Is climate change real?

Is climate change happening? I'll pull the latest scientific evidence to give you a clear answer.

Yes — climate change is real, and is happening now.

What science says

There is unequivocal evidence that Earth is warming at an unprecedented rate. Human activity is the principal cause.

•Warming of the climate system is unequivocal, as evidenced by increases in global average air and ocean temperatures, the widespread melting of snow and ice, and rising global average sea level.

•Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate system has evolved from theory to established fact.

Is this just natural change?

While Earth's climate has changed throughout its history, the current warming is different:

> The current warming trend is different because it is clearly the result of human activities since the mid-1800s, and is proceeding at a rate not seen over many recent millennia.

•Current warming is happening at a rate not seen in the past 10,000 years.

•Current warming is occurring roughly 10 times faster than the average rate of warming after an ice age. Carbon dioxide from human activities is increasing about 250 times faster than it did from natural sources after the last Ice Age.

•While the Sun has played a role in past climate changes, the evidence shows the current warming cannot be explained by the Sun.

Scientists attribute the global warming trend observed since the mid-20th century to the human expansion of the greenhouse effect — warming that results when the atmosphere traps heat radiating from Earth toward space.

Evidence for rapid climate change is compelling

From global temperature rise to melting ice sheets, the evidence of a warming planet abounds. The Evidence for Rapid Climate Change Is Compelling includes:

•Global Temperature Is Rising: The planet's average surface temperature has risen about 2 degrees Fahrenheit (1 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide emissions into the atmosphere and other human activities.

•The Ocean Is Getting Warmer, The Ice Sheets Are Shrinking, Glaciers Are Retreating, Snow Cover Is Decreasing, Sea Level Is Rising, Arctic Sea Ice Is Declining, Extreme Events Are Increasing, Ocean Acidification Is Increasing.

For example, global sea level rose about 8 inches (20 centimeters) in the last century and the rate is accelerating, and ice sheets and glaciers are retreating almost everywhere around the world.

How strong is the scientific agreement?

•The overwhelming majority of climate scientists agree that climate change is real and primarily caused by human activities, especially greenhouse gas emissions.

•Yes, the vast majority of actively publishing climate scientists – 97 percent – agree that humans are causing global warming and climate change.

•A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems.

This consensus is shared by leading science organizations around the world, including international and U.S. science academies, the United Nations Intergovernmental Panel on Climate Change, and many other reputable scientific bodies.

In short: The Earth is warming, it is warming much faster than natural cycles can explain, and human activities — especially burning fossil fuels and deforestation which release greenhouse gases — are the principal cause.

Citations (2)

1nasa.govGovernment
Climate Change - NASA Science
Backs: “What science says. There is unequivocal evidence that Earth is warming at an unprecedented rate.”
2nasa.govGovernment
Evidence - NASA Science
Backs: “Warming of the climate system is unequivocal, as evidenced by increases in global average air and ocean temperatures, the widespread melting of snow and ice, and rising global average sea level. Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate…”