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.