In the summer of 2012, a small group of the Haida people, a native community in Canada, had a problem. The salmon they rely on were disappearing. So the Haida took matters into their own hands.
They partnered with an American businessman, drew up plans and then took a boat full of iron dust into the waters off their home island and put the dust in the ocean.
When they spread the iron dust, it created a big algae bloom. They hoped the algae would soak up carbon dioxide and bring back the fish.
The reaction to the experiment was immediate and negative, and described by some media as the "world's first rogue geoengineering project."
While it scared a lot of people and angered a lot of scientists, this event could be a sign of what's to come. Because some very mainstream scientists are saying that the climate change situation is so bad, that saving life as we know it might require something radical: like shooting chemicals into the stratosphere to protect earth from the sun. In essence, these scientists are talking about hacking the climate.
In scientific circles, what the Haida did is called ocean fertilization. Jason McNamee, a spokesman for the group that carried out the experiment, says the goal was to protect the Haida people who live off the coast of Canada
"They get most of their protein straight out of the ocean," McNamee says. "What they have noticed over the last hundred or so years is that the fisheries have become less predictable and less abundant."
And while it's still unclear how successful the operation was scientifically, the legal and social backlash was immediately apparent. The Canadian government condemned the dump and has launched an investigation, seizing documents and data from the headquarters of the company.
"So this is the really knotty problem," says Matthew Watson, a climate scientist at the University of Bristol, "if that experiment had been solely about salmon, nobody would have batted an eyelid. But because it was really about geoengineering, people got very worried."
Watson is also the author The Reluctant Geoengineer blog.
People get scared because a lot of these plans sound like mad scientist schemes. Ocean fertilization is just one of a wide array of climate-engineering techniques that are out there.
One technique is to suck the carbon dioxide out from the atmosphere and put it somewhere else.
"You might do that by planting lots of trees or setting up machines that draw down CO2 and store it somewhere, or generating ocean fertilization where you add iron to the ocean and that generates phytoplankton, which locks up carbon dioxide," Watson tells NPR's Arun Rath. "The whole point is that you're trying to take CO2 out of the atmosphere and put it somewhere else."
A second technique is to try and reflect sunlight away from the earth to keep the earth cooler. You can do that, Watson says, by painting roofs white, through making natural clouds a little brighter or through volcanic aerosols.
In fact, there is evidence of volcanic eruptions that have dramatically lowered the temperature on earth. Scientists want to replicate that. But the catch is that scientists haven't really tested either technique.
"For the most part we've got more questions than answers," Watson says. "It's a very emotive subject and a divisive subject. I can think of academics who agree on almost everything else in terms of science who are diametrically opposed on geoengineering."