April 22 marks Earth Day, a celebration long marked by festivals, concerts, clean-ups and nature activities. It’s also an occasion to look at the environmental movement kickstarted in 1970 that has evolved—through public policy, government regulation and activism—from an early focus on conservation to an attempt to meet the enormous challenges presented by climate change.
In international affairs education, environmental policy has become an important area of study, intersecting with security, public health and human rights in ways that impact the lives of billions. SFS Professor Marcus King—director of one of SFS’s newest degree programs, the Master of Science in Environment and International Affairs (MS-EIA) with The Earth Commons—answers questions about current U.S. environmental policy, the move toward renewable sources of energy and the changing attitudes animating the green movement over the past five decades.
Q. Earlier this year, the Trump Administration repealed the Endangerment Finding, the central legal underpinning for U.S. climate policy since 2009. What have the immediate impacts of this decision been for climate policy?
A. The Endangerment Finding was the EPA’s 2009 determination under the Clean Air Act that six greenhouse gases endanger public health and welfare and that motor vehicle emissions contribute to that harm. EPA’s 2025–2026 rescission of the Endangerment Finding removes the legal basis for federal regulation of greenhouse-gas emissions expressly tied to motor vehicles and repeals those emissions standards. Broader pollution source-category rollbacks still require their own rulemakings. While the repeal of the finding itself does not automatically eliminate all downstream climate rules tied to vehicles, including state-level measures, it significantly weakens the federal climate regulatory framework. The repeal shifts more responsibility to states and other statutes and creates substantial legal uncertainty as the rescission is now challenged in court. Most importantly, the immediate policy effects are for now more symbolic than tangible, because the repeal represents a dramatic shift in federal attitude toward the overall applications of climate regulations.
Q. The U.S. Department of the Interior is paying TotalEnergies, a French company, $1 billion to stop plans to build two wind farms off the coast of North Carolina and the coast of New York. What is the current state of renewable energy in the U.S.?
A. U.S. renewable energy is actually in a strong but paradoxical position: it is expanding rapidly in market terms, especially in solar and battery storage, even as federal policy has become more hostile to parts of the sector, particularly offshore wind. Developers plan to add a record 86 GW of new utility-scale capacity in 2026, with solar, batteries and wind accounting for the vast majority of those additions, and wind and solar together already produced a record 17% of U.S. electricity in 2025. At the same time, actions such as the Interior Department’s agreement with TotalEnergies to terminate offshore wind leases underscore that Washington is now creating greater regulatory and political risk for renewable deployment. The result is a renewable sector that is still growing but in a less stable and more fragmented policy environment, with increasing reliance on state governments, private markets and other more local support rather than the consistent federal backing it had enjoyed in the past.
Q. As part of the ongoing war in Iran, the U.S. Navy had begun a blockade of Iranian ports in the Strait of Hormuz, itself an attempt to punish Iranians for acting to block access to the Strait for the 20% of the world’s energy shipments that typically pass through. What kind of progress has been made to move the world’s economy away from fossil fuels?
A. Major progress has been made in building alternatives to fossil fuels, particularly in the electricity and transportation sectors, but the global economy remains structurally exposed to oil and gas shocks such as a disruption in the Strait of Hormuz. Clean energy investment now exceeds fossil-fuel investment by roughly two to one, global renewable power capacity is projected to expand by about 4,600 GW between 2025 and 2030 and more than one in four cars sold worldwide in 2025 is expected to be electric. These trends reflect meaningful momentum in the global energy transition and suggest that the world is gradually reducing its long-term dependence on hydrocarbons. Even so, fossil fuels still underpin shipping, aviation, heavy industry, petrochemicals and much of global trade, meaning the transition is real but not yet far enough advanced to shield the world economy from a major supply shock in the Gulf.
Q. Earth Day was established in 1970 at the dawn of the modern environmental movement. How have public attitudes towards environmental policy evolved in the last 50 years?
A. Since Earth Day’s launch in 1970, American public attitudes toward environmental policy have evolved from broad bipartisan support for controlling visible pollution like smog to a more polarized debate centered on climate change, high energy prices and the proper role of government in environmental protection. Most Americans still believe the country as a whole should do more to protect the environment, and many continue to support specific measures related to clean energy, resilience and public health. At the same time, partisan divisions over climate policy have arisen and grown much sharper than they were in the early decades of the modern environmental movement. This is especially true as environmental issues have become more closely tied to broader ideological conflicts. In that sense, public concern about environmental degradation has remained strong, but political consensus about how to respond has really weakened significantly over time.
Q. What would you say to a student who wants to work on climate policy but is discouraged by the climate policy actions of the Trump Administration?
A. I am often asked this question by my students in the Master of Science in Environment and International Affairs Program (MS-EIA). I tell them that it has never been more urgent for students to meet the moment and study the global environmental crisis. Now is the time to gain scientific literacy and policy knowledge and develop an ethical framework that foregrounds environmental justice so that they can make up for lost ground as political conditions change in the coming months and years.