We all know about climate change now, but when did it become a thing and who discovered it? Way back in 1988, NASA scientist James Hansen testified before the Senate Committee on Energy and Natural Resources. He presented his findings that the greenhouse effect was and would have a strong impact on rising global temperatures. Thus “global warming” was born.
Hansen and a co-author published the first ever NASA Goddard Institute of Space Studies global temperature analysis in 1981. After analyzing surface temperatures from 1880-1985, they concluded that the Earth’s temperature had risen 0.5-0.7 celcius in the last century. Hansen’s prepared statement to congress in 1988 said:
My principle conclusions are: (1) The Earth is warmer in 1988 than any time in the history of instrumental measurements, (2) the global warming is now sufficiently large that we can ascribe with a high degree of confidence to the cause and effect relationship to the greenhouse effect, and (3) in our computer science simulations, the greenhouse effect is already large enough to begin to affect the probability of occurrence of extreme events such as summer heat wave; the model results imply that the heat wave/drought occurrences in the Southeast and Midwest United States may be more frequent in the next decade than in climatological (1950-1980) statistics.
Some other key quotes from his testimony:
The present temperature is the highest in the period of record. The rate of warming in the past 25 years…is the highest on record. The four warmest years…have all been in the 1980’s, and 1988 is so far is so much warmer than 1987, that barring remarkable and improbably cooling, 1988 will be the warmest year on the record.
…this change in the frequency of hots summers is large enough to be noticeable to the average person. So, we have already reached a point that the greenhouse effect is important.
Altogether the evidence that the Earth is warming by an amount which is too large to be a chance fluctuation and the similarity of the warming to that expected from the greenhouse effect represents a very strong case. It may also have important implications other than for creature comfort.
Hansen retired from his service at NASA in 2013 after 46 years. He still remains an active political and legal activist for climate change and even has gotten himself arrested a few times in the name of saving the planet.