Climate Change — Definition
Definition
Climate change refers to long-term shifts in global or regional climate patterns, primarily attributed to human activities since the mid-20th century, particularly the increased levels of greenhouse gases in the atmosphere from fossil fuel combustion.
Unlike weather, which describes short-term atmospheric conditions, climate represents long-term patterns typically measured over decades or centuries. The phenomenon is fundamentally different from natural climate variability, which occurs due to solar variations, volcanic eruptions, or ocean circulation changes.
Climate change encompasses global warming (the increase in Earth's average surface temperature) but extends beyond temperature to include changes in precipitation patterns, extreme weather events, sea level rise, and ecosystem disruptions.
The greenhouse effect, while natural and essential for life on Earth, has been intensified by human activities. When solar radiation reaches Earth, some is reflected back to space while the rest is absorbed and re-radiated as heat.
Greenhouse gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) trap this heat in the atmosphere, creating a warming effect. Pre-industrial atmospheric CO2 levels were around 280 parts per million (ppm), but have risen to over 420 ppm today due to fossil fuel burning, deforestation, and industrial processes.
For India, climate change poses multifaceted challenges affecting monsoon patterns, agricultural productivity, water resources, coastal areas, and human health. The country experiences diverse climate impacts from Himalayan glacier retreat affecting river systems to increased cyclone intensity in coastal regions.
India's vulnerability stems from its large population dependent on climate-sensitive sectors like agriculture, its extensive coastline, and significant poverty levels limiting adaptive capacity. However, India also presents opportunities as a leader in renewable energy deployment, sustainable development practices, and South-South climate cooperation.
The country's approach balances development imperatives with climate action, emphasizing that poverty eradication remains the overriding priority while pursuing low-carbon growth pathways. Understanding climate change is crucial for UPSC aspirants as it intersects with multiple subjects including geography (physical processes), polity (constitutional provisions and governance), international relations (climate diplomacy), economics (sustainable development), and current affairs (ongoing negotiations and policy developments).
The topic requires grasping both scientific fundamentals and policy dimensions, making it a comprehensive subject for examination purposes.