What more can we do to manage climate change?
Can we do more? It is clear that even if the international community manages to make further progress, it has a long way to go before it has exhausted its current agenda of negotiated restrictions on carbon emissions. It should also be clear that even with unimaginably successful negotiations, restrictions on carbon emissions will not do the job.
To be blunt: there is too much carbon in the atmosphere and existing technology – cars, factories, airplanes, ships, buildings – will continue to emit huge amounts more into the foreseeable future.
The only thing to do is to reduce the amount of atmospheric carbon.
There are many experiments underway to find ways to do this. So far, only a few processes show promise. While different in many ways, these processes are similar in one critical way: they all remove carbon from the atmosphere by converting it into an inert form that can be sequestered permanently, that is, returned to a form where, like the fossil carbon forms, it is truly out of sight, out of mind and out of the atmosphere – forever.
New techniques for doing this are remarkably simple chemically, but the innovations in business modeling to make them work are complex. In Iceland, for example, scientists have demonstrated that CO2 pumped underground into porous basalt formations will quickly turn to stone. (Ten percent of continental land and the entire seabed are basalt; the technology already costs less than one half as much as current (and unreliable) underground sequestration techniques.)
Another technology passes air across a huge surface of flowing alkali bath to capture CO2 so that it can then be converted to pellets. (Unfortunately, because CO2 is just 0.04% of the air, meaningful systems will have to be huge and much more efficient.) In each case, and in those of many other possible technologies, the issues are not scientific, but how to scale production cost-effectively.
Can we do more?
The second method of sequestration is at least 4,000 years old: biochar production. The “pyrolysis” of biomass, or heating it to high temperatures (450⁰-750⁰ C) in the absence of oxygen produces a pure form of carbon known as “biochar.”
From a global climate change point of view, biochar production has great potential as it eliminates all of the black carbon and long-term GHGs from biomass burning, and is carbon negative.
Estimates of sequestration rates vary, but by atomic weight, the production of 1 ton of biochar permanently removes 3 tons of CO2 from the atmosphere, as well as 6 kilograms of particulates and large amounts of NOx and SO2.
Widespread biochar production in the developing world where most agricultural waste is field burned would annually remove millions of tons of CO2 from the atmosphere, and eliminate millions of tons of black carbon and GHGs.