Likewise, there is nothing which will stop CEOs from ruining the environment unless the externalities of their industries cost them money. It doesn't matter how many scientific pronouncements are made or if the CEOs of gas and oil companies know in their heart of hearts what they are doing has terrible long term consequences, they will continue on the current course.
Yes, individuals can help by choosing to driving less and changing their thermostat, but many/most won't do enough. The most free market solution is to make the polluting companies pay for their externalities. Yes, dividends will go down. Yes, the costs of some goods will go up, but only up to their true costs since we won't be giving the companies a free pass to use the atmosphere as a trash can. Once things have their full costs baked in, everyone will adjust their consumption, not just the environmentally conscious. I doubt even that is enough, but it is more than we are currently doing.