These are highly politicized times, and, in this context, scientists may feel compelled into taking sides on important policy issues. But, at a time when hypothermic pipeline protesters are pitted against oil-company cabinet picks, scientists should stay true to doing what they are best at -- providing evidence to inform wise decision-making. Our newest science finding regarding the Deepwater Horizon oil spill provides a good example of why.
Six years ago, during that spill in which 160 million gallons of oil gushed for 87 days into the Gulf of Mexico, the responders had a decision to make: whether to inject chemical dispersants at the bottom of the ocean floor and sea surface.
From a scientist's point of view, the Gulf of Mexico is a vast beaker and this disaster represents a massive unprecedented experiment that we can learn lessons from and apply to future oil spills: What happens to a mega-infusion of oil spilled in the cold ocean depths? Was discharging 1.6 million gallons of chemicals into the ocean to disperse the oil good or bad for the environment?
The decision to use dispersants remains controversial, and it seems counterintuitive that adding unnatural chemicals to the environment could be beneficial. On the other hand, we do it routinely to combat perceived larger threats: we drop flame retardants to control wildfires and use chemotherapy to stop cancer in the smaller environment of our bodies.
People on either side of the issue seem convinced that dispersants are an extremely useful or dangerous tool, but there has been little field-based evidence to support either view. That's because studying oil spills is hard, especially in the earliest stages, when it reasonably takes a back seat to the more pressing issues of saving lives and reducing damages. Studying a spill during an active response is akin to asking firefighters to step aside, so we can sample some smoke or water runoff from the burning home. But once the fire is out, only forensics remain.
Our forensic investigation of the Deepwater Horizon oil spill has involved many field-based investigations and analyses. We have published >20 papers on aspects of the spill, and in a study we published last month in the Proceedings of the National Academy of Sciences, we examined what happened to the portion of Deepwater Horizon oil that settled on the deep seafloor.
When it comes to degrading oil in the environment, it is all about the microbes: what they will eat, and how fast. We uncovered evidence that microbes ate oil more readily when it came in smaller oil droplets suspended in water before it clumped with other material and settled to the seafloor. That is just what dispersants do: They break up oil into smaller drops so that they don't readily clump together or settle, but rather disperse in the ocean. They also temporarily increase the availability of some toxic compounds to sea life until the pollution levels decrease from dilution.
In short, we have compelling circumstantial evidence that dispersants may have boosted the breakdown of spilled oil. That is a useful finding, right? But how will our study be assessed by the public, the media, and people with strongly held emotions, opinions, and agendas? And how will those opinions influence officials faced with a decision on whether or not to use dispersants during the next oil spill?
In this case, the National Academy of Sciences is planning to perform an objective, fact-based, science-rich review of dispersants. But that's only useful if people will listen with open minds to evidence.
In our current polarized political climate, people increasingly are predisposed to conclusions before hearing the evidence. Or they ignore, spin, or debunk evidence, and sometimes create unsubstantiated facts, to buttress their positions.
Against this backdrop, many scientists feel that their voices are being drowned out, and that is stirring more scientists to step beyond their role as evidence collectors to become activists. We do need to be more active about communicating our findings to help policymakers make the wisest decisions. But as scientists, we believe our greatest value lies in holding--not crossing or blurring--the line that separates science from activism.
If we fail to remain independent, objective and apolitical, we risk attacks that will further mute the collective voice of all scientists.