Border Carbon Adjustments: Background and
June 28, 2022
Recent Developments
Jonathan L. Ramseur
A key concern among policymakers is that differing climate change mitigation policies could
Specialist in Environmental
create a competitive disadvantage for some domestic businesses—for example, by raising
Policy
production costs compared to another country. In addition, differences among countries’ climate

policies could create incentives to shift economic activities to countries with less stringent or less
Brandon J. Murrill
comprehensive climate policies, ultimately leading to “emissions leakage.” In general,
Legislative Attorney
greenhouse gas (GHG) emissions leakage can occur if a domestic policy to reduce domestic

emissions leads to an increase in emissions in another location, thus undermining emission
reductions resulting from the domestic climate policy. Policymakers might consider several
Christopher A. Casey
approaches to address these potential concerns. One approach that has received interest in recent
Analyst in International
years is a border carbon adjustment (BCA).
Trade and Finance

A BCA is a potential trade-related option, such as an import fee or tariff, intended to mitigate

adverse competitiveness effects and other concerns when one or more countries establish more
ambitious policies to reduce GHG emissions than others. Although no countries have yet
implemented a BCA as part of their climate change policies, the European Commission—which functions as the executive of
the European Union (EU)—released a proposal in July 2021 for a BCA to complement its mandatory emissions reduction
program. The Council of the EU reached agreement on a BCA framework in March 2022, and the European Parliament
adopted its own position on a BCA framework in June 2022. The European Parliament and the Council of the EU share
legislative power and must both approve a European Commission proposal for it to become EU law.
When establishing a BCA, several key questions would need to be addressed: (1) which materials or products would likely be
subject? (2) how would the BCA fee on imports be determined? and (3) which countries’ materials or products would be
subject?
Establishing a BCA would likely present substantial implementation challenges. Depending on design specifics, a BCA
would require calculating the economic impact of a domestic climate policy on a wide range of domestically produced goods
as well as the analogous costs in other countries. To alleviate some of these challenges, policymakers could limit the program
to a select number of industries and apply a simplified set of default values and assumptions for categories of goods.
The potential imposition of BCAs raises a range of trade issues and other related concerns. Some analysts have expressed
concern that BCAs could be (or be interpreted as) disguised protections for domestic industry. Some experts have suggested
that BCAs could negatively affect developing countries in the short run. Further, some researchers have highlighted the
potential for unintended consequences from a BCA, including impacts to U.S. currency.
The World Trade Organization (WTO) oversees and administers multilateral trade rules, and serves as a forum for trade
negotiations and trade disputes. It is uncertain whether a BCA would comply with WTO rules because a WTO dispute
settlement panel has never considered the issue. In particular, it is uncertain whether a BCA would be consistent with General
Agreement on Tariffs and Trade (GATT) principles. It is also uncertain whether specific GATT exceptions might allow a
BCA that is otherwise deemed inconsistent with key GATT principles.
Some studies have questioned whether BCAs would be effective, considering the balance between expected benefits and
implementation challenges, and potential consequences that may result from them. Policymakers have alternatives to BCAs
that could be used to address leakage or competitiveness concerns. For example, within the framework of a cap-and-trade
system, covered entities could receive emission allowances at no cost. This has occurred in the EU’s cap-and-trade system,
California’s cap-and-trade program, and in the Regional Greenhouse Gas Initiative to a lesser extent. In addition,
policymakers could support carbon-intensive, trade-exposed industries by funding research, development, and deployment
efforts in particular sectors or for specific technologies. Climate policies could include funding to support transition
assistance for specific industries or communities with large concentrations of impacted industries.

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Border Carbon Adjustments: Background and Recent Developments

Introduction
A border carbon adjustment (BCA) is a potential trade-related option intended to mitigate adverse
competitiveness effects and other concerns when one or more countries establish more ambitious
policies to reduce greenhouse gas (GHG)1 emissions than others. Other countries may also have
an incentive to adopt more stringent climate policies to avoid the BCAs.
BCAs have been a subject of high-level bilateral and multilateral discussions among countries in
recent months. The 27-member European Union (EU) is considering a proposed BCA framework
among its institutions.2 The European Commission, which represents the interests of the EU as a
whole and functions as the EU’s executive, introduced a BCA legislative proposal in July 2021.3
The Council of the EU (which represents the interests of the national governments of the member
states) reached agreement on the proposed BCA framework in March 2022.4 The European
Parliament adopted its own position on the BCA framework in June 2022.5 The European
Parliament and the Council of the EU share legislative power and must both approve a European
Commission proposal for it to become EU law.
The EU proposal, which is still under development and could take a year or more to enact and
implement, has raised concerns in a number of other countries, including the United States. In
addition, in August 2021, Canadian government officials initiated a consultation process among
stakeholders seeking input on BCA issues in the context of Canada’s national carbon tax
framework.6
This report explains what BCAs are and examines some of the international challenges they
might present if pursued in government policies. In addition, the report discusses alternatives to
BCAs and includes selected viewpoints from a range of stakeholders.
Background and Context
Under the 2015 Paris Agreement, all Parties agreed to submit “Nationally Determined
Contributions” (NDCs) containing nonbinding pledges to mitigate GHG emissions, among other

1 The primary greenhouse gases (GHGs) emitted by human activities—and estimated by the U.S. Environmental
Protection Agency (EPA) in its annual inventories—include carbon dioxide (CO2), methane, nitrous oxide, sulfur
hexafluoride, chlorofluorocarbons, hydrofluorocarbons, and perfluorocarbons. Other GHGs include carbonaceous and
sulfuric aerosols, hydrochlorofluorocarbons, and elevated tropospheric ozone pollution generated by emissions of
nitrogen oxides and volatile organic compounds, such as solvents.
2 For more details, see CRS In Focus IF11211, The European Parliament and U.S. Interests, by Kristin Archick; see
also European Parliamentary Research Service, EU Carbon Border Adjustment Mechanism Implications for Climate
and Competitiveness, June 2022, https://www.europarl.europa.eu/thinktank/en/document/EPRS_ATA(2022)729462.
3 For more information, see European Commission, “Carbon Border Adjustment Mechanism,” https://ec.europa.eu/
taxation_customs/green-taxation-0/carbon-border-adjustment-mechanism_en.
4 Council of the European Union, “Council Agrees on the Carbon Border Adjustment Mechanism (CBAM),” press
release, March 15, 2022, https://www.consilium.europa.eu/en/press/press-releases/2022/03/15/carbon-border-
adjustment-mechanism-cbam-council-agrees-its-negotiating-mandate/.
5 European Parliament, “CBAM: Parliament Pushes for Higher Ambition in New Carbon Leakage Instrument,” press
release, June 22, 2022, https://www.europarl.europa.eu/news/en/press-room/20220516IPR29636/climate-change-meps-
push-for-accelerated-eu-action-and-energy-independence.
6 Government of Canada, Department of Finance, Exploring Border Carbon Adjustments for Canada, 2021,
https://www.canada.ca/en/department-finance/programs/consultations/2021/border-carbon-adjustments/exploring-
border-carbon-adjustments-canada.html.
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actions.7 Parties agreed to update or submit new NDCs by 2020 and every five years thereafter.8
GHG emission reduction goals in the NDCs vary across countries, according to their “common
but differentiated responsibilities,” under the United Nations Framework Convention on Climate
Change (UNFCCC) and the Paris Agreement.9 The national climate change policies required to
achieve these commitments would likely differ in terms of scope, stringency, and timing.
Assuming these policies are implemented and the goals achieved,10 they would likely result in a
range of economic impacts across countries.
For example, a 2017 study estimated the cost of emission reduction in selected countries to meet
their individual NDCs.11 The study’s cost estimates are comparable to an estimate of the carbon
price (e.g., tax or fee) that would be needed in particular countries to achieve their NDCs.
Although the study’s estimated results are outdated for several reasons (e.g., many countries have
updated their NDCs since the study’s publication), the relative cost estimates may be instructive.
The cost estimates ranged from zero (e.g., China and India)12 to hundreds of dollars per metric ton
of carbon dioxide (e.g., the European Union, Japan). The estimate for the United States was
roughly $100 per metric ton.
One key concern among policymakers is that differing climate policies could cause the domestic
price of goods to increase more than the prices of similar goods manufactured abroad, potentially
creating a competitive disadvantage for some domestic businesses.13 This is a particular concern
for “emissions-intensive, trade-exposed” (EITE) industries, such as steel manufacture, as
discussed below. A second key concern is that differences among countries’ climate policies could
create incentives to shift economic activities to countries with less stringent or less
comprehensive climate policies, ultimately leading to “emissions leakage.” In general, GHG
emissions leakage can occur if a domestic policy to reduce domestic emissions leads to an
increase in emissions in another location, thus undermining emission reductions resulting from
the domestic climate policy.14

7 The Paris Agreement is an international treaty under the United Nations Framework Convention on Climate Change
(UNFCCC), which since 1992 has been the primary international forum among national governments to address GHG-
induced climate change. Two principles agreed to in the UNFCCC are that (1) Parties should act “on the basis of equity
and in accordance with their common but differentiated responsibilities and respective capabilities” and (2) developed
country Parties should take the lead in combating climate change. For more information about the treaties, see CRS
Report R46204, The United Nations Framework Convention on Climate Change, the Kyoto Protocol, and the Paris
Agreement: A Summary, by Jane A. Leggett.
8 Each successive NDC of a Party “will represent a progression” and “reflect its highest possible ambition, reflecting its
common but differentiated responsibilities and respective capabilities, in light of different national circumstances.”
9 The UNFCCC Article 2 includes the principle of “common but differentiated responsibilities and respective
capabilities,” sometimes with the acronym CBD-RC, which carries over in its subsidiary Paris Agreement.
10 Based on past experience with international commitments to reduce GHG emissions (including prior U.S. targets),
the degree to which these emission targets will be met is uncertain. This issue is beyond the scope of this report.
11 See Keigo Akimoto et al., “The Analyses on the Economic Costs for Achieving the Nationally Determined
Contributions and the Expected Global Emission Pathways,” Evolutionary and Institutional Economics Review, vol. 14
(2017).
12 The study authors stated that some countries’ estimated abatement costs were zero, because these countries could
meet their NDCs using “business-as-usual” climate policies.
13 Although some industries may become less profitable, lose market share, and reduce jobs, not all businesses within a
sector may be affected similarly. For example, under an emission cap or carbon price framework, a company using
electricity produced with hydropower would experience less cost increase than a company using electricity produced
with coal. In addition, some businesses may be more energy efficient than others or use less emitting processes. Some
may be able to reduce their emissions in response to the new policies at lower cost than others.
14 Some studies have raised questions regarding the degree to which emissions leakage would be a concern under a
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Policymakers might consider several approaches to address these potential concerns. One
approach that has received interest in recent years is a BCA.15 The sections below discuss the
concept, scope, and logistics of a BCA approach.
What Are Border Carbon Adjustments?
To address the potential impacts associated with different climate policies across countries, a
BCA would impose a trade measure, such as a fee or tariff,16 on certain imported materials or
products. BCA frameworks could also provide a rebate to exporters of certain materials or
products based on increased costs from a domestic climate policy. Generally, a BCA would seek
to promote “equal conditions of competition” for foreign and domestic companies supplying
products or services within a taxing jurisdiction.17 Some observers have noted that BCAs could
encourage other countries to adopt comparable climate policies.18
Although no countries have yet implemented a BCA as part of their climate change policies,19 the
European Commission released a proposal in July 2021 for a BCA that would complement its
mandatory emissions reduction program.20 This proposal is under discussion and debate among
the legislative institutions of the EU. In Congress, most of the recent carbon tax or emission fee
legislative proposals include a BCA.21
When establishing a BCA, several key questions would need to be addressed, which are discussed
below.22

unilateral approach. This issue is beyond the scope of this report. See, for example, Warwick McKibbin et al., “The
Role of Border Carbon Adjustments in a U.S. Carbon Tax,” Climate Change Economics, vol. 9, no. 1 (2018); Adele
Morris, Making Border Carbon Adjustments Work in Law and Practice, Tax Policy Center, July 26, 2018; and Joseph
Aldy, “Frameworks for Evaluating Policy Approaches to Address the Competitiveness Concerns of Mitigating
Greenhouse Gas Emissions,” National Tax Journal, vol. 70, no. 2 (2017).
15 Policymakers, stakeholders, and researchers refer to these mechanisms by a variety of names, including border
adjustments, border tax adjustments, border carbon adjustment mechanism, or carbon border adjustment mechanism
(the term used in the EU), among others. This report uses the term border carbon adjustments (BCAs).
16 A tariff is a customs duty levied on imported and exported goods and services. For more background, see CRS In
Focus IF11030, U.S. Tariff Policy: Overview, by Christopher A. Casey.
17 Organisation for Economic Co-Operation and Development (OECD), OECD International VAT/GST Guidelines on
Neutrality, 2011, https://www.oecd.org/tax/consumption/guidelinesneutrality2011.pdf.
18 See for example, Adele Morris, Making Border Carbon Adjustments Work in Law and Practice, Tax Policy Center,
July 26, 2018.
19 As a component of its climate policy, California has a mechanism to address imported electricity from surrounding
states (California Air Resources Board cap-and-trade program, https://ww2.arb.ca.gov/our-work/programs/cap-and-
trade-program). Some argue this is a form of a BCA. See, for example, Aaron Cosbey et al., “Developing Guidance for
Implementing Border Carbon Adjustments: Lessons, Cautions, and Research Needs from the Literature,” Review of
Environmental Economics and Policy, vol. 13, no. 1 (2019).
20 European Commission, Proposal for a Regulation of the European Parliament and of the Council Establishing a
Carbon Border Adjustment Mechanism, July 14, 2021, COM/2021/564 final, https://eur-lex.europa.eu/legal-content/
EN/TXT/?uri=CELEX:52021PC0564.
21 See CRS Report R45472, Market-Based Greenhouse Gas Emission Reduction Legislation: 108th Through 117th
Congresses, by Jonathan L. Ramseur.
22 A number of researchers have examined these questions and other design issues associated with BCAs. See, for
example, Brian Flannery et al., Framework Proposal for a US Upstream GHG Tax with WTO-Compliant Border
Adjustments: 2020 Update, Resources for the Future, 2020; Aaron Cosbey et al., “Developing Guidance for
Implementing Border Carbon Adjustments: Lessons, Cautions, and Research Needs from the Literature,” Review of
Environmental Economics and Policy, vol. 13, no. 1 (2019); Samuel Kortum and David Weisbach, “The Design of
Border Adjustments for Carbon Prices,” National Tax Journal, vol. 70, no. 2 (June 2017).
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Which Materials or Products Would Likely Be Subject to a BCA?
Many BCA approaches would apply a fee to imported goods from industrial sectors that are
expected to experience the greatest impacts from unilateral climate policies. These industries are
often described as “emission-intensive, trade-exposed.”
An industry’s GHG emission intensity is a function of the following:
1. direct emissions from its manufacturing process, such as carbon dioxide (CO2)
from cement or steel production; and
2. indirect emissions from the inputs (e.g., electricity, natural gas) to the
manufacturing processes (e.g., steel, cement, and chemical production).
“Emissions-intensive” industries would be impacted by climate policies affecting direct emissions
during manufacture and climate policies affecting “upstream” emissions by suppliers, such as
electricity generators, that may pass higher costs through to electricity consumers. Emission-
intensive industries are likely to experience greater cost increases than less emission intensive
industries, all else being equal.23
Trade-exposed industries are those that face greater international competition, compared to other
domestic industries. One potential measure of a sector’s trade exposure would compare the
combined value of a sector’s exports and imports with the value of its domestic production and
imports.
A 2009 interagency report prepared during the consideration of federal GHG reduction legislation
identified industrial sectors that would meet specific emission-intensive, trade-exposed criteria.24
For the most part, these sectors included industries in chemical, paper, nonmetallic minerals (e.g.,
cement and glass), and primary metals (e.g., aluminum and steel) sectors.
The European Commission BCA would initially apply only to a selected number of goods: iron
and steel, cement, fertilizer, aluminum, and imported electricity.25 The European Parliament
framework would add organic chemicals, plastics, hydrogen, and ammonia to the scope of
coverage.26

23 A 2015 study estimated that the “energy-intensive industries of iron and steel, aluminum, pulp and paper, cement,
glass, and industrial chemicals would bear total percentage declines in domestic production, on the order of 3 to 5
percent, in excess of the manufacturing sector average of 1.5 percent.” See Joseph Aldy and William Pizer, “The
Competitiveness Impacts of Climate Change Mitigation Policies,” The Harvard Project on Climate Agreements, 2015.
24 Interagency Report, The Effects of H.R. 2454 on International Competitiveness and Emission Leakage in Energy-
Intensive Trade-Exposed Industries, 2009, https://www.epa.gov/sites/default/files/2016-07/documents/
interagencyreport_competitiveness-emissionleakage.pdf. Federal agencies in the Obama Administration prepared this
report in response to a request from several Senators considering H.R. 2454 (111th Congress) and related legislation.
H.R. 2454 (“Waxman-Markey”) passed the House in 2009 and would have established a GHG emission cap-and-trade
program, among other provisions. The legislation included emission allowance rebates and other assistance for
industries based on their energy intensity and trade intensity.
25 European Commission, Proposal for a Regulation of the European Parliament and of the Council Establishing a
Carbon Border Adjustment Mechanism, July 14, 2021, COM/2021/564 final, https://eur-lex.europa.eu/legal-content/
EN/TXT/?uri=CELEX:52021PC0564; see also the commission website explaining the framework, https://ec.europa.eu/
taxation_customs/green-taxation-0/carbon-border-adjustment-mechanism_en.
26 European Parliament, “CBAM: Parliament pushes for higher ambition in new carbon leakage instrument,” press
release, June 22, 2022, https://www.europarl.europa.eu/news/en/press-room/20220516IPR29636/climate-change-meps-
push-for-accelerated-eu-action-and-energy-independence.
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How Would the BCA Fee on Imports Be Determined?
In general, a BCA would likely levy a fee on the estimated tons of GHG emissions associated
with imported goods (often described as its carbon or emissions content). The rate of the fee
would likely be based on a domestic carbon price in the country of import, such as a carbon tax or
emissions fee, or a calculated implicit carbon price from a regulatory program or other related
policies.27 To achieve this objective, one government may levy a fee on an imported product from
another country, based on estimates of the GHG emissions generated during the manufacturing
process of the imported product. Estimated emissions would include direct emissions from onsite
processes and may also include indirect emissions associated with the product’s manufacture,
such as emissions from electricity generation at offsite locations.
The European Commission BCA would apply only to direct GHG emissions generated from the
onsite production of covered materials (e.g., iron and steel). The European Commission approach
includes a plan to evaluate whether its BCA should include indirect emissions from these
materials.28 The European Parliament framework would include indirect emissions.29
In addition, some proposed BCA frameworks further adjust the import fee to account for the
climate policies (and costs) in place in the exporting country.30 The EU BCA includes this type of
adjustment.
Which Countries’ Materials or Products Would Be Subject to a
BCA?
Policymakers may consider including or excluding materials from some countries from a BCA
for a range of reasons. For example, a BCA may exclude imports from countries that have climate
policies (e.g., carbon prices) that are comparable to domestic policies. In the EU, imports of
goods from all non-EU countries would be covered by the EU’s BCA. Certain countries that
participate or link with the EU’s emission trading system would be excluded from the EU BCA.31
In recent U.S. federal legislative proposals, BCAs would apply fees to imported goods from
countries that do not have climate policies comparable with those of the United States. Under
these approaches, the federal agency in charge of implementing the BCA program, such as the
Department of the Treasury, would generally be required to make this determination. How such
determinations of climate policy parity are made, and by whom, can raise challenging technical
and policy issues.
Policymakers may consider excluding goods from less developed countries or materials from
countries whose trade of covered materials is below certain volume thresholds.32 The former

27 Calculating a BCA fee for imports from regulatory programs or policies may present greater challenges than a
calculation based on explicit carbon prices, such as taxes or fees.
28 European Commission, “Carbon Border Adjustment Mechanism: Questions and Answers,” https://ec.europa.eu/
commission/presscorner/detail/en/qanda_21_3661.
29 EU Parliament, “CBAM: Parliament Pushes for Higher Ambition in New Carbon Leakage Instrument,” press release,
June 22, 2022, https://www.europarl.europa.eu/news/en/press-room/20220603IPR32157/cbam-parliament-pushes-for-
higher-ambition-in-new-carbon-leakage-instrument.
30 See CRS Report R45472, Market-Based Greenhouse Gas Emission Reduction Legislation: 108th Through 117th
Congresses, by Jonathan L. Ramseur.
31 European Commission, “Carbon Border Adjustment Mechanism: Questions and Answers,” July 2021,
https://ec.europa.eu/commission/presscorner/detail/en/qanda_21_3661.
32 See, for example, Aaron Cosbey et al., “Developing Guidance for Implementing Border Carbon Adjustments:
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might encourage economic development in the exporting country. The latter might reduce the
administrative burden on the country with the BCA. However, such exclusions might raise
concerns in the World Trade Organization (discussed below).
BCA Implementation Challenges and Options
Establishing and operating a BCA would likely present implementation challenges.33 Depending
on design specifics, a BCA would require calculating the economic impact resulting from a
domestic climate policy on domestically produced goods and materials as well as the analogous
costs in other countries. A calculation involving a carbon price and its impact on materials
directly subject to the price—often coal, natural gas, and oil—could be relatively straightforward.
A calculation involving a carbon price and its impact on materials indirectly affected by a carbon
price—such as steel or fertilizer—would be more complicated. Analogous calculations might be
needed for imported goods produced in many countries—goods that might cross national borders
multiple times before being shipped to the importing country—further increasing the complexity
of the program.
To alleviate some of the measurement complexity, policymakers could limit the program to a
select number of industries and apply default values and assumptions to particular manufacturing
processes. For example, some have proposed using average emission values for particular sectors
(e.g., steel) and for different countries.34 However, this simplified approach could result in less
accurate import price adjustments, which could potentially affect the accuracy of GHG emission
reductions achieved by the program.35
Another option would be to allow companies to provide measured, independently verified
emissions data as an alternative to default values. Emerging technologies, such as improved
sensors and digital ledgers, may allow for increasing reliability of tracking products through
supply chains.
World Trade Organization Issues
The World Trade Organization (WTO) is the 164-member international organization created to
oversee and administer multilateral trade rules, serve as a forum for trade negotiations, and
resolve trade disputes. The WTO encompassed and succeeded the General Agreement on Tariffs
and Trade (GATT), which was established in 1947.36 The GATT is one of the WTO agreements

Lessons, Cautions, and Research Needs from the Literature,” Review of Environmental Economics and Policy, vol. 13,
no. 1 (2019).
33 See, for example, Marco Sakai and John Barrett, “Border Carbon Adjustments: Addressing Emissions Embodied in
Trade,” Energy Policy, vol. 92 (2016); Sam Kortum and David Weisbach, “Border Adjustment for Carbon Emissions,”
Resources for the Future, 2016; Carolyn Fischer et al., “Carbon Taxes and Energy-Intensive Trade-Exposed
Industries,” in Implementing a U.S. Carbon Tax: Challenges and Debates, ed. Ian Parry et al. (Washington, DC:
International Monetary Fund, 2015).
34 See, for example, Michael A. Mehling et al., “Designing Border Carbon Adjustments for Enhanced Climate Action,”
The American Society of International Law, vol. 113, no. 3 (2019); Aaron Cosbey et al., “Developing Guidance for
Implementing Border Carbon Adjustments: Lessons, Cautions, and Research Needs from the Literature,” Review of
Environmental Economics and Policy, vol. 13, no. 1 (2019).
35 Congressional Budget Office, Border Adjustments for Economywide Policies That Impose a Price on Greenhouse
Gas Emissions, 2013.
36 For an overview of the WTO, see CRS Report R45417, World Trade Organization: Overview and Future Direction,
coordinated by Cathleen D. Cimino-Isaacs.
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that set forth rules and disciplines for practices that affect international trade in goods and
services.37 These rules can be enforced by the WTO’s dispute settlement mechanism, which
provides a means for the resolution of trade disputes between members concerning these rules
and may decide whether a member has complied with its WTO obligations.38
It is uncertain whether a BCA would comply with WTO rules because a WTO dispute settlement
panel has never considered the issue. In particular, it is uncertain whether a BCA would be
consistent with key GATT principles, such as nondiscrimination obligations. It is also uncertain
whether specific GATT exceptions, such as those for national security39 and the protection of
human, animal, or plant life or health,40 may allow a BCA that is otherwise deemed inconsistent
with key GATT principles.
GATT Obligations Related to Border Adjustments
GATT explicitly allows WTO members to impose, “on the importation of any product … a charge
equivalent to an internal tax … in respect of the like domestic product or in respect of an article
from which the imported product has been manufactured or produced in whole or in part.”41
Some recent U.S. legislative proposals that would levy an emission fee or carbon tax apply the
fee or tax not on particular products but rather on emissions or the inputs that result in emissions,
namely fossil fuels.42 Under these proposals, carbon-intensive materials, such as steel, cement,
and certain chemicals, would not be directly subject to the proposed tax or fee. Some observers
contend that a tax on products based on emissions or inputs could be used to establish a BCA, but
this notion is untested.43 In addition, it is unclear whether GATT contemplates the adjustment of
an implicit tax on domestic products that would arguably result from the imposition of domestic
environmental regulations.44
A key WTO issue is whether a country’s BCA imposes a fee on imported products in excess of
like domestic products. Under the GATT’s national treatment requirement for taxation
measures,45 a country may not impose a BCA on imported products in excess of the internal tax
imposed on like domestic products.46 Depending on the design and scope of a BCA, it may be
difficult to determine if a BCA were in excess of the tax or fee on domestic products.

37 For a link to all of the WTO Agreements discussed in this report see Legal Texts: The WTO Agreements, WORLD
TRADE ORG., https://www.wto.org/english/docs_e/legal_e/final_e.htm.
38 WTO, Understanding on Rules and Procedures Governing the Settlement of Disputes (DSU), https://www.wto.org/
english/docs_e/legal_e/28-dsu.pdf.
39 GATT art. XXI.
40 Id. art. XX(b).
41 Id. art. II:2(a) (emphasis added).
42 See CRS Report R45472, Market-Based Greenhouse Gas Emission Reduction Legislation: 108th Through 117th
Congresses, by Jonathan L. Ramseur.
43 See, for example, Jennifer Hillman, Changing Climate for Carbon Taxes: Who’s Afraid of the WTO?, at 6, 9 (2013),
http://www.climateadvisers.com/wp-content/uploads/2014/01/2013-07-Changing-Climate-for-Carbon-Taxes.pdf.
44 Two proposals in the 117th Congress would arguably base a BCA on such an implicit tax. The BCA framework that
would be established under S. 2378 and H.R. 4534 would not be linked to a federal carbon tax or fee but would base a
BCA on “domestic environmental costs,” which would include existing Clean Air Act regulations, among other costs.
45 GATT art. III:2.
46 Id. In addition, Article I of the GATT sets forth the Agreement’s most-favored-nation (MFN) treatment obligation,
which generally prohibits a WTO member from discriminating against imported products of one WTO member country
as compared to products of another WTO member, including by taxing one WTO member’s products in excess of
another member’s like products. This provision might be relevant if a BCA imposes a higher tax on the products of one
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Based on a GATT panel decision in another context, it is uncertain whether a BCA based on the
amount of GHGs emitted during the manufacture or production of an imported product would
conform to WTO rules, because this BCA would be based on the method of production rather
than the product itself.47 However, some scholars have argued that a BCA could be designed to
allocate GHG emissions from the production process to particular products.48
GATT Exceptions
If a BCA is adopted and later found to violate the GATT’s requirements, a country could seek to
retain the BCA under one of the GATT’s general exceptions.49 For example, one exception
involves measures “necessary to protect human, animal or plant life or health.”50 Another
exception provisionally allows GATT-inconsistent measures “relating to the conservation of
exhaustible natural resources if such measures are made effective in conjunction with restrictions
on domestic production or consumption.”51 Certain conditions must be demonstrated to meet
these exceptions. Whether a BCA would satisfy any of these exceptions and their associated
conditions would likely be fact-dependent.52
In addition, another GATT provision contains an exception for national security.53 A country
could argue that a BCA falls within the scope of that exception because climate change is a
national security emergency. It is unclear whether a WTO panel would accept this rationale. Some
WTO members have expressed concern that overuse of the national security exception will
undermine the world trading system, because countries might enact a multitude of protectionist
measures under the guise of national security.54
Other Trade-Related Issues
The potential imposition of BCAs raises a range of trade issues and other related concerns. For
example, some analysts have expressed concern that carbon border adjustment tariffs could be (or
be interpreted as) disguised protections for domestic industry.55 That is, some have argued that

WTO member as compared to another.
47 This reasoning stems from a 1991 GATT panel decision that considered whether the United States could treat
imported Mexican tuna differently than United States tuna because the Mexican tuna’s production method resulted in
the incidental killing of dolphins. The Panel determined that the regulation was directed at the method of production of
the tuna rather than the tuna itself. The Panel determined that distinguishing between tuna based on the production
method was impermissible under Article III because it was not a regulation of a product. See GATT Panel Report,
United States – Restrictions on Imports of Tuna, GATT Doc. DS21/R, GATT BISD 39S/155, para. 5.15 (Sept. 3, 1991)
(unadopted).
48 See, for example, Hillman, supra note 31, at 6, 9.
49 These are found in GATT Article XX, ¶¶ (a) through (j).
50 GATT art. XX(b).
51 Id. art. XX(g).
52 See Appellate Body Report, United States – Import Prohibition of Certain Shrimp and Shrimp Products,
WT/DS58/AB/R, paras. 158-59 (Oct. 12, 1998).
53 GATT art. XXI.
54 See, for example, WTO Council for Trade in Goods, National Security Cited in Two Trade Concerns at Goods
Council Meeting, June 30, 2017, https://www.wto.org/english/news_e/news17_e/good_10jul17_e.htm.
55 Peter Holmes et al., “Border Carbon Adjustments and the Potential for Protectionism,” Climate Policy, vol. 11, no. 2
(2011); Gary Clyde Hufbauer, “Divergent Climate Change Policies Among Countries Could Spark a Trade War. The
WTO Should Step In,” Peterson Institution for International Economics, 2021, https://www.piie.com/blogs/trade-and-
investment-policy-watch/divergent-climate-change-policies-among-countries-could.
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countries could use subtle adjustments to the complex calculations often involved in the proposed
BCAs to privilege domestic industries.56
Similarly, experts have suggested that BCAs could negatively affect developing countries in the
short run.57 A survey conducted by the United Nations Conference on Trade and Development
(UNCTAD) notes that the EU’s proposed carbon border adjustment mechanism, for example,
“could impact the development of poorer countries and reduce their opportunities for export-led
development.” However, the study also noted that the impact would be highly variable, and
certain developing countries could gain advantages. For example, a 2020 study argued that
because the steel industries of India and Turkey are relatively carbon efficient, they would likely
“take crude steel share from China, Russia, and the Ukraine” if the EU implemented a carbon
border adjustment tariff.58
Further, some researchers have highlighted the potential for unintended consequences from a
BCA. For example, some studies have found that a border adjustment may lead to lower net
exports than the carbon price alone, due to the adjustment’s terms-of-trade effect on U.S.
currency.59 Some of the concerns may be lessened to some degree if a larger number of nations
establish comparable emission reduction policies.
Alternatives to BCAs
Some studies have questioned whether BCAs would be justified, considering the expected
benefits, implementation challenges, and potential consequences that may result. For example, a
2017 study concluded that “our review of the economics of unilateral carbon taxes, however, does
not find strong justifications for [BCAs].”60 A 2015 study concluded that “attempting to ‘protect’
energy-intensive U.S. manufacturing firms from international competitive pressures through
various policies may have only a limited impact on these firms.… [G]iven the magnitude of the
competitiveness impacts on climate policy in our simulation, the potential economic and
diplomatic costs of such policies may outweigh the benefits and justify no action.”61
Policymakers have alternatives to BCAs, which could be used to address leakage or
competitiveness concerns. For example, within the framework of a cap-and-trade system, one
alternative is to provide emission allowances to covered entities at no cost. This has occurred in
the EU-ETS, California’s cap-and-trade program, and in the Regional Greenhouse Gas Initiative
(RGGI) to a lesser extent.62 Policymakers could support carbon-intensive, trade-exposed
industries by funding research, development, and deployment efforts in particular sectors or for

56 Ibid.
57 For example, Elena Ianchovichina and Harun Onder, “Carbon Border Taxes: What Are Their Implications for
Developing Countries?” Brookings Institution, October 5, 2021, https://www.brookings.edu/blog/future-development/
2021/10/05/carbon-border-taxes-what-are-their-implications-for-developing-countries/.
58 Ben Aylor et al., “How an EU Carbon Border Tax Could Jolt World Trade,” Boston Consulting Group, 2020,
https://www.bcg.com/publications/2020/how-an-eu-carbon-border-tax-could-jolt-world-trade.
59 See, for example, Warwick McKibbin et al., “The Role of Border Carbon Adjustments in a U.S. Carbon Tax,”
Climate Change Economics, vol. 9, no. 1 (2018).
60 Samuel Kortum and David Weisbach, “The Design of Border Adjustments for Carbon Prices,” National Tax Journal,
vol. 70, no. 2 (June 2017).
61 Joseph Aldy and William Pizer, “The Competitiveness Impacts of Climate Change Mitigation Policies,” The Harvard
Project on Climate Agreements, 2015.
62 The Regional Greenhouse Gas Initiative is a regional cap-and-trade system on CO2 emissions from electric power
plants in 11 U.S. states: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New
York, Rhode Island, Vermont, and Virginia.
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specific technologies. In addition, climate policies could include funding to support transition
assistance for specific industries or communities with large concentrations of impacted industries.
Selected Viewpoints from Government Leaders and
Officials
Government leaders and officials from around the world have expressed a range of varying
viewpoints regarding BCAs and their possible implementation. This section provides selected
examples of these viewpoints. The examples below do not represent an exhaustive list.
 The U.S. 2021 NDC states, “The United States will work to ensure that our firms
and workers are not put at an unfair competitive disadvantage and cooperate with
allies and partners that are committed to fighting climate change. As appropriate,
and consistent with domestic approaches to reduce United States greenhouse gas
emissions, this includes consideration of carbon border adjustments in relation to
carbon-intensive goods.”63
 The Government of Canada stated that “whether BCAs are necessary to mitigate
carbon leakage risks ultimately depends on the level of ambition and
effectiveness of other countries’ GHG emission curbing actions….This is why
the Government wants to engage with key trading partners and other like-minded
countries who are taking climate action to better understand their perspectives
and plans for BCAs or alternative measures and ensure there is as much
coherence and coordination as possible among different policies and
approaches.”64
 Officials from the BASIC country group—Brazil, South Africa, India and
China—issued a Joint Statement in April 2021, expressing “grave concern
regarding the proposal for introducing trade barriers, such as unilateral carbon
border adjustment, that are discriminatory and against the principles of Equity
and CBDR-RC [the UNFCCC principle of Common but Differentiated
Responsibilities and Respective Capabilities].”65
 Artyom Bulatov, deputy head of the European Co-operation Department at
Russia’s Foreign Ministry, reportedly stated that “it appears that some of our
partners cannot resist the temptation to instrumentalise the climate agenda for the
benefit of their economies…. We took note of the plans to use the CBAM as an
additional source of income for the EU budget.... And frankly speaking it goes
fully in line with protectionism in the trade sphere.”66

63 The United States of America Nationally Determined Contribution, Reducing Greenhouse Gases in the United
States: A 2030 Emissions Target, Submitted April 2021, https://www4.unfccc.int/sites/NDCStaging/Pages/All.aspx.
64 Government of Canada, Exploring Border Carbon Adjustments for Canada, August 2021, https://www.canada.ca/en/
department-finance/programs/consultations/2021/border-carbon-adjustments/exploring-border-carbon-adjustments-
canada.html.
65 Joint Statement issued at the conclusion of the 30th BASIC Ministerial Meeting on Climate Change hosted by India
on April 8, 2021, https://www.environment.gov.za/mediarelease/basic_ministerialmeeting_climatechange_india.
66 Nastassia Astrasheuskaya and Mehreen Khan, “Russian Businesses Start Counting Cost of EU Carbon Border Tax,”
Financial Times, May 17, 2021.
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 Indian Trade Minister Piyush Goyal reportedly stated it would be “very unfair
today to bring trade policy and trade barriers and use trade as a means to foist
[new restrictions] upon the developing world or the less developed countries.”67

Author Information

Jonathan L. Ramseur
Christopher A. Casey
Specialist in Environmental Policy
Analyst in International Trade and Finance

Brandon J. Murrill

Legislative Attorney

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67 Mark Linscott, “Carbon Border Adjustment Mechanisms: Will Innovative Climate Policy Launch a Trade War?”
New Atlantacist, June 2021, https://www.atlanticcouncil.org.
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