Scott Pruitt on Ocean Acidification: Wrong Again

Credit: Photo by Gage Skidmore / Flickr. Creative Commons

Much has been written about how Scott Pruitt, President Trump’s nominee to head the Environmental Protection Agency (EPA), has tried to reject the science of climate change. Pruitt’s answers to Senators’ questions about ocean acidification—another destructive effect of carbon pollution—follow the same pattern.

Ocean acidification poses a serious threat to sensitive marine species (shellfish such as oysters, clams, crabs, and coral) and the web of life underwater. But it can also seriously harm people by changing the ways we eat, earn a living, and support our communities. Ocean acidification has already cost the shellfish industry of the Pacific Northwest—a $110 million industry—significant amounts of money and has threatened thousands of jobs.

In his responses, Pruitt dodges and weaves in an effort to reject the science of ocean acidification while trying to appear reasonable. But his answers follow the typical pattern of climate deniers.

Here are key examples from Pruitt’s written exchanges with Senators probing his record before voting on his confirmation.

(1) Question: “Do you accept the science of ocean acidification that has directly connected the increase in human-caused carbon dioxide emissions with decreases in ocean pH?”

Pruitt’s response (a): “First, I would note that the oceans are alkaline and are projected to remain so.”

Tactic: Distraction. This is a deliberate effort to distract from the real issue by beginning with a true but unrelated assertion. It’s true that the ocean is alkaline. What’s at issue is that it’s becoming more acidic because of carbon pollution and that has consequences. When scientists say the ocean is “acidifying,” they are not saying the ocean is acidic; they are saying it’s becoming more acidic. 

Fact: Since the industrial revolution, the pH of the world’s ocean surface waters has declined by 0.11 pH units—meaning it has become nearly 30% more acidic, on average. This change is caused by rising carbon dioxide from the burning of coal, oil, and gas. There is no meaningful scientific debate over whether acidification is occurring or what causes it. This is simple textbook chemistry, coupled with thousands of reliable measurements.

Prediction: If we continue on the current trajectory for fossil-fuel use and rising atmospheric CO2, pH is likely to drop by a shocking 0.3 - 0.4 log units by the end of the 21st century and increase ocean hydrogen ion concentration (or acidity) by more than double of what it was in preindustrial times. This degree of change is expected to lead to many species losses, including tropical coral reefs and many economically valuable commercial fisheries.  

Pruitt’s response (b): [I]t is my understanding that the degree of alkalinity in the ocean is highly variable and therefore it is difficult to attribute that variability to any single cause.”

Tactic: Distract from the trend; focus on fluctuations. In this response, Pruitt deliberately overstates the natural variability, to the point of being false. In addition he falsely states that scientists cannot distinguish between short-term variation and long-term trends.

Fact: The alkalinity of open-ocean water does vary naturally, but within a narrow range, roughly between 2200 and 2500 microequivalents per liter. This is much less natural variability than fresh water, which varies forty times more than sea water (and even then, the effects of acid rain are discernible). The progressive increase in acidity over the past two hundred years is discernible in the open ocean, where alkalinity and pH are more uniform. It is also based on thousands of measurements made at numerous locations over many decades.

All scientific experts who have knowledge of this problem attribute the recent decline in ocean pH to rising atmospheric carbon dioxide. There is no alternative explanation supported by any independent scientists. There is no question that it is caused by humans.

(2) Question: Do you accept that the oceans are currently acidifying at a rate unprecedented in tens of millions of years?

Pruitt response: “I am unaware of tens of millions of years of data on the pH of oceans.”

Tactic: Dispute the data. If Pruitt means direct pH measurements, of course we do not have 10 million years’ worth of records. But there are well-established data proving that current changes are unprecedented. Scientists often use proxies, or measurable quantities that closely track the desired but unobserved quantity. Historical ocean pH has been revealed by using shells, or skeletons of marine organisms that lived for the past several million years. (You can often see these remnants when you look at marine sediment or sand.) The ratio of the stable isotopes of boron in the shells of these ancient animals has provided solid evidence that average surface ocean pH has not been much lower than 8.2 for millions of years. This past consistency is striking.

As head of the EPA, it will be Pruitt’s job to protect Americans from toxic and harmful pollutants. Science is at the foundation of this job. Someone who picks and chooses from scientific facts and obfuscates this way, echoing polluters’ false arguments on a critical scientific issue, is the wrong person for the job.