COULD vegetation help to offset global warming? Not if grazing animals such as caribou and musk oxen are allowed to do their worst.
As global temperatures rise, the shrubby vegetation at high latitudes should grow more strongly, allowing it to act as a green lung to soak up carbon dioxide. To test the effect of grazing on these growth rates, Eric Post from Penn State University in University Park, Pennsylvania, placed 25 open-topped glass cones, each one 30 centimetres high, in 15 square kilometres of shrubland in West Greenland.
The glass sides act like a greenhouse, trapping warm air inside,…
