When Human Activity Fits into Only One of the 15 Boxes

Imagine if this diagram of interactive systems was more widely adopted

Robert Butler
3 min readJun 2, 2021


Bretherton Diagram (NASA 1988)

In the 1980s, the scientific disciplines that studied the Earth’s atmosphere as separate subjects — oceans, land, cryosphere, ecology — realised they should present their work as one big subject.

Since the Earth was an interactive set of systems, and since human activity affected these systems directly and indirectly, it would be good to convey this to the public in a way that could be easily grasped.

To do this, NASA produced a series of reports led by a meteorologist called Francis Bretherton. The reports came up with a diagram — or conceptual framework — the so-called “Bretherton diagram”.

Bretherton is an applied mathematician from Britain – born in Oxford, educated at Cambridge – who went to the United States and became professor emeritus of the Department of Atmospheric and Oceanic Sciences at the University of Wisconsin, Madison.

In one simple version of this diagram, “human activities” are placed in a single orange rectangle on the right-hand side. Arrows lead out from that rectangle to “land use”, “CO2” and “pollutants”. Beyond that, the arrows lead to “tropospheric chemistry”, “terrestrial ecosystems” and “marine biogeochemistry”.

On the left-hand side of the diagram there is a rectangle called “external forcing”. This is illustrated by a radiant sun and a volcano with smoke billowing out. Arrows lead from the sun and the volcano to rectangles called “stratospheric chemistry” and “atmospheric physics” and from there to “tropospheric chemistry” and “terrestrial ecosystems”.

In the Bretherton diagram, the whole of human activity is placed in only one of the 15 boxes. That’s 7.6 billion people! Imagine if this insight was adopted more widely.

Imagine, for instance, going to the theatre and discovering that the director and designer had spent time at NASA and were taking the Bretherton diagram seriously.

On the stage they had created 15 performance areas. The play that you had bought tickets to watch was taking place in only one…



Robert Butler

Tell me who to read. Just no-one explaining how to get 1000 followers in half a day