Planetary Desolation

… please remember what the nation’s top climate scientist has said:

… the most serious effects will be visited upon the young and the unborn, the generations that bear no responsibility for the problem.

The most important effects, I believe, will be those that are irreversible for all practical purposes, specifically (1) extermination of species, and (2) ice sheet disintegration and sea level rise. If we continue business-as-usual energy policy, using more and more fossil fuels, it is likely that we will have:  (1) rapid climate change that will combine with other pressures on species to cause the rate of extinction of plants and animals to increase markedly, leading in some cases to ecosystem collapse, snowballing extinctions, and a more desolate planet for future generations.  (2) meter-scale sea level rise this century, and ice sheets in a state of disintegration that guarantees future sea level rise in the 10-meter-scale, with a continual reworking of future global coastlines out of humanity’s control.

I would add that the planetary desolation our continued inaction would leave our children includes the loss of the inland glaciers that provide fresh water for a billion people, irreversible ocean acidification and Dust-Bowlification across much of the habited land mass (see “Hell and High Water “).
Back when I wrote my 2006 book, it took a lot of effort interviewing top climate scientists and finding relevant studies to figure out what will happen in the world of tripled or quadrupled CO2 concentrations (from preindustrial levels) we are heading toward on our current emissions path.  Scientists hadn’t been doing a lot of analysis of those ’scary’ scenarios because they had assumedHomo ’sapiens’ sapiens would not be so stupid as to ignore their science-based warnings.
Now that the scientific community knows better, we’re seeing more and more studies of the impact of a tripling (825 ppm) or quadrupling (1100 ppm) — which is not to say that a doubling (to 550 ppm) wouldn’t be catastrophic:

• Science: CO2 levels haven’t been this high for 15 million years, when it was 5° to 10°F warmer and seas were 75 to 120 feet higher — “We have shown that this dramatic rise in sea level is associated with an increase in CO2 levels of about 100 ppm.”
• New study of Greenland under “more realistic forcings” concludes “collapse of the ice-sheet was found to occur between 400 and 560 ppm” of CO2

It’s just that a tripling or quadrupling leads to impacts that are as far beyond catastrophic as those catastrophic impacts are beyond our current climate.  Here’s just a few analyses from the last two years:

• U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm … the worst-case IPCC scenario trajectories (or even worse) are being realised” — 1000 ppm.
• Our hellish future: Definitive NOAA-led report on U.S. climate impacts warns of scorching 9 to 11°F warming over most of inland U.S. by 2090 with Kansas above 90°F some 120 days a year — and that isn’t the worst case, it’s business as usual!”
• New study puts the ‘hell’ in Hell and High Water:  Must-read NCAR analysis warns we risk multiple, devastating global droughts even on moderate emissions path
• Climate change expected to sharply increase Western wildfire burn area — as much as 175% by the 2050
• Ocean dead zones to expand, “remain for thousands of years”
• Sea levels may rise 3 times faster than IPCC estimated, could hit 6 feet by 2100
• Science: CO2 levels haven’t been this high for 15 million years, when it was 5° to 10°F warmer and seas were 75 to 120 feet higher — “We have shown that this dramatic rise in sea level is associated with an increase in CO2 levels of about 100 ppm.”
• Nature Geoscience study: Oceans are acidifying 10 times faster today than 55 million years ago when a mass extinction of marine species occurred
• Half of world’s population could face climate-driven food crisis by 2100

And that isn’t the worst case.  No, the worst case is that the temperature rise occurs in 50 years, not 90 — and that the impacts last for centuries:

• UK Met Office: Catastrophic climate change, 13-18°F over most of U.S. and 27°F in the Arctic, could happen in 50 years, but “we do have time to stop it if we cut greenhouse gas emissions soon.”
• NOAA: Climate change “largely irreversible for 1000 years,” with permanent Dust Bowls in Southwest and around the globe

This is the “plausible worst case scenario” for 2060 from the UK Met Office that occurs in 10% of model runs of high emissions with the carbon cycle feedbacks [temperature in degrees Celsius, multiple by 1.8 for Fahrenheit]:

Of course, the above temperature plot is just for a mean global warming 5.4°C (9.7°F), which is business as usual for 2100 according to many analyses (see M.I.T. doubles its 2095 warming projection to 10°F — with 866 ppm and Arctic warming of 20° F).
But what’s really scary is that:

1. All of those beyond catastrophic impacts would be happening simultaneously, making it all but impossible to imagine that the devastated rich countries would be able to offer much assistance to the beyond-devastated poorer countries.
2. We’re doing this to our children in spite of being warned (see Is the global economy a Ponzi scheme?) — in spite of being told by virtually every major economic analysis that it could be avoided at a net cost of 1/10 of a penny on the dollar, not counting all of the ancillary benefits (improved public health, sharp drop in money flowing overseas to buy oil).

Post  from climate progress