I have “mixed feelings” about “elective surgery” but, if I decided to have it done, I would want a competent surgeon, and I would not want to be her first patient.
Here’s the tack I’ve taken since about 2000, regarding “geo-engineering,” we’d better start experimenting now (then), because “mixed feelings” or not, we’re going to be forced to take actions like this in the near future. It would be best if we knew what we were doing once we did.
In 2008, Hansen et al advised:
A practical global strategy almost surely requires a rising global price on CO₂ emissions and phase-out of coal use except for cases where the CO₂ is captured and sequestered. The carbon price should eliminate use of unconventional fossil fuels, unless, as is unlikely, the CO₂ can be captured. A reward system for improved agricultural and forestry practices that sequester carbon could remove the current CO₂ overshoot. With simultaneous policies to reduce non-CO₂ greenhouse gases, it appears still feasible to avert catastrophic climate change.
(“
Unconventional fossil fuels” = “fracking,” “tar sands” etc.)
At that time, they advised:
… If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO₂ will need to be reduced from its current 385 ppm to at most 350 ppm, but likely less than that. …
(
This is where 350 in
350.org came from.) How many people who are aware of the 350 ppm
goal appreciate that 350 ppm is only a starting point. The logic was that if we could figure out how to lower CO₂ levels
that far, then we could employ the same (or similar) techniques to lower it
further. (Say to
280 ppm or lower.)
Of course, since 2008, we have gleefully done just the opposite of what Hansen et al advised, using fracking, digging up “tar sands” and
not employing “natural” methods to sequester carbon. Instead of phasing out coal by 2030 (as Hansen et al advised) we’re using
more of it to generate electricity!
IEA (2024), Global electricity generation from coal and COP28 pathway, 2030, IEA, Paris https://www.iea.org/data-and-statistics/charts/global-electricity-generation-from-coal-and-cop28-pathway-2030 , Licence: CC BY 4.0
Ironically, in 15 years, instead of
lowering CO₂ levels 35 ppm (to 350 ppm) we
increased them 35 ppm to 420 ppm. At this rate, in another 15 years, we’ll almost certainly be in excess of 450 ppm, and, while we know how to cut
emissions, cutting emissions
does not lower the level of CO₂ already in the atmosphere.
Our estimated history of CO₂ through the Cenozoic Era provides a sobering perspective for assessing an appropriate target for future CO₂ levels. A CO₂ amount of order 450 ppm or larger, if long maintained, would push Earth toward the ice-free state. Although ocean and ice sheet inertia limit the rate of climate change, such a CO₂ level likely would cause the passing of climate tipping points and initiate dynamic responses that could be out of humanity’s control.
= new reply since forum marked as read