40 Years of Charney Report: Starting of the Assessment of Global Climate Change

Climate change and the consequent global warming is a well-acknowledged issue today, at least in the scientific world. But when scientists talked about global warming initially, it was not very easy for them to be accepted widely, not even within the scientific community. Few scientists could guess what the Earth is witnessing today, but their prediction seemed to be difficult to grasp by the world communities. 

The journey of the science of global warming has now become 40 years old. Yes, 40 years ago a group of climate scientists came together and sat down at Woods Hole Ocenographic Institution in Massachusetts and that was their first meeting of the ad hoc group on carbon dioxide and climate. This meeting heralded the science of global climate change. What came out of the meeting was known as the Charney Report, which is the first comprehensive assessment of global climate change due to carbon dioxide. The report or the deliberation of the meeting was certainly not something that was waited by millions and was not as impressive as a moon voyage was, but, certainly the success of its predictions over the last 40 years has established the science of global climate change very firmly. 

The Story of Green House Gas

It has been more than 150 years now that the molecular basis of the greenhouse effect was discovered. John Tyndall, one of the greatest physicists of history, showed for the first time that gases in the atmosphere absorb heat to very different degrees. Carbon dioxide is one of the gases could increase the temperature if it is present at a high concentration in the atmosphere. It was the early instance of a global warming.

By 1950s, scientists started to predict that the Earth is going to witness a warming of several degrees by burning of fossil fuels. 

In a paper published in Nature, John Sawyer, the then head of research at UK meteorological office, reported that Earth is going to have a warming of 0.6 degree Celsius by the end of the 20th century. It was in the year 1972.  But the paper was not free of controversy at that time. In and around that time, there was speculation of some kind, at least in the media that said that the Earth is going towards another ice age. This was the outcome of another finding, which said that the world had cooled since the middle of the 20th century. 

The meeting at Woods Hole in 1979 was led by Jule Charney, MIT, USA. The report clearly spelled out what would have happened by the increasing concentration of carbon dioxide in the atmosphere. The report concluded—“We estimate the most probable warming for a doubling of CO2 to be near 3°C with a probable error of 1.5°C.” 

Since this prediction was made, the global carbon dioxide concentration in the atmosphere has increased by 21%. And during the same period, the global average surface temperature has gone up by 0.66 degree Celsius. This shows how remarkable their prediction was. 

However remarkable their prediction was, the report could not trigger any change in the behavior of public or the politicians. But over time, as the world has witnessed warming at a global level due to carbon emission out of mainly fossil fuel burning, the report has become accepted as a milestone in setting our understanding about the consequences on global climate due to our activities. 

Over the past 40 years – since Charney and his colleagues came out with a brilliant estimate of an inevitable global warming – the climate change science has undergone pretty much improvement. Now we have better models of climate predictions, which include the parameters that were missing from the 1979 Charney Report.