Is climate change real?

Yes, climate change is real.

There is an overwhelming scientific consensus—with more than 99% of peer-reviewed scientific papers and actively publishing climate scientists in agreement—that the Earth's climate is warming and that human activities are the primary cause. Leading scientific organizations worldwide, including NASA, the National Oceanic and Atmospheric Administration (NOAA), and the Intergovernmental Panel on Climate Change (IPCC), state that the evidence of global warming is unequivocal.

The reality of climate change is supported by several key areas of observational evidence:

1. Rising Global Temperatures

The Earth’s average surface temperature has risen by about 2° Fahrenheit (1.1° Celsius) since the late 19th century. This warming is driven largely by increased carbon dioxide and other greenhouse gas emissions into the atmosphere. The last decade has been the warmest on record since modern recordkeeping began in 1880.

2. Ocean Warming and Acidification

The planet's oceans absorb the vast majority of the excess heat trapped by greenhouse gases—more than 90% of global warming over the past 50 years has occurred in the oceans. This has led to rapidly rising water temperatures, which fuels stronger hurricanes and disrupts marine life. Additionally, as the oceans absorb excess carbon dioxide, they become more acidic, threatening marine ecosystems like coral reefs.

3. Shrinking Ice Sheets and Glaciers

Data from NASA’s gravity-monitoring satellites show that the Earth's major ice sheets in Greenland and Antarctica are losing hundreds of billions of tons of mass per year. Glaciers around the world are in rapid retreat, and the extent of Arctic sea ice has declined dramatically over the last several decades.

4. Rising Sea Levels

Global sea levels have risen by about 8 to 9 inches (21 to 24 centimeters) since 1880, and the rate of rise is accelerating. This is caused by two main factors: water from melting glaciers and ice sheets flowing into the ocean, and the thermal expansion of seawater as it warms.

5. More Extreme Weather Events

Climate change is shifting weather patterns globally. Across the world, there has been a documented increase in the frequency and intensity of extreme weather events, including longer and more intense heatwaves, severe droughts, heavier rainfall causing destructive floods, and more volatile wildfire seasons.

What Is Causing It?

While the Earth’s climate has gone through natural cycles of warming and cooling over millions of years (often due to slight variations in the Earth's orbit), the current warming trend is different. It is happening at a rate unprecedented in modern history, and it is directly linked to human activities since the Industrial Revolution.

By burning fossil fuels (like coal, oil, and natural gas), clearing forests, and engaging in intensive agriculture, humans have released massive amounts of greenhouse gases—such as carbon dioxide ($CO_2$) and methane—into the atmosphere. These gases act like a blanket around the Earth, trapping heat that would otherwise escape into space (a process known as the greenhouse effect). Direct atmospheric measurements show that $CO_2$ levels are higher today than they have been at any point in the last 3 million years.