We all know that human activity has increased the CO₂ content of the atmosphere since we started burning fossil fuels, but what’s less well known is that vapour – also a heat-trapping gas – from the warming waters of the melting Arctic is building energy into the atmosphere to drive storms.

Similarly, as the soils of the Arctic thaw, the huge depths of organic matter in the tundra is releasing methane as well as CO₂ into the atmosphere, warming the planet even more.

What can we do? George is very clear. Eliminate fossil fuel consumption, refreeze the arctic, shift to renewable energies – and stop deforestation immediately. The role of photosynthesis is so key that in the summer, for example, it pulls the CO₂ concentration in the atmosphere down by several parts per million.