The EU’s Carbon Border Adjustment Mechanism (CBAM): A Plain-English Explainer

The European Union’s Carbon Border Adjustment Mechanism (CBAM) is one of the most ambitious climate policies ever applied to international trade. Introduced as part of the EU’s broader climate strategy, it aims to ensure that efforts to cut emissions within Europe are not undermined by imports from countries with weaker environmental rules.

What is CBAM?

At its core, CBAM is a system that puts a carbon price on certain imported goods. Specifically, it requires EU importers to pay for the greenhouse gas emissions embedded in the products they bring into the EU.

The idea is simple:

• EU companies already pay for their emissions through the EU Emissions Trading System (ETS).
• Without CBAM, foreign producers could export cheaper, high-carbon goods into the EU without facing similar costs.
• CBAM closes this gap by equalising the carbon price between domestic and imported goods.

Why was CBAM introduced?

The main problem CBAM addresses is something called “carbon leakage.”

Carbon leakage happens when:

• Companies move production abroad to countries with weaker climate policies, or
• The EU imports more carbon-intensive goods instead of producing them locally.

Either way, global emissions don’t fall—they just shift location.

CBAM is designed to:

• Protect EU industries from unfair competition
• Prevent emissions from being outsourced
• Encourage other countries to adopt cleaner production methods

How does CBAM work?

CBAM operates through a certificate system, rather than a traditional tariff or tax.

Here’s the basic process:

1. Importers report emissions
   Companies importing covered goods must calculate and report the emissions embedded in those products.
2. Purchase of CBAM certificates
   Importers must buy certificates corresponding to those emissions.
   Each certificate represents one tonne of CO₂ and is priced in line with the EU carbon market (ETS).
3. Annual reconciliation
   Importers submit an annual declaration and surrender the required number of certificates.

If a carbon price has already been paid in the country of origin, that cost can typically be deducted—avoiding double pricing.

Which sectors are covered?

Initially, CBAM focuses on carbon-intensive industries, including:

• Cement
• Iron and steel
• Aluminium
• Fertilisers
• Electricity
• Hydrogen

These sectors were chosen because they:

• Produce high emissions
• Are heavily traded internationally
• Face strong risk of carbon leakage

The EU may expand CBAM to more products over time.

Timeline: From trial to full implementation

CBAM has been introduced gradually:

• 2023–2025 (Transitional phase):
  Companies only had to report emissions—no financial payments.
• From 2026 (Definitive phase):
  Importers must buy and surrender CBAM certificates, making the system financially binding.

This gradual rollout allows businesses to adapt while the EU phases out free emissions allowances previously given to its own industries.

How is CBAM different from a carbon tax?

CBAM is often described as a “carbon tariff,” but that’s not quite accurate.

Key differences:

• It is not a fixed tax at the border
• It uses a market-based certificate system
• Prices fluctuate with the EU carbon market

In effect, CBAM mirrors the EU’s internal carbon pricing system rather than creating a separate one.

Economic and global implications

CBAM is expected to have wide-ranging effects:

1. Trade impacts

Exporters to the EU may face higher costs if their production is carbon-intensive. This could shift global trade patterns toward cleaner producers.

2. Supply chain changes

EU companies may:

• Switch to lower-emission suppliers
• Demand better emissions data from partners

3. International tensions

Some countries argue CBAM could act like protectionism, while others see it as a necessary climate tool.

4. Climate policy ripple effect

CBAM may encourage other countries to introduce their own carbon pricing systems to remain competitive.

Criticisms and challenges

Despite its goals, CBAM faces several criticisms:

• Complexity: Measuring embedded emissions across global supply chains is difficult
• Impact on developing countries: Exporters with limited resources may struggle to comply
• Trade disputes: Some nations may challenge CBAM under global trade rules

At the same time, supporters argue that without such measures, ambitious climate policies risk being ineffective.

Why CBAM matters

CBAM represents a major shift in how climate policy interacts with global trade. Rather than focusing only on domestic emissions, the EU is effectively extending its carbon pricing system beyond its borders.

If successful, CBAM could:

• Reduce global emissions—not just European ones
• Set a precedent for “climate-linked trade policy”
• Push industries worldwide toward cleaner production