Tar sands are the dirtiest fossil fuels. These are low-quality heavy tar-like oils that are mined from sand or rock. Much of the mining occurs in Alberta Canada, but it is also mined elsewhere, in lesser quantities.

Tar sands are the worst. Not only are they really hard to get out of the ground, requiring enormous amounts of energy; not only are they difficult to transport and to refine; not only are they more polluting than regular oils; they even have a by-product called “petcoke” that’s used in power plants, but is dirtier than regular coal.



This stuff is worse than regular oil, worse than coal, worse than anything. Anyone who is serious about climate change cannot agree to mine and burn tar sands. To maintain climate change below critical thresholds, tar sands need to be left in the ground.

This fact is what motivated me to testify to the Minnesota Public Utilities Commission last November, to inform my state’s ruling commission about the impact of tar sands on the climate. Canadian energy company Enbridge has petitioned to put a pipeline through my state to carry this dirty tar to refining sites on the coast.



The proposed pipeline is called “Line 3.” The pipeline would carry approximately 760,000 barrels per day – the new pipeline would make it easier and cheaper for the oil companies to transport tar sands and consequently, would boost their bottom line. We already move over two million barrels per day through Minnesota in Enbridge pipelines. This new pipeline would encourage them to extract and sell more tar sands.

So, how much pollution would this pipeline carry? 170bn kilograms of carbon dioxide each year. The emissions are equal to approximately 50 coal power plants. These are huge numbers, but more importantly, approval of pipelines like this make it more likely that all of the tar sands in Alberta will be extracted. If that happens, global temperatures will increase by approximately 0.65°F (0.36°C). An astonishing number – approximately three decades worth of global warming.

If you care about climate change, then it is not logically possible to approve any pipeline or other infrastructure that may further worsen our climate. We are already screwing up the climate enough as it is.



The decision-making body in my state has heard climate arguments before. In fact, in 2016, the same body ruled against the coal giant Peabody. That ruling decided that fossil fuel companies low-balled the social cost of carbon. Back then, Peabody brought in a group of climate contrarians to argue their nonsense. My colleagues and I were able to convince the Commission that the facts were clear – we are causing climate change, and our decisions today can make tomorrow’s climate worse. This ruling was used when evaluating the social cost of carbon pollution for a new Line 3 pipeline. A judge found that emissions from this project would impose $287bn in social costs over 30 years.

In this case, the oil company Enbridge did not invite any contrarian climate scientists. They simply focused on arguments that a new pipeline will be safer to operate (fewer spills) and lessen other issues like rail traffic. They effectively conceded the climate arguments.

The decision will be revealed later this month. But already, an Administrative Law Judge has given a recommendation that the new pipeline be built, but in the exact same location as the current pipe. While this recommendation presents large costs to Enbridge, it completely misses the science. The judge’s opinion made no mention of climate change. How can a decision on extracting tar sands be made without considering climate effects?

Just last week, the staff of the commission also recommended construction of the new pipeline. They too omitted climate change from their decision.

I was proud to be able to stand alongside tomorrow’s leaders. Courageous youth became parties to the litigation and helped arrange the testimony of various climate experts like myself. One of the youth involved in the litigation, Frances Wetherall, summarized her view and told me why she was involved in the case.

With every barrel of oil burned, my future children and grandchildren’s chances of a long and happy life diminish. I can’t stand by while Big Oil profits off the destruction of future generations.

Whether or not these youth prevail in this case, their courage, intelligence, and drive give me hope for a better future.

Frances Wetherall, a youth involved in climate litigation

I am hopeful that the commission dismisses these opinions. It is clear to me that not only must tar sands be kept in the ground, but actions to assist in their extraction make one complicit. I believe that decisions have consequences and we must take responsibility for our decisions. We cannot say “climate matters” and then facilitate tar sands extractions. We also cannot say “we didn’t know” when our children ask us why we made poor decisions.

I would hate to be a fossil fuel lawyer, or executive, or lawmaker who fights for climate destruction today and has to justify his actions to his kids tomorrow. History will be a very harsh judge to them; but of course it will be too late for the rest of us.

I’ve said this before and I will say it again, if we cannot say no to tar sands, what can we say no to?

Disclosure: I testified as an unpaid expert witness on behalf of Youth Climate Intervenors.