And so, with our sponsors, BMW and Conde Nast Portfolio magazine, TED hosted a salon on climate change. The goal: Inspire a debate that goes beyond conventional rhetoric, and explore some radical scientific solutions that just might be ideas worth spreading …

Guest host Stephen Petranek began the night with a spirit of discovery. Seen from one angle, “global warming is a very simple chemistry problem,” he said, and removing CO2 from the air shouldn’t actually be that hard. In exploring the problem of climate change, his search for solutions (and speakers) turned up a wide range of unconventional thinkers and remarkable ideas — all of which are within the realm of near-term possibility.

First up: Michael Oppenheimer (pictured above), former chief scientist at the Environmental Defense Fund, who was one of first to sound the warning about global warming. “I’m the depressing and immobilizing part of the program,” he joked. “I don’t propose any solutions …. So pop your Prozac and let’s go.” Oppenheimer set up the evening by demonstrating the overwhelming evidence that “pervasive climate change is already under way” and “further warming is physically inevitable.” (For a refresher on the causes of climate change, and the role of carbon dioxide, there’s no better primer than Al Gore’s An Inconvenient Truth).

Physicist Martin Hoffert took the stage next. A staunch advocate for getting off fossil fuels, Hoffert takes what might fairly be called an expansive approach to alternative energy, urging the systematic use of all our planet’s available energy sources: not only the wind and the sun, but ultimately all the star-power in our galaxy. Viewed from this angle, our singular focus on earth-bound fossil fuels seems not just misguided, but small-minded: “We’re relying on sources that represent only an infinitesimal portion of available energy,” Hoffert said.

His proposals — which range from wind farms (like the one atop the original Freedom Tower design) to a global power grid for collecting and distributing solar power, to an idea (“usually considered pretty far out … but maybe not for this audience”) for collecting solar power from space — all push the limits on conventional thinking and urged us, essentially, to think bigger.

Now, just as the evening’s speakers are all testing the edge of science, performer Sxip Shirey is pushing the edge of music. A circus composer and all-round showman, Shirey uses bowls and marbles, music boxes, bells and whistles to create beautiful, otherworldly sounds unlike anything you’ve heard. His short piece, “Pandora” — beautiful, haunting, eerie, sexy, mind-bending in its own right — provided a bit of mental cross-training, mid-evening. Murmurs of “How does he do that?” could be heard through the crowd …

Next, environmental scientist David Keith put forth another controversial solution: What if we injected levitated particles (likely sulfurous) into the middle atmosphere, to deflect sunlight and heat? The method is “absurdly cheap,” mimics a natural process that occurs when volcanoes erupt, and could be deployed in a localized fashion above the poles, as an emergency measure to slow a melting ice cap.

Now, this might may not be a GOOD idea, Keith warns. But it’s crucial that it enters the realm of public discourse. The idea has been around since the Johnson administration, but public debate has been squelched for a number of reasons, including this central problem: The knowledge that geo-engineering is possible makes climate change less fearsome, and reduces the political will to cut emissions (which we must do). “This is what economists cause a moral hazard,” Keith concludes. But it’s no reason to avoid a discussion: “We don’t make good policy decisions by hiding things in a drawer.”

The next speaker, Russ George, brought our focus down from the stratosphere and into the oceans, where climate change and rising CO2 levels have caused a dramatic loss of ocean productivity, particularly in the southern hemisphere. George focused on the disappearance of plankton blooms along the water’s surface (think of them as ocean forests). His proposal: the controlled release of iron filings in the Pacific to stimulate a plankton bloom, and therefore increase uptake of atmospheric carbon dioxide. George’s firm, Planktos, would then sell carbon offsets, based on the productivity of the “iron bloom.” Like Keith’s solution (injecting particles into the atmosphere), this approach mimics a natural process caused when dust storms swirl out over the sea. And it similarly (let’s face it) triggers serious concern about unintended consequences.

The evening’s final speaker, TED veteran Juan Enriquez, offered us a glimpse at some ground-breaking research to explore the potential of bioenergy. He looked at the way our current energy sources — coal, oil, gas — are ultimately derived from ancient plants, and are in some way “concentrated sunlight.” Can we learn from that process and accelerate it? Can we apply biological principles to the problem of fuel creation? Can we get to the point where we grow our own energy as efficiently as we grow wheat? Looking at a photo of a pile of surplus grain, he notes, “That would probably be a good outcome for energy.”

After five provocative speakers, and many more mind-bending proposals, Stephen Petranek neatly summed up the thoughts swirling through all of our minds: “Humans are at a place in their history when we can actually engineer our own planet and fool mother nature,” he reflected. And while we must be absolutely mindful of the unintended consequences (they inevitably occur), “It’s incredibly uplifting to know we can control our own destiny.”

The talks from this Salon will be made available on TED.com over the months to come.

Photo of Michael Oppenheimer by Myrna Suarez, Condé Nast Portfolio

The first speaker, Michael Oppenheimer, began by saying: “I’m the depressing, immobilizing part of the talk.” He went on to make this point: While Hurricane Katrina can’t be directly tied to climate change, it did teach us one thing:

You can’t count on the government to save you from global warming. They’re still inept to this day, and half an American city is gone, and how the hell are we going to deal with this? And what are we doing instead?

He puts up a devastating slide of the hyperdevelopment on the beach at Atlantic City — which would lose 100 feet of beachfront if global sea levels rise 1 foot, as they will.

Alternative energy expert Martin Hoffert is a staunch advocate for getting off fossil fuels altogether. He spun out one scenario:

Let me say a few words about space solar power. The advantage of putting solar collectors in orbit: The sun is basically shining 24/7. We already have thousands of satellites up there — suppose you could build a transmitting antenna in orbit that would beam energy down to collectors, beaming energy using lasers (not microwaves) from geostationary orbit? We could send it up in one launch vehicle, and power a village, maybe in Africa, to demonstrate the viability of solar power. We could do this in 3 to 5 years.

Environmental scientist David Keith talked about geoengineering — dramatic, cheap solutions to a warming atmosphere, such as blowing a Mt. Pinatubo-size cloud of sulfur into the sky to bring the global temperature down. Such ideas seem overly dramatic, and even immoral, but they are out there, and he argues:

We should move this out of the shadows and talk about this seriously, because sooner or later we will be confronted with a decision on this. We would do [geoengineering] instead of cutting emissions, instead of mitigation, because it’s cheaper. It’s very cheap. It’s not a GOOD idea, but that’s how big the [incentive] is. That is not in dispute, though we might argue over the sanity of it …

Russ George, the chief scientist of Planktos, offered a way to think about all the factors contributing to the larger issue of climate change:

We have a bunch of aberrant applications in this planet, jamming a lot of errors against that primary operating system, and it’s threatening to reboot and give us that blue screen of death, threatening a reboot back to 16 million years ago.

Juan Enriquez (pictured above) talked about how much of our energy, such as coal and oil — made from ancient plants — is simply “concentrated sunlight.” How can we get to the point where we grow our own energy as efficiently as we grow wheat? Looking at a photo of a pile of surplus grain, Enriquez notes:

That would probably be a good outcome for energy.

Photo of Juan Enriquez by Myrna Suarez, Condé Nast Portfolio