Communicating uncertainty – a scientific or a political question?

This post was contributed by ESA’s Director of Public Affairs, Nadine Lymn.

While other voices boldly make authoritative assertions over issues that may be deeply nuanced, scientists tend to communicate their considerable knowledge in ways which make them sound wishy-washy at best and completely uncertain at worst.  This was the theme of a symposium session, “Global Sustainability in the Face of Uncertainty: How to More Effectively Translate Ecological Knowledge to Policy Makers, Managers, and the Public” that took place at ESA’s Annual Meeting earlier this week.

Why this tends to be true is partly the dynamic nature of science in its quest to prove new hypothesis, and partly because scientists often fail to clearly convey the state of scientific consensus on a particular issue.  A rare exception is the IPCC, which carefully chose words that convey levels of certainty about climate change:

Virtually certain > 99% probability of occurrence

Very likely > 90% probability

Likely > 66% probability

About as likely as not 33 to 66% probability

Unlikely < 33% probability

Very unlikely < 10% probability

Exceptionally unlikely < 1% probability

The session also pointed out the unfortunate reality that many questions may in fact not be science questions at all but rather policy questions.  Both the policy and scientific communities are to blame for this phenomenon.  Policymakers like to hang the cloak of science on an issue because they believe this will make them look cleaner and above the political fray.  Meanwhile, too often scientists delude themselves into thinking science should always dominate in addressing a policy question, when, in fact, other considerations, such as value judgments or economics, are required.
The session concluded that ultimately, what to do in the face of scientific uncertainty is in fact a political decision, not a scientific one.