topicclimatechange

Climate change refers to long-term shifts in global or regional climate patterns, including changes in temperature, precipitation, and the frequency or intensity of extreme weather events. It results from natural variability and, to a large extent, from human activities that alter the composition of the atmosphere, especially the rise in greenhouse gases such as carbon dioxide, methane, and nitrous oxide.

Causes include the burning of fossil fuels for electricity, heat, and transportation, which releases substantial amounts of CO2 and other pollutants. Deforestation and changes in land use reduce the land’s capacity to absorb CO2. Industrial processes and agricultural practices also contribute. While natural climate cycles exist, the rapid warming observed over the past century is largely anthropogenic.

Evidence for climate change is grounded in multiple lines of observation: rising global surface temperatures, warming oceans, melting ice sheets and glaciers, and sea-level rise. In addition, the atmosphere and oceans show patterns of change—such as altered precipitation and increased frequency of certain extreme events—that align with greenhouse gas forcing.

Impacts span environmental, economic, and social dimensions. Ecosystems shift and species migrate, while water resources, agriculture, and infrastructure face greater stress. Coastal areas confront higher flood risk, and health outcomes can be affected by heat, air quality, and vector-borne diseases. Economic costs arise from damages, adaptation, and transitions in energy systems.

Responses focus on mitigation and adaptation. Mitigation aims to reduce or remove greenhouse gas emissions through decarbonization of energy, electrification, energy efficiency, and deployment of low-carbon technologies. Adaptation seeks to increase resilience through climate-smart planning, resilient infrastructure, and improved disaster risk management. International cooperation, including the Paris Agreement, coordinates national actions toward limiting warming.