Global warming is the name given to the observed increase in the average temperature of the Earth’s atmosphere and oceans. The main component of global warming is an increased emission of greenhouse gases. These gases form a “blanket” around Earth that trap energy from the sun. This trapped energy makes the Earth’s atmosphere warm, and disturbs the Earth’s climate. It is not just humans who are responsible for increased greenhouse gas emissions – natural sources also play a role. However, human activity is thought to be the main cause of global warming since the Industrial Revolution (about 1750). Burning fossil fuels such as coal and oil releases these gases into the air. Deforestation also contributes to global warming by reducing trees that would otherwise absorb some of these gases.
Over time, increasing levels of greenhouse gases in Earth’s atmosphere are expected to cause ongoing increases in average global temperatures and associated impacts, including more frequent and more intense extreme weather events; rising sea level; melting glaciers and Arctic sea ice; shifts in plant and animal ranges; coral reef bleaching; ocean acidification; and increased drought conditions. Global action to reduce emissions will help limit future temperature increase, but additional impacts from past emissions will continue even if we take immediate steps to reduce our output of greenhouse gases.
What can we do about it? We must first stop emitting so many greenhouse gases! Second, we can work on removing some of the excess greenhouse gases that are already in our atmosphere using “carbon capture” technology (which takes carbon dioxide out of power plant smokestacks before it gets into our atmosphere) or planting trees (which absorb carbon dioxide). Third, we can adapt to changes that are already happening or will happen in response to climate change – for example, by building seawalls to protect against rising seas or developing drought-resistant crops. Finally, we must research new technologies and approaches that could help us further reduce our emissions or remove atmospheric greenhouse gases on a large scale over time – for example, geoengineering projects aimed at reflecting sunlight away from Earth or directly removing carbon dioxide from our atmosphere.