When buying a new fridge, freezer or washing machine, ask about energy efficiency and choose the most efficient. Fit aluminium foil to the walls behind radiators which are set on outside walls. This will reflect the heat back into the room. If possible, have a shower instead of bath as this uses less energy and water. When buying a new car, choose a small, energy efficient one.
Caribou are migratory grazers which travel huge distances over the tundra in search of food.
In the short arctic summer, they gather in large herds of tens of thousands in their calving grounds in northern areas of North America. Here, they must make the most of the small tundra shrubs that provide them with enough food to give birth and to rear their young. The average temperatures in western areas of Canada and Alaska have been increasing at a rate of at least 0.5 degrees centigrade per decade over the past 30 years, a rate of between 3 and 5 times faster than the rest of the world. Griffith's research, using data from polar orbiting satellites, shows how this warming has increased the amount of forage material available to caribou in their calving grounds. He focused on one particular herd, The Porcupine herd, so called because the animals calve near to the Porcupine river.