We humans have proven our ability to affect an entire planet’s temperature, albeit unintentionally. Does this mean we have the ability — or the right — to deploy planetary-scale technology to rapidly bring those temperatures back down?

That’s the main idea behind geoengineering, a catch-all term for various technological approaches to quickly rejiggering the Earth’s climate. The potential schemes run the gamut, but are generally divided into two categories: shield the Earth from the sun’s rays (Solar Radiation Management, or SRM), or remove the carbon dioxide from the atmosphere (Carbon Dioxide Removal, or CRM).

In this multi-part series, filmmaker Ian Cheney examines the scale of climate change, in all its many dimensions

In this multi-part series, filmmaker Ian Cheney examines the scale of climate change, in all its many dimensions. Click the play button in the video above to view the short documentary.

At this point, with the exception of rogue experiments, most geoengineering is still in the “what if” phase, and the precautionary principle would seem to dictate that we avoid tinkering with something until all of the potential impacts are understood. At the same time, the appeal of geoengineering stems from a pragmatic — and increasingly pressing — observation: Collectively, nations of the world are not taking the necessary steps to curb carbon emissions — at least not as quickly as many scientists believe is necessary.

If carbon continues to collect in the atmosphere unabated, we will almost certainly have to find other ways to offset the harm.

Unfortunately, managing an entire planet’s climate is as hard as it sounds. Take the example of ocean fertilization, which seeks to create algae blooms that would draw carbon out of the atmosphere. According to a recent MIT study, the blooms would have the added benefit of increasing sulfur emissions, which would help reflect some of the sun’s energy back into space. That sounds great, but these emissions would also disrupt rain patterns, leading to potential adverse effects on water resources around the globe.

This mixed bag of potential effects offers just a hint of the staggering complexity of our climate system — the full scope of which scientists still don’t fully understand, even without additional tweaking. How can we predict which regions of the globe will benefit, and which will suffer if we were to, say, inject reflective aerosols into the atmosphere, or increase ocean foam for the same purpose? If we remove carbon dioxide from the atmosphere, can it be safely stored underground? And can computers reliably model all the potential side effects of such grand-scale endeavors?

The idea of “playing God” has made many observers uncomfortable with even discussing geoengineering. Others suggest that geoengineering distracts us from the task at hand: reducing carbon emissions. Still others suggest that technologies aimed at reducing carbon emissions, like solar panels and electric cars, should be considered a kind of geoengineering — a global scale effort to rein in the rising temperatures.

Whatever the nomenclature, it’s probably worth noting that two centuries of human industry and economic progress have altered the planet’s climate machinery. In that sense, if you eat food, use lights, drive a car, or otherwise take part in our energy-intensive civilization, you’re already a geoengineer. What happens next is a matter of scale — technological, political, and ethical.

After all, who gets to decide, going forward, what the temperature of the Earth shall be?