Climate change facts for kids

Climate change means big, lasting changes to Earth's weather patterns. It includes global warming, which is the ongoing rise in the planet's average temperature. These changes are mostly caused by human activities.

Since the Industrial Revolution, people have burned lots of fossil fuels like coal, oil, and natural gas. This releases greenhouse gases into the air. These gases trap heat, making the Earth warmer. Our atmosphere now has about 50% more carbon dioxide, the main warming gas, than it did before the Industrial Revolution.

Climate change is having a growing impact on the environment. We see more heatwaves and wildfires. The Arctic is warming very fast, causing permafrost to thaw and glaciers to melt. Higher temperatures also lead to more intense storms, droughts, and other extreme weather. Many plants and animals are struggling to adapt.

Climate change also affects people. It can cause more flooding, extreme heat, and make food and water harder to find. The World Health Organization says climate change is a huge threat to global health. We can reduce these risks by limiting warming and adapting to the changes.

Many impacts have been seen in the early 21st century. The year 2024 was the warmest on record since 1850, at +1.60 °C (2.88 °F). More warming will make these problems worse. Countries agreed in the 2015 Paris Agreement to keep warming "well under 2 °C". However, current plans suggest warming could still reach about 2.8 °C (5.0 °F) by 2100.

People worldwide support climate action. Most countries want to stop releasing carbon dioxide. We can do this by using clean energy like wind, solar, hydro, and nuclear power. We can also remove carbon from the air by planting more trees.

What is Climate Change?

Understanding the Terms: Global Warming and Climate Change

Before the 1980s, scientists weren't sure if warming from greenhouse gases was stronger than cooling from air pollution. They used terms like "inadvertent climate modification."

In the 1980s, "global warming" and "climate change" became common. Global warming means the increase in Earth's average surface temperature. Climate change includes global warming and all its wider effects on Earth's climate system, like changes in rainfall.

Sometimes, people use anthropogenic climate change to specifically mean climate change caused by humans. Scientists, politicians, and media sometimes use stronger terms like climate crisis or climate emergency to show how serious the situation is.

How Our Planet is Warming

Past Temperatures on Earth

Over millions of years, Earth's climate has naturally gone through ice ages and warmer times. About 125,000 years ago, it was warmer than before modern global warming. Sea levels were 5 to 10 meters higher then.

About 20,000 years ago, during the Last Glacial Maximum, it was 5–7 °C colder. Sea levels were over 125 metres (410 ft) lower. Earth's temperatures became stable about 11,700 years ago, which is when farming began.

Recent Warming Trends

Around 1850, we started keeping global temperature records using thermometers. From the 18th century until 1970, there wasn't much warming. This was because the warming from greenhouse gases was partly hidden by the cooling effect of sulfur dioxide pollution. Sulfur dioxide creates tiny particles that reflect sunlight.

After 1970, greenhouse gases increased a lot, and pollution controls reduced sulfur. This led to a clear increase in temperature. The changes we see now are unlike anything in the last few thousand years. Global surface temperatures are rising by about 0.2 °C every decade.

The decade from 2014–2023 was 1.19 °C warmer than the period 1850–1900. Not every year is warmer than the last. Natural changes can make some years hotter or colder. For example, 2024 was much warmer than the recent average, over +1.5 °C. This is why scientists look at long-term averages to see the real warming trend.

Other signs also show warming. The upper atmosphere is cooling because greenhouse gases trap heat closer to Earth. Snow cover and glaciers are shrinking. Oceans are evaporating more, leading to more moisture in the air and heavier rainfall. Plants are flowering earlier, and many animals are moving to cooler places.

Regional Differences in Warming

Different parts of the world warm at different speeds. This doesn't depend on where the greenhouse gases are released. The gases spread across the whole planet. Land areas have warmed almost twice as fast as the global average. This is because oceans can store a lot of heat and lose more heat through evaporation. Over 90% of the extra heat in Earth's climate system since 1970 has been stored in the ocean.

The Northern Hemisphere and the North Pole have warmed much faster than the South Pole. The Northern Hemisphere has more land, snow, and sea ice. When ice melts, dark ocean or land is exposed, which absorbs more heat. The Arctic is warming three to four times faster than the rest of the world.

Future Global Temperatures

The World Meteorological Organization estimated there was almost a 50% chance that the five-year average global temperature would exceed +1.5 °C between 2024 and 2028. The IPCC expects the 20-year average to go above +1.5 °C in the early 2030s.

The IPCC Sixth Assessment Report (2021) predicted that by 2100, global warming could reach 1.0–1.8 °C with very low emissions. With high emissions, it could be 3.3–5.7 °C warmer. This warming would continue past 2100.

To stay below 2.0 °C warming with a 50% chance, emissions after 2023 should not go over 900 gigatonnes of CO₂. This is about 16 years of current emissions.

Why is Earth Warming?

Earth's climate system has natural cycles that last for years or centuries. For example, El Niño events cause short-term warming, while La Niña events cause short-term cooling.

Scientists look for unique "fingerprints" to see what causes climate change. For instance, if the Sun were causing warming, the whole atmosphere would warm. But only the lower atmosphere is warming, which points to greenhouse gases.

Greenhouse Gases and Our Activities

Greenhouse gases let sunlight pass through to heat Earth's surface. But when Earth radiates that heat back, these gases absorb some of it. This traps heat near the surface, warming the planet.

Water vapour and clouds are the biggest natural greenhouse contributors. However, gases like CO₂, methane, and nitrous oxide are added by human activities. These are the main drivers of current warming.

Before the Industrial Revolution, natural greenhouse gases made Earth about 33 °C warmer than it would have been. Since then, human activities, mainly burning fossil fuels, have greatly increased these gases. By 2022, CO₂ and methane levels had risen by about 50% and 164% since 1750. These CO₂ levels are higher than they have been in 14 million years.

In 2019, human-caused greenhouse gas emissions were equal to 59 billion tonnes of CO₂. Most of this was CO₂ (75%), followed by methane (18%). CO₂ mainly comes from burning fossil fuels for transport, factories, heating, and electricity. Cutting down forests and industrial processes (like making cement or steel) also release CO₂.

Methane comes from livestock, rice farming, landfills, and coal mining or oil and gas extraction. Nitrous oxide mainly comes from fertilizers.

CO₂ stays in the atmosphere much longer than methane. Plants and oceans absorb some CO₂ each year. However, this CO₂ can return to the atmosphere when plants decay or burn. Oceans have absorbed 20-30% of emitted CO₂ in recent decades.

Changes to Land and Forests

About 26% of Earth's land is forests, and 34% is agricultural land. Deforestation (cutting down forests) is a major cause of global warming. When trees are destroyed, they release CO₂, and there are fewer trees to absorb carbon.

Between 2001 and 2018, much deforestation was for agricultural expansion (farms and livestock). Logging and wildfires also caused significant forest loss. Restoring forests helps them absorb more carbon.

Changes in land use also affect how much sunlight Earth reflects. For example, changing a dark forest to grassland makes the surface lighter, reflecting more sunlight. In warm areas, deforestation usually causes warming. Globally, land use changes have had a slight cooling effect so far, mainly by making surfaces more reflective.

Other Influences on Climate

Air Pollution and Clouds

Air pollution, made of tiny particles called aerosols, affects the climate. Aerosols can scatter and absorb sunlight. From 1961 to 1990, less sunlight reached Earth's surface, a phenomenon called global dimming. This was mainly due to sulfate aerosols from burning fossil fuels.

Since 1990, aerosols have decreased because of pollution controls. This means they no longer hide as much of the warming caused by greenhouse gases. Aerosols also affect clouds, making them more reflective and reducing warming.

However, black carbon (soot) that falls on snow or ice can increase warming. It makes the surface darker, absorbing more sunlight and speeding up melting. Reducing black carbon could help slow global warming.

Sun and Volcanoes

The Sun is Earth's main energy source. Changes in sunlight affect climate. However, since 1880, there has been no increase in the Sun's energy reaching Earth. If the Sun were causing warming, the upper atmosphere would also warm, but it has been cooling. This shows that greenhouse gases trapping heat are the cause.

Large volcanic eruptions can release gases and ash that block sunlight and cool Earth for a few years. But these effects are temporary. Volcanic CO₂ emissions are very small compared to human-caused emissions. So, volcanoes have had little impact on global temperature trends since the Industrial Revolution.

Climate Feedbacks

The climate system has "feedbacks" that can make changes bigger or smaller. Positive feedbacks make warming worse. For example, warmer air holds more water vapour, which is a powerful greenhouse gas, causing more warming.

Melting snow and sea ice is another positive feedback. Darker ocean or land absorbs more heat, speeding up warming in the Arctic. This extra warming also thaws permafrost, releasing methane and CO₂.

About half of human-caused CO₂ emissions have been absorbed by plants and oceans. However, if emissions keep rising, this absorption might slow down. Climate change can increase droughts and heatwaves, which hurt plant growth. Oceans also absorb less carbon as they become more acidic.

What are the Effects of Climate Change?

The environmental effects of climate change are widespread. They affect oceans, ice, and weather. Changes can happen slowly or quickly. Since the 1950s, droughts and heatwaves have become more frequent. Heavy rainfall during monsoons has increased in some areas. The intensity of hurricanes and typhoons is likely increasing.

Changes to Nature and Wildlife

Global sea level is rising because of thermal expansion (warmer water takes up more space) and melting glaciers. Sea level rise has sped up, reaching 4.8 cm per decade between 2014 and 2023. By 2100, sea levels could rise by 32–101 cm, depending on emissions.

Arctic sea ice has been shrinking and thinning for decades. Summers without ice are expected to be rare at 1.5 °C warming, but could happen every 3 to 10 years at 2 °C warming. More CO₂ in the air means more dissolves in the oceans, making them more acidic. Warmer water also holds less oxygen, leading to less oxygen in the ocean and expanding dead zones.

Big, Lasting Changes

More warming increases the risk of reaching 'tipping points'. These are thresholds where major impacts can no longer be avoided, even if temperatures later drop. For example, the Greenland ice sheet is already melting. If warming reaches 1.7 °C to 2.3 °C, it will continue to melt until it's gone, even if temperatures are later reduced.

While ice sheets melt over thousands of years, other tipping points could happen faster. The collapse of major ocean currents or damage to ecosystems like the Amazon rainforest and coral reefs could happen in decades.

Long-term effects on oceans include more ice melt, ocean warming, sea level rise, and ocean acidification. These effects will last for centuries or millennia.

Wildlife and Ecosystems

Many land and freshwater species are moving towards the poles or higher altitudes to find cooler conditions. For example, hundreds of North American birds have shifted northward by about 1.5 km/year over the last 55 years.

Higher CO₂ levels and longer growing seasons have made some parts of the world greener. However, heatwaves and drought have harmed ecosystems in other regions. Climate change is also causing deserts to expand. Overall, many species are expected to face extinction.

Oceans have warmed slower than land, but marine animals are also moving towards colder poles. Ocean heatwaves are more frequent, harming corals, kelp, and seabirds. Ocean acidification makes it hard for creatures like mussels and corals to build their shells. Bleached coral reefs are a big problem. Harmful algal blooms also reduce oxygen and disrupt food webs. Coastal ecosystems are especially at risk.

Climate change impacts on the environment

Ecological collapse. Coral bleaching from thermal stress damages coral reefs worldwide. Extreme weather. Drought and high temperatures worsened the 2020 bushfires in Australia. Arctic warming. Permafrost thaws and releases methane, a greenhouse gas. Habitat destruction. Many arctic animals rely on sea ice, which is disappearing. Pest propagation. Mild winters allow more pine beetles to survive and harm forests.

Impacts on People and Communities

Climate change affects people everywhere. Less developed areas face the greatest risks. Continued warming could have "severe, widespread and irreversible impacts" on people. These risks are not spread equally; disadvantaged people are often most affected.

Health and Food

The World Health Organization calls climate change one of the biggest threats to global health. Extreme weather events affect public health, food, and water security. Extreme temperatures lead to more illness and death. Climate change can also affect the spread of infectious diseases like dengue fever.

The World Economic Forum expects 14.5 million more deaths due to climate change by 2050. Currently, 30% of the global population lives in areas with extreme heat and humidity that cause more deaths. By 2100, this could be 50% to 75% of the world's population.

While total crop yields have increased, climate change has slowed this growth. Fisheries are also negatively affected. If emissions continue to rise, over 9 million climate-related deaths could occur annually by 2100.

Economy and Fairness

Climate change can cause severe economic damage. South-East Asia and sub-Saharan Africa are expected to be hit hard. Many people there rely on natural resources and farming. Heat stress can stop outdoor workers from doing their jobs. If warming reaches 4 °C, labor capacity in these regions could drop by 30-50%. The World Bank estimates that climate change could push over 120 million people into extreme poverty by 2030 without action.

Climate change makes existing inequalities worse. People with fewer resources struggle more to adapt and recover from climate shocks. Indigenous people, who depend on their land, face threats to their way of life.

Women often face greater challenges during climate shocks. Their work, especially in agriculture, tends to be harder during heat stress. Climate change also threatens the sports economy by disrupting seasons and damaging facilities.

People Moving Due to Climate

Low-lying islands and coastal areas are threatened by rising sea levels. This causes urban flooding and can permanently flood land. This could lead to people in island nations like the Maldives losing their homes. In some regions, heat and humidity may become too extreme for humans to live there.

These factors can cause people to move within or between countries. More people are expected to be displaced by sea level rise, extreme weather, and disputes over natural resources.

Climate change impacts on people

Environmental migration. Less rainfall leads to desertification that harms farming and can displace people. Shown: Telly, Mali (2008). Agricultural changes. Droughts, rising temperatures, and extreme weather harm farming. 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) shows catastrophic flooding from increased rainfall. Heat wave intensification. Events like the 2022 Southern Cone heat wave are becoming more common.

How Can We Help?

We can limit climate change by reducing greenhouse gas emissions and removing carbon dioxide from the atmosphere. To keep global warming below 2 °C, global emissions need to reach net-zero by 2070. This requires huge changes in how we get energy, use land, build cities, and travel.

The United Nations Environment Programme says countries need to triple their pledges under the Paris Agreement to limit warming to 2 °C. Current pledges suggest warming could still reach 2.8 °C by 2100. Limiting warming to 2 °C could bring more economic benefits than costs.

Most plans to limit warming involve a big increase in renewable energy and more energy efficiency. We also need changes in farming and forestry, like stopping deforestation and restoring natural areas.

Some other ideas, like Solar radiation modification (SRM), involve reflecting sunlight away from Earth. This could reduce warming but doesn't fix ocean acidification and has risks. It should only be a backup plan, not a replacement for reducing emissions.

Using Clean Energy

Renewable energy is key to fighting climate change. For decades, fossil fuels made up about 80% of the world's energy. Now, renewables (like wind, solar, hydro, and geothermal energy) are growing fast. Fossil fuel use is expected to start declining before 2030.

In 2023, renewables made up 86% of all new electricity generation. Solar panels and onshore wind are now among the cheapest ways to add new power. To become carbon-neutral by 2050, renewable energy needs to be the main source of electricity.

Clean electricity can power electric vehicles, heat buildings, and run factories. For shipping and flying, we need low-carbon fuels. There are challenges, like wind and solar not always producing energy. But battery storage and better power grids can help.

Using low-carbon energy also improves human health by reducing air pollution. Meeting climate goals could save millions of lives each year and improve energy security.

Saving Energy

Reducing how much energy we use is another big part of cutting emissions. If we need less energy, it's easier to switch to clean sources. It also helps manage the electricity grid and reduces the need for carbon-heavy infrastructure. We need to invest a lot more in energy efficiency.

Ways to save energy differ by sector. In transport, people can use buses, trains, or electric vehicles. Factories can improve heating systems and design products that use less energy. Buildings can be designed better and made more energy-efficient. Technologies like heat pumps also help buildings save energy.

Smart Farming and Industry

Farming and forestry have a big challenge: reduce emissions, protect forests, and feed a growing world. We can cut emissions by two-thirds by reducing food demand, increasing farm productivity, restoring forests, and using better farming methods.

A key way to reduce emissions is to shift towards plant-based diets. Producing less meat and dairy would cut about three-quarters of farm emissions. Livestock also use a lot of land, leading to deforestation.

Making steel and cement causes about 13% of industrial CO₂ emissions. These industries need new ways to produce materials with less CO₂. For industries that still produce CO₂, technology like carbon capture and storage (CCS) can capture and store most of the gas. This technology is expensive and currently removes only a small amount of emissions.

Removing Carbon Dioxide

We can boost natural ways to remove CO₂ from the air. Reforestation (replanting forests) and afforestation (planting new forests) are good ways. Farmers can also store carbon in soils by using cover crops and reducing tillage. Restoring forests and landscapes helps absorb greenhouse gases.

Restoring coastal wetlands and seagrass meadows also increases carbon uptake. However, carbon stored in soils and trees can be released later by land use changes or fires.

Using bioenergy with carbon capture and storage (BECCS) can remove CO₂ from the atmosphere. It's still uncertain how big a role these technologies will play in limiting warming.

Adapting to a Changing Climate

Adaptation means adjusting to current or expected climate changes. Without reducing emissions, adaptation alone cannot prevent "severe, widespread and irreversible" impacts. More extreme climate change requires more costly adaptation. The ability to adapt varies greatly, with developing countries often having less capacity. Many countries have adaptation plans, but they need more funding.

To adapt to sea level rise, communities can avoid risky areas, learn to live with more flooding, or build flood controls. If these fail, people may need to move. For farming, options include switching to sustainable diets, diversifying crops, and growing drought-resistant crops. Education and early warning systems can also help. Planting mangroves or other coastal plants can protect against storms.

Ecosystems also adapt, and humans can help. Connecting ecosystems allows species to move to better climates. Protecting and restoring natural areas helps ecosystems become stronger. Many actions that help ecosystems also help humans, like restoring natural fire regimes to reduce wildfires.

Sometimes, adaptation and reducing emissions work together. For example, increased food production helps both. But sometimes they conflict. More air conditioning helps people cope with heat but uses more energy.

Examples of adaptation methods

Mangrove planting and other habitat conservation can reduce coastal flooding. Seawalls protect against storm surge worsened by sea level rise. Green roofs provide cooling in cities. Selective breeding for drought-resistant crops.

Working Together: Policies and Agreements

Countries most affected by climate change are often those that have contributed the least to emissions. This raises questions about fairness. Limiting global warming helps achieve the UN's Sustainable Development Goals, like ending poverty.

Climate change is a complex global issue. Some policies, like ending fossil fuel subsidies, can reduce emissions and improve public health. Money saved could support the switch to clean energy. Other methods include setting standards for vehicle efficiency and promoting renewable energy.

Climate Justice

Climate justice policies aim to address human rights and social inequality. They suggest that those most responsible for climate change should pay for adaptation efforts. Wealthy nations, for example, could help poorer countries adapt.

Oxfam found that in 2023, the wealthiest 10% of people caused 50% of global emissions. The poorest 50% caused only 8%. To ensure a fair transition, workers in the fossil fuel industry would need new jobs and support for their communities.

International Climate Agreements

Almost all countries are part of the 1994 United Nations Framework Convention on Climate Change (UNFCCC). Its goal is to prevent dangerous human interference with the climate. The UNFCCC provides a framework for agreements that limit emissions. Global emissions have risen since it was signed.

The 2015 Paris Agreement aims to keep global warming well below 2.0 °C, with a goal of 1.5 °C. Countries must regularly set more ambitious goals every five years. The agreement also states that developing countries need financial support. By March 2025, 194 states and the European Union had joined or officially approved the agreement.

The 1987 Montreal Protocol, which phased out ozone-depleting gases, also helped fight climate change. Many of these gases were powerful greenhouse gases. This agreement may have prevented a temperature rise of 0.5 °C–1.0 °C.

National Actions

In 2019, the UK parliament was the first national government to declare a climate emergency. Other countries and regions followed. The European Commission aims to make the EU carbon-neutral by 2050. By 2035, all new cars in Europe must be zero-emission.

Major Asian countries like South Korea and Japan aim to be carbon-neutral by 2050. China aims for 2060. As of 2021, national climate plans showed that total greenhouse gas emissions were estimated to be 0.5% lower compared to 2010 levels. This is still below the goals needed to limit global warming to 1.5 °C or 2 °C.

Understanding Climate Change: Public Awareness

Misinformation and Doubt

Public discussions about climate change have been affected by misinformation. This often comes from fossil fuel companies and other groups. Their main strategy is to create doubt about scientific findings. People who spread unwarranted doubt are sometimes called "deniers."

Some deny warming is happening, others say it's natural, and some downplay its impacts. Creating uncertainty about the science can delay policy changes. This includes criticizing scientists and their work.

Public Opinion and Concern

Climate change became widely known in the late 1980s. People sometimes confused it with other environmental issues. Movies like The Day After Tomorrow (2004) and documentaries like An Inconvenient Truth (2006) helped raise awareness.

Concern about climate change varies by region, age, and politics. More educated people, and often younger people, see it as a serious threat. Countries with high Template:CO2 emissions tend to be less concerned. Worry has increased over time. In 2021, most people in 30 countries were very worried about climate change. A 2024 survey found that 89% of people worldwide want more political action.

Climate Movement

Climate protests demand that leaders take action. These include public demonstrations and lawsuits. The School Strike for Climate started in 2018, with young people skipping school on Fridays. This was inspired by Swedish activist Greta Thunberg. Groups like Extinction Rebellion have also used civil disobedience.

Lawsuits are increasingly used to push governments and companies to take climate action. Activists sue governments to demand they enforce climate laws. Lawsuits against fossil fuel companies often seek money for damages. On 23 July 2025, the UN's International Court of Justice shared its official advice. It clearly stated that countries must act to stop climate change.

The Story of Climate Science

Early Discoveries

Scientists in the 19th century began to understand climate change. In the 1820s, Joseph Fourier suggested the greenhouse effect. He explained that Earth's atmosphere traps some of the heat radiated from the surface, making the planet warmer.

In 1856, Eunice Newton Foote showed that air with water vapour or carbon dioxide (CO
2) warms more in sunlight. She concluded that "An atmosphere of that gas would give to our earth a high temperature."

Starting in 1859, John Tyndall found that gases like water vapour, methane, and carbon dioxide absorb and re-radiate heat. He thought changes in these gases could have caused past climate changes, like ice ages.

Svante Arrhenius noted that CO
2 levels were affected by long-term geological processes. In 1896, he created the first climate model. He predicted that doubling CO
2 could increase temperatures by 5–6 °C. Other scientists were unsure at first.

How Scientists Reached Agreement

In the 1950s, Gilbert Plass used computer models to predict that rising CO
2 would cause warming. At the same time, Hans Suess found CO
2 levels were increasing. Roger Revelle showed that oceans wouldn't absorb all the extra CO
2. These scientists helped Charles Keeling start measuring CO
2 levels, creating the "Keeling Curve."

The Intergovernmental Panel on Climate Change (IPCC) was set up in 1988. It provides formal advice to governments and encourages research. There is now a nearly unanimous scientific agreement that the climate is warming because of human activities. No major scientific group disagrees with this. The 2021 IPCC Report stated it is "unequivocal" that humans cause climate change.

Recent Science Tools

Extreme event attribution (EEA) was developed in the early 21st century. This science uses climate models to figure out how much human-caused climate change affects specific extreme weather events. Scientists can now say things like, "this heatwave was made 'm' degrees hotter because of global warming." This helps us understand the link between climate change and recent weather events.

Images for kids

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  Bobcat Fire in Monrovia, CA, September 10, 2020

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  Bleached colony of Acropora coral

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  A dry lakebed in California, which is experiencing its worst megadrought in 1,200 years.

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  Some people pick out data from short periods to wrongly say that global temperatures are not rising. Blue lines show short periods that hide longer-term warming trends (red lines). Blue dots show what some call the "global warming pause."

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  The 2017 People's Climate March happened in many places. Shown: the Washington, D.C. march, protesting policies of the U.S. President at the time.

Related Pages

• Deforestation
• Earth Hour
• Ecology
• Natural disaster
• United Nations Framework Convention on Climate Change

See also

In Spanish: Cambio climático para niños