James Hansen Calls on Scientists to Be Assertive About Climate Change

World's leading scientist on climate change has issued a call to other scientists to get together and clearly communicate the threat of rising sea level

Dr. James Hansen, head of NASA's Goddard Institute for Space Studies and a longtime critic of US policy towards climate change is another hero of mine. Hansen has been called a "whistle blower" in the past for his role in exposing how NASA and the Bush administration edits and censors scientific reports that go against their policy. In this post I highlight what Hansen refers to as the gap in public and scientific perception of climate change, what causes that gap and how it affects policy.

The huge gap between public and scientists

Hansen often refers to "a huge gap" that exists between "what is understood about global warming and what is known about global warming – understood by the relevant scientific community, and known by those who need to know, the public and policy-makers." He further adds that the "scientific knowledge that has emerged in the past several years is startling, and it has dramatic implications for the fate of life on this planet – if we fail to communicate it well enough to drive prompt actions."

In a recent interview, Al Gore too spoke of this gap. When asked to comment on IPCC findings, he said that recent results show IPCC's worst scenarios coming true. "Many scientists are now uncharacteristically scared," he said. As a way of explanation he added that typically what happens is that people and the media exaggerate scientific claims and the scientists themselves are conservative. But today, "this situation is exactly the reverse. Those who are most expert in the science are way more concerned than the general public" on the issue of climate change.

This is clearly is a failure of communication between the scientists and the public. James Hansen has now issued a call to fellow scientists to shed their reluctance and alert the public of the reality. The following is abstract of his paper:

I suggest that a `scientific reticence' is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue.

The problem with science

Hansen has been at the forefront of educating the public of the impending dangers of climate change and the need for worldwide action. Unfortunately, not all scientists are as outspoken as him. Most scientists, by the very nature of their work, are conservative people. They are paid to ask questions, to raise doubts and to pick holes in arguments and analysis. This is also how a typical peer-reviewed scientific publication works.

All that is fine, of course. You don't want junk science to bypass the filter of peer reviews and get published. The movie, An Inconvenient Truth, for example, quotes from a survey that found that in the last 10 years there were no articles in peer reviewed journals that questioned global warming. The so called "scientists" that have been questioning the phenomenon in popular media would never stand a chance of getting published because of the peer review process.

Therefore, this "scientific reticence" - the reluctance of scientists to endorse an idea wholeheartedly even with compelling evidence is an inherent part of the scientific process. The problem comes, when evidence of an idea, such as climate change, is so overwhelming that any scientific reticence hurts the process of communicating the importance of the idea. In the paper on scientific reticence, James Hansen argues:

I believe there is a pressure on scientists to be conservative. Papers are accepted for publication more readily if they do not push too far and are larded with caveats. Caveats are essential to science, being born in skepticism, which is essential to the process of investigation and verification. But there is a question of degree.

Scientific reticence and climate change

Hansen argues that this is precisely what is happening in the climate change discussion. George Monbiot recently recounted an event that's a perfect example of scientific reticence in the context of climate change:

At a meeting I attended in 2005, Sir David King, the British government’s chief scientist, proposed that a ‘reasonable’ target for stabilizing carbon dioxide in the atmosphere was 550ppm CO2 (which means approximately 630ppm CO2e). It would be ‘politically unrealistic’, he said, to demand anything lower. Simon Retallack from the Institute for Public Policy Research reminded Sir David that his duty is not to convey political reality but to represent scientific reality. King replied that if he recommended a lower limit, he would lose credibility with the government

So, lets get this: the chief scientist to the British Government admitted in public that he was reluctant to convey the reality of the threat to the government because he was afraid of being laughed at? Incredible as it sounds this is exactly what happened. And it's not an isolated incident either. In the paper Hansen shares his own account:

`Scientific reticence' leapt to mind as I was being questioned, and boxed-in, by a lawyer for the plaintiff in Automobile Manufacturers versus California Air Resources Board. I conceded that I was not a glaciologist. The lawyer then, with aplomb, requested that I identify glaciologists who agreed publicly with my assertion that the sea level was likely to rise more than one meter this century if greenhouse gas emissions followed an IPCC business-as-usual scenario: `Name one!'

I could not, instantly. I was dismayed, because, in conversation and e-mail exchange with relevant scientists I sensed a deep concern about likely consequences of business-as-usual global warming for ice sheet stability. What would be the legal standing of such a lame response as `scientific reticence'? Why would scientists be reticent to express concerns about something so important?

IPCC: a failure

With thousands of scientists from world over, IPCC is perhaps the biggest collaborative scientific effort in history. The three IPCC reports that have come out in recent months have had significant impact. Yet, despite the "political buy-in" (their panel had hundreds of government reps who had to agree to everything), they have failed to move the world leaders to accept any tangible cuts in emissions, as evidenced in the recently concluded G8 summit. Al Gore recently referred to the summit as a disgrace. That's not all, even scientific studies that have surfaced in past few months have repeatedly shown IPCC estimates of extent of climate change to be extremely conservative.

Therefore, if success of IPCC is to be measured in terms of conveying the reality of the science of climate change and whether it led to action, IPCC has been a dismal failure so far.

The implications of this are obvious. Scientists have the responsibility to communicate science - not to toe a political line. If they fail to deliver, the public and the policymakers remain in dark and base their decisions on a flawed sense of reality. It's like the doctor giving a patient an incorrect diagnosis of his heart condition, making him believe he's better than he actually is. If the patient continues to live the way he has in the past, very soon it may be too late to save him.

References and Links

Dr. James Hansen's latest paper: Scientific reticence and sea level rise

NYT report from Jan 2006 Climate Expert Says NASA Tried to Silence Him

Hansen's earlier paper referring to the gap between public and scientists [PDF]

Al Gore's interview that carries his comment that scientists are scared

Monbiot's article and video that carry accounts of chief British scientist Sir David King admitting to what Hansen calls scientific reticence

Arctic melting beyond IPCC worst scenarios

G8 agreement a "disgrace": Al Gore<