Is climate change real?

Yes, climate change is real. The overwhelming consensus of the global scientific community is that the Earth is warming, and that this warming is primarily driven by human activities.

According to major scientific institutions worldwide—including NASA, the National Oceanic and Atmospheric Administration (NOAA), the Intergovernmental Panel on Climate Change (IPCC), and the national science academies of nearly every major country—the evidence is unequivocal.

An analysis of peer-reviewed scientific literature shows that 97% to over 99% of actively publishing climate scientists agree that human activities are the principal cause of recent global warming.

What is causing it?

The primary driver of modern climate change is the greenhouse effect.

•Greenhouse Gases: When humans burn fossil fuels (like coal, oil, and natural gas) for energy, clear forests for agriculture, or run industrial processes, we release vast amounts of greenhouse gases into the atmosphere—principally carbon dioxide ($CO_2$), methane, and nitrous oxide.

•Trapping Heat: These gases act like a blanket around the Earth. They allow sunlight to pass through the atmosphere to warm the planet, but prevent that warmth from escaping back into space.

•Accelerated Growth: While $CO_2$ levels have fluctuated naturally over hundreds of thousands of years, $CO_2$ from human activities is currently increasing about 250 times faster than it did from natural sources after the last Ice Age.

What is the evidence?

Scientists track global warming using data from satellites, ocean buoys, weather stations, and natural records like ice cores, tree rings, and coral reefs. Key indicators of a changing climate include:

1.Rising Temperatures: The planet’s average surface temperature has risen by about $1.1^\circ\text{C}$ ($2^\circ\text{F}$) since the late 19th century. The vast majority of this warming has occurred in recent decades, with the past ten years being the warmest on record.

2.Warming Oceans: The oceans absorb over 90% of the excess heat trapped in the atmosphere. This is causing ocean temperatures to rise, which stresses marine life and fuels stronger tropical storms.

3.Shrinking Ice Sheets and Glaciers: Data from NASA’s gravity recovery satellites show that the Greenland and Antarctic ice sheets are losing billions of tons of mass every year. Glaciers in the Alps, Himalayas, Andes, Rockies, and Alaska are also in rapid retreat.

4.Rising Sea Levels: Global sea levels have risen as a result of water expanding as it warms (thermal expansion) and the melting of land-based glaciers and ice sheets.

5.Extreme Weather: Around the world, we are seeing an increase in the frequency, intensity, and duration of extreme weather events, including severe heatwaves, intense droughts, devastating wildfires, and heavy precipitation events.

How is this different from past natural cycles?

Earth's climate has changed throughout history due to natural causes, such as slight variations in the Earth's orbit, volcanic eruptions, and solar activity.

However, the current period of warming is fundamentally different:

•The Speed: Modern warming is happening at a rate not seen in at least 10,000 years. Natural transitions out of ice ages typically take thousands of years, whereas the current warming is occurring roughly 10 times faster.

•The Cause: Natural factors alone cannot explain the current warming. When scientists run computer models of Earth’s climate using only natural influences (like the sun and volcanoes), the models show little to no warming over the last century. It is only when human-emitted greenhouse gases are added to the models that they match the real-world temperatures we observe today.

Citations (4)

1nasa.govGovernment
nasa.gov
Backs: “Yes, climate change is real. The overwhelming consensus of the global scientific community is that the Earth is warming, and that this warming is primarily driven by human activities.”
2wikipedia.orgEncyclopedias and referencequality 0.83
wikipedia.org
Backs: “Yes, climate change is real. The overwhelming consensus of the global scientific community is that the Earth is warming, and that this warming is primarily driven by human activities.”
3nasa.govGovernment
nasa.gov
Backs: “According to major scientific institutions worldwide—including NASA, the National Oceanic and Atmospheric Administration (NOAA), the Intergovernmental Panel on Climate Change (IPCC), and the national science academies of nearly every major country—the evidence is unequivocal. An analysis of peer-reviewed scientific…”
4aaas.orgNonprofits and think tanks
aaas.org
Backs: “An analysis of peer-reviewed scientific literature shows that 97% to over 99% of actively publishing climate scientists agree that human activities are the principal cause of recent global warming.”