SafekipediaClimate change
Adapted from Wikipedia · Adventurer experience
Earth's average temperature has gone up by almost 1.5 °C since the Industrial Revolution. This rise is mostly because people burn fuels like coal, oil, and natural gas. Burning these fuels lets out gases that trap heat, which is called global warming. This is changing our planet's climate system.
Climate change affects the world in many ways. Deserts are growing, heat waves are happening more often, wildfires are stronger, glaciers are melting, sea ice is shrinking, and sea levels are rising. Animals are also affected, and some may have to move to new places or could disappear. Even if we work to slow warming, some changes will stay for a very long time, like changes in the oceans and sea level rise.
People everywhere face new dangers because of climate change, such as floods, very hot weather, and not enough food or water. It can also cause health problems and money losses. Sadly, poorer communities that do the least to cause these changes are often the most affected. The World Health Organization says climate change is one of the biggest threats to global health this century.
Many countries have agreed to the Paris Agreement to try to keep warming below 2 °C. To fight climate change, we can use cleaner energy like wind, solar, hydro, and nuclear power. Taking care of forests and using farming ways that keep carbon in the soil are also important ways to help reduce these heat-trapping gases.
Terminology
Before the 1980s, scientists were not sure if greenhouse gases or air pollution affected Earth's temperature more. They used the term inadvertent climate modification to describe human effects on the climate. Later, the terms global warming and climate change became common. Global warming means the rise in Earth's average temperature. Climate change includes this warming and its effects on weather patterns like precipitation.
Today, climate change is the most used term. Some people also use words like climate crisis or climate emergency to show how serious the situation is.
Global temperature rise
Further information: Global surface temperature
Main articles: Climate variability and change; Temperature record of the last 2,000 years; and Paleoclimatology
Earth's climate has changed a lot over millions of years. Long ago, there were times when it was very cold, like during ice ages, and times when it was warmer.
Since around 1850, people have been burning fuels that release gases into the atmosphere. These gases trap heat and make the Earth warmer. Since 1970, we have seen the Earth's temperature go up. This warming is causing changes like melting glaciers and heavier rains. Some places, like the Arctic, are warming faster than others. Scientists think temperatures will keep rising, depending on how we change our habits in the future.
Causes of recent global temperature rise
Main article: Causes of climate change
The Earth's climate changes naturally over time, but the warming we see today is mostly because of things people do. One big reason is the increase of greenhouse gases in the air. These gases, like carbon dioxide (CO2), trap heat from the sun and keep it close to Earth, making our planet warmer. Since the Industrial Revolution, burning fossil fuels such as coal, oil, and natural gas has put a lot of these gases into the air.
Greenhouse gases let sunlight reach Earth, but they trap the heat that Earth sends back into space. This is called the greenhouse effect. While some gases like water vapor change with temperature, others like CO2 are added to the air by human actions. Since 1750, levels of CO2 have gone up a lot, and methane, another greenhouse gas, has also gone up. These increases come mainly from burning fossil fuels, cutting down forests, and farming. These gases stay in the air for a long time, keeping the planet warmer.
Modelling
A climate model is a tool that helps us learn about Earth’s climate. It studies natural changes, like shifts in Earth’s path around the Sun or volcanic eruptions, and how they change the weather. Scientists use these models to guess how much Earth’s temperature will rise in the future based on things we do, like burning fossil fuels.
These models are tested to see if they can show the climate we already know. Sometimes, older models did not predict things like shrinking Arctic ice very well, but newer models are improving. Some models also look at how human choices, like how much energy we use, will change the climate in the future. These models help us understand what might happen based on the choices we make.
Impacts
Main article: Effects of climate change
The environment feels the effects of climate change in many ways. It changes oceans, ice, and weather. Since the 1950s, we have seen more droughts, heat waves, and big storms. Sea levels are going up because ice is melting and oceans are warming. This will keep happening in the future.
Arctic ice is getting smaller, and oceans are changing as they take in carbon dioxide from the air.
Climate change also changes nature and animals. Many plants and animals are moving to cooler places, and some are having a hard time living. In the oceans, creatures like corals and shellfish are finding it tough to build their homes. People are affected too. Extreme heat can make us sick, and changes in weather can affect our food and water. Some people may need to leave their homes if they become too hard to live in.
Ecological collapse. Coral bleaching from thermal stress has damaged the Great Barrier Reef and threatens coral reefs worldwide. Extreme weather. Drought and high temperatures worsened the 2020 bushfires in Australia. Habitat destruction. Many arctic animals rely on sea ice, which has been disappearing in a warming Arctic. Pest propagation. Mild winters allow more pine beetles to survive to kill large swaths of forest. |
Environmental migration. Sparser rainfall leads to desertification that harms agriculture and can displace populations. Shown: Telly, Mali (2008). Agricultural changes. Droughts, rising temperatures, and extreme weather negatively impact agriculture. Shown: Texas, US (2013). Tidal flooding. Sea-level rise increases flooding in low-lying coastal regions. Shown: Venice, Italy (2004). Storm intensification. Bangladesh after Cyclone Sidr (2007) is an example of catastrophic flooding from increased rainfall. Heat wave intensification. Events like the 2022 Southern Cone heat wave are becoming more common. |
Reducing and recapturing emissions
Climate change can be slowed by using less pollution and finding ways to take carbon dioxide out of the air. To stop the Earth from getting too warm, the world needs to reach “net-zero” emissions by 2070. This means big changes in how we use energy, where we live, and how we travel.
Renewable energy sources like solar and wind power are very important. Many countries are working to use less coal and oil. By 2050, most electricity could come from clean energy sources. We can also use less energy by making buildings and machines more efficient. Farming and industry can help too by using methods that create less pollution and by protecting forests, which naturally absorb carbon dioxide.
Other ideas, like taking carbon out of the air directly, are being studied but have risks. For example, some scientists suggest reflecting a tiny bit of sunlight away from Earth to cool it down, but this idea has risks and isn’t a replacement for cutting emissions. The best path forward is to use clean energy and protect natural areas that help keep our planet healthy.
Adaptation
Adaptation is how people and nature change to deal with climate change. This can mean moving away from places that might flood, building walls to keep water out, and finding new ways to grow crops.
Not all places can adapt easily. Some countries, especially those with fewer resources, find it more difficult.
Nature also changes with climate. Animals and plants can move to places with better weather. Humans can help by protecting nature and making it easier for species to move. These actions help nature and keep people safe from problems like flooding and very hot weather.
Policies and politics
See also: Politics of climate change and Climate change mitigation § Policies
Countries that are most vulnerable to climate change have usually added little to global emissions. This brings up questions about fairness. Working on climate change helps reach the UN's Sustainable Development Goals, such as ending poverty and reducing inequality. Sustainable Development Goal 13 calls for quick action on climate change.
The geopolitics of climate change is complex. It is sometimes called a free-rider problem, where all countries gain from others cutting emissions, but might lose by moving to a low-carbon economy themselves. However, ending fossil fuel subsidies can cut emissions and save lives by lowering air pollution. The money saved could help a transition to clean energy.
Policy options
Further information: Climate policy
Many policies aim to cut emissions. Carbon pricing covers about 20% of global emissions. This includes carbon taxes and emissions trading systems. Ending fossil fuel subsidies could cut global emissions by 28%. The money saved could fund clean energy. Other ways include setting rules for vehicles and industries. Some countries require more renewable energy in power production.
Climate justice
Policy through climate justice tries to address inequality. Richer nations, which have caused most emissions, should help poorer countries adapt. For example, the richest 10% of people caused 50% of emissions in 2023, while the poorest 50% caused only 8%.
International climate agreements
Further information: United Nations Framework Convention on Climate Change
Almost all countries are part of the 1994 United Nations Framework Convention on Climate Change (UNFCCC), which aims to stop harmful human effects on the climate. The 1997 Kyoto Protocol set emission limits for developed countries. The 2015 Paris Agreement aims to keep warming below 2.0 °C, with a goal of 1.5 °C. Countries must set stronger goals regularly. The 1987 Montreal Protocol helped by banning gases that harm the ozone layer and also warm the climate.
National responses
In 2019, the United Kingdom parliament declared a climate emergency, and others followed. The European Commission aims for carbon neutrality by 2050, with all new cars in Europe to be zero-emission vehicles from 2035. Countries like South Korea, Japan, and China aim for carbon neutrality by 2050 or 2060. However, many nations still plan to use coal. Current plans suggest only small emission cuts compared to what is needed to limit warming.
Society and culture
Public debate about climate change has been affected by denial and misinformation. This started in the United States and spread to other countries. Fossil fuel companies and some groups try to create doubt about scientific findings. This can make people unsure about climate change.
Climate change became a big topic worldwide in the late 1980s. Movies and documentaries helped many people learn about it. Different groups of people think about climate change in various ways. For example, younger people and those with more education often worry more about it. Over time, more people have become concerned, and many say that strong action is needed.
People have held many protests to call for action on climate change. These include students skipping school on Fridays to demand better policies, and groups disrupting traffic to get attention. Lawsuits are also being used to push governments and companies to take stronger action on reducing harmful emissions. In 2025, an international court said that countries must work to stop climate change.
History
For broader coverage of this topic, see History of climate change science.
In the 1800s, scientists like Alexander von Humboldt and Joseph Fourier began to learn how Earth's climate works. They found that gases in the air, like water vapor and carbon dioxide (CO2), trap heat and warm the planet. This is called the greenhouse effect.
Later, scientists like Svante Arrhenius and Guy Stewart Callendar showed that human actions, such as burning fossil fuels, raise CO2 levels and warm the Earth. By the late 20th century, most scientists agreed that humans were changing the climate. Today, scientists study how these changes affect weather and the world around us.
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