You don’t get out much/read much on the subject do you? It has been posted before,….
and more,.....
Business as usual typically means continuing at recent growth rates of carbon dioxide emissions, which we now know would likely take us to atmospheric concentrations of CO2 greater than 850 ppm if not above 1000 ppm (see U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm … the worst-case IPCC scenario trajectories are being realised”). Annual emissions now exceed 10 billion metric tons of carbon (~37 billions metric tons of CO2). Emissions have been rising about 3% per year for the past decade.
What is less well understood is that even a very strong mitigation effort that kept carbon emissions this century to 11 billion tons a year on average would still probably take us to 1000 ppm (A1FI scenario) — a little noted conclusion of the 2007 Intergovernmental Panel on Climate Change (IPCC) report (see “Nature publishes my climate analysis and solution“).
Until recently, the scientific community has spent little time modeling the impacts of a tripling (~830 ppm) or quadrupling (~1100 ppm) carbon dioxide concentrations from preindustrial levels. In part, I think, that’s because they never believed humanity would be so self-destructive as to ignore their science-based warnings and simply continue on its unsustainable path. In part, they lowballed the difficult-to-model amplifying feedbacks in the carbon cycle.
So I pieced together those impacts from available studies and from discussions with leading climate scientists for my 2006 book, Hell and High Water. But now the scientific literature on what we face is much richer — as climate scientists have sobered up to their painful role as modern-day Cassandra’s (see Lonnie Thompson on why climatologists are speaking out: “Virtually all of us are now convinced that global warming poses a clear and present danger to civilization”).
In a 2010 AAAS presentation, the late William R. Freudenburg of UC Santa Barbara discussed his research on “the Asymmetry of Scientific Challenge“: New scientific findings since the 2007 IPCC report are found to be more than twenty times as likely to indicate that global climate disruption is “worse than previously expected,” rather than “not as bad as previously expected.”
This post will review the latest findings. It will serve as a foundation for a multi-part series that attempts to clear up some of the confusion over the supposed high degree of “uncertainty” surrounding climate impacts. That series will make clear that we have an unusually high degree of certainty around future climate impacts if we stay anywhere near our current emissions path.
This post — an update — covers more than 60 recent scientific studies along with numerous review pieces that themselves each cover a large segment of the recent literature. Please add links to more studies in the comments.
We will see why inaction on climate change is “incompatible with organized global community, is likely to be beyond ‘adaptation’, is devastating to the majority of ecosystems & has a high probability of not being stable (i.e. 4°C [7F] would be an interim temperature on the way to a much higher equilibrium level),” according to Professor Kevin Anderson, director of the Tyndall Centre for Climate Change in Britain (see here).
TEMPERATURE
Three of the best recent analyses of what we are headed towards can be found here:
M.I.T. doubles its 2095 warming projection to 10°F — with 866 ppm and Arctic warming of 20°F
Hadley Center: “Catastrophic” 5-7°C warming by 2100 on current emissions path
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!
As Dr. Vicky Pope, Head of Climate Change Advice for the Met Office’s Hadley Centre has explained:
… where no action is taken to check the rise in Greenhouse gas emissions, temperatures would most likely rise by more than 5°C by the end of the century. This would lead to significant risks of severe and irreversible impacts.