Earth’s atmosphere is made up of oxygen, a large amount of nitrogen and a small percentage of greenhouse gases, such as carbon dioxide and methane. Greenhouse gases act like insulation around the Earth, trapping warmth from the sun and making life on Earth possible - without them, too much heat would escape and the surface of the planet would freeze.
However, increasing the concentration of greenhouse gases in the atmosphere causes the Earth to heat up, driving changes to our climate including more extreme weather events such as floods, storms, cyclones and droughts. It also leads to sea level rise by melting land-based ice and thermal expansion as seas get warmer.
While Earth’s climate has always been changeable, there is evidence that human activity (such as industry, agriculture and transportation) is increasing the level of greenhouse gases in our atmosphere and causing warming at an unprecedented rate.
For more on information on climate change visit: www.mfe.govt.nz/climate-change