With over 13 million residents, Pennsylvania is the fifth most populated state in America, behind only California, Texas, Florida, and New York. It is the 33rd largest in the US, with 46,055 square miles and forests covering 58% of its land. The commonwealth also has many lakes, rivers, and wetlands.
CLIMATE IMPACTS
- In the wake of climate change, Pennsylvania is facing more flooding, heat and respiratory deaths, as well as disruptions to its agricultural systems. Like other northeastern states, Pennsylvania will see far more rainfall and extreme weather than experienced in the past. Already, between 1958 and 2010, the Northeast saw more than a 70% increase in precipitation during powerful weather events. Under updated state modeling, average annual precipitation is projected to increase by 9% by 2050, driven by a staggering 15% spike in very heavy precipitation events.
- While the Pennsylvania Department of Transportation historically absorbed over $105 million extra in emergency costs during the unprecedented floods and landslides of 2018, these events foreshadowed a much larger budget crisis. Landmark economic assessments indicate that Pennsylvania municipalities now face over $15 billion in cumulative climate adaptation and road resilience costs by 2040—including nearly $3 billion for climate-related road maintenance, $935 million for landslide protection, and $268 million to structurally reinforce vulnerable bridges against extreme rainfall.
- Rising sea levels could exacerbate the risk of coastal flooding along the Delaware River and Estuary, threatening the tidal wetlands, ecosystems, infrastructure, and drinking water supplies, and Lake Erie is also projected to experience changes in water level, temperature, quality and coastal erosion.
- Pennsylvania is one of seven states in the Mid-Atlantic and Northeast to have record sweltering heat in July 2020, with records dating back to 1895. However, this trend has dramatically escalated. During the historic July 2026 heat wave—which became the hottest single month ever recorded in U.S. history—Pennsylvania experienced unprecedented local extremes. Philadelphia shattered a 153-year-old record by exceeding 101°F for three consecutive days, while the Susquehanna Valley endured its hottest weather in 15 years, prompting widespread grid strain and acute health emergencies.
- Revised climate assessments now project that average annual temperatures in Pennsylvania will surge by 7°F by mid-century, pushing the state to an average of 37 days per year reaching at least 90°F. As temperatures rise, heat deaths rise too; the 2026 heat dome alone caused over 1,300 emergency room visits across the state in a single week. This extreme heat also leads to increased air pollution as it slows air flow and aids a reaction that creates ground-level ozone. Localized health data highlights severe regional risks, with fine particulate matter (PM2.5) pollution now estimated to account for roughly 11% to 12.5% of all adult deaths annually within major hubs like the Pittsburgh metropolitan region.
- Pennsylvania’s increasingly frequent hot days and extreme weather events are taking a severe toll on agriculture, one of the state’s most important industries. In just one example, a Penn State study found that corn production in Southeastern PA was especially vulnerable to the effects of climate change. This has cascading effects on Pennsylvania’s dairy industry, where corn is a major food for cows. Climate change’s effect on rainfall is also causing farmers to resort to irrigation, which has historically been unnecessary in Pennsylvania. Farmers also endure the extra expense of adding more cover crops in order to protect their soil against erosion. Furthermore, shifting climates are driving massive regional realignments; as southern states become too hot, heavy agricultural investments are pushing northward, with livestock and poultry farming in Pennsylvania projected to nearly double by 2050, introducing entirely new watershed and runoff management challenges for the commonwealth.
- Faced with these crushing financial burdens, a growing movement of local leaders and climate advocates is fighting to shift the multi-billion-dollar cost of climate resilience away from local taxpayers and onto major fossil fuel corporations. Landmark corporate accountability efforts took center stage when Bucks County filed a historic lawsuit against major oil giants, accusing them of intentional public deception regarding climate risks and demanding compensation for climate-related damages. While the initial state-level suit faced intense jurisdictional battles and was dismissed by a judge who ruled that greenhouse gas regulations are strictly a federal matter under the Clean Air Act, local advocates continue to push for legal accountability. Polling indicates that 90% of Pennsylvania voters support making oil and gas companies pay for these municipal adaptation costs, driving ongoing legal strategies and multi-state coalitions aimed at forcing polluters to pay their fair share for the infrastructure upgrades protecting the state’s communities. The lawsuits, as of October 2026, have not yet succeeded.
ENERGY
Pennsylvania is the nation's third-largest net energy supplier and third-highest electricity generator, trailing only Texas and Florida. It holds nearly all U.S. anthracite coal reserves—making it the only state that produces it—and ranks second in both natural gas reserves and nuclear capacity. Because of this massive footprint, Pennsylvania's energy policy shifts significantly impact the entire country.
Natural gas has led state generation since 2019, supplying roughly 59% of total electricity, followed by nuclear at 31%. Conversely, coal generation plunged from 36% in 2014 to just 5%, driven by 5,300 megawatts of retirements. Renewables provide the remaining 5%, led by wind energy. Despite early clean energy goals, Pennsylvania now ranks an abysmal 47th in renewable energy growth due to a heavy reliance on natural gas.
This reliance faces a new turning point as massive tech data centers drive up energy demands. In a landmark deal, Constellation Energy partnered with Microsoft for a $1.6 billion restart of the dormant Unit 1 reactor at Three Mile Island, now the Crane Clean Energy Center. Backed by a $1 billion federal loan, grid-rights waivers, and a favorable Nuclear Regulatory Commission environmental review, the 835-megawatt project is fast-tracked for a 2027 restart to power Microsoft’s AI infrastructure. Even with this nuclear pivot, fossil fuel interests remain politically dominant; Republican Attorney General Dave Sunday was elected in 2024 with heavy backing from oil and gas political action committees.
CLIMATE PLANS AND LEGISLATION
- Pennsylvania established its Alternative Energy Portfolio Standards Act (AEPS) in 2004, requiring utilities to buy a specific percentage of electricity from renewable and environmentally beneficial sources by 2019. These alternative energy resources include byproducts of pulping and wood manufacturing, landfill methane gas, geothermal energy, low-impact hydropower, and fuel cells. To modernize this decades-old framework, the state legislature is actively evaluating a massive regulatory overhaul known as the Pennsylvania Reliable Energy Sustainability Standard (PRESS). Introduced under Governor Josh Shapiro's comprehensive energy agenda, PRESS aims to mandate that utilities source 35% of their electricity from clean energy resources by 2035.
- In 2008, the state passed the Pennsylvania Climate Change Act, requiring an annual greenhouse gas (GHG) emissions inventory administered by a Climate Change Advisory Committee, alongside triennial Climate Change Impacts Assessments and updated Action Plans. Complementing this overarching strategy, Pennsylvania’s Green Energy Loan Fund (GELF)—created in 2009—reached a milestone of over $30 million invested in low-interest loans for high-impact efficiency upgrades, successfully averting 110,000 tons of carbon dioxide emissions since its inception.
- By 2019, Executive Order 2019-1 committed the commonwealth to striving for a 26% reduction in GHG emissions by 2025 and an 80% reduction by 2050 (relative to 2005 levels), while creating the GreenGov Council to enforce sustainability benchmarks across state executive agencies. These benchmarks were heavily integrated into the Pennsylvania Climate Action Plan 2024 Under Governor Josh Shapiro, the commonwealth leveraged these strategies to submit its Priority Climate Action Plan (PCAP) to the federal government. This directly secured a landmark $396 million Climate Pollution Reduction Grant from the EPA to launch the Reducing Industrial Sector Emissions in Pennsylvania (RISE PA) program, a statewide initiative providing competitive decarbonization incentives to the industrial sector—the state's highest-emitting sector.
- Pennsylvania’s broader climate strategy underwent a historic structural realignment following the official termination of the state's multi-year effort to join the Regional Greenhouse Gas Initiative (RGGI). After state courts blocked the multi-state cap-and-trade program, Governor Shapiro pivoted to a state-specific alternative called the Pennsylvania Climate Emissions Reduction (PACER) program. Designed to establish an independent, Pennsylvania-controlled carbon pricing mechanism, PACER structurally guarantees that 70% of all generated cap-and-invest revenues are funneled directly back to Pennsylvania households via electric bill rebates to shield consumers against rising energy costs.
COLLABORATIONS WITH OTHER STATES
Pennsylvania announced in 2020 that it would join seven other states (Kansas, Maryland, Louisiana, Montana, North Dakota, Oklahoma, and Wyoming) in committing to develop a safe carbon dioxide transport and storage infrastructure plan. By October 2021, those states released their Regional CO2 Transport Infrastructure Action Plan, detailing policies for states to consider to facilitate carbon infrastructure project deployment, enhance capture safety, and optimize project financing.
Furthermore, Pennsylvania officially joined the U.S. Climate Alliance in 2019 under former Governor Tom Wolf. The commonwealth stands alongside a bipartisan coalition of 24 state governors -- alongside the leadership of Puerto Rico, American Samoa, and Guam—representing approximately 60 percent of the U.S. economy and 55 percent of the U.S. population—committed to implementing state-level frameworks that advance the goals of the Paris Agreement. Under this alliance, Pennsylvania collaborates on key cross-border strategies, including establishing robust building energy efficiency standards, implementing methane data integrity efforts, and building out resilient regional clean energy incentives.
ENVIRONMENTAL JUSTICE
Pennsylvania has emerged as an "epicenter of the data center boom," drawn by cheap land and heavy power connections in old coal territory. In the borough of Archbald, major data center campuses have sparked fierce resistance from the grassroots group Stop Archbald Data Centers, which has mobilized residents to crowd-fund legal counsel against industrial encroachment into residential zones. Furthermore, developers are targeting the state's abundant abandoned coal mines, offering to offset cleanup costs to build on the land. However, building on legacy sites introduces complex risks to mining communities already facing lower median incomes and generational pollution.
In response, Senator Katie Muth introduced Senate Bill 1359, proposing a three-year moratorium on hyperscale data center permitting. Governor Josh Shapiro also signed Executive Order 2026-05, removing these projects from fast-track permitting, banning corporate nondisclosure agreements, and forcing developers to pay for their own grid upgrades to shield consumers from rising utility rates.
These policies are backed by a landmark report from Data & Society. Tracking Pennsylvania's 66 active or proposed data center projects, the study found little evidence of long-term job growth and warned that the massive land, water, and energy footprints of the AI industry repeat a historical pattern of industrial exploitation. For more, see PennFuture’s legal work defending the Environmental Rights Amendment, the Penn State Climate Consortium, the Philadelphia Climate Justice Collective, and Pennsylvania Action on Climate.
For more on environmental justice in Pennsylvania, see PennFuture’s legal work defending the Environmental Rights Amendment, the Penn State Climate Consortium, the Philadelphia Climate Justice Collective, and Pennsylvania Action on Climate.
