV Melville and RV Knorr tracking such chemicals across the planet’s oceans, a debate raged. Was cutting down forests releasing more CO2 than burning fossil fuels? Dave Keeling’s measurements showed the amount of CO2 being added to the air was about half the amount produced by fossil fuels. But plants and the oceans could be taking up huge amounts, scientists argued. Thanks to the H-bomb carbon, Wally’s team found the CO2 going into the oceans was just 1/3 of what fossil fuels had emitted. Faster-growing plants therefore seemed to be balancing out the impact of deforestation, and taking up the remaining 1/6 portion of the fossil fuel emissions. Read the rest of this entry »