The majority of carbon offset schemes are significantly overestimating the levels of deforestation they are preventing, according to a study published in Science.

This means that many of the “carbon credits” bought by companies to balance out emissions are not tied to real-world forest preservation as claimed.

An international team of scientists and economists led by the University of Cambridge and VU Amsterdam found that millions of carbon credits are based on crude calculations that inflate the conservation successes of voluntary REDD+ projects.