Climate change

The weather in Exeter can vary day by day and even hour by hour. The climate can be thought of as the average weather over a period of years, and the climate in Exeter is ‘temperate’ or middling – not as hot or cold or dry or wet as other parts of the world.

The sun is the main influence on the climate, interacting with the atmosphere, land, plants, oceans and ice sheets. We need some gases in the air, such as carbon dioxide and methane, to trap radiation from the sun and make the Earth warm enough for life. This is known as the Greenhouse Effect.

Greenhouse gases occur naturally. But over the last century, humans have burnt lots of coal, oil and gas, cut down lots of forest, and changed farming practices. So the quantity of greenhouse gases in the atmosphere has increased. Carbon dioxide concentrations have increased by 40% since 1750, which this can’t be explained by natural processes alone.

In turn, these higher concentrations are causing the climate to warm. The average temperature across the world has risen by 0.7°C or 1.3°F. That doesn’t seem like much, but it is causing changes in weather patterns such as droughts and fiercer storms. It is also causing the ice caps to melt, which has the effect of accelerating the warming.

Many people living in developing countries where the climate is less temperate are already struggling with the impacts of climate change. In the south west, half of the main rail lines are at risk of flooding due to extreme rainfall events.

Exeter is home to two world-class climate research centres at the Met Office and the University. They and other scientists are advising the government on how human activity is changing the climate, and how we can avoid dangerous climate change.

The scientists recommend that the average temperature increase has to be kept below 2°C or 3.6°F, and to do that we need to dramatically reduce our emissions of greenhouse gases. That is why governments are meeting in Paris in December 2015 to try and come to an agreement on who will commit to what reductions.

We only have one planet, and we need to look after it and make sure our children and grandchildren can live on it. Exeter is quite small compared with the rest of the Earth, but that doesn’t mean we can’t do something.