Is climate change real?

Is climate change real? I'll pull the latest scientific evidence to answer.

Yes, climate change is real according to the overwhelming scientific evidence and consensus.

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

Evidence that Earth is warming

Multiple independent teams of climate scientists have measured this warming:

> People have been recording daily high and low temperatures at thousands of weather stations worldwide, over land and ocean, for many decades... When different teams of climate scientists in different agencies (e.g., NOAA and NASA) and in other countries (e.g., the U.K.’s Hadley Centre) average these data together, they all find essentially the same result: Earth’s average surface temperature has risen by about 1.8°F (1.0°C) since 1880.

Other lines of evidence include:

•Birds are migrating earlier, and their migration patterns are changing

•Mountain glaciers are melting worldwide, and snow cover is declining in the Northern Hemisphere

•Greenland’s ice sheet is melting at an accelerating rate, mean global sea level is rising, and Arctic sea ice is declining rapidly

Human activity is the primary cause

The warming is largely caused by human activities because the key role that carbon dioxide plays in maintaining Earth's natural greenhouse effect has been understood since the mid-1800s, and more atmospheric carbon dioxide will lead to warmer surface temperatures.

Since 1800, the amount of carbon dioxide in the atmosphere has increased from about 280 parts per million to 410 ppm in 2019, and the isotopic "fingerprint" shows the source is fossil fuels.

The Intergovernmental Panel on Climate Change (IPCC) has assessed this extensively:

•The IPCC is now 95 percent certain that humans are the main cause of current global warming

•Human activities, principally through emissions of greenhouse gases, have unequivocally caused global warming, with global surface temperature reaching 1.1°C above 1850–1900 in 2011–2020

•Recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems

No other known climate influences have changed enough to account for the observed warming trend, and taken together these lines of evidence point squarely to human activities as the cause of recent global warming.

Scientific consensus

Multiple large-scale assessments, including those by the Intergovernmental Panel on Climate Change (IPCC), have established a strong consensus among climate scientists that global warming is real and largely human-induced.

Major scientific organizations agree:

> The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society - American Association for the Advancement of Science

NASA summarizes:

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

Most of the leading science organizations around the world have issued public statements expressing this, including international and U.S. science academies and the United Nations Intergovernmental Panel on Climate Change

Citations (2)

1nasa.govGovernment
Climate Change - NASA Science
Backs: “There is unequivocal evidence that Earth is warming at an unprecedented rate.”
2climate.govGovernment
What evidence exists that Earth is warming and that humans are the main cause?
Backs: “People have been recording daily high and low temperatures at thousands of weather stations worldwide, over land and ocean, for many decades... When different teams of climate scientists in different agencies (e.g., NOAA and NASA) and in other countries (e.g., the U.K.’s Hadley Centre) average these data together,…”