State Climate Policy Maps


  • Twenty-three states plus the District of Columbia have adopted specific greenhouse gas reduction targets to address climate change.
  • As states fit policies to their unique circumstances, they help innovate and test climate policy design.
  • Policies include carbon pricing, emission limits, energy efficiency mandates and incentives, and steps to promote cleaner transportation.

For years, U.S. states and regions have been addressing climate change in the absence of stronger federal action. A wide range of policies have been adopted at the state and regional levels to reduce greenhouse gas emissions, develop clean energy resources, promote alternative fuel vehicles, and promote more energy-efficient buildings and appliances, among other things. Although climate change ultimately requires an effective national and international response, the actions taken by states and regions play a vital role by developing and testing innovative solutions, delivering near-term emission reductions, and laying the groundwork for broader action.

Twenty-two states plus the District of Columbia have adopted specific greenhouse gas emissions targets. While each state has adopted a target and baseline year that suits its circumstances, the prevalence of these targets shows the widespread support for climate action.

Many other state policies not directly linked to greenhouse gas targets also help reduce emissions. Such policies exist in every state in the nation.

Greenhouse Gas Emissions Targets

Carbon Pricing

One of the most direct policies that states use to address emissions is carbon pricing. Currently, this is only implemented via cap-and-trade programs, though carbon taxes are being considered in a few states as well.

The nine states in the Regional Greenhouse Gas Initiative (RGGI) have implemented cap and trade in the power sector. New Jersey will re-join in 2020 as the tenth state.  California’s cap-and-trade program covers nearly its entire economy. Washington state adopted a trading program that sets individual emissions caps for large sources across the economy (in contrast to the other programs that have a single cap for all covered sources). That policy is currently suspended pending a court ruling. Massachusetts has two separate cap-and-trade programs to reduce GHG emissions in the power sector: It participates in RGGI and also has a separate cap-and-trade program (Reducing CO2 Emissions from Electricity Generating Facilities) that runs in parallel to RGGI.

State Carbon Pricing Policies

States and regions play a vital role by developing and testing innovative solutions, delivering near-term emission reductions, and laying the groundwork for broader action.

Electricity Sector Policies

A wide range of state policies help to reduce greenhouse gas emissions from the power sector. Some were enacted explicitly to address climate change, while others have complementary objectives such as supporting in-state producers of preferred energy sources (typically wind, solar, or nuclear) or reducing customer costs by promoting energy efficiency.

One of the most common state policies is a renewable portfolio standard (RPS) that requires electric utilities to deliver a certain amount of electricity from renewable or alternative energy sources. These are currently in effect in 29 states plus the District of Columbia (another eight states have voluntary RPS programs).

U.S. State Electricity Portfolio Standards

Energy Efficiency Policies

States can promote energy efficiency projects and practices through mandates or incentives. Many states take both approaches. Mandatory energy efficiency policies include building codes that require low-energy features or appliance standards. Currently 15 states plus the District of Columbia have some appliance efficiency standards that exceed federal requirements.

Incentives for energy efficiency are provided chiefly through tax credits and/or rebates for energy efficiency products. Another way to promote energy sector efficiency is decoupling—changes in power regulation that base utility revenue on factors other than volume of electricity sold.

Decoupling Policies

Transportation Policies

A popular policy choice today is providing rebates or other incentives for consumers who purchase electric vehicles. But state policies can reduce transportation sector emissions in other ways as well.

A low-carbon fuel standard (LCFS) is aimed at reducing greenhouse gas emissions by requiring a shift to lower-carbon transportation fuels, such as biofuels, without prescribing a particular fuel type. Currently only California and Oregon have LCFS policies in place. They require fuel providers to continually decrease the carbon intensity of the fuels they sell, and allow for credit trading to reduce costs of compliance.

Land use decisions and public transportation investments also affect transportation sector emissions.


Low Carbon and Alternative Fuel Standard

Climate Resilience

No matter how successful these mitigation policies are at reducing greenhouse gases, climate change impacts will continue to grow. Some states recognize the risks these pose to their businesses and residents, and are taking action to prepare for changes and reduce those risks. Twenty-seven states plus the District of Columbia have either written plans to prepare for climate change or are considering it.