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.

Consequently, many tonnes of greenhouse gas emissions considered “offset” by trees that would not otherwise exist have, in fact, only added to our planetary carbon debt, say researchers.

REDD+ schemes generate carbon credits by investing in the protection of sections of the world’s most important forests – from the Congo to the Amazon basin. These credits represent the carbon that will no longer be released through deforestation.

Organisations and individuals can then offset their own carbon footp