evidence: Geological records show that there have been a number of large variations in the Earth’s climate. These have been caused by many natural factors, including changes in the sun, emissions from volcanoes, variations in Earth’s orbit and levels of carbon dioxide (CO2). Global climate change has typically occurred very slowly, over thousands or millions of years. However, research shows that the current climate is changing more rapidly than shown in geological records. [...] Each of these factors contributes to changes in the Earth’s climate, but the way they interact with each other makes it more complicated. A change in any one of these can lead to additional and enhanced or reduced changes in the others.