Global Warming
Global warming refers to the long-term increase in Earth's average surface temperature, primarily caused by the enhanced greenhouse effect resulting from human-induced emissions of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Since the pre-industrial era (before 1850), global average temperatures have risen by approximately 1.2°C, with the rate of warming accelerating significantly since the mid-20th century. This warming drives profound changes in climate patterns, sea levels, ice cover, and biodiversity worldwide.
Global Temperature Anomalies and Key Milestones
| Period / Year | Temperature Anomaly | CO₂ Concentration | Key Event |
|---|---|---|---|
| Pre-industrial (1850) | Baseline (0°C) | 280 ppm | Reference period |
| 1950 | +0.1°C | 311 ppm | Post-WWII industrial expansion |
| 1988 | +0.4°C | 351 ppm | IPCC established |
| 2016 | +1.0°C | 403 ppm | Hottest year at that time |
| 2023 | +1.4°C | 419 ppm | Hottest year on record |
| Paris Agreement target | +1.5°C limit | Stabilisation goal | Threshold to limit severe impacts |
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Related Terms
Greenhouse Effect
The greenhouse effect is the process by which certain gases in Earth's atmosphere — primarily water vapour, carbon dioxide, methane, and nitrous oxide — absorb and re-emit infrared radiation from the planet's surface, trapping heat and warming the lower atmosphere. This natural phenomenon is essential for life on Earth, raising the average surface temperature from a frigid −18°C (without greenhouse gases) to the current mean of approximately 15°C. Human activities that increase greenhouse gas concentrations enhance this effect, driving global warming and climate change.
Climate Change
Climate change refers to long-term shifts in global and regional climate patterns, including changes in temperature, precipitation, wind patterns, and the frequency of extreme weather events, driven largely by human activities since the mid-20th century. While Earth's climate has always varied naturally due to orbital cycles, volcanic eruptions, and solar variability, the current rate and magnitude of change are unprecedented in the geological record of the past 800,000 years. The primary driver is the increased atmospheric concentration of greenhouse gases from burning fossil fuels, deforestation, and agricultural practices.
El Niño
El Niño is the warm phase of the El Niño–Southern Oscillation (ENSO), a periodic climate pattern involving anomalously warm sea surface temperatures in the central and eastern tropical Pacific Ocean that typically occurs every 2 to 7 years and lasts 9 to 12 months. This ocean–atmosphere interaction disrupts normal trade wind patterns, suppresses the cold upwelling of the Peruvian coast, and triggers widespread alterations in global precipitation and temperature distributions. El Niño events are associated with droughts in Australia and South Asia, flooding in South America and East Africa, and unusually warm global mean temperatures.
The phrase "global warming" was popularised in the 1970s and 1980s to describe the rising mean surface temperature of the Earth. Wallace Broecker is often credited with bringing the term to wider scientific attention in his 1975 paper "Climatic Change: Are We on the Brink of a Pronounced Global Warming?" The words derive from Latin globus (sphere) and Old English wearmian (to become warm).