Climate change is a long-term trend in the average temperature of the Earth’s surface. It is caused by human activity, mostly the burning of fossil fuels such as coal and oil, but natural causes can also affect our climate.
The Sun supplies most of the energy that drives our planet’s weather patterns. Some of the incoming solar radiation is reflected directly back into space; much of it is absorbed by the atmosphere and is then released as heat (longwave or infrared radiation). The balance between incoming and outgoing energy can change quickly and dramatically due to small changes in output from the Sun or internal climate variability.
Fossil fuel use is the largest source of greenhouse gases, which absorb and release heat into the atmosphere. These emissions come from a variety of sources, including power plants, cars, buildings and factories.
Carbon dioxide is the main greenhouse gas, but other gases are also important, including methane, which is produced by decaying organic matter such as garbage and animal waste. The amount of carbon dioxide in the atmosphere is increasing due to the burning of fossil fuels.
Temperatures across the globe are rising faster than at any time in the past 50 years, and are likely to continue to rise as the greenhouse effect is supercharged by human activities.
Global warming has many consequences, affecting people in different ways. It can lead to extreme temperatures, flooding, drought, thawing of permafrost and changes in water resources. It can reduce crop yields and result in loss of forests, sea ice and wildlife.
The impacts of climate change are expected to become increasingly disruptive throughout this century and beyond. They are evident in many parts of the world and in many sectors that are important to society, such as human health, agriculture and food security, water supply, transportation, energy, and ecosystems.
Extreme heat and heavy precipitation events are occurring more frequently in many regions around the world. These events can cause major damage, particularly in urban areas where people are vulnerable to the impacts of climate change.
In addition, climate change is likely to affect the geographical ranges of plant and animal species, with some moving to higher latitudes or elevations. If these animals and plants cannot adapt to the changes, they may be unable to survive or reproduce and eventually become extinct.
These impacts will be felt by every living being on our planet, although some groups are more susceptible to them than others. In fact, people living in low-income and disadvantaged countries and communities are at the greatest risk of suffering from the negative effects of climate change.
Everyone can make a difference in helping to solve the climate crisis. By limiting greenhouse gas emissions, we can help to avoid the worst impacts of climate change.