UN Secretary General Antonio Guterres Wednesday accused Big Oil of peddling a “big lie” about their contribution in global warming. Speaking at the World Economic Forum Annual Meeting in Davos, Switzerland, Guterres said, “We learned last week that certain fossil fuel producers were fully aware in the 1970s that their core product was baking our planet.”

Guterres was referring to a study on the oil giant ExxonMobil published last week in the Science Journal. The study found that the firm has known the climate consequences of their fossil fuel products since the 1970s but rejected the predictions of its own panel of in-house scientists on the role of fossil fuels in global warming. General Motors and Ford are also implicated in denying scientific predictions about environmental harms.

ExxonMobil is embroiled in a number of lawsuits in US. The state of Massachusetts sued the corporation for misleading consumers and investors about the risks of their fossil fuel products. Several jurisdictions in California also sued the company in an attempt to hold them accountable for their role in inducing climate change.

The WEF annual meeting is taking place from January 16 to 20. This year’s convention examines the theme of “Cooperation in a Fragmented World.” It brings together leaders, innovators and visionaries from spheres of government, business and civil society to discuss issues plaguing human life and find solutions through public-private partnership.