Human-caused global warming from greenhouse gases

Summary

Human-caused global warming is the long-term rise in Earth’s average temperature primarily driven by increasing concentrations of greenhouse gases in the atmosphere. Human activities such as burning coal, oil, and gas, deforestation, and industrial processes release carbon dioxide, methane, and other gases that trap heat. Although Earth’s climate has changed naturally in the past because of factors such as orbital shifts, volcanic activity, and solar variations, these natural influences cannot explain the rapid warming occurring today. The current warming is producing significant effects, including more extreme weather, rising sea levels, ecosystem disruption, threats to coral reefs, and impacts on agriculture. Scientific evidence shows that greenhouse-gas warming is far stronger than recent changes in solar activity. Reducing emissions through sustainable and renewable energy sources, such as solar, wind, hydropower, geothermal, tidal, and biomass energy, is an important way to limit further climate change.

Key Points

• 1

  Human activities increase atmospheric greenhouse gases, especially carbon dioxide and methane, causing the planet to warm.

• 2

  Natural climate changes have occurred throughout Earth’s history, but they do not account for the rapid, modern warming caused mainly by human emissions.

• 3

  Global warming contributes to extreme weather, sea-level rise, ecosystem damage, coral-reef decline, and agricultural disruption.

• 4

  Solar activity has only a very small influence on current warming compared with the much stronger effect of human-produced greenhouse gases.

• 5

  Renewable energy and other sustainable practices can help reduce greenhouse-gas emissions and mitigate climate change.