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The Science of Climate Change Explained: Facts, Evidence and Proof
Definitive answers to the big questions.
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The science of climate change is more solid and widely agreed upon than you might think. But the scope of the topic, as well as rampant disinformation, can make it hard to separate fact from fiction. Here, we’ve done our best to present you with not only the most accurate scientific information, but also an explanation of how we know it.
- How do we know climate change is really happening?
- How much agreement is there among scientists about climate change?
- Do we really only have 150 years of climate data? How is that enough to tell us about centuries of change?
- How do we know climate change is caused by humans?
- Since greenhouse gases occur naturally, how do we know they’re causing Earth’s temperature to rise?
- Why should we be worried that the planet has warmed 2°F since the 1800s?
- Is climate change a part of the planet’s natural warming and cooling cycles?
- How do we know global warming is not because of the sun or volcanoes?
- How can winters and certain places be getting colder if the planet is warming?
- Wildfires and bad weather have always happened. How do we know there’s a connection to climate change?
- How bad are the effects of climate change going to be?
- What will it cost to do something about climate change, versus doing nothing?
How do we know climate change is really happening?
Climate change is often cast as a prediction made by complicated computer models. But the scientific basis for climate change is much broader, and models are actually only one part of it (and, for what it’s worth, they’re surprisingly accurate).
For more than a century, scientists have understood the basic physics behind why greenhouse gases like carbon dioxide cause warming. These gases make up just a small fraction of the atmosphere but exert outsized control on Earth’s climate by trapping some of the planet’s heat before it escapes into space. This greenhouse effect is important: It’s why a planet so far from the sun has liquid water and life!
However, during the Industrial Revolution, people started burning coal and other fossil fuels to power factories, smelters and steam engines, which added more greenhouse gases to the atmosphere. Ever since, human activities have been heating the planet.
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