In the Urgenda climate case of 24 June 2015, the Dutch court ruled that by 2020, GHG emissions must be reduced by at least 25 percent relative to 1990. This ruling was confirmed by the Court of Justice in The Hague on 9 October 2018, and by the Dutch Supreme Court on 20 December 2019. Based on this ruling, GHG emissions may not exceed 165.4 megatonnes of CO2 equivalents in 2020 and beyond.
The 2020 emissions were estimated three times: (1) as the sum of the four quarterly estimates by CBS (March 2021), (2) the provisional annual estimate of the emissions register (September 2021) and (3) the final annual estimate of the emissions register (February 2022). The accuracy of the estimate increased each time because increasingly better data sources could be used. According to the March 2021 estimate, it seemed that the Urgenda target would not be met entirely (-24.5 percent). According to the September 2021 estimate, it was almost met (-25.4 percent). The final February 2022 estimate stands at -25.5 percent.
Through progressive insight (better data sources and/or different methodology), the entire time series starting from 1990 as compiled for the Netherlands Pollutant Release and Transfer Register will be subject to annual revisions in line with IPCC guidelines. As a result, slight changes may occur in the emission figures over 1990 as well as 2020, which may also affect the reduction percentage. Although most adjustments will be minor, it cannot be ruled out that future calculations will show less than 25 percent emission reduction.