For years, economists and environmentalists alike have argued that reducing global trade could help curb the carbon footprint of our modern economy. Yet, despite clear evidence that the transportation of goods across oceans and continents generates massive greenhouse gas emissions, policymakers have largely not addressed this powerful climate lever. That is, until now.

So let me take a moment to express my gratitude to the Republican Party for its enthusiastic embrace of tariffs — an effective, if unintended, tool to mitigate climate change. By slowing global trade, these tariffs are doing what countless climate policies have struggled to achieve by reducing emissions generated by the production and transportation of goods worldwide.

Global cargo shipping accounts for nearly 3% of all carbon emissions, a number projected to rise without intervention. The steel and aluminum tariffs, proposed auto tariffs and broader restrictions on imports from China and other major manufacturing hubs all contribute to a decline in trade flows. 

While the primary intention behind these tariffs may not have been to address climate change, their effect aligns with long-standing economic arguments that shorter supply chains can be more sustainable. 

Reduced dependency on imports means fewer cargo ships burning heavy fuel oil and fewer trucks carrying goods over vast distances, ultimately leading to lower emissions. This is, frankly, an environmentalist’s dream.

For years, many Republicans have been skeptical of government-led climate action, rejecting carbon pricing and emissions regulations as heavy-handed overreach. Yet here they are, enthusiastically backing a policy that achieves the very thing climate-conscious economists have been advocating. Higher costs on global trade make domestic production more attractive. But of course the argument of cost and slower economic growth applies to tariffs as it does for climate policy. Free lunches are rare whether the motive is to protect jobs or protect the environment.

Perhaps the GOP didn’t set out to be the party of climate action. Their tariffs are driven by economic nationalism and a desire to protect American jobs, not necessarily by concerns over rising global temperatures. 

Wyoming’s Republican Sens. John Barrasso and Cynthia Lummis have endorsed the tariffs as a way to hold other countries accountable. Likewise, GOP Rep. Harriet Hageman calls tariffs a tool to re-domesticate a variety of businesses and secure the border against things we do not want. 

Sometimes, good policy happens by accident. Intentional or not, the effect is the same: Tariffs reduce emissions by discouraging unnecessary trade, reshaping supply chains and lowering the carbon footprint of imported goods. If the result is a healthier planet, should we really quibble over motives?

This is a rare moment of bipartisan alignment — albeit an unspoken one — on the importance of curbing global emissions. While climate-conscious policymakers have long struggled to gain traction on carbon pricing or emissions limits, the GOP’s tariff agenda has done much of the heavy lifting for them. The world’s most powerful free-market advocates have accidentally embraced a fundamental principle of climate economics: that trade has a cost, and sometimes, that cost is too high for the planet to bear.

So, to my friends, let me say: Thank you. Thank you for leading the charge in reducing the carbon footprint of global trade. Thank you for doing what climate activists and economists have been urging for years. And thank you for proving that, whether by design or default, conservative economic policies can be a force for environmental good. 

Now, if we could just get you on board with a carbon tax.

Wait, come to think of it — tariffs are a carbon tax on international shipping paid for by U.S. citizens.