Archive for the ‘Climate change’ Category

Climate change

Tuesday, May 19th, 2009

Global temperatures have risen by more than 0.7 degrees centigrade in the last 300 years, of which 0.5 degrees has occurred since 1900.

In fact five of the warmest years ever recorded were in the 1990s.

The Challenge

This changing climate poses a great environmental challenge for today’s world.

Very few scientists now doubt that such temperature rises are a result of human behaviour. In 2001 the Intergovernmental Panel on Climate Change (IPCC), set up in 1988 to assess information on climate change and its impact, declared that “most of the warming observed over the last 50 years is likely to be attributable to human activities.”

The Impact

The IPCC’s third assessment report predicts global temperatures will rise by between 1.4 and 5.8 degrees centigrade by 2100. These increasing temperatures are already having, and will continue to have, a huge impact on the world. We are experiencing changing weather patterns, rising sea levels and increased frequency and intensity of extreme weather events.

In the UK we will see hotter, drier summers and milder, wetter winters. Some areas of the world are suffering droughts whilst others are experiencing heavy rainfall. Higher temperatures have led to rising sea levels as the sea absorbs heat from the atmosphere and expands. Average sea levels have increased by between 10 and 20cms over the last 100 years, which in turn is increasing the risk of flooding. Scientists predict flooding will occur more often as a result of climate change, and in places never previously affected by floods.

These changes will have knock on effects on other aspects of life, such as health. Higher temperatures are likely to lead to an increase in heat related deaths, and skin cancer. Flooding may increase the risk of water-borne diseases.

Agriculture and wildlife are also likely to be effected; with changing climate leading to a change in what crops can be grown and what habitats can survive.

The Cause

The main human influence on the world’s climate has been caused by our emissions of greenhouse gases such as carbon dioxide, methane and nitrous oxide. The accumulation of these gases in the earth’s atmosphere has strengthened the greenhouse effect, where energy from the sun is trapped inside the atmosphere. The atmosphere is acting like the walls of a greenhouse, and the world is gradually heating it up. Currently more than 7 billion tonnes of carbon dioxide are emitted globally each year through fossil fuel use, a level that must be reduced if we are to curb future climate change.

Climate Change is largely, though not exclusively an energy issue.

The Future

Increased use of renewable energy will help reduce the emission of greenhouse gases which are a major contributor to climate change. UK Government policy is increasingly encouraging households and businesses to switch to greener sources of energy. Whilst our climate is already changing, reducing our contribution to the causes of climate change can slow this change and limit its future effects.