Apple CEO Tim Cook took on so-called climate change "deniers," issuing a stern message to anyone who disagrees with the company's clean energy push.

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According to a report by Mashable, the exchange occurred Friday at an annual meeting with the company's shareholders.

He was pressed on the issue by a general counsel for the National Center for Public Policy Research, a D.C.-based conservative think tank that owns Apple shares. He asked Cook to pledge not to go forward with any new energy initiatives that do not improve the company's bottom line.

"We want to leave the world better than we found it," Cook responded, telling any shareholder who doesn't like the policy "to get out of the stock."

Cook has ramped up Apple's use of renewable energy since taking over for Steve Jobs, hiring former EPA administrator Lisa Jackson to lead Apple's sustainability efforts.

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