Evil Exxon and it's climate cover up

It's very simple. Climate change action lost 20 years because the fossil fuel corporations lied to us. 

As far back as the early 1980's Exxon was doing masterful climate research and finding that the burning of fossil fuels was warming the planet. Instead of sharing their message though they set about disproving this to the people, going so far as to lie publicly and take the opposite view. 

Surely someone in those corporations must take responsibility for what they did. It was absolutely criminal. 

The question could be raised surely, are they now open to be sued by those who will now be affected by climate change? Could Pacific Island nations that get flooded or go under take up a law suit against them for example?