When should scientists talk politics, and when should they shut up?S

Scientists who study the environment often find themselves stuck. They see problems with how humans are affecting the planet, and they want to advocate for changing the way we are doing things. At the same time, they aren't political experts. How can they offer informed opinions, without falling prey to propagandizing?

Carnegie Institution global ecologist Ken Caldeira believes that scientists can strike a good balance, advocating within the scientific domains where they are experts — but leaving specific policy suggestions to others.

Over at Andrew Revkin's DotEarth, Caldeira offers a really great summation of what this kind of advocacy stance might look like:

The issue of going beyond expertise is an important one.

There is a disease wherein one develops expertise in one area and then feels free to pontificate on other areas about which one knows nothing. This is an affliction of many senior scientists, common even among Nobel Prize winners, and an affliction to which I have not been immune.

If someone is speaking with great confidence while uttering pure hogwash, this does tend to reduce confidence in the utterances of the scientist.

So, there is a cost to science and to our personal credibility when scientists make poorly supported assertions in areas outside of their expertise.

In any case, scientists should be clear when they are making an assertion that is an empirical fact and when they are simply expressing their values and political opinions.

Human beings do have a responsibility to speak out on issues that we feel strongly about.

One way to thread the needle is for climate scientists to speak out loudly and in detail about the areas we know something about — climate change and its consequences — but then speak with a greater degree of generality when coming to prescriptions about what exactly we should do.

In other words, it is one thing to say (as a human being who happens to be a scientist) that we need to stop using the sky as a waste dump for our greenhouse gas pollution. It is another thing entirely to wegh in on specific policy instruments (taxes versus cap-and-trade versus regulations), specific energy technologies, and so on.

It is fine for climate scientists to say (as human beings) that we need policies to rein in greenhouse gas emissions, that to do this we will need energy technologies with near-zero emissions, etc, and that we need to do all of this very soon.

It disturbs me when anyone, including climate scientists, (1) fails to distinguish between matters of empirical fact and matters of values and political opinion, and (2) speaks with an air of authority on topics about which they are largely ignorant.

I do not claim to be entirely innocent of either of these transgressions. Although I work to try to keep myself on the straight and narrow, I do sometimes succumb to temptation.

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