For four days last August, a thick slick of maroon bruised the waters of the Gulf of Maine. The scene, not unlike a toxic red tide, was the result of 65,000 litres of an alkaline chemical, tagged with a red dye, that had been deliberately pumped by scientists into the ocean.
Though it sounds perverse, the event was part of a scientific experiment that could advance a technology to combat both global heating and ocean acidification. Ocean alkalinity enhancement (OAE), as the approach is called, acts like natural weathering, but on human – rather than geological – timescales.
“The ocean is already incredibly alkaline. [It holds] 38,000bn tonnes of carbon, stored as dissolved bicarbonate, or baking soda,” says Adam Subhas, the lead oceanographer of the research team who announced early results from their test at the AGU Ocean Sciences Meeting in Glasgow.
Boosting this natural alkalinity using a chemical antacid should, in theory, encourage the ocean to absorb more carbon. Over a large surface area, and in combination with sharp emissions reductions, OAE could prevent global temperatures exceeding 2C above preindustrial levels, while locally reducing ocean acidity, which is now higher than at any point in the past million years and poses a dire threat to marine life and fisheries.
To be viable, a solution is going to have to include replacement for the functions provided by fossil fuels. Without those functions, we’re back in the stone age. Scientists might tolerate that, but the general public will not. Electric cars and electrified trains will solve a large part of that problem, but sea and air transport aren’t anywhere close.
Synthetic gaseous and liquid fuels and lubricants can be produced using atmospheric CO2 as a feedstock. The problem is that the process is energy intensive. But, that very problem is also a solution to another one.
Solar and wind electrical generation has a massive problem with seasonal variability. We can solve the daily variability with various storage methods, but there is no viable way for storage to manage seasonal variation. Basically, a solar panel that is sized to meet our needs in the short days of low-angle sunlight we get in winter will produce more than three times as much energy as we need under long, high-angle sunlight in summer.
Excess production reduces the profitability of every generator on the grid. So we get to a situation where profits are maximized long before we meet our generation needs. Any further increase in generation capacity decreases expected revenues. We are motivated to reduce solar generation capacity before our needs are fully met, rather than increasing it to fully meet our needs. This is the real problem currently coming over the horizon; the one we need to begin addressing.
We can frame this as a problem of variation in supply. Or we can reframe it as a problem with lack of variation in demand. The latter is a much simpler problem to solve. The problem isn’t that we produce too much power in the summer. The problem is that we use too much power in the winter, but not nearly enough in the summer. We need to decrease our winter consumption, and increase our summer consumption to match what we produce.
If we soak up the excess energy in spring, summer, and autumn to produce synthetic fuel and lubricants from atmospheric CO2, we keep renewable generation profitable year round, while also producing a carbon-neutral replacement for petroleum oil.
(This is not a theoretical: the Air Force has certified all of its aircraft to operate on Fisher-Tropsch-produced synfuels. These fuels are direct replacements for petroleum fuels, but are developed from catylizing CO2 and hydrogen into long-chained hydrocarbons, rather than refining from petroleum.)