Delaware is the second smallest state by land area, the sixth least populated state in the US but also the sixth most densely populated. According to the NOAA’s State Summary, Delaware has warmed over 3 degrees (F) since the beginning of the twentieth century. Delaware will also face more intense heat waves, more frequent heavy rainstorms, and rising sea levels, which will especially put it at risk as the lowest-lying state. Sea levels have increased by 15 inches in Delaware since the early twentieth century. Higher water levels are eroding beaches, submerging lowlands, exacerbating coastal flooding, and increasing the salinity of estuaries and aquifers. In the coming decades, the changing climate is likely to accelerate flooding harming marine, wetland, and inland ecosystems; disrupting farming; and increasing some risks to human health.
Delaware produces the least total energy of any state, and uses less energy than all states but Vermont and Rhode Island. Delaware has no crude oil or natural gas reserves. Its largest energy supply comes from natural gas, largely transported from Pennsylvania. Delaware began transitioning its electricity generation from coal to natural gas in 2010, and the state’s last coal-fired power plant was retired in February 2025. Delaware generates none of its own energy except in the renewable energy sector, which, in 2025, was responsible for 8% of the state’s net electricity generation (up from 2% in 2018). Solar made up the most of this generation, contributing 7% in 2025. While the state has 16 utility-scale solar power plants, the majority of the solar energy generated came from small-scale, consumer-based sites like rooftop solar panels. Biomass accounts for the second largest share of renewable generation. The state has three biomass power plants and a fourth one in development that will utilize chicken manure. Some environmental groups are opposed to the plant, claiming it will worsen climate change and environmental injustice.
In December 2019, Delaware joined a coalition of mid-Atlantic and Northeastern states (PA, NY, NJ, VA, MA, MD, CT, ME, DE, RI, VT and the District of Columbia) in drafting a plan for a multi-state gasoline cap-and-trade program. The plan’s aim is to reduce transportation-related tailpipe emissions, levying a tax on fuel companies based on carbon dioxide emissions. The most ambitious version of the plan is projected to reduce the area’s tailpipe emissions by 25% between 2022 and 2032. Transportation is the leading source of planet-warming emissions in 10 of these eleven states.
In the spring of 2020, State Senator Harris McDowell proposed new legislation to update the Renewable Portfolio Standard. Signed by Governor John Carney in February 2021, the legislation raised the state’s Renewable Portfolio Standard— which sets requirements for the amount of renewable electricity Delmarva Power must source—to 40% by 2035.
In 2021, Delaware released its first Climate Action Plan under Governor John Carney. According to the executive summary, the Plan outlines a path for the state to minimize greenhouse gas emissions and maximize resilience to climate impacts.
The Climate Change Solutions Act of 2023 requires regular updates to the 2021 Climate Action Plan in the form of an Implementation Report every 2 years. The Act also created Climate Change Officers for state agencies and set a greenhouse gas emissions reduction target of 50% by 2030 and net-zero by 2050.
The first CAP Implementation Report (2023) outlined policies, programs and progress since the Plan was released in 2021. These included a law requiring commercial buildings to include a solar-ready zone on the roof, an Ocean and Bay Plan for offshore wind, the Green Energy Fund’s Low-to-Moderate Income Solar Pilot Program and a Clean Vehicle Rebate program. Governor Carney’s Tree for Every Delawarean Initiative was launched in 2021, a reforestation program with the goal of planting one million trees in the state by 2030. According to the tracker, over 400,000 trees have been planted thus far under the program.
Multiple towns in Delaware have released their own comprehensive Climate Action Plans including New Castle County’s NCC2050, Rehoboth Beach, Middletown and Odessa’s climate action plans, and Wilmington’s “Resilient Wilmington” & “A Plan for Restoring Wilmington’s Rivers.”
In September 2024, Governor Carney signed a package of laws relating to climate change, including a bill to develop offshore wind, another to provide financial assistance for electric vehicle equipment, and another to convert all state vehicles to electric by 2040.
Delaware’s most recent and most ambitious Climate Action Plan was released in December 2025. Estimating that climate change will cost Delaware over $1 billion if nothing is done, the plan identifies four main high-level goals: Toward Net-Zero Emissions, Protecting Our Communities, Land Use Intersections, and Preparing Delaware’s Workforce. Specific strategies outlined in the plan include expanding electric vehicle infrastructure (with the state also releasing a separate Roadmap to Electric Vehicle Plan in 2025), developing offshore wind, modernizing the electric grid, disaster preparedness, sustainable and heat-resilient design practices, protection of wetlands and forests to promote carbon sequestration, and integrated analyses of climate change, housing and land use. The next Implementation Report will be due in 2027, and the next updated Climate Action Plan will be due in 2030.
In March 2026, Senator Stephanie Hansen introduced the Wetlands Stewardship Act which would create Delaware’s first combined wetlands preservation program. Following a 2022 report that found 30,000 acres of wetlands remain unprotected in Delaware - which has since risen to 75,000 acres after the Supreme Court’s Sackett decision - the legislation would establish state-level protections for wetlands, as federal protection is lacking.
Delaware is one of twenty four states and territories committed to the U.S. Climate Alliance, which is working to implement policies that advance the goals of the Paris Agreement.
Delaware established an Environmental Justice Office in 2023. The EJ Office develops digital mapping tools, provides weatherization assistance and wastewater assistance, and manages the Community Environmental Project Fund, which in 2026 is funding projects such as cleanups in a parkland riddled by illegal dumping, planting a native tree barrier, and a solar powered irrigation system at a community garden.
Organizers across environmental and political groups in the state have recently come together to form the Delaware Data Center Coalition for Local, Environmental and Accountable Regulation (DE-CLEAR) to protect residents from the environmental impacts and rising electricity costs associated with hyper-scale data centers by demanding accountability, transparency, education, and increased guardrails for development. The group secured a victory in February 2026 when the state’s Department of Natural Resources and Environmental Control decided a proposed hyperscale data center was prohibited from development in a coastal zone. There are also currently two bills proposed in Delaware’s legislature regarding potential guardrails for data center development.
Watch this Data Center Impacts and Community Organizing Forum held by Sierra Club Delaware in February 2026.
The Trump administration has heavily impacted Delaware’s clean energy goals by cutting millions in funding for state projects, pausing offshore wind development, and repealing environmental regulations.
Despite these actions, Delaware officials have challenged these moves through lawsuits, including joining a suit against the EPA's rollback of air quality standards and challenging the cancellation of offshore wind projects. Furthermore, the state has continued to push its own sustainability goals, releasing a 2026 climate plan designed to cut emissions by 50% by 2030, despite the federal shift in policy.
CREDIT: DNREC
