Justin King has warned that government changes to the Carbon Reduction Commitment scheme could slash corporate carbon investment almost to zero but vowed Sainsbury's would remain "one step ahead" on energy efficiency.

In October, the government decided that the money raised by the energy efficiency scheme would go straight to government rather than to the businesses taking part as originally intended.

Speaking at a Sainsbury's Carbon Reduction Debate hours before the release of the government's fourth carbon reduction budget this week, the Sainsbury's CEO predicted the change could result in a "90% reduction" in planned carbon investments by companies.

"Before, the government had a proven incentive. Now it is just a tax," said King. "How companies respond to a tax will be far different. Now there are certain investments they won't make."

Sainsbury's would continue to invest in carbon reduction initiatives but not if it "interfered with shoppers", he promised.

"There is a danger of being too far ahead," he said. "Sainsbury's objective is to be one step ahead. It is ridiculous to be two or three steps ahead because if the consumer doesn't like it they'll simply go elsewhere."

Customers were happy to accept the trade-off of doors on freezers, he said, but did not accept doors on chillers.

"We've tried doors on chillers. The customers don't like them and if they are being opened wide every 20 to 30 seconds and that happens hundreds of times a day, they're not actually saving that much energy. Instead of stopping the air from falling out, it is better to harness that air and put it to good use somewhere else in the store."

The retailer launched the Sainsbury's Carbon Academy this week to provide environmental training to 20,000 people by 2020.

The Carbon Reduction Commitment scheme is expected to raise up to £1bn a year for the government.