Is climate change real?

Yes, climate change is real. The scientific evidence demonstrating that the Earth is warming at an unprecedented rate is unequivocal.

There is an overwhelming scientific consensus—with between 97% and over 99% of actively publishing climate scientists agreeing—that climate change is happening and is primarily caused by human activities. Virtually every major scientific organization in the world, including NASA, the Intergovernmental Panel on Climate Change (IPCC), and the National Academies of Sciences of major industrialized countries, formally recognizes this reality.

The Scientific Evidence

Scientists track climate change using direct modern measurements (from satellites, weather stations, and ocean buoys) alongside paleoclimate records (from ice cores, tree rings, and coral reefs). This body of data reveals several undeniable trends:

1.Rapidly Rising Global Temperatures: The planet's average surface temperature has risen by about 2°F (roughly 1.1°C) since the late 19th century. The decade leading up to the mid-2020s has been the warmest on record.

2.Warming and Acidifying Oceans: Earth's oceans absorb over 90% of the excess heat trapped by greenhouse gases. As oceans absorb this heat, water temperatures rise. Additionally, the oceans have absorbed about 30% of human-emitted carbon dioxide, causing ocean acidification that threatens marine ecosystems.

3.Melting Ice and Glaciers: Ice sheets in Greenland and Antarctica are losing hundreds of billions of tons of mass per year. Glaciers are retreating rapidly in almost every mountain range worldwide, and Arctic sea ice is shrinking at an alarming rate.

4.Rising Sea Levels: Global sea levels rose about 8 inches (20 cm) in the last century, and the rate of rise is accelerating due to both the melting of land-based ice and the thermal expansion of warming ocean water.

5.Increased Extreme Weather: Heatwaves are hotter and last longer, droughts are more intense, wildfires are more destructive, and hurricanes are growing stronger and carrying more water because a warmer atmosphere holds more moisture.

What is Causing It?

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

Certain gases in Earth’s atmosphere (like carbon dioxide, methane, and nitrous oxide) act like a blanket, trapping heat from the Sun that would otherwise escape back into space.

Since the Industrial Revolution in the mid-1800s, human activities have flooded the atmosphere with these gases. The main contributors include:

•Burning fossil fuels (coal, oil, and natural gas) for electricity, heat, and transportation.

•Deforestation, as trees that would otherwise absorb carbon dioxide are cut down and burned.

•Industrial agriculture and livestock, which release large amounts of methane and nitrous oxide.

As a result, atmospheric carbon dioxide levels are now higher than they have been at any point in human history, increasing roughly 250 times faster than they did from natural sources after the last Ice Age.

Isn't the Climate Always Changing?

It is true that Earth’s climate has gone through natural cycles of warming and cooling over millions of years (such as ice ages). However, those historical shifts were triggered by very gradual, natural factors, such as slight variations in the Earth's orbit over tens of thousands of years.

The current period of warming is fundamentally different:

•The Speed: Modern warming is occurring roughly 10 times faster than the average rate of natural warming following an ice age.

•The Cause: Natural factors (like solar output or volcanic activity) cannot explain the rapid temperature spikes observed over the last 150 years. When scientists input only natural factors into climate models, the models show flat or even cooling temperatures. It is only when human-emitted greenhouse gases are added that the models align with the real-world warming trend.

For more in-depth data, interactive visualizations, and local impact reports, you can explore resources from NASA's Global Climate Change Portal or the Intergovernmental Panel on Climate Change (IPCC).

Citations (7)

1nasa.govGovernment
nasa.gov
Backs: “Yes, climate change is real. The scientific evidence demonstrating that the Earth is warming at an unprecedented rate is unequivocal.”
2aaas.orgNonprofits and think tanks
aaas.org
Backs: “There is an overwhelming scientific consensus—with between 97% and over 99% of actively publishing climate scientists agreeing—that climate change is happening and is primarily caused by human activities. Virtually every major scientific organization in the world, including NASA, the Intergovernmental Panel on Climate…”
3nasa.govGovernment
nasa.gov
Backs: “There is an overwhelming scientific consensus—with between 97% and over 99% of actively publishing climate scientists agreeing—that climate change is happening and is primarily caused by human activities. Virtually every major scientific organization in the world, including NASA, the Intergovernmental Panel on Climate…”
4wikipedia.orgEncyclopedias and referencequality 0.83
wikipedia.org
Backs: “There is an overwhelming scientific consensus—with between 97% and over 99% of actively publishing climate scientists agreeing—that climate change is happening and is primarily caused by human activities. Virtually every major scientific organization in the world, including NASA, the Intergovernmental Panel on Climate…”
5edf.orgNonprofits and think tanks
edf.org
Backs: “Virtually every major scientific organization in the world, including NASA, the Intergovernmental Panel on Climate Change (IPCC), and the National Academies of Sciences of major industrialized countries, formally recognizes this reality.”
6nasa.govGovernment
nasa.gov
Backs: “Virtually every major scientific organization in the world, including NASA, the Intergovernmental Panel on Climate Change (IPCC), and the National Academies of Sciences of major industrialized countries, formally recognizes this reality.”
7arizona.eduAcademic
arizona.edu
Backs: “It is true that Earth’s climate has gone through natural cycles of warming and cooling over millions of years (such as ice ages). However, those historical shifts were triggered by very gradual, natural factors, such as slight variations in the Earth's orbit over tens of thousands of years.”