George Monbiot writes:

I don’t expect much joy in writing about climate breakdown. On one side, there is grief and fear; on the other side, machines. I became an environmentalist because I love the living world, but I spend much of my life thinking about electricity, industrial processes and civil engineering. Technological change is essential, but to a natural historian it often feels cold and distancing. Today, however, I can write about something that thrills me: the most exciting field of research I have covered in years.

Most climate scientists agree that it is now too late to prevent 1.5C or more of global heating only by cutting our production of greenhouse gases. Even if we reduced our emissions to zero tomorrow, we would probably overshoot this crucial temperature limit. To prevent a full-spectrum catastrophe, we need not only to decarbonise our economy in the shortest possible time, but also to draw down carbon dioxide that has already been released.

But how? The best-known proposal is called bio-energy with carbon capture and storage (BECCS). This means growing wood or straw in plantations, burning it in power stations to produce electricity, capturing the carbon dioxide from the exhaust gases and burying it in geological formations. Yet, if deployed at scale, it is likely to trigger either an ecological or a humanitarian disaster.

One BECCS proposal, favoured by certain governments, would cover an area three times the size of India with plantations. This involves converting agricultural land, in which case BECCS would cause mass starvation, or converting wild land, in which case almost lifeless plantations would replace 50% of the world’s remaining natural forests. Even so, it might not be effective, as any carbon savings would be counteracted by the use of nitrogen fertiliser and the release of greenhouse gases from the soil as it’s churned up for planting. BECCS can lead only to catastrophe, and should be immediately abandoned.

Another option is direct air capture: extracting carbon dioxide with machines. Aside from the expense, which is likely to be massive, the amount of steel and concrete required to build these machines could help to push the world beyond certain climate tipping points before the positive effects are felt.

None of this is necessary, however, because there is a much better and cheaper way of drawing carbon from the air. [Continue reading…]