Sunday, June 12, 2016

30 Years Ago Scientists Warned Congress on Global Warming.  What They Said Sounds Eerily Familiar

It was such a different time — and yet, the message was so similar.
John H. Chafee, the late Republican senator from Rhode Island. He died in 1999. (Credit: Getty Images) Click to Enlarge.
Thirty years ago, on June 10 and 11 of 1986, the U.S. Senate Committee on the Environment and Public Works commenced two days of hearings, convened by Sen. John H. Chafee (R-R.I.), on the subject of “Ozone Depletion, the Greenhouse Effect, and Climate Change.”

“This is not a matter of Chicken Little telling us the sky is falling,” Chafee said at the hearing.  “The scientific evidence … is telling us we have a problem, a serious problem.”

The hearings garnered considerable media coverage, including on the front page of The Washington Post.

“There is no longer any significant difference of opinion within the scientific community about the fact that the greenhouse effect is real and already occurring,” said newly elected Sen. Al Gore, who, as a congressman, had already held several House hearings on the matter.  Gore cited the Villach Conference, a scientific meeting held in Austria the previous year (1985), which concluded that “as a result of the increasing greenhouse gases it is now believed that in the first half of the next century (21st century) a rise of global mean temperature could occur which is greater than in any man’s history.”

“They were the breakthrough hearings,” remembers Rafe Pomerance, then a staffer with the World Resources Institute, who helped suggest witnesses. “You never saw front-page coverage of this stuff.”

The scientists assembled included some of the voices that would be unmistakable and constant in coming decades.  They included NASA’s James Hansen, who would go on to become the most visible scientist in the world on the topic, and Robert Watson, who would go on to chair the soon-to-be formed United Nations’ Intergovernmental Panel on Climate Change.

And what they said was clear:  Human greenhouse gas emissions would cause a major warming trend, and sea level rise to boot.
The New York Times also covered the hearings, writing that “The rise in carbon dioxide and other gases in the earth’s atmosphere will have an earlier and more pronounced impact on global temperature and climate than previously expected, according to evidence presented to a Senate subcommittee today.”

Two years later, still more famously, Hansen would testify in another series of hearings that had an even greater public impact when it came to consciousness-raising — in part because at that point, he said that the warming of the globe caused by humans was already detectable. “It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here,” he said then. In 1986, by contrast, scientists were still mostly predicting the future, rather than saying they had measured and documented a clear warming trend — one that could be clearly distinguished from natural climate variability — and that it was already having demonstrable consequences.

“The 1986 testimony is interesting because it was so similar to my 1988 testimony,” Hansen recalls. “I already had, and showed, some of the climate modeling results that formed the basis for my 1988 testimony.”

Granted, in some cases the future temperature projections made in the 1986 hearings — based on assumptions about the rate of increase in greenhouse gas emissions and a high sensitivity of the climate to them — suggested temperatures might rise even more, or even faster, than scientists now believe they will.  By email, Hansen clarified that we now know the world is closer to one scenario he presented in 1986 — called Scenario B — than to Scenario A, which assumed a much more rapid rate of greenhouse gas growth, and accordingly, much faster warming.

Still, the theoretical understanding was in place for why temperatures would rise as greenhouse gases filled the atmosphere — simply because scientists knew enough physics to know that that’s what greenhouse gases do.

“We knew in the ’70s what the problem was,” said George Woodwell, founding director of the Woods Hole Research Center, who also testified in 1986.  “We knew there was a problem with sea level rise, all disruptions of climate.  And the disruptions of climate are fundamental in that they undermine all the life on the Earth.”

Read more at 30 Years Ago Scientists Warned Congress on Global Warming.  What They Said Sounds Eerily Familiar

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