Is climate change real? I'll pull the latest scientific evidence to answer.
Yes, according to the overwhelming scientific consensus and evidence, climate change is real and is currently happening.
Scientific Consensus
•There is overwhelming scientific evidence that the Earth is warming and that human activities, especially the emission of greenhouse gases, are the primary cause.
•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.
•According to the Intergovernmental Panel on Climate Change (IPCC), "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."
•There is unequivocal evidence that Earth is warming at an unprecedented rate. Human activity is the principal cause.
Commonly cited figures for the consensus include:
•Yes, the vast majority of actively publishing climate scientists – 97 percent – agree that humans are causing global warming and climate change.
•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 activities.
Evidence That Climate Change Is Occurring
Scientists use information taken from natural sources (such as ice cores, rocks, and tree rings) and from modern equipment (like satellites and instruments) that all show the signs of a changing climate.
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.
Key evidence cited by NASA and others 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. Most of the warming occurred in the past 40 years, with the seven most recent years being the warmest. The years 2016 and 2020 are tied for the warmest year on record.
•The Ocean Is Getting Warmer: The ocean has absorbed much of this increased heat, with the top 100 meters (about 328 feet) of ocean showing warming of 0.67 degrees Fahrenheit (0.33 degrees Celsius) since 1969. Earth stores 90% of the extra energy in the ocean.
•Ice Sheets and Glaciers Are Shrinking: The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost an average of 279 billion tons of ice per year between 1993 and 2019, while Antarctica lost about 148 billion tons of ice per year. Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska, and Africa.
•Sea Level Is Rising: Global sea level rose about 8 inches (20 centimeters) in the last century. The rate in the last two decades, however, is nearly double that of the last century and accelerating slightly every year.
•Arctic Sea Ice Is Declining: Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.
•Other indicators include decreasing spring snow cover in the Northern Hemisphere, increasing frequency of extreme temperature and rainfall events, and ocean acidification — since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30%.
Natural vs. Human-Caused
Earth's climate has naturally changed throughout history, with eight cycles of ice ages and warmer periods in the last 800,000 years attributed to very small variations in Earth's orbit. However:
> 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.
It is undeniable that human activities have produced the atmospheric gases that have trapped more of the Sun's energy in the Earth system, and scientists demonstrated the heat-trapping nature of carbon dioxide and other gases in the mid-19th century.
In short, major scientific organizations worldwide, including NASA, NOAA, the IPCC, and national academies of science, agree that climate change is real, is currently happening, and is primarily driven by human activities since the mid-20th century.