Human activity is not solely responsible for climate change. It can occur due to natural causes as well. Large volumes of sulphur dioxide, ash, water vapor and dust escape into the atmosphere when a volcano erupts. Volcanoes also produce aerosols which reflect solar energy back into space. This cools the atmosphere. However, although volcanoes produce CO2 and greenhouse gases it is minor when compared to what we humans emit into the atmosphere. Changes in the Earth’s orbit and changes to the ocean’s currents are also natural causes that cause climate change.