### 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 s ecretariat its inte nded 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 wi th 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 Celsi us, 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%.

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Information provided in order to facilitate clarity, transparency, and understandin g

Scope and coverage:

Gases :

The U.S. target covers all greenhouse gases included in the 2014 Inventory of U nited States
Greenhouse Gas Emissions and Sinks : carbon dioxide ( CO 2 ), methane ( CH 4 ), nitrous oxide ( N 2 O ), perfluorocarbons ( PFCs )

, hydrofluorocarbons ( HFCs )

, sulfur hexafluoride ( SF 6 ), and nitrogen trifluoride ( NF 3 ).

Sectors :

The U.S. target covers all IPCC sectors.

Per cent age of total greenhouse gas e missions:

The U nited S tates intends to account for 100 per cent of U.S. greenhouse gas emissions and
removals for the base year 2005 as published in the Inventory of United States G reenhouse
G as 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 f or anthropogenic greenhouse gas emissions and removals:

Timeframe and reference point:

The U.S. target is for a single year : 2 025. The base year against which the target is measured
is 2005.Accounting approach for land sector:

The U nited S tates 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 a nd
removals in the land sector. Consistent with IPCC Good Practice, the United States has continued to improve its land sector greenhouse gas reporting, which invol ves updating its methodologies. The bas e 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
CO 2 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 fo r 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 address ing buildings sector emissions including energy conservation standards for 29 categoriesof appliances and equipment as well as a building code determination for commercial buildings.

• Under the Clean Air Act, the United States Environmental Protection Agen cy 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 finaliz e 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 A gency are moving to promulgate post

- 2018
f uel 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 E nvironmental Protection Agency is moving to reduce the use and emissions of high

- GWP HFCs through the Significant
New Alternatives Policy p rogram.

• Under the Energy Policy Act and the Energy Independence and Security Act, the United States Department of Ene rgy is continuing to reduce buildings sector emissions including by promulgat ing energy conservation standards for a broad range of appliance s and equipment

, as well as a building code determination for residential buildings.

In addition, since 2008 the U nited States has reduced greenho use gas emissions from Federal
G overnment operations by 17 per cent and

, under Executive Order 13693 issued on March 25 th 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