What the EU Emissions Trading Scheme is and how it operates

The EU Emissions Trading Scheme (ETS) is a system where large factories, power plants, and airlines operating in Europe must buy permits to release carbon dioxide and other greenhouse gases. Instead of governments setting strict limits on each facility, the ETS creates a market: there are only so many permits available each year, and companies that pollute less can sell their unused permits to companies that pollute more. The price of permits rises and falls based on supply and demand, which pushes companies toward cleaner operations because reducing emissions becomes cheaper than buying expensive permits.

The scheme launched in 2005 and now covers roughly 40% of the EU's greenhouse gas emissions. It applies to power generation, manufacturing (cement, steel, chemicals, refineries), and aviation within European airspace. Each year, the total number of permits shrinks by a set percentage, making it progressively harder and more expensive to pollute without changing how you operate. Companies receive some permits free based on historical emissions or benchmarks, but must purchase the rest at auctions or on the secondary market.

Key Takeaways

  • The ETS requires large polluters to hold permits for each ton of carbon dioxide they emit, with the total number of permits declining each year.
  • Companies can buy permits at government auctions, trade them on secondary markets, or receive free allowances based on their sector and past emissions.
  • The scheme covers power plants, factories, and airlines, but excludes most small businesses, vehicles, and heating systems in homes.
  • Permit prices have risen significantly since 2020, making emissions reductions more economically attractive than purchasing permits.
  • A separate system called the Carbon Border Adjustment Mechanism (CBAM) is being introduced to prevent companies from moving production outside the EU to avoid the scheme.

Which industries and companies are covered

The ETS covers large stationary sources—power plants, refineries, steel mills, cement factories, chemical plants, and paper mills. A facility must emit at least 25,000 tons of carbon dioxide per year to fall under the scheme, though some smaller emitters in certain sectors are also included. Aviation is covered for flights departing from or landing in EU airports, regardless of the airline's origin.

Small and medium-sized businesses, vehicles, heating oil for homes, and agriculture are not part of the ETS. The EU is developing separate policies for these sectors. This means a local manufacturing business, a delivery truck, or a homeowner's heating system does not participate in the trading scheme directly, though they may be affected indirectly if energy prices rise due to the scheme's impact on power generation costs.

How permits are allocated and priced

Each year, the EU sets a cap on total emissions and issues permits equal to that cap. Companies receive some permits free, though the proportion has shrunk over time. The rest are sold at government auctions, typically held monthly. A company that emits more than its permits allow must buy additional permits from other companies or at auction; a company that emits less can sell or bank unused permits for future years.

Permit prices fluctuate based on market conditions. In the scheme's early years, prices were very low because too many permits were issued. Since 2020, prices have risen substantially—reaching over €80 per ton in 2023—because the cap tightened and demand for permits grew as companies faced pressure to reduce emissions. Higher prices make it more economical for a company to invest in cleaner technology than to buy expensive permits.

The Carbon Border Adjustment Mechanism and trade concerns

A core problem with the ETS is that companies can relocate production to countries outside the scheme to avoid permit costs. To address this, the EU introduced the Carbon Border Adjustment Mechanism (CBAM), which is being phased in starting in 2023. CBAM requires importers of certain goods—steel, cement, fertilizers, aluminum, and electricity—to buy CBAM certificates reflecting the carbon cost of production abroad.

In effect, CBAM extends the logic of the ETS to imported goods. If a steel mill in India produces steel without paying for emissions, and that steel is imported into the EU, the importer must now account for those emissions. This prevents companies from straightforward moving production overseas to escape the scheme. CBAM is still being rolled out, and the rules continue to evolve.

How emissions reductions actually happen under the scheme

The ETS does not tell companies how to reduce emissions—it only makes emissions expensive. A power plant might switch from coal to natural gas or renewables. A cement factory might invest in carbon capture technology or use alternative fuels. An airline might buy more fuel-efficient aircraft. The rising cost of permits creates an incentive, and companies choose the path that makes economic sense for their operation.

Because the cap tightens each year, companies cannot straightforward buy their way out indefinitely. Eventually, they must change operations. This is why the scheme is considered more flexible than a direct regulation that mandates specific technologies, but also why it has faced criticism: the pace of emissions reduction depends on how fast the cap falls and how high permit prices rise, not on a fixed timeline.

Criticism and ongoing debate about the scheme's effectiveness

The ETS has been credited with stabilizing EU emissions in covered sectors, but critics argue it has not driven emissions down fast enough to meet climate targets. Some point out that free permits given to heavy industry reduce the financial pressure to change. Others note that permit prices, while rising, may still be too low to justify the fastest transition to zero-carbon technology. Environmental groups have pushed for a steeper annual cap reduction and fewer free permits.

A separate debate concerns fairness: the scheme raises energy costs, which can disproportionately affect lower-income households if power prices rise. The EU has created a Social Climate Fund to help vulnerable people manage higher energy costs, but the adequacy of this support remains contested. Industry groups, meanwhile, argue that the scheme puts European companies at a disadvantage against competitors in countries without similar carbon pricing.

How the scheme connects to broader EU climate policy

The ETS is one tool in the EU's climate strategy, not the only one. The EU also sets fuel efficiency standards for vehicles, building codes for new construction, renewable energy targets, and regulations on methane from agriculture and waste. The ETS covers large stationary emitters; other policies address transport, buildings, and agriculture. Together, these policies aim to reduce EU greenhouse gas emissions by 55% by 2030 compared to 1990 levels.

The scheme has also influenced climate policy globally. Several countries and regions—the UK, Switzerland, California, and others—have created their own emissions trading systems or are considering them, partly inspired by the EU's model. Some of these systems are now linked to the EU ETS, meaning permits can be traded across borders.

Frequently Asked Questions

Can a company just buy permits forever instead of reducing emissions?

Technically yes, but only until the cap makes it impossible. The total number of permits shrinks each year, so eventually there are not enough permits available at any price. Companies must reduce emissions to survive long-term. In the short term, buying permits is often cheaper than investing in new technology, so some do choose that path.

Does the ETS explore to my car or home heating?

No. The ETS covers large industrial facilities and aviation. Cars, home heating, and small businesses are not part of the scheme. However, if your electricity comes from a power plant covered by the ETS, higher permit costs may eventually be reflected in your electricity bill.

What happens if a company exceeds its permits?

A company that emits more carbon than its permits allow must buy additional permits from other companies or at auction. If it fails to surrender enough permits by the important date, it faces a financial penalty (currently €100 per ton of excess emissions) and must still buy the permits retroactively. Repeated violations can result in exclusion from the scheme.

How does the ETS affect energy prices?

Permit costs are passed through to consumers in the form of higher electricity and heating prices, though the magnitude varies by country and energy mix. Countries relying heavily on coal-fired power see larger increases than those with more renewable or nuclear energy. The EU's Social Climate Fund aims to offset these costs for lower-income households.

Why do some companies get free permits while others have to buy them?

Free permits are given to sectors considered at risk of relocating production outside the EU to avoid the scheme—primarily heavy industry like steel and cement. The idea is to keep these industries competitive. Over time, the proportion of free permits has declined, and the EU plans to phase them out entirely by 2035 as CBAM becomes fully operational.