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Climate models can seem like black boxes: huge programs on supercomputers. Syukuro Manabe's first model was the opposite, a single column of air simple enough to reason about. That simplicity let him see what carbon dioxide does and why. This post covers his path, the 1967 model, a worked energy-balance example, and the working habits you can borrow.
Where did Syukuro Manabe start?
The Nobel Prize facts page records that he was born on 21 September 1931 in Shingu, Ehime, Japan, and was at Princeton University when he shared the 2021 Nobel Prize in Physics "for the physical modelling of Earth's climate, quantifying variability and reliably predicting global warming".
His Nobel biography says his father and grandfather were village doctors, and his family expected him to study medicine. Instead he majored in meteorology at the University of Tokyo, earning a BA in 1953, an MA in 1955 and a DSc in 1959. He explained the choice in his own words: "I had a horrible memory and I was clumsy with my hands. I thought that my only good trait was to gaze at the sky and get lost in my thoughts."
In 1959 he joined the US Weather Bureau's General Circulation Research Section, which became NOAA's Geophysical Fluid Dynamics Laboratory, and worked there until 1997.
What was the 1967 model?
The Nobel Committee's popular science background explains the problem. Earlier work, going back to Svante Arrhenius, looked only at the balance of radiation. Manabe added the vertical movement of air by convection and the latent heat of water vapour. To keep the calculation manageable he reduced the model to one dimension: a vertical column 40 km high.
With Richard Wetherald he published Thermal equilibrium of the atmosphere with a given distribution of relative humidity024%3C0241:TEOTAW%3E2.0.CO;2) in 1967. The Nobel background says that in this model oxygen and nitrogen had negligible effects on surface temperature, while doubling carbon dioxide raised the global temperature by over 2 °C.
What is the fingerprint of greenhouse warming?
The model warmed near the ground but cooled higher up. His biography states it plainly: with more carbon dioxide the temperature rises at the surface and in the troposphere, and falls in the stratosphere. The Nobel background explains why this matters: if the Sun were responsible, the whole atmosphere should warm together.
Worked example: why does Earth need a greenhouse effect at all?
Start without one. NASA's Earth fact sheet gives the solar irradiance as 1361 W/m² and Earth's Bond albedo as 0.294.
Step 1: absorbed sunlight per square metre of surface. Earth intercepts sunlight over a disc of area πR² but radiates from a sphere of area 4πR², so the average absorbed flux is S(1 − A) ÷ 4 = 1361 × 0.706 ÷ 4 ≈ 240 W/m².
Step 2: temperature needed to radiate that away. Using the Stefan-Boltzmann law, σT⁴ = 240, with σ = 5.67 × 10^-8 W m^-2 K^-4: T⁴ = 240 ÷ (5.67 × 10^-8) ≈ 4.24 × 10^9, so T ≈ 255 K. NASA's fact sheet lists a black-body temperature of 254 K; the small difference is rounding.
Step 3: compare with reality. The fact sheet gives Earth's average temperature as 288 K. The gap, about 33 K, is the natural greenhouse effect.
A single equation like this cannot tell you how the warmth is shared between the ground and the sky, or what happens when you add carbon dioxide. That needed Manabe's column, with radiation, convection and water vapour all included.
What came next?
His biography lists the steps: a three-dimensional simulation of the response to increased carbon dioxide in 1975 with Wetherald, and, in 1969 with Kirk Bryan, the first climate simulations coupling an ocean model to an atmosphere model. In 2018 he shared the Crafoord Prize in Geosciences with Susan Solomon.
What mistakes do students make about climate models?
Thinking a model must include everything to be useful. Manabe's 1967 model was one column, and it got the key features right.
Forgetting the factor of 4. Sunlight hits a disc but Earth radiates from a whole sphere.
Treating "warming" as uniform with height. The cooling stratosphere is part of the evidence.
What can a student learn from Manabe?
He chose the simplest model that still contained the physics that mattered, and then asked it a sharp question. That is how you should approach a hard numerical: strip it to the essential balance first, then add detail. For more on why weather, unlike climate, stays hard to predict, see our post on Edward Lorenz, and for the measurements that showed carbon dioxide rising, see the Keeling curve.
If radiation laws feel abstract, the Fermi Simulation Lab has interactive simulations for ideas that are easier to see than read.
Try it now: redo the worked example with an albedo of 0.35 and see how far the temperature falls.
