An Inconvenient Truth -- May 15, 2018

This is an incredible story. Many decades ago, I spent a summer north of the Arctic Circle, near Barrow, Alaska, studying the photosynthesis of grasses growing that far north. We assumed --one of many potential fudge factors -- that atmospheric CO2 would not change. Arctic grasses are much more efficient than Iowa corn using solar energy to convert CO2 to carbohydrate energy. We were studying whether it was possible to help Iowa corn increase its photosynthetic efficiency based on what we learned in Alaska. Something tells me that research came to a dead end.

Had we known that atmospheric CO2 would increase over the ensuing decades, our research would have been redundant, as the British say.

So, here it is, from the Brits:

Global greening is the name given to a gradual, but large, increase in green vegetation on the planet over the past three decades. The climate change lobby is keen to ensure that if you hear about it at all, you hear that it is a minor thing, dwarfed by the dangers of global warming. Actually, it could be the other way round: greening is a bigger effect than warming.

It is a story in which I have been both vilified and vindicated. Four years ago, I came across an online video of a lecture given by Ranga Myneni of Boston University in which he presented an ingenious analysis of data from satellites. This proved that much of the vegetated area of the planet was getting greener, and only a little bit was getting browner. In fact, overall in 30 years, the green vegetation on planet Earth had increased by a rather extraordinary 14 per cent. He said this was occurring in all vegetation types — from tropical rainforests to arctic tundra.

What was responsible for this ecological good news? He credited rising carbon dioxide concentrations in the atmosphere for half of the greening — rather than, say, the application of agricultural fertiliser, warmer temperatures or increased rainfall.

Carbon dioxide, along with water, is the raw material that plants use to make carbohydrates, with the help of sunlight. So it stands to reason that raising its concentration should help plants grow.