A while back, we broke news of a concept floated by former Microsoft technology chief Nathan Myhrvold and associates -- including Bill Gates -- to suppress hurricanes through a system that would literally mix up the water in the Gulf of Mexico and other areas vulnerable to tropical storms.

But it turns out that's far from the only idea Myhrvold's Intellectual Ventures has dreamed up to save the planet from calamity.

Here's another one: Combat climate change by pumping liquid sulfur dioxide into the stratosphere through nozzles in a hose lifted more than 15 miles into the atmosphere using helium-filled balloons. As described by Myhrvold in an interview this week, the idea behind this "Stratoshield" would be to dim the sun in critical areas of the world by just enough to reduce or reverse the effects of global warming.

"We think it's a simple, relatively cost-effective, pretty practical way that you could intervene and cool Earth off enough to present disaster," Myhrvold said.

No, this is not a joke, or a plot from a bad science-fiction movie. In fact, Myhrvold is talking about the idea now because the Stratoshield and hurricane-stopper ideas are both documented in the new book, "SuperFreakonomics," the follow-up to the hit "Freakonomics" by Steven Levitt and Stephen Dubner.

As Myhrvold explains in the video above, he thinks the Stratoshield approach should be seriously considered in the event of a global climate emergency. As few as two of the hoses would be needed -- one in each hemisphere. Intellectual Ventures' models suggest it would work, and the company hopes to find experts interested in developing and studying the concept further.

As for potential negative environmental effects, Myhrvold points out that sulfur occurs naturally in the environment, and the amount that would be needed is relatively small in the scheme of things -- less than 1 percent of the sulfur already in the atmosphere.

In the book, Levitt and Dunber describe the project as "basically a controlled mimicry of Mount Pinatubo's eruption, whose cooling effects were exhaustively studied and remain unchallenged."

A few hours after speaking with Myhrvold, I happened to be meeting separately with Rob Bernard, Microsoft's chief environmental officer. I described the Stratoshield idea and asked Bernard what he thought.

"There's always a possibility, but I think any dependency on geoengineering is kind of frightening," he said. "At a simple level, think about all the invasive species we've introduced inadvertently through unintended consequences. You never can predict everything."

But Myhrvold said we may ultimately need to take such extraordinary steps to combat global warming. He's not convinced that current efforts to slow climate change will be enough. At the very least, he said, geoengineering concepts should be studied and understood so that they can be implemented if needed.

"Look, I'd prefer not to do it," he said. "I'd prefer we weren't in this pickle, but we seem to be, and our political and diplomatic efforts to get out of the problem so far aren't getting any traction."