global warming 200 words essay
The current warming trend is unmistakably the result of human activity since the 1950s, and it is occurring at an unprecedented rate in millennia. Climate change is defined as a long-term shift in the average weather patterns that have come to characterise Earth’s local, regional, and global climates. Human activities, particularly the use of fossil fuels, have contributed to the observed changes in Earth’s climate since the mid-20th century, increasing heat-trapping greenhouse gas levels in the atmosphere and thus raising the average surface temperature. Internal variability (e.g., cyclical ocean patterns like El Nio, La Nia, and the Pacific Decadal Oscillation) and external forcings (e.g., volcanic activity, changes in the Sun’s energy output, variations in Earth’s orbit) are examples of natural processes that can contribute to climate change.
Global warming is the long-term rise in the global temperature. Though this warming trend has been going on for a long time, it has accelerated in the last century due to the use of fossil fuels. As the human population has grown, so has the number of fossil fuels consumed. Coal, oil, and natural gas are examples of fossil fuels, and their combustion causes the “greenhouse effect” in the Earth’s atmosphere. The greenhouse effect occurs when the Sun’s rays penetrate the atmosphere but cannot escape back into space because heat is reflected off the surface.