The filmmaker and environmental activist explains whether or not, with proper regulation and precautions taken, he could support a safer form of hydraulic fracturing:

Michael Coren points out an alternative to liquid-based fracking that may be a climate win-win:

A technique of pumping pressurized carbon dioxide (CO2) into wells to shatter the rock and push out more oil and gas is gaining steam. Researchers in Japan, publishing in Geophysical Research Letters, showed injecting super-critical CO2 into granite blocks creates more extensive fracture patterns and theoretically outperforms conventional water-based techniques. Eliminating the need to truck, pump and process millions of gallons of water, compared to CO2 is a major benefit. But the most promising, if still uncertain, advantage is using shale formations for carbon dioxide storage, potentially removing a major source of warming greenhouse gas emissions (GHG) to the atmosphere while extracting cleaner energy than today’s coal mines. …

But it’s not without costs. Carbon dioxide from wells must be separated out from the natural gas, and CO2 pipelines– 3,900 miles of the infrastructure already exists–will never reach every well. Finally, the economics aren’t always a money maker. For CO2 to gain traction away from existing pipelines, either hydraulic fracking must cost more due to its risks or water scarcity, or the benefits of CO2 from carbon sequestration and lower pollution must be monetized. Still, the potential to tap into cleaner burning energy while slashing carbon emitted into the atmosphere may change the equation for the future of fracking.

Josh Fox’s Gasland Part II will air on HBO this summer. His other Ask Anything answers are here. Full archive here.