The science

Burning fossil fuels (coal, oil, natural gas) releases carbon dioxide into the atmosphere. Other human activities (deforestation, agriculture, industrial processes) also release greenhouse gases including methane and nitrous oxide. These gases trap heat in the atmosphere, warming the planet. The atmospheric concentration of carbon dioxide has risen from about 280 parts per million before the Industrial Revolution to over 420 parts per million today. The global average temperature has risen approximately 1.2°C above pre-industrial levels. The Intergovernmental Panel on Climate Change (IPCC), established in 1988 by the United Nations, has documented these changes through reports drawing on thousands of scientific studies.