Photosynthesis.

Fast-growing trees turned into biochar in my opinion. Partially because, well, every HN user’s got to have their favorite piece of “proven” old tech.

Thermal Depolymerization.

Will taking carbon out of the atmosphere suffice if we don’t also stop putting carbon into the atmosphere? We need a way of recycling carbon on human time scales, not geologic time scales. We need a way of converting six-billion polluters into six-billion obsessive cleaner-uppers.

Thermal depolymerization deployed on a homeowner scale, might fill that need.

Instead of making monthly payments to the gas and electric utilities, homeowners could gather trash, recycle food waste, and recycle unwanted, broken, or obsolete possessions to produce their own energy. Surplus production would become an income source; something to be sold utilities for transport to factories for production of new products. Right now this is science fiction but thermal depolymerization research suggests that we could make oil pipelines run backwards;

Previous attempts to burn garbage for energy have failed because the energy output of trash was entirely consumed by the need to dry garbage before it will burn.

Researchers have demonstrated a process for turning carbon-based trash into "sweet Texas crude" while generating an energy surplus. Instead of drying the garbage stream, they added water, then pressure cooked it. There were four outputs streams: inorganics, steam (used for preheating), methane (used to cook the next batch), and low-sulfur, light-weight crude oil. Since the process accepts all carbon-base materials, no sorting is necessary.

Our shelters, farms, industrial production, transportation, and communication systems are all dependent upon some form of burning carbon. How many decades will it take to redesign those processes and retire all of those vehicles and structures? Can it be done quick enough to save us?

Depolymerization might be a way of retrofitting houses to produce their own energy until their end-of-life.

Imagine a world where a homeowner's computing, cooking, heating, A/C, and personal transportation are powered by an input stream of organic waste. "Mom, can I go outside and look for trash? I want to play Fortnight." Thermal depolymerization could turn beach trash, micro-plastics, storm damage, and food waste into comfort, convenience, and income. Much better than a government mandated “return deposit” or voluntary “recycling” industry that recycles only 9% of what it collects.

If no other benefit accrued, home power production would save on transmission losses. Pipelines might be repurposed for collecting oil from household reactors and selling it to industry for production of new products.

By making plastic waste valuable, we could get it off our beaches, out of oceans, and out of our food chain.

(Imagine forests that won’t burn because gangs sneak into forests at night to steal fallen branches and dead animals. Or public toilets that pay depositors by the ounce. Taxes might be paid in oil produced in every garage. (Fantasy. Pure fantasy.))

Thermal depolymerization … a phrase to remember.

(Reads like a screen play, doesn’t it.)