Scientific advocacy and the science-policy handshake

I have been meaning to start a blog for some time, but it needed an issue that I felt strongly about to finally turn this intention into a reality. The trigger has been an excellent and thought-provoking piece written by Tamsin Edwards for the Guardian last week, entitled Climate scientists must not advocate particular policies. This generated a passionate debate on Twitter, prompting responses such as these by James AnnanOliver BotheSophie Lewis and Doug McNeall.

At heart is the issue of scientific advocacy and whether there is a “line” that professional scientists should not cross. Should we advocate for some things, but remain impartial at other times so as to preserve our credibility in the public eye?

As I followed the debate online and contemplated my own views on this issue, I found myself turning to the Oxford English Dictionary to check the definition of the word “advocate”:

To act as an advocate for; to support, recommend, or speak in favour of (a person or thing).

But what does this mean for scientists when we enter into the arena of public policy? And should we be entering into this domain at all?

In areas such as climate change, the formulation of good public policy depends upon an accurate understanding of the underlying science (including an understanding of the uncertainties involved). To generate the best possible outcomes for society, it is therefore critically important that scientists do engage with policymakers. After all, we are the ones in the best position to communicate our own science.

The question then becomes one of the “handshake” between scientists and policymakers. What roles should the scientists and the policymakers each play in this exchange of information? How far should the scientific community go when it engages? And are there lines that we should not cross when we make public comments?

Critically important in all this is that people restrict themselves to their own individual spheres of professional expertise. No-one is served when people speak out on issues with which they are unfamiliar.

So, in terms of interaction with policymakers, it is entirely appropriate that we communicate our science and that we offer feedback on proposed policies. However, scientists are not generally experts in the process of policy formulation, and so we should leave this aspect of the process to those that have the appropriate experience. Our own involvement should be restricted to our individual areas of expertise, which will generally be the basic science.

In terms of public commentary, there’s no reason why we shouldn’t comment on policy – but again, bearing in mind that we only serve public debate well when we comment on our own areas of expertise. By all means, let us comment on the underlying scientific basis. But whether one piece of public policy is “better” than another is ultimately a value judgement, involving factors such as economic, social and moral considerations. As professional scientists, we are generally not experts in these areas.

We will undoubtedly have our own personal views. We are, of course, entirely entitled to these. We can, and should, participate in democratic processes, just the same as everyone else. Ultimately, in a democratic society, it is up for the public as a whole to have the final say on policy alternatives via the electoral process – and the public includes us.

However, we threaten our credibility as scientists when we air our personal views in a professional capacity. Offering public opinions on policy alternatives creates the appearance of partiality. And if the public cannot turn to the scientific community as a source of objective information on critical issues such as climate change, then who can they trust? I therefore find myself agreeing with Tamsin’s central argument: that we, as climate scientists, should not advocate for specific policies.

So what does all this mean in terms of science communication? It definitely does not mean that we should retreat to our ivory towers. Rather, it means quite the opposite. Public debate is best served when we contribute by communicating our science strongly and loudly. We should seize on every possible opportunity to share our passion and expertise with the wider public. This is our role as scientific advocates.

However, we should also understand and respect the fact that public debate is best served when all participants restrict their contributions to their own individual areas of expertise. This applies to us as climate scientists, just the same as it applies to everyone else.

Long-term warming, short-term variability: why climate change is still an issue

This article was originally published at The Conversation

new study published today suggests that the short-term warming due to increasing greenhouse gases may be less than previously feared. However, when we look at the bigger picture, we still find that climate change is an issue that demands our attention.

The new work by Alexander Otto of Oxford University and colleagues, published in the journal Nature Geoscience, uses observations of surface temperature and Earth’s heat budget spanning the last 40 years. This differs from many previous studies, which have been based on computer models of the climate system.

The sensitivity of our planet to a doubling of the atmospheric carbon dioxide concentration can be expressed using two different measures. One measure, the transient climate response, describes the immediate, short-term warming. This figure is the one that really matters to policy makers. The other measure, the equilibrium climate sensitivity, describes the long-term commitment once the climate system has come into balance with the enhanced level of greenhouse gases.

Using observations from the period 2000 to 2009, a decade when global warming appeared to slow down, Otto and colleagues obtain a “best estimate” for the transient climate response: 1.3ºC. This is smaller than the value of 1.6ºC obtained when they look at observations from the 1990s instead. We might conclude from this that we need to reduce our estimates of the climate sensitivity.

However, natural variability needs to be considered as well. Internal variations within the atmosphere and oceans matter when we look at just ten years of observations. When Otto and colleagues look at the entire period from 1970 to 2009, the last decade starts to look less unusual. Their best estimate for the transient climate response is now 1.4ºC – just 0.1ºC greater than the value estimated from the last ten years.

This suggests that it might be the 1990s that was unusual, rather then the first decade of the 21st century. Indeed, another recent study by Myles Allen and colleagues evaluates a long-term climate model projection made back in 1999. That projection turned out to be extremely accurate. However, the real world warmed faster than the model prediction during the 1990s, before returning to the predicted long-term trend during the decade that followed.

So natural variability might have caused Earth to warm a little faster than expected during the 1990s. Then, during the following decade, it had the opposite effect, cancelling out some of the warming due to increasing concentrations of greenhouse gases. The period from 2000 to 2009 may therefore have seen the climate system “pausing for breath” before the long-term warming trend continues in future.

Using observations from the past decade, Otto and colleagues derive a best estimate for the long-term equilibrium climate sensitivity of 2.0ºC. This is consistent with the estimates obtained when they look at observations over longer periods of time, including the whole of the period from 1970 to 2009. The apparent slow-down in global warming over the past decade has therefore done nothing to change our best estimates of the long-term response.

This new work by Otto and colleagues refines our estimates of the climate sensitivity, but the overall picture remains unchanged. Even medium-range climate scenarios suggest that the atmospheric carbon dioxide concentration will have doubled, relative to pre-industrial levels, well before the end of the current century. If our emissions of greenhouse gases continue unabated, we still face an uncomfortable future.