Tillerson rejected the claim, but also took the opportunity to weigh in on the existential threat of global warming. During 3 1/2 hours of testimony, he cast Exxon in a favourable light, in contrast to claims by environmentalists and some government officials that the company helped trigger climate change and exacerbated the crisis by hiding it from the public. We knew it was a serious issue and we knew it was one that's going to be with us now, forevermore. Rex Tillerson Tillerson didn't deny Exxon's role in creating the problem -- which wasn't what the trial was about -- but in his nuanced view, the company had done its best to address the issue once it became apparent. He also said there may be plenty of blame to share, given that Exxon was providing products demanded by society. Humanity has a hard time making changes to address the impacts of climate change because of the world's never-ending demand for economic development and improved standards of living, which is tied directly to fossil fuels, he said.

"If the economies are going to continue to not just perform, but grow, if people are going to continue to want to improve their quality of life, sustain their quality of life, they're going to have to have energy, a lot of it, and the demand is going to keep growing," Tillerson said. 'Natural tension' "So there's this natural tension" between that desire for growth and fixing climate change, "and that's really the challenge that policymakers and legislators are confronted with," he said. One example of that challenge may be in Alberta, Canada, where Exxon has multibillion dollar oil sands projects. It may not be unrealistic to assume that those projects will operate for decades without an increase in provincial taxes on greenhouse gas emissions, he said. "We have been through many changes in Alberta provincial government," Tillerson said. "What I do know is the Alberta government doesn't want to put the oil sands out of business. It's important to them from a jobs, economic, tax revenue. And they always -- in Alberta, the industry has always had a very kind of healthy dialogue with them, and they listened."

The Alberta projects were part of the case brought by New York, which claimed Exxon was deceiving investors by predicting the province's tax on greenhouse gas would remain steady, even as the company predicted rising levies on other projects through 2040. Estimating cost The ex-CEO was also asked to explain why Exxon put in place proxy costs for carbon to estimate demand and greenhouse gas costs for expenses when it wasn't required to do so. (Those costs are at the heart of the New York lawsuit. The state claims they were a sham.) "We would have been irresponsible in our positions if we didn't think about the strategic implications of this," Tillerson said. But such costs weren't the same everywhere Exxon operates, he said.

"It may be emissions are so de minimis that they're inconsequential, or you may be in a business environment where the government is just not likely to do anything," Tillerson said. "You know, if you're in a third-world developing country." Loading When he was CEO, Tillerson said the company had sought to promote the idea of a carbon tax to help ease society off fossil fuels. "We had watched the European emission-trading system evolve and, in fact, we were a participant in it because of our operations there," Tillerson said. "We had to be part of the trading system, and we saw a number of flaws with that system. In fact, if you look at what it has accomplished over its existence, it never has accomplished what it was intended to do. It hasn't reduced any emissions. "We looked at what are other alternative mechanisms to influence people's choices. And we felt a carbon tax was the most simplistic. It is transparent. You can't game a carbon tax."

Bloomberg