As climate negotiations kick off this week in Warsaw, Poland (COP 19), the stakes are high. The recently published UNEP Emissions Gap Report finds that countries are falling woefully short of the action required to avoid the worst effects of climate change. Designing an international climate agreement that can reduce global greenhouse gas (GHG) emissions over the coming decades will be a key focus of negotiators’ discussions this week.

A critical component of this new agreement will be the design of national mitigation commitments for countries’ emissions reductions post-2020. This is a complex process, involving a significant number of options. The ease with which emissions and emissions reductions associated with mitigation commitments can be measured is a key consideration. It is critical for strengthening domestic GHG management and helping track national and global emissions reductions. New WRI analysis focuses on how to maximize “measurability” and aims to shed light on how countries can most effectively design their commitments accordingly. There are also a wide range of additional factors Parties will weigh when determining their commitments, especially related to the issue of equity.

Achieving “Measurable” Emissions Reductions

Understanding the emissions reductions associated with mitigation commitments can be challenging, depending on the type of commitment. It may involve teasing apart hypothetical scenarios generated by modeling (e.g., in the case of baseline goals), varying methods, and different data sets and assumptions. Any uncertainty can lead to countries not knowing whether their plans are yielding the amount of reductions they've committed to, and whether their neighbors and competitors are committing to a comparable amount of emissions reductions. For a country to know whether it has achieved its intended emissions reductions, then, these reduction commitments must be as “measurable” as possible. Measurability can also boost transparency, accountability, trust, and ensure accurate measurement of GHG emissions reductions at the global scale.

Choosing the Right Commitment Type

Yet not all types of national mitigation commitments lend themselves to being measurable. Commitments can be categorized as economy-wide goals, sectoral goals, policies, or projects, depending on their scope. These categories contain further subcategories (see Box 1 for definitions). For example, economy-wide and sectoral goals can be framed as one of four different goal types: base year, intensity, baseline scenario, or fixed level. In addition, the timeframe for goals can be single year or multi-year, or follow a peak-and-decline pathway.

Box 1. Definitions

Economy-wide goals cover a country’s entire jurisdictional boundary and may include all sectors, ranging from energy to land use.

Sectoral goals cover one sector and are often put forward as a way to focus mitigation efforts and resources on the highest-emitting sector.

Economy-wide and sectoral goals can be framed as one of four goal types:

Base year goal: A commitment to reduce, or control the increase of, emissions by a specified quantity relative to a base year (e.g., 1990 or 2005).

Intensity goal: A commitment to reduce, or control the increase of, emissions intensity (emissions per unit of output) by a specified quantity relative to a base year. Examples of units of output include gross domestic product, population, and energy use.

Baseline scenario goal: A commitment to reduce, or control the increase of, emissions by a specific quantity relative to an emissions baseline scenario, or future projection of GHG emissions, sometimes also referred to as a “business-as-usual” scenario.

Fixed level goal: A commitment to reduce, or control the increase of, emissions to an absolute level in a target year. For example, a fixed level goal could be to achieve emissions of 200 million metric tons of CO2 equivalent (Mt CO2e) by 2020. The most common type of fixed level goal is a carbon neutrality goal, which is designed to reach zero net emissions by a certain date.

Policies include laws, regulations, and standards; economic instruments such as taxes, charges, subsidies, and incentives; information instruments; voluntary agreements; implementation of new technologies, processes, or practices; and public- or private-sector financing and investment, among others, intended to reduce emissions.

Projects are similar to policies in that they are also specific activities intended to reduce emissions. However, they tend to be smaller in scope and are not necessarily undertaken by a government. For example, a project may aim to reduce emissions at one coal power plant, while a policy could be an instrument that leads to the phase-out of coal across the country.

Timeframes for economy-wide and sectoral goals

Single-year goal: Aims to reduce emissions by a single target year.

Multi-year goal: Aims to reduce emissions each year over a defined target period. For example, a single year goal might aim to reduce emissions by 2025, whereas a multi-year goal would aim to reduce emissions in each of the five years from 2021 to 2025. Under the Kyoto Protocol, multi-year targets were embraced for the first and second commitment periods.

Peak-and-decline pathway: Specifies a year (or range of years) in which absolute emissions must peak and a year (or range of years) in which they must decline. A peak-and-decline pathway can accommodate emissions trajectories in developing countries, where emissions will likely continue to grow as countries pursue development objectives.

WRI’s analysis finds that all else being equal, countries should choose certain commitment types over others in order to maximize the measurability of their emissions reductions. Some important findings include:

On the scope of the commitment:

  • To maximize measureable emissions reductions, countries should embrace economy-wide goals. At the very least, countries that set an economy-wide goal for the pre-2020 period should also set one for post-2020. Parties with pre-2020 economy-wide goals include most major emitters, including all Annex I Parties as well as Brazil, Mexico, South Africa, and South Korea, among others.
  • If a country sets a sectoral goal, it should target the highest-emitting sector and achieve meaningful emissions reductions in that sector.

On the type of goal:

  • Commitments framed as goals (either economy-wide or sectoral) should be framed as reductions from a base year or to a fixed level.1 For countries that need to accommodate short-term emissions increases (e.g., major emerging economies), base year or fixed level goals should still be adopted, even if they are framed as an increase in emissions from a base year (as opposed to a reduction from a base year).2
  • Countries considering intensity or baseline scenario goals should adopt intensity goals given the variety of measurability challenges related to baseline scenario goals. Over the long term (e.g., from 2030 onward), Parties with relative goals should take on absolute goals that are framed as a reduction from a base year or a fixed level goal.

On the timeframe of the goal:

  • Parties with economy-wide and sectoral goal commitments should take on multi-year instead of single year goals.
  • If emissions growth is necessary for a short period, peak-and-decline pathways are preferable to single year goals because the overall emissions trajectory is made more transparent, and cumulative emissions can be more easily assessed. Peak-and-decline pathways should be designed to ensure that global emissions peak by 2020 and are reduced below 1990 levels by 2030 for a likely chance of limiting warming to 2°C.

On policies and projects:

  • Given the measurability challenges related to policies and projects, Parties should undertake efforts to:
  1. adopt standardized methods to attribute and report changes in emissions to individual policies and projects;
  2. assess and report leakage from policies and projects, where relevant; and
  3. adopt policies that facilitate long-term transformation, leading to significant emissions reductions in the most carbon-intensive sectors.

The next set of national mitigation commitments for the post-2020 period will determine whether the world shifts onto a low-carbon trajectory, or whether it falls short. Our hope is that our new research has identified a set of options for national commitments that can be embedded in an international agreement. Measureable commitments can result in trust, accountability, and tracking of national and global progress — and with the right amount of ambition, deliver the emissions reductions needed to prevent the worsening impacts of climate change.


  1. Assuming equally sufficient quality data and methods for goals, policies, and projects. ↩︎

  2. These types of goals should be designed to ensure that global emissions reductions still peak by 2020 and reduce below 1990 global emissions levels by 2030. See UNEP, 2013, The Emissions Gap Report 2013, United Nations Environment Programme (UNEP), Nairobi, https://www.unep.org/publications/ebooks/emissionsgapreport2013/. ↩︎