Climate change refers to long-term changes in temperatures and weather patterns. Although climate has changed naturally throughout Earth's history, human activities are now the dominant cause of the observed global warming.
1. What Is Climate Change?
Weather describes atmospheric conditions over short periods, such as a rainy afternoon or a hot day. Climate describes typical weather patterns over much longer periods, generally measured over decades.
Climate change can affect average temperatures, rainfall, snowfall, drought frequency, sea levels and the intensity of some extreme weather events. Its effects vary by region.
2. What Causes Global Warming?
Earth's atmosphere contains greenhouse gases that absorb and re-emit heat. This natural greenhouse effect keeps our planet warm enough to support life.
Burning coal, oil and natural gas releases carbon dioxide. Agriculture, land-use change and other human activities also contribute greenhouse gases, including methane and nitrous oxide. Increasing their concentrations strengthens the greenhouse effect.
- Energy production and transport using fossil fuels.
- Deforestation and changes in land use.
- Agriculture, industry and waste management.
3. How Does It Affect Our Planet?
A warming climate contributes to rising sea levels through ocean warming and the loss of land ice. It also changes water availability, increases heat risks and puts pressure on many ecosystems.
The impacts depend on location, exposure and preparedness. Communities may face risks to agriculture, infrastructure, public health and freshwater supplies.
4. How Can We Respond?
Climate action has two complementary parts: mitigation and adaptation. Mitigation reduces greenhouse gas emissions or increases carbon removal. Adaptation helps communities and ecosystems prepare for climate impacts that occur or are expected.
- Improve energy efficiency and expand low-carbon energy.
- Protect and restore forests and other natural ecosystems.
- Improve water management and climate-resilient infrastructure.
- Use reliable climate information in planning and decision-making.
5. Why Climate Science Matters
Climate observations, satellite measurements, ocean monitoring and computer models help researchers understand changes in the Earth system. Reliable evidence supports better decisions by governments, businesses and communities.