The US-China trade war has been a major topic of discussion this summer. The tit-for-tat sanctions and back-and-forth threats are already beginning to produce unforeseen side effects that will inevitably spread far beyond economics and trade policy. One such arena is the battlefield in the fight against global climate change.

The economic policies of the trade war threaten the very economic buffers that provide nations with resilience needed to adapt to an unpredictable environment: free and flexible international trade. Under policies of free trade, processes of imports and exports allow the market to adjust to shocks such as extreme weather and natural disasters by replacing lost supply from the affected country with production from an unaffected country.

A recent study found that President Trump’s conservative trade policies would cause the cost of climate changed-caused flooding to skyrocket by nearly 500 percent over the next two decades. Initial flood related losses vary greatly from region to region. In the next 20 years, the United States will suffer an estimated $30 billion worth of direct damages, while China will face $389 billion (an increase of 82 percent from the previous 20 years). A major reason for this discrepancy is that flooding in China affects its Eastern and Southern regions, where many crucial ports and factories are located (not to mention huge population epicenters). However, these direct losses are only the beginning of the problem.

Although China would bear the brunt of the direct economic damages, the United States would face far higher indirect losses, reaching $140 billion in the next twenty years. The $140 billion indirect losses need not be so great, the report author argues, and the key lies in the balance of the trade relationship. Whereas China and the European Union have made strides to strengthen trade ties, and will thus better weather the coming storm, the United States is increasingly turning towards economic isolationism, removing the exact mechanisms that could help relieve climate-related economic costs.

A more open, balanced trade network, such as that seen between China and the EU, allows markets to adjust to environmental shocks by transferring production and demand. If one region, say Shenzhen, a coastal city that houses much of the world’s electronics production, is hit by strong storms and ensuing floods one summer, balanced trade relations allow the markets to absorb or dampen economic shocks by shifting demand to a different supplier, possibly one thousands of miles away in Europe. The opposite is also true: if a European factory gets damaged, its supply drop can be picked up by producers in China.

By reducing international trade, however, President Trump destroys these safety nets: “While the president is right to worry about the trade balance, he is terribly wrong to seek reducing trade with other countries. On the contrary, increasing international trade would help climate-proof the U.S. economy.”

In addition to increasing the financial burden associated with climate change, Trump’s trade war has dealt a significant blow to the efforts to combat climate change in the first place.   In January of this year, President Trump placed 30% tariffs on Chinese solar panels, effectively disincentivizing American consumers from purchasing them. . Solar energy is one of the most efficient options on the market to reduce our reliance on fossil fuels, a major contributor to climate change. Furthermore, Trump’s tariffs prompted Beijing to cut subsidies for solar installation, creating a steep drop in the ability of solar power to provide clean energy to China’s huge energy consumption market.

Another unintended effect of the tradewar stems from the Chinese-instituted tariff on American soybeans. Soybeans have the unique ability to to absorb nitrate pollutants from the soil, pollutants that would otherwise end up in Americans’ drinking water. As China represents the largest market for American soybeans, this tariff will prompt a steep decline in soybean production and a corresponding increase increase in the nitrate levels in American drinking water.

There are other ways in which the trade war—and the deteriorating US-China relationship—can do serious damage to environmental protection efforts. Trade wars erode the channels of negotiation needed for cooperation in all diplomatic realms, leading to inefficient use of global resources, and limiting the benefits from the international sharing of technology. As Erik Solheim, executive director of the United Nations Environment Programme recently pointed out, “It will make the entire system for environment, for peace and for development, every issue, much more difficult if we were to see a major trade war.”

Contrary to what the American president thinks, trade wars are not good, nor are they easy to win. The domestic economic impact alone is is devastating, but the consequences go far beyond that. Economic policies need to be considered within a broader context. Tariffs do not fit into a strategy of adaptation and, in fact, threaten the possibilities of global adaptation. Climate change is a universal hazard, and in order to best combat it, we should be working to strengthen international cooperation and economic ties, rather than weakening them.

Hannah Caspar-Johnson is a research assistant at the Institute for China-America Studies.