Short answer: None. No US policy change will have an impact on global carbon dioxide emissions or climate change.
President Trump is widely expected to roll back policies aimed at fighting climate change, and to emphasize fossil fuel production, given his denial of the reality of climate change; and the climate-related policies outlined in Project 2025. However, none of those policies will have an effect on global climate change.
For one thing, regardless of any US policy change, it is only one country. Carbon emissions are global. In 2024, the top emitters were China (32%), United States (13%), India (8%), EU (7%), Russia (4%), and Japan (3%), according to the Global Carbon Budget. And, according to the UN, the world is failing to reduce greenhouse gas emissions enough to avoid a major temperature increase.
Although US carbon dioxide emissions are projected to decrease, overall global emissions will continue to rise, according to the Global Carbon Budget. In any case, reducing carbon dioxideemissions will not affect the continuing rise in carbon dioxide levels. Any such reductions are not a sign of “progress,” but rather a lowering of emissions amid a huge, continuing release of carbon dioxide into the atmosphere. Carbon dioxide levels will continue to rise because a large fraction of emitted carbon dioxidehas a hellishly long atmospheric lifetime—measured in centuries. The complexity of carbon dioxide processing in the environment means that millennia will pass before the carbon dioxide emitted today will be thoroughly absorbed.
No Trump policy, however regressive, will accelerate the continuing environmental impacts of climate change—for example, melting of Arctic, Antarctic, and Greenland ice sheets and weakening of the Atlantic Meridional Overturning Circulation.
In fact, an unrelenting global temperature rise is literally baked in because analyses have revealed that there is about a decade-long lag between a given carbon dioxide level and the maximum effect on temperature. And, since carbon dioxide levels have risen steadily over the past decade, so inevitably will temperatures.
President Trump will no doubt withdraw from the Paris Agreement, but that withdrawal will have no effect on climate change. The Agreement is toothless, with fatal structural flaws. Those flaws include that the agreement is voluntary, with no penalties for violating it, and with nebulous wording that allows evasion – e.g. “a Party may at any time adjust its existing nationally determined contribution. . .” What’s more, honoring the agreement would require countries to compromise their economic well-being, for example by giving up lucrative income from fossil fuels. And, no government will risk its survival by seeking to eliminate fossil fuels, given the economic disaster such an effort would create.
President Trump’s administration will likely skip the COP climate meetings. But those meetings have become little more than an empty spectacle that yield only weak, nonbinding declarations. For example, the call in the final text of the UN climate conference COP28 for a “transitioning away from fossil fuels” means nothing because it constitutes little more than naïve handwaving.
That naive advocacy of a phaseout of fossil fuels ignores that they are the overwhelming energy source powering the global economy and will continue to be. For example, coal power continues to increase globally, despite decreases in the US.
President Trump will likely gut policies aimed at encouraging renewable energy development, but such energy sources are trivial compared to fossil fuels. As of 2022, the share of the global energy supply of solar, wind, hydro, geothermal and ocean energy was only 5.5 percent, and renewable energy is failing to meet a goal of rising enough to even come close to replacing the massive contribution of fossil fuels and its huge production infrastructure and plans.
Understanding the impacts—or rather lack of impacts—of President Trump’s policies is critical to grasping the realities of the climate crisis discussed here. Those who warn of a dire climate future have been called “doomists.” It’s a simplistic pejorative of the type used to dismiss the validity of a group without actually examining its legitimacy—e.g. “fake news.” In fact, those who ignore such realities could be termed climate delusionists. Unlike climate denialists who reject the reality of climate change, climate delusionists, particularly scientists, tend to perpetuate comforting fallacies that have downplayed the true impacts of climate change. It is time to realistically face those impacts. It might just propel us to the unprecedented action to save ourselves. As journalist Katarina Zimmer wrote in Undark, “… climate communication should not just be about instilling hope. It means also confronting the worst possible outcomes and the tough, transformative work that lies ahead. That means inspiring not only the optimists among us but the pessimists, too.”
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