Fossil fuels have a number of intentionally "hidden" costs.
At current CO2 levels plants are starved for CO2. At 150 ppm there would be a massive extinction of land-based plant life.
Land-based plants evolved when CO2 levels were much higher than today. [1] In fact levels have been steadily declining from 3000 ppm 150 million years ago; the current, holocene rise is a relatively minor bump. [2]
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692178/
[2] http://caos.iisc.ernet.in/faculty/pghosh/content/Publication...
There's also the other ramifications of increased CO2 concentration like: ocean acidification, warmer overall climate globally and increased incidences of severe weather, rising seas resulting from the warmer temperatures, and not all plants will enjoy the higher temperatures (or the droughts, hailstorms, strong winds, too much rain all at once), especially those in the tropics which already get quite warm.
>Our results suggest that future climate change will push this ecosystem away from conditions that maximize NPP, but with large year-to-year variability
[0]http://www.pnas.org/content/pnas/early/2016/08/30/1606734113...
edit: less blunt.
Here is one of many scientific papers on the subject: "Carbon dioxide starvation, the development of C4 ecosystems, and mammalian evolution" [1]
[1] http://rstb.royalsocietypublishing.org/content/353/1365/159
>Global expansion of C4 biomass is recorded in the diets of mammals from Asia, Africa, North America, and South America during the interval from about 8 to 5 Ma.
That's a 3 million year period, ending 5ma. You say CO2 starvation is down to 150ppm, but atmospheric CO2 levels have fluctuated between 180-200 (ice ages) to 300ppm (warm periods) for the past half million years or so.[1] Meanwhile C3 plants (those supposedly which suffered during your linked expansion of C4 biomass) are around 95% of plant biomass currently. Doesn't seem like plants on the whole are starving for CO2 at this time.
I'm impressed by your method of argumentation.
Since we are already facing unprecedented growth that won't be stopped except by famine, world war or some other calamity, it's important we find a way to stretch our limited resources further and develop technologies that will help us expand beyond earth like nuclear fusion.
Price is important to motivate people to develop nuclear fusion technology, and to finally build commercial fusion plants when the time comes.
Nuclear fission is a superior power technology already, but we've largely stopped building new plants because of the exorbitant upstart costs compared to other technologies.
Price also tells us whether the new energy source would require government support, or require less resources than building and fueling a new fossil plant, or (if extremely cheap) would prompt people to shut down even brand-new fossil plants because the new energy source is cheaper than the cost of fuel.
I mean more expensive in inflation adjusted dollars.
At that point, fusion will go onto a Moore's Law curve and we will see exponential improvements for quite a few years.
Sure, more money means more improvements faster, but at best that can only amplify already-exponential progress. Unless, it leads to even more money? Or, that each improvement scales all factors? Or, that one improvement makes it easier to find subsequent improvements (a kind of positive feedback loop; accelerating returns).
Why should money make fusion have Moores-like growth? Not even silicon has it any more...
I'd say the key to the parent's premise, is they said it'd be exponential for quite a few years (rather than indefinitely). That's likely correct. The early improvements would probably leap substantially in regards to the output possible. We saw the same thing in nuclear reactor tech.
Because fusion research is critically underfunded and always has been. Like any project, there is probably a point where we'll hit diminishing returns, but right now we're barely keeping the lights on, much less hitting diminishing returns.
https://commons.wikimedia.org/wiki/File:U.S._historical_fusi...
Nothing resembling Moore’s law style advancement, despite a lot of money to be made.
It is likely exaggerated but the headlines claimed the big Australian battery returned the investment within a couple of months. There’s a LOT of money to be made on energy storage.
Why would fusion reactors be moorable?
As you say, batteries have been around for a long time. The rapid growth/improvement part of the battery curve happened back in the late 1800s/early 1900s.
The lead-acid grid lattice design, still the...errr...gold standard when it comes to the most amount of joules stored per buck, was invented in 1881.
(modern technologies like the various lithium battery chemistries win when it come to storage for a given mass -- thus their use in things like portable devices and cars, but lead-acid still wins when it comes to storage for a given cost).
Li-ion has caught up. If you have $400 to spend on batteries both li-ion [1] and comparable lead acid [2] (deep discharge, long cycle life) cost around 3 Wh/$.
[1] https://www.imrbatteries.com/samsung-29e-18650-2850mah-2-75a...
[2] https://www.powerstream.com/BBep.htm (EP100-12)
We also have lots of different designs to experiment with, and much better computers for running simulations. As the computers improve, fusion progress will speed up, if the funding is available.
* (The triple product of temperature, density, and confinement time is the critical fusion metric; for every fusion fuel there's a triple product above which you get net power.)
The original observation is basically a winner-take-all combined with the fact that transistors scale as the square of the minimum dimension. So, if there is linear improvement in dimension, there is exponential improvement in density.
The reason why Moore's Law continued on for so long was that companies were willing to spend exponentially increasing amounts of money to hit the next technology node because of the winner-take-all nature of the product. Anybody who got to the next node forced everybody else to the next node or wiped them out of business.
This is going to be the same thing with fusion. Linear improvements in the fundamentals translate to exponential improvements (fourth power or better) in the outputs. The first folks to fusion are going to force everyone to fusion or wipe them out of business.