ExxonMobil, the world's largest publicly traded international Oil and Gas Company, was aware of the dangers of the climate change since 1981. However, then also it has remained mum on topic since then. Even now, the oil giant continues to deny on the topic.

Lenny Bernstein, ExxonMobil's top climate scientist, who has worked with the company for three decades, has unveiled this and many facts in reports and letters written by him. The Union of Concerned Scientists has released the documents in a report titled, 'The Climate Deception Dossier'.

These documents clearly reveal about the harms of global warming due to carbon dioxide emissions. It is an irony that since Bernstein's first warning, the company has spent more than $30 million against climate change science.

Exxon has denied to harm it has done even when the scientific evidence was crystal clear. National Academy of Science said it has now become clear that Exxon was aware of the climate change dangers and the solutions 27 years ago. However, then also the company kept on funding climate denial.

Exxon spokesperson Richard Keil has completely refused that the company has funded groups to promote climate denial. He stated, "We have been factoring the likelihood of some kind of carbon tax into our business planning since 2007. We do not fund or support those who deny the reality of climate change".