Climate experts have called for stricter regulations to prevent companies buying ineffectual offsets in the future.
"There are rules emerging to help us understand what high quality looks like, the trick now is to take those rules and ensure that they're really widely adhered to."
The group's executive director Mark Kenber told Sky News:"Carbon credits can be a powerful tool for decarbonisation - but only if we can make sure they're used correctly, above and beyond action companies are taking to cut their own emissions. "VCMI's Code of Practice - which is currently being trialed by leading climate-conscious businesses - will create a commonly agreed set of standards to allow companies who are genuinely making progress to demonstrate this."How to save money on energy bills