HOUSTON (Reuters) - Exxon Mobil Corp is running television advertisements at the Rio Olympics to showcase its work on clean energy, a high-profile blitz as the company faces pressure over global warming in an intense year of climate politics.

The suite of four ads tout oil major Exxon’s work to capture carbon dioxide from power plants, turn algae into biofuel and develop fuel-efficient cars. Together, they offer a glimpse into the future of a lower carbon world.

Though oil companies typically advertise at big sporting events, the ads are being run as Exxon faces growing pressure on multiple fronts - from shareholders, green groups and state attorney generals - to respond to global warming.

Many other fossil fuel companies also face pressure from shareholders, specifically over whether the value of their oil and gas assets would be slashed as governments clamp down on carbon emissions.

From the opening ceremony of the Games on Aug. 5 to Aug. 17, Exxon spent $19.3 million to air ads 233 times in the U.S. market, reaching about 335 million TV screens, according to iSpot.tv, which tracks ad viewership in real time using advanced analytics.

While small in relative terms for a global company, the TV spending is the most by an oil company during the Rio Olympics and the eighth out of corporates overall. Berkshire Hathaway’s Geico was the largest at $33.5 million.

iSpot.tv said comparative data from Exxon’s previous Olympic spending was not available. Exxon declined to comment on its outlays on advertisements.

Exxon spokesman Alan Jeffers said the new TV ads are part of a longstanding advertising program.

“Our main objective is to provide people with more information about the important role Exxon Mobil plays in safely and responsibly meeting the world’s growing energy demands,” he said. “We want to inform people about the technology and innovation that go into providing energy.”

Exxon’s work on algae dates to 2009. Its carbon capture projects have existed for three decades. Both have been talked about at least once in previous ads, in 2009 and 2011. Now, fresh ads on the themes are in a package at the Olympics.

Pressure on Exxon over climate change has heated up this year. In May, the company’s shareholders approved a measure that could put an outside climate expert on its board, marking the first time since 2006 that a shareholder proposal passed.

In March, more than a dozen state prosecutors said they would probe whether current and former Exxon executives in the past misled the public by contradicting research from company scientists that spelled out the threats of climate change.

The attorneys general have partly based their inquiries, which have faced setbacks, on news articles published in late 2015 that Exxon has criticized.

Exxon has said it has been unfairly singled out by environmental groups, that it has acknowledged the risks of climate change for more than a decade, and that it supports a revenue-neutral carbon tax.

John Doorley, a former Merck & Co. executive and public relations professor at Elon University who has studied Exxon’s past communications efforts, said so long as its ads are accurate it should be playing offense.

Exxon should be “as activist as the most ardent environmentalist when communicating about environmental issues and challenges,” he said.

Last December, 195 governments agreed a radical shift away from fossil fuels with a goal of limiting a rise in average global temperatures to well below 2 degrees Celsius (3.6 Fahrenheit).