Critically Insufficient4°C+
NDCs with this rating fall well outside of a country’s “fair share” range and are not at all consistent with holding warming to below 2°C let alone with the Paris Agreement’s stronger 1.5°C limit. If all government NDCs were in this range, warming would exceed 4°C. For sectors, the rating indicates that the target is consistent with warming of greater than 4°C if all other sectors were to follow the same approach.
Highly insufficient< 4°C
NDCs with this rating fall outside of a country’s “fair share” range and are not at all consistent with holding warming to below 2°C let alone with the Paris Agreement’s stronger 1.5°C limit. If all government NDCs were in this range, warming would reach between 3°C and 4°C. For sectors, the rating indicates that the target is consistent with warming between 3°C and 4°C if all other sectors were to follow the same approach.
Insufficient< 3°C
NDCs with this rating are in the least stringent part of a country’s “fair share” range and not consistent with holding warming below 2°C let alone with the Paris Agreement’s stronger 1.5°C limit. If all government NDCs were in this range, warming would reach over 2°C and up to 3°C. For sectors, the rating indicates that the target is consistent with warming over 2°C and up to 3°C if all other sectors were to follow the same approach.
2°C Compatible< 2°C
NDCs with this rating are consistent with the 2009 Copenhagen 2°C goal and therefore fall within a country’s “fair share” range, but are not fully consistent with the Paris Agreement long term temperature goal. If all government NDCs were in this range, warming could be held below, but not well below, 2°C and still be too high to be consistent with the Paris Agreement 1.5°C limit. For sectors, the rating indicates that the target is consistent with holding warming below, but not well below, 2°C if all other sectors were to follow the same approach.
1.5°C Paris Agreement Compatible< 1.5°C
This rating indicates that a government’s NDCs in the most stringent part of its “fair share” range: it is consistent with the Paris Agreement’s 1.5°C limit. For sectors, the rating indicates that the target is consistent with the Paris Agreement’s 1.5°C limit.
Role model<< 1.5°C
This rating indicates that a government’s NDC is more ambitious than what is considered a “fair” contribution: it is more than consistent with the Paris Agreement’s 1.5°C limit. No “role model” rating has been developed for the sectors.


US emissions are projected to decrease slightly in the next decade, reaching between 6.3 and 6.4 GtCO2e/year by 2025 (excl. LULUCF), and between 6.2 and 6.3 GtCO2­/year by 2030. This level of emissions in 2025 is equivalent to or slightly below (0–2%) 1990 levels of emissions, and only 13 to 15% below 2005 levels. Under this policy scenario, which includes current federal and state level policies, the US will not meet its (already weak) NDC target. The US is very close to achieving the less ambitious end of its 2020 target as current policies are projected to result in emissions of 12% below 2005 levels in 2020 (excl. LULUCF) and its 2020 target is 13–17% below 2005 levels (excl. LULUCF).

Projected emissions in 2030 are lower than the CAT projected in 2018, driven by increased gas and renewables and decreased coal in electricity generation. The EIA’s Annual Energy Outlook 2019 (AEO) projects 8% lower emissions from electricity generation as compared to the 2018 outlook (reference case), despite increased generation overall, with increased electricity generation from gas and renewables, and decreased generation from coal (U.S. Energy Information Administration, 2019). Coal is projected to account for 22% of generation in 2030 (down from the 26% projected in 2018), gas for 38% (compared to 34% projected in 2018), and renewables for 24% (compared to 23% projected in 2018), with nuclear making up the rest.

Since the beginning of 2018, the US Environmental Protection Agency (EPA) has proposed a weak replacement for the Clean Power Plan (U.S. Environmental Protection Agency, 2018a)(U.S. Energy Information Administration, 2018a), has weakened methane emissions standards for oil and gas facilities (U.S. Environmental Protection Agency, 2018b), has proposed freezing emissions standards for light duty vehicles after 2020 (U.S. Environmental Protection Agency, Administration, & U.S. National Highway Safety Administration, 2018), and will not enforce measures to reduce HFC emissions (U.S. Environmental Protection Agency, 2018e).

Depending on the outcome of legal action against some of these proposals (see Columbia Law School Sabin Center for Climate Change Law, 2019 for details), emissions could rise 110 to 185 MtCO2e/yr above the current policy scenario in 2030, which already excludes the Clean Power Plan (see footnote 1 and table in assumptions section). Conversely, increased state and local action, in addition to market pressures, may contribute to additional reductions. An analysis of recorded and quantified commitments from sub-national and non-state actors in the US suggests that if these commitments were fully implemented, they could result in emissions reductions of 17–24% below 2005 levels in 2025 (incl. LULUCF), and thus bring the country within striking distance of its NDC target (America’s Pledge, 2018; Data Driven Yale, NewClimate Institute, & PBL, 2018). These commitments are not included in the CAT current policy scenario unless they are supported by implemented policies (see table below).

Selected state level policies included in CAT projections

The CAT current policy projections for energy-related CO2 emissions are based on the EIA’s Annual Energy Outlook, which includes the following state level policies:

  • California Global Warming Solutions Act of 2006 (SB32)
  • California’s cap and trade system (California Assembly Bill 32)
  • California Advanced Clean Cars program including the Zero Emissions Vehicle program
  • 29 State Renewable Portfolio Standards
  • Northeast Regional Greenhouse Gas Initiative
  • State motor fuels taxes

Also not included in the CAT current policy scenario, but politically important in the US, is the Green New Deal resolution that was introduced in the US House of Representatives in February 2019 (Ocasio-Cortez, 2019). The non-binding resolution calls for reaching net-zero GHG emissions and would serve as an overarching strategy document that would still need to be implemented through specific policies.

The plan broadly addresses all major emitting sectors including targets to meet 100% of power demand through zero-emission energy sources, increase energy efficiency in buildings, grow clean manufacturing, overhaul transportation systems, work with farmers and ranchers to reduce emissions from agriculture, preserve and afforest land, and support other countries to achieve their own Green New Deals.

While the Green New Deal is unlikely to be voted into any kind of law under this administration (the Senate Leader, Mitch McConnell, put it to the vote immediately, and it was rejected 57-0), it nevertheless has sparked a discussion about the need for a much stronger approach to climate action in the US.

Some democratic presidential candidates, including Jay Inslee (Inslee, 2019) and Beto O’Rourke (O’Rourke, 2019), have put forward their own progressive climate plans. Such plans, if implemented through concrete policies, would be a major step forward to reduce US emissions.

Energy supply

The Clean Power Plan (CPP), which the Obama Administration issued under the Clean Air Act, aimed to reduce emissions from the power sector by 32% below 2005 levels by 2030 by setting targets for each state individually. The successful implementation of the CPP would have been an important step in strengthening US climate action.

However, in August 2018, the EPA proposed a replacement for the CPP called the Affordable Clean Energy (ACE) rule that would limit the scope of the plan to emissions reductions inside the fence at individual power plants, for example through efficiency measures or carbon capture and storage technologies and give states the ability to set their own rules (U.S. Environmental Protection Agency, 2018a).

The proposed ACE rule is a significant departure from the CPP, which would have required entire states to meet emissions standards and is likely to result in emissions that are up to 81 MtCO2e/yr higher in 2025 and 212 MtCO2e/yr higher in 2030 than if the CPP had been fully implemented (U.S. Energy Information Administration, 2018a). The latest indication is that the EPA will fully implement the ACE rule in June 2019 (The National Law Review, 2019).

Additionally, the Trump Administration has proposed weakening emissions standards for new coal-fired power plants from the 2015 standard of 635 gCO­2/kWh to between 860 and 1000 gCO2/kWh depending on the type of plant (U.S. Environmental Protection Agency, 2018d). The EPA expects to issue a final rule in September 2019 (U.S. Office of Information and Regulatory Affairs, 2019).

The emissions intensity of total electricity generation in the US has decreased over the past 15 years, from a high point of 631 gCO2/kWh in 2001 to 455 gCO2/kWh in 2015.

Over the same time period, the share of renewables has increased. US government projections expect renewables to reach 24% in 2030 and 31% in 2050 (U.S. Energy Information Administration, 2019). Bloomberg New Energy Finance projects much higher renewables shares of 55% in 2050 (BloombergNEF, 2018). On a global level, Paris Agreement compatibility requires a completely decarbonised electricity sector by 2050 (Climate Action Tracker, 2016a). Utility scale solar PV installations were up 10% in the US in the first half of 2018 from the first half of 2017 (Jan-Jun); coal plant retirements doubled (CAT analysis based on (U.S. Energy Information Administration, 2018b)). Onshore wind installations were down 44% from the first half of 2017 (CAT analysis based on (U.S. Energy Information Administration, 2018b)). At the subnational level, 29 states have mandatory renewable portfolio standards, and nine have voluntary renewable energy targets. Five US cities have already achieved their goals of 100% renewable energy (America’s Pledge, 2017).

In the past, the EPA and the Bureau of Land Management (BLM) have set a series of standards to reduce methane and volatile organic compounds emissions from oil and gas production. However, in 2018, the EPA proposed to change emissions standards for new, reconstructed, and modified sources in the oil and natural gas sector, the effect of which is to allow methane leaks to continue for longer before they are found and fixed (U.S. Environmental Protection Agency, 2018b). The BLM has also reinstated pre-2016 regulations, replacing more recent regulations that were designed to limit methane waste from oil and gas production on public lands (U.S. Bureau of Land Management, 2018).

In 2018, the US became the world’s largest producer of crude oil (U.S. Energy Information Administration, 2018c); it is already the largest producer of natural gas (U.S. Energy Information Administration, 2018d). US LNG exports grew by 53% in 2018 (Lester, 2019). Although natural gas is often seen as a ‘clean’ source of energy, burning it still emits CO2. To achieve the Paris Agreement’s long-term temperature goal, the power sector needs to rapidly transition to being carbon-free by around 2050. This requirement for a complete CO2 emissions phase-out results in a dwindling role for natural gas in the power sector towards the middle of the century (Climate Action Tracker, 2017a).


Through the Significant New Alternatives Policy (SNAP) programme, the Obama Administration prohibited the use of certain hydrofluorocarbons (HFCs) in various end uses in 2015, and specified acceptable alternatives. In April 2018, in light of a court ruling, the EPA announced that it would not enforce the 2015 rule, allowing these HFCs to continue to be used (U.S. Environmental Protection Agency, 2018e). The original SNAP rule was estimated to reduce emissions by 54–64 MtCO2e/yr in 2025 and by 78–101 MtCO2e/yr in 2030 in comparison to a business as usual scenario (U.S. Environmental Protection Agency, 2015). HFCs are among the world’s most potent greenhouse gases, with warming potentials hundreds of times higher than CO2. To meet the requirements of the Kigali Amendment of the Montreal Protocol, which the US has not yet ratified, it would need to implement more stringent standards than the SNAP programme.


In passenger transport, the Corporate Average Fuel Economy (CAFE) standards for Light Duty Vehicles (LDV) limit greenhouse gas emissions from cars and trucks through fuel efficiency and were set through 2025 under the Obama Administration.

In August 2018, the EPA and National Highway Safety Administration (NHTSA) proposed a replacement rule called the Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule that would freeze standards at 2020 values, instead of requiring the phasing in of more stringent standards over time (U.S. Environmental Protection Agency et al., 2018). CAT calculations suggest that this could result in emissions increases of 22 MtCO2e/yr in 2025 and 76 MtCO2e/yr in 2030 (Climate Action Tracker, 2017b). The state of California, joined by other states, has filed multiple lawsuits against this rule, most recently in April 2019, after negotiations with the Trump Administration broke down in February (Volcovici & Shepardson, 2019). The EPA has announced that it plans to release final emissions rules by summer 2019 (Volcovici & Shepardson, 2019), at which time further lawsuits might be expected.

Some states have further programmes to reduce emissions from LDVs, such as California’s Advanced Clean Cars programme (California Air Resources Board, 2012). Ten states have Zero Emissions Vehicle targets (America’s Pledge, 2017), and electric vehicles reached 2% of new vehicle sales nationwide in July 2018 (Kane, 2018). In San Jose, California, 13% of all new vehicles sold in 2017 were electric (Lutsey, 2018). On a global level, the last fossil fuel powered car will need to be sold by 2035 for Paris Agreement compatibility (Climate Action Tracker, 2016a).

In freight transport, the Heavy-Duty Vehicle National Program sets greenhouse gas emissions and fuel efficiency standards for heavy-duty vehicles, which the EPA estimates will reduce emissions by 200 MtCO2/year by 2050 (U.S. Environmental Protection Agency & U.S. National Highway Safety Administration, 2016). To be compatible with the Paris Agreement’s long-term goal, freight trucks need to be almost fully decarbonised by around 2050 (Climate Action Tracker, 2018).


The US has numerous federal and state level policies in the buildings sector, primarily focused on energy efficiency. These include the National Appliance Energy Conservation Act of 1987, with appliance standards that have been updated as recently as 2015, and the Energy Policy Act of 1992 and 2005, which includes whole house efficiency minimums. The EPA runs the Energy Star program, which uses a voluntary labelling system to increase consumer awareness of energy efficiency (U.S. Environmental Protection Agency and U.S. Department of Energy, 2019).

The US does not have federal targets for constructing net zero energy buildings (nZEBs), although the states of California and Massachusetts do. This is in contrast to the EU, for example, which requires all new buildings to be nZEBs starting in 2020. For Paris Agreement-compatibility, all new buildings globally should be nZEBs starting in 2020, and renovation rates should increase to 3–5% per year (Climate Action Tracker, 2016a).


The US Department of Agriculture (USDA)’s “Building Blocks for Climate Smart Agriculture & Forestry” foresees a set of voluntary activities involving farmers and companies (U.S. Department of Agriculture, 2015). The measures target reductions in emissions from agriculture (e.g. improved fertiliser use and other agricultural practices, avoiding methane from livestock) and land use and forestry (e.g. improved soil management, avoid deforestation and reforestation).


Historically, the LULUCF sector has been a net sink for greenhouse gas emissions in the US, ranging between 0.6 and 0.8 GtCO2e annually between 1990 and 2017. The achievement of future mitigation targets can also depend on the level of sinks coming from the forestry sector (LULUCF): the 6th National Communication, used in the CAT analysis, projected that the US forestry sector will absorb between 0.6 and 0.9 GtCO2e/year between 2020 and 2030 (10–17% of the NDC target) (U.S. Department of State, 2014). In the 2nd Biennial Report, these numbers were revised upwards, with a projected forestry sector sink of between 1.0 and 1.2 GtCO2e/year in 2020, 0.9 and 1.2 GtCO2e/year in 2025 (16–23% of NDC target), and 0.7 to 1.1 GtCO2e/year in 2030. These higher values would make it easier for the US to achieve its NDC.


The EPA finalised standards to reduce methane emissions from new, modified, and reconstructed municipal solid waste landfills in 2016. In October 2018, the EPA proposed to amend the standards, postpone the compliance period, and postpone the due date for state plans to limit methane emissions from landfills (U.S. Environmental Protection Agency, 2018c). This could mean increased emissions from landfills in the future.

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