Countries at the United Nations shipping agency have reached an agreement on global fuel emissions standards for the maritime industry.

More than 60 countries of the International Maritime Organization (IMO) have voted to impose a minimum charge of $100 for each tonne of greenhouse gas emissions from ships that exceed certain thresholds. This is considered the first global tax on greenhouse gas emissions, proposed by the organization at a conference in London, England.

The UN agency estimates that the levy would raise $11-$13 billion a year, which would be used to invest in the fuels and technologies needed to transition to green shipping, reward low-emission ships, and support developing countries so they don’t fall behind with dirty fuels and older ships.

Under the plan, from 2028, ships will be fined $380 for each tonne of CO2 equivalent they emit above a fixed emission threshold.

Countries also agreed to cut CO2 to achieve a 20% reduction in net emissions from international shipping by 2030 and a complete elimination by 2050.

IMO also sets a marine fuel standard to gradually transition to cleaner fuels.

Final approval will be given at the IMO meeting next October.

Emissions from the shipping industry have increased over the past decade, accounting for about 3% of global emissions. Some environmentalists at the meeting called the agreement a “historic decision” and a step in the right direction. But others said it did not go far enough to cut emissions and did not generate enough revenue to support developing countries.