I've just read The Burning Question by Mike Berners-Lee and Duncan Clark.
As Caroline Lucas points out in her book review, when it comes to replacing fossil fuels, nuclear power is not ruled out. In fact my reading is that if fossil fuel use is reduced to sustainable levels, we will need every energy source we can find. Nuclear power in some of the new forms could even burn up plutonium, putting it truly beyond use in nuclear weapons.
I learned a few interesting things from this book. I had noticed how in spite of all the carbon targets, we don't seem to be making a dent in our increasing use of fossil fuels. Here they explain clearly how, without a world wide scheme, individual efforts to emit less carbon through efficiency can actually produce more fossil fuel use - squeezing a balloon that bulges elsewhere. Also they make it clear that fossil fuels must be controlled at source, which confirms my thoughts that controlling carbon emissions as we do now is futile - we just export the emissions.
I also learned about the Kaya Identity, an equation relating emissions to population, affluence, energy intensity and carbon intensity. In light of this equation I was disappointed when I saw my old idea for carbon cap and trade, with a quota based on population by country, did not include reducing quota by the population index, as well as over time. Without the population index, there is a perverse incentive to increase population.
The book repeatedly talks about tipping points and catastrophic climate change, but omits to give examples of just how bad the models look. It does give figures for sea level rises, but omits scenarios like; melting Greenland ice stopping the Gulf Stream, the Amazon basin turning to savannah, and other horrors I've heard predicted. Maybe those horrors are so controversial, they could discredit the book, which leans over backwards to be balanced.
I like the way the book divides our possible future actions into a Plan A: (Burn less fossil
fuel) and Plan B: (Long shot geoengineering). Although I suppose that global warming is in itself a form of accidental geoengineering. Part of the debate about The Anthropocene age we humans have caused.
When it comes to geoengineering from space, the only example given is orbiting reflective particles as a sun screen. A more controllable scheme would be a sun shade balanced at the L1 Lagrange point between us and the sun. If we think of sustainability in terms of billions of years, something like this will be needed anyway as the sun gets hotter. So why not start building it now?