“Greenhouse gases are the second most important factor for climate, after the Sun.” -Syukuro Manabe
In 1967, a groundbreaking paper in climate science was published, detailing the inputs and feedbacks for the first accurate climate model. You don’t have to look far to find contentions that climate models are wrong, inaccurate and unreliable: 8 of the first 10 results on google state it. Yet if you look at the science, the original model, even at age 50, does a remarkable job of getting things right.
The increased emission of greenhouse gases, notably CO2, can have a massive impact on Earth’s climate in just a few hundred years. We’re witnessing that happen today. Image credit: U.S. National Parks Service.
The biggest success? Understanding how large-scale processes work, including the thermodynamic effects of adding additional greenhouse gases to Earth’s atmosphere. The increase of temperature — approximately 2 degrees C for a doubling of CO2 — was well known then, and continues to be well known today. There are uncertainties and difficulties in modern models, but that doesn’t mean there’s uncertainty surrounding global warming. Quite to the contrary, the evidence has never been better.
Concentration of CO2 in the atmosphere over the past few hundred thousand years. Image credit: NASA / NOAA.