Petrol from algae. Bit of GM, we know that the chemistry is possible. Atmospheric CO2, seawater, few other bits and bobs, sunshine.
So we can make something akin to oil that way.
Obvs, price is a bit of a handicap. But now think that we get that down. To where we’re actually price competitive. $30 a barrel oil equivalent. Yes, OK, a what if but still.
So, what’s the cheapest way of beating climate change? Run those plants at double volume and pump the new algal oil back into the old fossil reservoirs. That’ll be fun, won’t it?