The price for 1 ton of CO2 emissions has risen to a record high.
On Tuesday the price rose above 50 euros for the first time.
There is a lively trade in CO2 rights, which companies can buy if they exceed their own limits in terms of emissions.
Within Europe there is a cap on the amount of CO2 that can be emitted by companies.
That is translated into emission rights, which can be traded.
The number of available allowances is constantly being reduced to encourage companies to produce more cleanly.
These sharpened ambitions of Europe to accelerate the reduction of CO2 emissions contribute to the price rising faster.
In the meantime, the rights have also become pure commodity, which also pushes up prices.
According to the emissions authority, most companies participating in the EU Emissions Trading System (EU ETS) are allocated a quantity of emission allowances each year for free.
Every year, companies have to surrender as many allowances as they have emitted tons of greenhouse gas.
"When a company emits more than they have in rights, they can buy it through auctions or trade."
If, on the contrary, less is emitted, then the company has rights over and they can do with it.
"Companies can therefore decide for themselves what is the most cost-effective: invest in cleaner technology or buy additional emission rights", according to the Dutch Emissions Authority (NEA).
Last year, the rights had become very cheap, because large parts of production came to a standstill as a result of the corona crisis.