Causes of climate change
Natural greenhouse gases, include atmospheric water vapour and carbon dioxide. These gases act as an insular blanket by retaining heat from the sun which keeps the earth warm. Without these gases, the earth would be much colder than it is.
However, increased concentrations of these gases, especially carbon dioxide can cause global warming.
There is now significant scientific evidence that points to human activities, such as burning of fossil fuels, as being mainly responsible for the current increased levels of greenhouse gases in the atmosphere.
The IPPC's reports on climate change highlight how human activities have affected global temperature in the past 50 years. A majority of scientists now accept these findings.
Here are some key human activities that contribute to climate change:
Burning of Fossil (Mineral) Fuels
This tops the list of human activities that contribute to increased levels of greenhouse gases in the atmosphere. Mineral fuels such as petroleum, natural gas and coal constitute major energy sources for industries, transport and heating in our homes. It is estimated that burning of fuels (world wide) produces around 21.3 billion tons (21.3 gigatons) of carbon dioxide every year. Part of the carbon dioxide released from fossil fuels is absorbed naturally but the remainder gets caught up in the atmosphere and contributes to global greenhouse gas warming.
Poor use of land
Poor land use is directly linked to climate change partly because when soil and vegetation is lost, more carbon dioxide is released into atmosphere which results in further global warming.
Examples of poor use of land include urban sprawl (uncontrolled urban development), destruction of forests and excessive farming.
If waste is not properly treated or disposed of, it produces greenhouse gas emissions such as methane and carbon dioxide. These gases contribute to global warming. Land fill disposal of waste is a key source of man-made methane emissions in the atmosphere.This is why it is so important to reduce waste or recycle it.
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) previously used as coolants in fridges, freezers and air conditioners are a major source of ozone layer depletion. However regulatory measures have been taken to phase out the use of such coolants in cooling appliances and aerosol sprays. They have now been replaced with substitutes hydroflurocarbons (HFCs). The use of HFCs is restricted in the UK as they also contribute to the green house gas effect.