Global warming is a long-term change in the average weather patterns that have come to define Earth’s local, regional, and global climates. It is the long-term heating of Earth’s surface observed since the pre-industrial period due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere. Global warming occurs when carbon dioxide (CO2) and other air pollutants collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. Normally this radiation would escape into space, but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter.

The impacts of global warming are already harming people around the world. The planet has never been hotter, and nine of the 10 warmest years since 1880 have occurred since 2005. The five warmest years on record have all occurred since 2015. Climate change deniers have argued that there has been a “pause” or a “slowdown” in rising global temperatures, but numerous studies have disproved this claim.

Global warming is different from climate change, although the two terms are often used interchangeably. Climate change refers to long-term shifts in temperatures and weather patterns, while global warming is the long-term heating of Earth’s surface observed since the pre-industrial period due to human activities.