Human activities, mainly the burning of fossil fuels such as coal, oil and natural gas have released large quantities of gases into the atmosphere over the last century. These gases trap heat energy and are thus called greenhouse gases. There has been an increase in average global surface temperatures of 0.7 degrees Celsius since 1900 and the United Nations’ Intergovernmental Panel of Climate Change believes that most of this global warming has been caused by man made atmospheric emissions resulting in heatwaves, extreme rainfall and other significant climatic impacts (or climate change) in many regions, together with an increase in sea levels of 1.8mm per year since 1950 and the melting of ice sheets in the Arctic and the Antarctica.

Changes in climate may result in increased heat waves, more extreme winds, higher fire risk and more droughts and intense storms. Reductions in rainfall and higher evaporation rates might result in lower river and stream flow with downstream consequences for water storages.

Climate change will have both positive and negative impacts on agricultural productivity. For example higher levels of carbon dioxide in the atmosphere could increase plant growth and benefit beef cattle, but the protein content of plants is expected to be lower and very hot days or droughts could damage crops and cause heat stress in livestock. Higher temperatures will lead to inadequate winter chilling for some fruit trees, which may reduce fruit yield and quality, but will also reduce the risk of damaging winter frosts. New growing conditions could increasingly favour subtropical and tropical species. Heavy rains and winds are likely to cause greater crop damage and soil erosion.

Changes to the climate will also have significant effects in terms of natural environment, health and disease, energy use, and infrastructure. Climate change will effect the natural environment and could change the distribution of some plant and animal species. Warmer winters could reduce cold related illnesses, but warmer summers are likely to increase the risk of heat related health problems. Warmer temperatures may also contribute to the spread of some infectious diseases. Increased temperatures could significantly increase demands for domestic cooling but reduce winter heating costs. Increases in the intensity of peak rainfall events will increase the risks of flash flooding, placing strains on roads, bridges, and sewerage and drainage systems.