There has been debate over the cause of rising global temperatures. Some argued it was a natural fluctuation, whilst others that it was caused by human activity. This debate is now over.
In February 2007, an international panel of experts (the Inter-Governmental Panel on Climate Change) concluded:
- Global warming is occurring.
- Increase in global temperature is a result of human activities.
- Given current trends, temperature extremes, heat waves, and heavy rains will continue to escalate in frequency. The earth’s temperature and seas will continue to rise into the next millennium.
These climate change effects are due to an increase in greenhouse gases in the atmosphere. The main gases are carbon dioxide, methane, nitrous oxide and fluorocarbons, principally from the burning of fossil fuels, forest destruction and agriculture (rice field cultivation and the keeping of livestock). Water vapour in the atmosphere also plays a role.
The scientific community often talk about global warming potential. This relates to the warming effect of a greenhouse gas in relation to the measured effect for carbon dioxide.
This web site, and most other sources of information on global warming, looks only at carbon dioxide. It is the major greenhouse gas produced by humans, which is having the single greatest effect on climate change.
The graph below shows the link between increasing levels of carbon dioxide in the atmosphere and global temperature change.