South Pole, the world’s leading seller of carbon offsets, has been forced to suspend a flagship forest protection project in Zimbabwe amid allegations of exaggerated claims. Around one-fifth of the Swiss firm’s staff could also lose their jobs, according to media reports.

Carbon offsets allow firms and individuals to compensate for the carbon emissions they create – through, for example, an airplane flight or a building project – by paying to pull carbon out of the air elsewhere. Voluntary offsets have developed into a billion-dollar global market.

Last week the Washington, D.C.-based certification body Verra, the world’s leading carbon standard setter for the offsets market, announced it had launched an investigation into the Kariba REDD+ forest conservation project in northern Zimbabwe, one of South Pole’s largest climate protection projects. REDD stands for “Reducing emissions from deforestation and forest degradation in developing countries”.

This follows a critical report published on October 16 by the NewYorker magazine, entitled “The Great Cash-for-Carbon Hustle”, which claimed South Pole sold millions of credits for carbon reductions that weren’t real. …