Cause for concern
The climate has always been changing, from ice ages to warm periods. So why is there such concern over the latest changes in our global climate?
Nature alone is unlikely to explain recent increases in temperature, according to the IPCC (Intergovernmental Panel on Climate Change)
Instead they think it is very likely the changes are due to increases in human-related greenhouse gas concentrations.
As such it is likely to be faster and more extreme than the changes of the past, leaving life on earth less time to adjust.
To complicate things further, there are a great many more people on the earth today, enjoying a higher quality of life than there have been in previous climate changes.
Global greenhouse gas emissions caused by people shot up by 70% between 1970 and 2004.
Carbon dioxide (CO2) is the most important human-related greenhouse gas. The atmospheric concentrations of CO2, amongst other gases, in 2005 were far higher than the natural range over the last 650,000 years!
Global increases in CO2 concentrations are due mainly to using fossil fuels and changes in land use (including agriculture and deforestation).
The Royal Society is the independent scientific academy of the UK and the Commonwealth dedicated to promoting excellence in science. Look at what they have to say: