Is climate change real?

Answering whether climate change is real — I'll gather the latest scientific consensus and evidence.

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

The Scientific Consensus

There is scientific consensus that the Earth has been consistently warming since the start of the Industrial Revolution, that the rate of recent warming is largely unprecedented, and that this warming is mainly the result of a rapid increase in atmospheric greenhouse gases.

This consensus is documented by major scientific bodies:

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

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

•Human activities are driving the global warming trend observed since the mid-20th century.

The Intergovernmental Panel on Climate Change (IPCC), the international body that assesses climate science, concludes:

> It is unequivocal that human influence has warmed the atmosphere, ocean and land.

Comparing observations with model runs that include and exclude human influence led the IPCC to state that it is unequivocal that human influence has warmed the atmosphere, ocean and land.

The IPCC also states:

> “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.”

And:

> “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.”

Multiple studies published in peer-reviewed scientific journals show that 97 percent or more of actively publishing climate scientists agree: Climate-warming trends over the past century are extremely likely due to human activity. A statement cited by NASA notes:

> Based on well-established evidence, about 97% of climate scientists have concluded that human-caused climate change is happening.

More recent literature surveys have found even higher agreement, including greater than 99% agreement in peer-reviewed literature.

More than 18 scientific associations have stated:

> "Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research demonstrates that the greenhouse gases emitted by human activities are the primary driver."

Evidence of Change

Scientists use measurements (temperature records, atmospheric CO2), understanding of the greenhouse effect, and computer models to attribute warming, and note that:

> 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.

Key lines of evidence include:

•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. Most warming occurred in the past 40 years.

•Rate of CO2 increase: Carbon dioxide from human activities is increasing about 250 times faster than it did from natural sources after the last Ice Age.

•While Earth's climate has changed throughout its history, the current warming is happening at a rate not seen in the past 10,000 years.

•Scientific information taken from natural sources (such as ice cores, rocks, and tree rings) and from modern equipment (like satellites and instruments) all show the signs of a changing climate.

Other observed signs listed by NASA include:

•The ocean has absorbed much of this increased heat

•The Greenland and Antarctic ice sheets have decreased in mass

•Glaciers are retreating almost everywhere around the world

•Global sea level rise and Arctic sea ice decline

•Increasing frequency of extreme events and ocean acidification

The cause is the human expansion of the "greenhouse effect" — scientists attribute the global warming trend observed since the mid-20th century to the human expansion of the "greenhouse effect". While the Sun has played a role in past climate changes, the evidence shows the current warming cannot be explained by the Sun.

In short, the scientific community treats human-caused climate change not as a debate, but as an established fact supported by converging evidence from temperature records, ocean heat content, ice loss, sea-level rise, and the physics of greenhouse gases.

Citations (2)

1nasa.govGovernment
Scientific Consensus - NASA Science
Backs: “There is scientific consensus that the Earth has been consistently warming since the start of the Industrial Revolution, that the rate of recent warming is largely unprecedented, and that this warming is mainly the result of a rapid increase in atmospheric greenhouse gases. This consensus is documented by major…”
2nasa.govGovernment
Evidence - NASA Science
Backs: “Comparing observations with model runs that include and exclude human influence led the IPCC to state that it is unequivocal that human influence has warmed the atmosphere, ocean and land. The IPCC also states: “Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming…”