The United States is pleased to communicate its intended nationally determined 

contribution, as well as information to facilitate the clarity, transparency, and 

understanding of the contribution.

The United States is strongly committed to reducing greenhouse gas pollution, thereby 

contributing to the objective of the Convention. In response to the request in Lima to 

communicate to the secretariat its intended nationally determined contribution towards 

achieving the objective of the Convention as set out in its Article 2—the stabilization of 

greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous 

anthropogenic interference with the climate system—the United States intends to achieve 

an economy-wide target of reducing its greenhouse gas emissions by 26-28 per cent 

below its 2005 level in 2025 and to make best efforts to reduce its emissions by 28%. 

The target is fair and ambitious. The United States has already undertaken substantial 

policy action to reduce its emissions, taking the necessary steps to place us on a path to 

achieve the 2020 target of reducing emissions in the range of 17 percent below the 2005 

level in 2020. Additional action to achieve the 2025 target represents a substantial 

acceleration of the current pace of greenhouse gas emission reductions. Achieving the 

2025 target will require a further emission reduction of 9-11% beyond our 2020 target 

compared to the 2005 baseline and a substantial acceleration of the 2005-2020 annual 

pace of reduction, to 2.3-2.8 percent per year, or an approximate doubling.

Substantial global emission reductions are needed to keep the global temperature rise 

below 2 degrees Celsius, and the 2025 target is consistent with a path to deep 
decarbonization. This target is consistent with a straight line emission reduction pathway 

from 2020 to deep, economy-wide emission reductions of 80% or more by 2050. The 

target is part of a longer range, collective effort to transition to a low-carbon global 

economy as rapidly as possible. 

The target reflects a planning process that examined opportunities under existing 

regulatory authorities to reduce emissions in 2025 of all greenhouse gases from all 

sources in every economic sector. A number of existing laws, regulations, and other

domestically mandatory measures are relevant to the implementation of the target, which 

we detail in the information provided. 
Party: United States of America

Intended nationally determined contribution

The United States intends to achieve an economy-wide target of reducing its greenhouse gas 

emissions by 26%-28% below its 2005 level in 2025 and to make best efforts to reduce its 

emissions by 28%.

******************************************************************************

Information provided in order to facilitate clarity, transparency, and understanding

Scope and coverage:

Gases:

The U.S. target covers all greenhouse gases included in the 2014 Inventory of United States 

Greenhouse Gas Emissions and Sinks: carbon dioxide (CO2), methane (CH4), nitrous oxide 

(N2O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), sulfur hexafluoride (SF6), and

nitrogen trifluoride (NF3).

Sectors:

The U.S. target covers all IPCC sectors.

Percentage of total greenhouse gas emissions:

The United States intends to account for 100 percent of U.S. greenhouse gas emissions and 

removals for the base year 2005 as published in the Inventory of United States Greenhouse 

Gas Emissions and Sinks, on a net-net basis.

Quantifiable information on the reference point, time frames, assumptions and 

methodological approaches including those for estimating and accounting for 

anthropogenic greenhouse gas emissions and removals: 

Timeframe and reference point:

The U.S. target is for a single year: 2025. The base year against which the target is measured 

is 2005.
Accounting approach for land sector:

The United States intends to include all categories of emissions by sources and removals by 

sinks, and all pools and gases, as reported in the Inventory of United States Greenhouse Gas 

Emissions and Sinks; to account for the land sector using a net-net approach; and to use 

a “production approach” to account for harvested wood products consistent with IPCC 

guidance. The United States may also exclude emissions from natural disturbances, consistent 

with available IPCC guidance.

There are material data collection and methodological challenges to estimating emissions and 

removals in the land sector. Consistent with IPCC Good Practice, the United States has 

continued to improve its land sector greenhouse gas reporting, which involves updating its 

methodologies. The base year and target for the U.S. INDC were established on the basis of 

the methodologies used for the land sector in the 2014 Inventory of United States Greenhouse 

Gas Emissions and Sinks and the United States 2014 Biennial Report.

Metric:

The United States intends to use 100-year global warming potential (GWP) values to calculate 

CO2 equivalent totals. The United States intends to report emissions totals using Fourth 

Assessment Report values, and will consider future updates to GWP values from the IPCC.

Use of markets: 

At this time, the United States does not intend to utilize international market mechanisms to 

implement its 2025 target. 

Domestic laws, regulations, and measures relevant to implementation:

Several U.S. laws, as well as existing and proposed regulations thereunder, are relevant to the 

implementation of the U.S. target, including the Clean Air Act (42 U.S.C. §7401 et seq.), the 

Energy Policy Act (42 U.S.C. §13201 et seq.), and the Energy Independence and Security Act 

(42 U.S.C. § 17001 et seq.).

Since 2009, the United States has completed the following regulatory actions:

• Under the Clean Air Act, the United States Department of Transportation and the 

United States Environmental Protection Agency adopted fuel economy standards for 

light-duty vehicles for model years 2012-2025 and for heavy-duty vehicles for model 

years 2014-2018. 

• Under the Energy Policy Act and the Energy Independence and Security Act, the 

United States Department of Energy has finalized multiple measures addressing 

buildings sector emissions including energy conservation standards for 29 categories 
of appliances and equipment as well as a building code determination for commercial 

buildings.

• Under the Clean Air Act, the United States Environmental Protection Agency has 

approved the use of specific alternatives to high-GWP HFCs in certain applications 

through the Significant New Alternatives Policy program.

At this time:

• Under the Clean Air Act, the United States Environmental Protection Agency is 

moving to finalize by summer 2015 regulations to cut carbon pollution from new and 

existing power plants. 

• Under the Clean Air Act, the United States Department of Transportation and the 

United States Environmental Protection Agency are moving to promulgate post-2018 

fuel economy standards for heavy-duty vehicles. 

• Under the Clean Air Act, the United States Environmental Protection Agency is 

developing standards to address methane emissions from landfills and the oil and gas 

sector.

• Under the Clean Air Act, the United States Environmental Protection Agency is 

moving to reduce the use and emissions of high-GWP HFCs through the Significant 

New Alternatives Policy program.

• Under the Energy Policy Act and the Energy Independence and Security Act, the 

United States Department of Energy is continuing to reduce buildings sector 

emissions including by promulgating energy conservation standards for a broad range 

of appliances and equipment, as well as a building code determination for residential 

buildings.

In addition, since 2008 the United States has reduced greenhouse gas emissions from Federal 

Government operations by 17 percent and, under Executive Order 13693 issued on March 25th

2015, has set a new target to reduce these emissions 40 percent below 2005 levels by 2025.

Relationship with inventory:

This approach, and the definitions and metrics used, are fully consistent with our greenhouse 

gas inventory. The United States intends to continue to improve its greenhouse gas inventory 

over time, and may incorporate these improvements into its intended nationally determined 

contribution accordingly. Additional information on the greenhouse gas inventory, including 

calculations, models, data sources, and references can be found here: 

www.epa.gov/climatechange/ghgemissions/usinventoryreport.html#about