Past our peak: plants and a burgeoning problem with CO2

The growing season has lengthened across the northern hemisphere, helping keep a lid on global warming - but for how much longer?In recent decades warmer temperatures have led to shorter winters, and in the UK the plant growing season is now a full month longer than it was in 1990. The same is true across much of the northern hemisphere, and this extra plant growth has helped to mop up atmospheric carbon dioxide and keep a lid on global warming. But no longer.Related: Let’s make Britain wi