Definition of Global Warming
Global warming refers to the long-term increase in Earth's average surface temperature due primarily to human activities that enhance the greenhouse effect. This phenomenon traps heat in the atmosphere through elevated levels of gases like carbon dioxide (CO2) and methane, leading to a warmer planet overall.
Key Causes and Mechanisms
The primary causes include burning fossil fuels for energy, deforestation, and industrial processes, which release greenhouse gases. These gases absorb and re-emit infrared radiation, preventing heat from escaping into space. A common misconception is that natural factors like solar activity drive most warming; however, scientific evidence shows human influence accounts for over 90% of recent temperature rises.
Practical Example: Melting Polar Ice Caps
In the Arctic, global warming has accelerated ice melt, with summer sea ice extent decreasing by about 13% per decade since 1979. This example illustrates rising sea levels and disrupted wildlife habitats, such as polar bears losing hunting grounds, demonstrating how temperature increases translate to tangible environmental changes.
Major Effects and Global Importance
Effects include intensified extreme weather events like hurricanes and droughts, biodiversity loss through habitat shifts, ocean acidification harming marine life, and threats to food security via altered agricultural patterns. These impacts underscore global warming's role in climate change, affecting ecosystems, economies, and human health worldwide, emphasizing the need for mitigation strategies.