Revealed: top carbon offset projects may not cut planet-heating emissions

The vast majority of the environmental projects most frequently used to offset greenhouse gas emissions appear to have fundamental failings suggesting they cannot be relied upon to cut planet-heating emissions, according to a new analysis.

The global, multibillion-dollar voluntary carbon trading industry has been embraced by governments, organisations and corporations including oil and gas companies, airlines, fast-food brands, fashion houses, tech firms, art galleries and universities as a way of claiming to reduce their greenhouse gas footprint.

It works by carbon offset credits being tradable “allowances” or certificates that allows the purchaser to compensate for 1 ton of carbon dioxide or the equivalent in greenhouse gases by investing in environmental projects that claim to reduce carbon emissions.

But there is mounting evidence suggesting that many of these offset schemes exaggerate climate benefits and underestimate potential harms.