International Climate Challenge

The term ‘climate change’ refers to the long-term and widespread change in the Earth’s weather patterns brought about by humanity’s emissions of carbon dioxide (CO2) and other greenhouse gases such as methane and nitrous oxide.

The Earth’s climate has always undergone change through natural processes, but the climate change observed today is 100 times greater than anything that has occurred before and is, without doubt, man made.

The most simple and commonly used indicator of climate change is the increase in global average temperature over time – hence climate change is often referred to as global warming. However, not all regions are experiencing simply warmer weather – climate change is bringing more rainfall or drought to some, and more storms to others.

The global average temperature has increased by 0.74ºC over the last 100 years and scientists predict the Earth’s average temperature is likely to rise between 1.1 and 6.4°C above 1990 levels by the end of this century (see below), depending on our emissions. This will result in a further rise in global sea levels of between 20 and 60cm by the end of this century, continued melting of ice caps, glaciers and sea ice, changes in rainfall patterns and intensification of tropical cyclones.

How do we know climate change exists?

We know that climate change exists because of detailed, long-term measurements of climate variables that have been recorded by a global network of measurement devices. These devices, such as the ocean floats illustrated below, measure variables as diverse as snow cover over land and stratospheric temperatures. Detectors are located in many environments, from satellite networks in space to thermometers underground.

Resources

If you want to know more go to the Links page within Resources for useful websites and other material.