In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth’s climate system. Climate change in a broader sense also includes previous long-term changes to Earth’s climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels.[1] Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane.[2] Greenhouse gases absorb some of the heat that the Earth radiates after it warms from sunlight. Larger amounts of these gases trap more heat in Earth’s lower atmosphere, causing global warming.
Due to climate change, deserts are expanding, while heat waves and wildfires are becoming more common. Increased warming in the Arctic has contributed to melting permafrost, glacial retreat and sea ice loss.[3] Higher temperatures are also causing more intense storms, droughts, and other weather extremes.[4] Rapid environmental change in mountains, coral reefs, and the Arctic is forcing many species to relocate or become extinct.[5] Even if efforts to minimise future warming are successful, some effects will continue for centuries. These include ocean heating, ocean acidification and sea level rise.[6]
Climate change threatens people with increased flooding, extreme heat, increased food and water scarcity, more disease, and economic loss. Human migration and conflict can also be a result.[7][8]
References
- Allen, M. R.; Dube, O. P.; Solecki, W.; Aragón-DLynas, Mark; Houlton, Benjamin Z.; Perry, Simon (2021) Greater than 99% consensus on human caused climate change in the peer-reviewed scientific literature Environmental Research Letters
- Ritchie, Hannah (2020) Sector by sector: where do global greenhouse gas emissions come from? Our World in Data
- IPCC SRCCL (2019) IPCC Special Report on Climate Change, Desertification, Land Degradation, Sustainable Land Management, Food Security, and Greenhouse gas fluxes in Terrestrial Ecosystems IPCC Climate Change and Land p.7, p.16, p.45
- Seneviratne, Sonia I.; Zhang, Xuebin; Adnan, M.; Badi, W.; et al. (2021) Chapter 11: Weather and climate extreme events in a changing climate IPCC AR6 WG1 Ch11
- EPA (2017) Climate Impacts on Ecosystems
- Allen, M. R.; Dube, O. P.; Solecki, W.; Aragón-Durand, F.; et al. (2018) SR15 Chapter 1 IPCC
- Cattaneo et al. (2019) Human Migration in the Era of Climate Change Review of Environmental Economics and Policy
- Pörtner H.O. et al. (2022) Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change IPCC AR6