Definition of Global Warming
Global warming refers to the long-term heating of Earth's climate system observed since the pre-industrial period (typically 1850-1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth's atmosphere. It is a specific aspect of climate change, focusing on the average rise in global temperature.
Primary Causes of Warming
The principal cause of global warming is the enhanced greenhouse effect. Gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) trap infrared radiation (heat) in the atmosphere, much like a greenhouse. While a natural greenhouse effect is vital for life, human activities significantly increase the concentration of these gases, leading to excess heat retention.
Observed Impacts and Evidence
Scientific evidence for global warming includes a consistent rise in global average surface temperatures, melting glaciers and ice sheets at accelerated rates, rising sea levels, and ocean warming. These observations are corroborated by extensive data from meteorological stations, satellites, and oceanographic measurements.
Consequences and Future Outlook
Continued global warming is projected to intensify extreme weather events, alter precipitation patterns, leading to more frequent droughts or severe floods, further exacerbate sea-level rise, and disrupt ecosystems and human societies. Addressing global warming requires substantial reductions in greenhouse gas emissions and a global transition to sustainable practices.