Are humans responsible for climate change?

Yes

I'll gather the scientific evidence on humanity's role in climate change.

I've gathered the key scientific findings — now I'll synthesize them into a comprehensive answer.

Yes — according to the overwhelming scientific evidence and consensus, humans are the dominant cause of current climate change.

Scientific Consensus

•Today, 97 percent to 99.9 percent of climate scientists agree that climate change is happening and that human activity is the primary cause.

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

•Multiple independent analyses of the peer-reviewed literature and surveys of climate experts put agreement at roughly 97% or higher.

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

What the Evidence Shows

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

•Scientific evidence continues to show that human activities (primarily the human burning of fossil fuels) have warmed Earth's surface and its ocean basins.

•The Intergovernmental Panel on Climate Change (IPCC) concluded in its AR6 Synthesis Report: '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.'

•In its Fifth Assessment Report (AR5) in 2013-2014, the IPCC concluded that it is 95% certain that human activities, primarily the emission of greenhouse gases, are the dominant cause of global warming since the mid-20th century.

•The preponderance of evidence indicates that human activities—particularly emissions of heat-trapping greenhouse gases—are mostly responsible for making our planet warmer.

How Humans Cause Warming

•Human Activity Is the Cause of Increased Greenhouse Gas Concentrations. Over the last century, burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2).

•Burning fossil fuels such as coal, oil, and gas has increased the concentration of atmospheric carbon dioxide (CO2) from 280 parts per million to 416 parts per million. These greenhouse gases absorb and then re-radiate heat in Earth's atmosphere, which causes increased surface warming.

•Global temperature and CO2 levels in the atmosphere have increased in lockstep since humans began burning large amounts of coal and other fossil fuels during the Industrial Revolution.

•To a lesser extent, clearing of land for agriculture, industry, and other human activities has increased concentrations of greenhouse gases.

Why Natural Causes Do Not Explain Current Warming

Climate has changed naturally in the past due to solar variations, volcanic activity, orbital cycles (Milankovitch cycles), and other factors, but current observations have failed to show any long-term changes that could fully account for the recent, rapid warming of Earth's temperature.

For example:

•The annual flux of CO2 emissions from volcanoes is under 260 million tonnes per year – much less than the 40 billion tonnes per year from human activities.

•There have been no major greenhouse gas-producing volcanic eruptions in the last 250 years, and changes in solar radiation and orbital cycles are too small or too slow to explain the warming since the late 20th century.

In short: while natural climate variability exists, the rapid warming observed since the mid-20th century is unequivocally attributed by NASA, NOAA, the IPCC, and the world's major scientific academies to human emissions of greenhouse gases, primarily from burning coal, oil, and gas.

Citations (2)

1nasa.govGovernment
Climate Change - NASA Science
Backs: “science academies, the United Nations Intergovernmental Panel on Climate Change, and a whole host of reputable scientific bodies around the world.”
attribution, article, points to yes. Claim: Major science organizations, including academies and the IPCC, have issued public statements that humans are causing climate change; NASA says 97% of publishing climate scientists agree.
2rsv.org.auNonprofits and think tanks
Climate Change: What... or Who... is to Blame?
Backs: “Human activity is the principal cause. Scientific evidence continues to show that human activities (primarily the human burning of fossil fuels) have warmed Earth's surface and its ocean basins. The Intergovernmental Panel on Climate Change (IPCC) concluded in its AR6 Synthesis Report: 'Human activities, principally…”
evidence, article, points to yes. Claim: Evidence shows human activities, mainly fossil fuel burning, have warmed Earth's surface and oceans; the IPCC AR6 says human activities unequivocally caused global warming.