, many strategies require relatively small actions from large numbers of people. It is about millions of us installing heat pumps, switching to electric vehicles,and so on. But given the sheer scale of the challenge, there are those who insist we need to think bigger and bolder too.
They are talking about audacious infrastructure projects that would cost billions and carry high risks, but could, if they work out, have a truly transformative impact on our stuttering efforts to get carbon emissions down to zero – and even mitigate the worst effects of current warming. They include plans to build a huge solar power station in space, regreen vast swathes of desert and prop up melting glaciers to hold back city-threatening sea level rise.