Geologist, author, environmentalist and energy executive Leighton Steward is still following his passions. This time, he’s researching carbon dioxide as it intersects with climate-change policy. The former chairman and chief executive of Louisiana Land & Exploration Co. may be retired in Cody, Wyoming, but he’s about to launch a website, plants­needco2.org, which goes with his new foundation, started with Houston friend Corbin Robertson, head of Quintana Minerals.

Separately, he is on the board of EOG Resources, the Southwest Research Institute and M. D. Anderson Cancer Center in Houston. He is also chairman of the Institute for the Study of Earth and Man at Southern Methodist University, Dallas, where he obtained a master’s in geology in 1960.

After time in the U.S. Air Force, he joined Shell Oil Co. in 1962 in Houston, later becoming manager of Shell’s Gulf of Mexico operations out of New Orleans. While there, Shell discovered the prolific Cognac and Eugene Island 230 fields. He worked with Shell colleague Mike Forrest to prove the latter’s discovery of bright spot technology for hydrocarbon indicators, today a standard tool used by geologists worldwide.

Steward later became the head of New Orleans independent LL&E, which was the largest owner of coastal wetlands in the Lower 48. Concerned that they were sinking, he self-published a 26-page booklet, “Louisiana’s National Treasure,” that explained why, and what might be done about it. Twice he was chairman of the Audubon Nature Institute and he chaired the National Wetlands Coalition for 10 years.

LL&E was acquired by Burlington Resources Corp. in 1997 for $3.2 billion, creating one of the first super-independents and the third-largest holder of U.S. gas reserves (now part of ConocoPhillips).

To the public, Steward is best known as lead author of 1995’s Sugar Busters, which sold more than 4 million copies and spent 16 weeks at No. 1 on the The New York Times bestseller list. It gave still-popular weight loss and diabetic advice.

He has won awards for leadership from the American Petroleum Institute, the Independent Petroleum Association of America and the American Association of Petroleum Geologists. Steward is past chairman of the United States Oil & Gas Association, All-American Wildcatters and the Natural Gas Supply Association. He represented the industry on Republican and Democratic presidential missions to the former Soviet Union, Turkey and Pakistan.

His latest project? Researching the agricultural benefits of increased airborne CO2, while countering what he calls “the misplaced blame on CO2 for causing global warming.” Steward is now revising his 2008 book on the topic, Fire, Ice and Paradise, for a second edition.

Investor How did the wetlands book come about?

Steward My wife says everybody has a book in them. I guess no one had really explained all this before in simple language, so I did. The booklet caught on quickly—we gave away 110,000 copies. It even focused our Louisiana congressional delegation at the time. Sadly, I’m afraid the wetlands are still sinking.

Investor Your third book may be the most important of all.

Steward This climate thing came about after I retired. Even as a geologist, I wasn’t aware of the effects of carbon dioxide, so I started documenting it. Did you know that CO2 levels used to be 10 to 15 times higher than they are now? And that ice cores show that temperatures rise before CO2 does, with CO2 lagging by an average 800 years?

The U.K., Germany, Russia, China, all agree…It was shocking information to me…a cause does not follow an effect! But some high-profile people are trying to stiff-arm scientists who believe this, and they want no debate on it.

Investor What is the agricultural angle?

Steward The more CO2 in the atmosphere, the lusher the vegetation. If the world’s population is going to 9 billion, we can’t feed them all on the existing arable land without converting wildlife habitat to farm land. Experiments show that CO2 has a dramatic impact on plant growth. If CO2 levels nearly double, barley would grow faster by 41.5%…rice growth goes up 34.3%. This is from 152 studies!

I challenge you to find where CO2 is a pollutant. We all breathe it in, then out—even into someone else when we do CPR! U.S. submarines let CO2 go to 8,000 parts per million—way above what climate-change advocates say is safe to allow. It’s in our soda pop and in dry ice. The public is not aware of this, that the science is definitely not settled on this. I am excited about this—it is highly documented and I’m not afraid to talk to anybody about it.

—Leslie Haines