Pressure on Exxon Mobil and the energy industry increased on Wednesday with the release of a new cache of decades-old industry documents about climate change, even as Exxon pushed back against efforts to investigate the company over its climate claims through the years.

The new documents were released by an activist research organization, the Center for International Environmental Law, which published the project on its website.

The documents, according to the environmental law center’s director, Carroll Muffett, suggest that the industry had the underlying knowledge of climate change even 60 years ago.