Almost all carbon offsets don’t work, says recently published research by the European Commission. The study, titled How additional is the Clean Development Mechanism?, was conducted in 2016 and published last month.

According to the report, “85% of the projects covered in this analysis, and 73% of the potential 2013-2020 supply, have a low likelihood that emission reductions are additional and not over-estimated.

Only 2% of the projects and 7% of potential supply have a high likelihood of ensuring that emission reductions are additional and not over-estimated.”

Meanwhile, according to data from the Commission, Europe’s aviation industry saw its annual emissions rise 8% in 2016 to 61.6 million tonnes of CO2e, while emissions from all other European transport sectors declined.

And last year the aviation industry hailed a “landmark accord” on climate change that it said would enable it to deliver “carbon neutrality” by 2020, yet relied heavily on the purchase of offsets.

Andrew Murphy, who analyses the industry for Brussels-based Transport and Environment, called the report “a wake-up call to the world that relying solely on offsets to address aviation’s climate impact is unsustainable. Instead, the EU needs to pursue policies such as fuel taxation, ending subsidies, reforming the EU ETS [emissions trading system], and ceasing support for airport expansion.”