An Illustrated Guide to the Science of Global Warming Impacts: How We Know Inaction Is the Gravest Threat Humanity Faces


Humanity’s Choice (via M.I.T.):  Inaction (“No Policy”) eliminates most of the uncertainty about whether or not future warming will be catastrophic.  Aggressive emissions reductions dramatically improves humanity’s chances.

In this post, I will summarize what the recent scientific literature says are the key impacts we face in the coming decades if we stay anywhere near our current emissions path.  These include:

  • Staggeringly high temperature rise, especially over land — some 10°F over much of the United States
  • Permanent Dust Bowl conditions over the U.S. Southwest and many other heavily populated regions around the globe
  • Sea level rise of around 1 foot by 2050, then 4 to 6 feet (or more) by 2100, rising some 6 to 12 inches (or more) each decade thereafter
  • Massive species loss on land and sea — perhaps 50% or more of all biodiversity
  • Unexpected impacts — the fearsome “unknown unknowns”
  • Much more extreme weather
  • Food insecurity — the increasingly difficult task of feeding 7 billion, then 8 billion, and then 9 billion people in a world with an ever-worsening climate.
  • Myriad direct health impacts

Remember, these will all be happening simultaneously and getting worse decade after decade.  Equally tragic, a 2009 NOAA-led study found the worst impacts would be largely irreversible for 1000 years.

The single biggest failure of messaging by climate scientists (until very recently) has been the failure to explain to the public, opinion makers, and the media that business-as-usual warming results in simultaneous, ever-worsening impacts that,  individually, are each beyond catastrophic, but combined are unimaginablly horrific.  For these impacts, terms like “global warming” and “climate change” are essentially euphemisms. That is why I have prefered the term “Hell and High Water.”

By virtue of their success in promoting doubt and inaction, the climate science deniers and disinformers have, tragically and ironically, turned the worst-case scenario into business as usual.

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”). We are at about 8.5 billion metric tons of carbon a year (31 billions metric tons of CO2) and, until the recent global economic recession, were rising about 3% per year.

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 stupid as to ignore the warnings and simply continue on its self-destructive 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 as climate scientists have sobered up to their painful role as modern-day Cassandra’s, the scientific literature on what we face is much richer.

In a AAAS presentation last year, 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 be a cornerstone of the Climate Progress archive I promised.  Please add links to more studies in the comments.


Three of the best recent analyses of what we are headed towards can be found here:

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.

That likely rise corresponds to roughly 9°F globally and typically 40% higher than that over inland mid-latitudes (i.e. much of this country) — or well over 10°F.

[Note: The MIT rise is compared to 1980-1999 levels see study here). So you can add at least 0.5 C and 1.0°F for comparison with pre-industrial temperatures.]

Based on two studies in the last few years:

By century’s end, extreme temperatures of up to 122°F would threaten most of the central, southern, and western U.S. Even worse, Houston and Washington, DC could experience temperatures exceeding 98°F for some 60 days a year. Much of Arizona would be subjected to temperatures of 105°F or more for 98 days out of the year–14 full weeks.

Yet that conclusion is based on studies of only 700 ppm and 850 ppm, so it could get much hotter than that.

And the Hadley Center adds, “By the 2090s close to one-fifth of the world’s population will be exposed to ozone levels well above the World Health Organization recommended safe-health level.”

The MIT press release calls for “rapid and massive” action to avoid this.  Study co-author Ronald Prinn, the co-director of the Joint Program and director of MIT’s Center for Global Change Science, says, it is important “to base our opinions and policies on the peer-reviewed science….  There’s no way the world can or should take these risks.”   Duh!

MIT put together a good figure that compares the temperatures we risk on our current do-nothing path with  those we might expect if we took serious action [see figure above].  Note that in the “no policy case” there is an extremely high probability of more than 4°C (7°F) global warming, an  about a 25% chance of more than 6°C (11°F) global warming.

In a terrific March 2010  presentation, Climate scientist Katherine Hayhoe has a figure of what 1000 ppm would mean (derived from the 2010 NOAA-led report):

For more of the literature on U.S. warming, see “Mother Nature is Just Getting Warmed Up.”

The Hadley Center has a huge but useful figure which I will reproduce here:

Note again that this is not the worst-case scenario.  It’s just business as usual out to 2100.

In the worst case, we get both continuing high levels of emissions and high carbon-cycle feedbacks.  That possibility was discussed here:

This would be the worst-case for the 2060s, but is in any case, close to business as usual for 2090s:

This is indeed 13-18°F over most of U.S. and 27°F in the Arctic.

And there is every reason to believe that the earth would just keep getting hotter and hotter:

UPDATE:  Steve Easterbrook’s post “A first glimpse at model results for the next IPCC assessment” shows that for the scenario where there is 9°F warming by 2100, you get another 7°F warming by 2300.  Of course, folks that aren’t motivated to avoid the civilization-destroying 9°F by 2100 won’t be moved by whatever happens after that.


Dust-bowlification — and its impact on food security —  may well be the impact that harms the most number of people over the next few decades.

As far back as 1990, scientists at NASA’s Goddard Institute of Space Studies projected that severe to extreme drought in the United States, then happening every 20 years, could become an every-other-year phenomenon by mid-century [Rind et al., 1990].

A number of major recent studies have confirmed those early findings.  They warn that the Southwest, parts of the Midwest, and many other highly populated parts of the globe are likely headed toward sustained — if not near permanent — drought and Dust Bowl-like conditions if we stay anywhere near our current emissions path (see “USGS on Dust-Bowlification“).

  • Back in October 2010, the National Center for Atmospheric Research published a complete literature review, “Drought under global warming: a review,” (See NCAR analysis warns we risk multiple, devastating global droughts even on moderate emissions path). That study makes clear that Dust-Bowlification may be the impact of human-caused climate change that hits the most people by mid-century, as the figure below suggests (click to enlarge, “a reading of -4 or below is considered extreme drought”):

drought map 3 2060-2069

The PDSI [Palmer Drought Severity Index] in the Great Plains during the Dust Bowl apparently spiked very briefly to -6, but otherwise rarely exceeded -3 for the decade (see here).

The large-scale pattern shown in Figure 11 [of which the figure above is part] appears to be a robust response to increased GHGs. This is very alarming because if the drying is anything resembling Figure 11, a very large population will be severely affected in the coming decades over the whole United States, southern Europe, Southeast Asia, Brazil, Chile, Australia, and most of Africa.

The National Center for Atmospheric Research notes “By the end of the century, many populated areas, including parts of the United States, could face readings in the range of -8 to -10, and much of the Mediterranean could fall to -15 to -20. Such readings would be almost unprecedented.”

For the record, the NCAR study merely models the IPCC’s “moderate” A1B scenario — atmospheric concentrations of CO2 around 520 ppm in 2050 and 700 in 2100.  We’re currently headed much higher by century’s end, but I’m sure with an aggressive program of energy R&D we could keep that to, say 800 ppm.

  • The UK Met Office came to a similar view four years ago in their analysis, projecting severe drought over 40% of the Earth’s habited landmass by century’s end (see “The Century of Drought“).

The projection of extended if not endless drought for the US Southwest has been studied a great deal:

The serious hydrological changes and impacts known to have occurred in both historic and prehistoric times over North America reflect large-scale changes in the climate system that can develop in a matter of years and, in the case of the more severe past megadroughts, persist for decades. Such hydrological changes fit the definition of abrupt change because they occur faster than the time scales needed for human and natural systems to adapt, leading to substantial disruptions in those systems. In the Southwest, for example, the models project a permanent drying by the mid-21st century that reaches the level of aridity seen in historical droughts, and a quarter of the projections may reach this level of aridity much earlier.

An unprecedented combination of heat plus decades of drought could be in store for the Southwest sometime this century, suggests new research from a University of Arizona-led team”….

“The bottom line is, we could have a Medieval-style drought with even warmer temperatures,” [lead author Connie] Woodhouse said.

The literature makes clear future droughts will be fundamentally different from all previous droughts that humanity has experienced because they will be very hot weather droughts (see Must-have PPT: The “global-change-type drought” and the future of extreme weather).

  • A 2011 Environmental Research Letters article, “Characterizing changes in drought risk for the United States from climate change,” comes to a similar conclusion as the NCAR study, “Drought frequencies and uncertainties in their projection tend to increase considerably over time and show a strong worsening trend along higher greenhouse gas emissions scenarios, suggesting substantial benefits for greenhouse gas emissions reductions.”  See especially Figure 4C.

Another 2011 study, “The Last Drop: Climate Change and the Southwest Water Crisis,” that actually looks in some detail at the scientific literature for just one region, finds that drought and reduced precipitation in the U.S. SW alone could cost up to $1 trillion by century’s end.

Finally, while the Dust Bowl lasted under a decade, the NOAA-led study found permanent Dust Bowls in Southwest and around the globe on our current emissions trajectory would be irreversible for 1000 years.

Again, this is all just business as usual.

From a worst-case perspective, Princeton has done an analysis on “Century-scale change in water availability: CO2-quadrupling experiment,” which is to say 1100 ppm. The grim result: Most of the South and Southwest ultimately sees a 20% to 50% (!) decline in soil moisture.

Finally, the heat and drought drives wildfires.  Here’s a National Academies figure from a presentation made by the President’s science adviser Dr. John Holdren in Oslo last year, about conditions projected for mid-century:


The 2007 IPCC Fourth Assessment Report (AR4) report ignored dynamic ice-sheet disintegration, which was already happening (see Nature: “Dynamic thinning of Greenland and Antarctic ice-sheet ocean margins is more sensitive, pervasive, enduring and important than previously realized”).  The IPCC therefore low-balled sea level rise estimates, suggesting seas might rise “only” a foot or two this century, greatly delighting the anti-science crowd (see here)

Within a year, even a major report signed off on by the Bush administration itself was forced to concede that the IPCC numbers were simply too out of date to be quoted anymore (see US Geological Survey stunner: Sea-level rise in 2100 will likely “substantially exceed” IPCC projections).  About half a dozen major studies since the IPCC report concluded that we face much higher sea level rise this century:

Needless to say, a sea level rise of one meter by 2100 would be an unmitigated catastrophe for the planet, even if sea levels didn’t keep rising several inches a decade for centuries, which they inevitably would. The first meter of SLR would flood 17% of Bangladesh, displacing tens of millions of people, and reducing its rice-farming land by 50 percent. Globally, it would create more than 100 million environmental refugees and inundate over 13,000 square miles of this country. Southern Louisiana and South Florida would inevitably be abandoned.


In 2007, the IPCC warned that as global average temperature increase exceeds about 3.5°C [relative to 1980 to 1999], model projections suggest significant extinctions (40-70% of species assessed) around the globe. That is a temperature rise over pre-industrial levels of a bit more than 4.0°C. So a 5.5°C rise would likely put extinctions beyond the high end of that range.

Many more studies have raised similar concerns:

And, of course, “When CO2 levels in the atmosphere reach about 500 parts per million, you put calcification out of business in the oceans.” There aren’t many studies of what happens to the oceans as we get toward 800 to 1000 ppm, but it appears likely that much of the world’s oceans, especially in the southern hemisphere, become inhospitable to many forms of marine life. A 2005 Nature study concluded these “detrimental” conditions “could develop within decades, not centuries as suggested previously.”

As for the worst-case scenario, we have

Yes, some scientists disputed the analysis, but I have seen no refutation in the scientific literature.


If we go to 800 ppm — let alone 1000 ppm or higher — we are far outside the bounds of simple linear projection. Some of the worst impacts may not be obvious — and there may be unexpected negative synergies. The best evidence that will happen is the fact that it is already happened with even a small amount of warming we have seen to date.

“The pine beetle infestation is the first major climate change crisis in Canada” notes Doug McArthur, a professor at Simon Fraser University in Vancouver. The pests areprojected to kill 80 per cent of merchantable and susceptible lodgepole pine” in parts of British Columbia within 10 years — and that’s why the harvest levels in the region have been “increased significantly.”

As quantified in the journal Nature, “Mountain pine beetle and forest carbon feedback to climate change,” (subs. req’d), which just looks at the current and future impact from the beetle’s warming-driven devastation in British Columbia:

the cumulative impact of the beetle outbreak in the affected region during 2000–2020 will be 270 megatonnes (Mt) carbon (or 36 g carbon m-2 yr-1 on average over 374,000 km2 of forest). This impact converted the forest from a small net carbon sink to a large net carbon source.

No wonder the carbon sinks are saturating faster than we thought (see here) — unmodeled impacts of climate change are destroying them:

Insect outbreaks such as this represent an important mechanism by which climate change may undermine the ability of northern forests to take up and store atmospheric carbon, and such impacts should be accounted for in large-scale modelling analyses.

And the bark beetle is slamming the Western U.S. and Alaska, too (see “Oldest Utah newspaper: Bark-beetle driven wildfires are a vicious climate cycle“).

The key point is this catastrophic climate change impact and its carbon-cycle feedback were not foreseen even a decade ago — which suggests future climate impacts will bring other equally unpleasant surprises, especially as we continue on our path of no resistance.


One of the basic predictions of climate science is that extreme weather will make the hydrological cycle more extreme.  I discussed the extensive literature on how dry areas will get drier.  But wet areas will also get wetter:

1) Here we show that human-induced increases in greenhouse gases have contributed to the observed intensification of heavy precipitation events found over approximately two-thirds of data-covered parts of Northern Hemisphere land areas. These results are based on a comparison of observed and multi-model simulated changes in extreme precipitation over the latter half of the twentieth century analysed with an optimal fingerprinting technique.

Changes in extreme precipitation projected by models, and thus the impacts of future changes in extreme precipitation, may be underestimated because models seem to underestimate the observed increase in heavy precipitation with warming.

2) Occurring during the wettest autumn in England and Wales since records began in 1766 these floods damaged nearly 10,000 properties across that region, disrupted services severely, and caused insured losses estimated at £1.3 billion….

it is very likely that global anthropogenic greenhouse gas emissions substantially increased the risk of flood occurrence in England and Wales in autumn 2000.

That post ended with its own review of the literature on the connection between global warming and extreme weather.  Here are a couple more studies:

A new study by a Duke University-led team of climate scientists suggests that global warming is the main cause of a significant intensification in the North Atlantic Subtropical High (NASH) that in recent decades has more than doubled the frequency of abnormally wet or dry summer weather in the southeastern United States….

The models – known as  Coupled Model Intercomparison Project Phase 3 (CMIP3) models – predict the NASH will continue to intensify and expand as concentrations of carbon dioxide and other greenhouse gases increase in Earth’s atmosphere in coming decades.”This intensification will further increase the likelihood of extreme summer precipitation variability – periods of drought or deluge – in southeastern states in coming decades,” Li says.

The team calculates that a 1 ºC increase in sea-surface temperatures would result in a 31% increase in the global frequency of category 4 and 5 storms per year: from 13 of those storms to 17. Since 1970, the tropical oceans have warmed on average by around 0.5 ºC. Computer models suggest they may warm by a further 2 ºC by 2100.


In over two decades of tracking world food prices, the U.N. Food and Agricultural organization index has never stayed so high for so long.

This represents true suffering for hundreds of millions of people who live on the edge, for whom food is a large fraction of their income like, say, North Africa (see Expert consensus grows on contribution of record high food prices to Middle East unrest).

Population growth, dietary shifts, growing use of crops for biofuels, peaking conventional oil production and increases in extreme weather have all played a part.

As the literature above makes clear, on our current emissions path, we face

One analysis just of the impact of temperature rise on food finds “Half of world’s population could face climate-driven food crisis by 2100.”  And this is just a 700 ppm analysis with no discussion of the impact of soil drying up or other well-understood climate impacts.


In April the British Medical Journal warned that climate change “poses an immediate and grave threat, driving ill-health and increasing the risk of conflict, such that each feeds upon the other.”  The UK’s Hadley Center notes that on our current one related impact, “By the 2090s close to one-fifth of the world’s population will be exposed to ozone levels well above the World Health Organization recommended safe-health level.”

A June 2011 peer-reviewed report released by the Union of Concerned Scientists (UCS) — “Climate Change and Your Health: Rising Temperatures, Worsening Ozone Pollution” — shows that the harm to Americans, especially children, from human-caused warming is upon us now.

A just-released September 2011 report by the European Lung Foundation finds:

Climate change set to increase ozone-related deaths over next 60 years

Scientists are warning that death rates linked to climate change will increase in several European countries over the next 60 yrs.

Earlier this year, Climate Progress reported on what the top medical and health groups warn are the health risks Americans face from climate change:

  • More than doubled asthma rates and lengthened asthma season (already 20 days longer)
  • Threatened access to clean drinking water
  • Increases in airborne and insect borne illnesses (e.g. mosquitos, ticks, tapeworm)
  • Increases in diarrheal, respiratory, and heart disease
  • Increased risk of salmonella spread as average temperatures rise
  • Increase in hospital use results in rising health care costs
  • Particular risk among low-income communities, children, the elderly, and the obese

See also The Lancet’s landmark Health Commission: “Climate change is the biggest global health threat of the 21st century”


The possibility that unrestricted emissions of greenhouse gases would not do unimaginable harm to humanity has become vanishingly small.  That’s because we remain near the worst-case emissions pathways, there is little prospect of national or global action any times soon (thank you, deniers), many impacts are coming faster than the models projected, and the overwhelming majority of the scientific literature in the past 5 years has been more dire than the 2007 IPCC report, which itself was more than enough motivation for the overwhelming majority of  climate scientists and countries to call for urgent action to reduce emissions.

And I haven’t even discussed the many, many studies that suggest in fact carbon-cycle feedbacks (like the defrosting tundra) are almost all positive (amplifying) and yet largely ignored in most  climate models — see NSIDC bombshell: Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100 and links therein.

We can’t let this happen.  It is indeed humanity’s self-destruction. We must pay any price or bear any burden to stop it.

64 Responses to An Illustrated Guide to the Science of Global Warming Impacts: How We Know Inaction Is the Gravest Threat Humanity Faces

  1. Bill Becker says:

    This is incredibly useful, as well as incredibly depressing, Joe. One suggestion: Let’s no longer talk about “business as usual” as an option. There’s no such thing. For most people, I expect the phrase implies life as usual. But life will change no matter what action we take, or don’t take. “Business as usual” ranks up there with asking people whether they “believe” in global warming. Perhaps “No Action” is a better way to label the path of suicidal stupidity

  2. Rabid Doomsayer says:

    What we have already started does not stop in 2100. We are already committed to a sea level rise tens of meters above today’s. If we follow BAU to 2100 it will be very much worse in 2200.

    What is so hard to understand; CO2 levels have not been this high for millions of years. Even if we stop polluting today, temperatures and sea levels will keep rising.

    The rate of forcing change is absolutely unprecedented, the is no paleo comparison. If we continue with BAU the unprecedented rate of change will be upped several notches.

    It is already inevitable that the natural carbon cycle will respond, we just do not know when and how fast.

    While many, many more species are already doomed to extinction, I do not want to add mankind to that list. BAU for even a few decades will make us extremely vulnerable in the next century.

    “Nature bats last” and she is just warming up.

  3. SecularAnimist says:

    Wow, Joe. As valuable as ClimateProgress is, this single article really stands out as a terrific resource. Hopefully it will be linked, reposted, tweeted, liked and otherwise distributed far and wide.

    Unfortunately, one thing that jumps out at me is noticing that your article “U.S. media largely ignores latest warning from climate scientists” (referring to the Copenhagen Climate Congress Key Message #1 that “Recent observations confirm … the worst-case IPCC scenario trajectories are being realised”) was written in March 2009 — two and a half years ago.

    And if anything, the US media today is even more aggressively and assiduously ignoring not only the increasingly urgent warnings from scientists, but even the increasingly catastrophic effects of AGW that are occurring before our very eyes.

    It would seem that the worse things get with global warming, the harder the US corporate media works to ignore it.

  4. Ominous Clouds Overhead says:

    Absolutely great article. After reading this, no one can say they weren’t warned.

    I truly believe we humans are engineering our own extinction, and it will come sooner than we think. Tragic in some ways, but good for the rest of the planet – if anything else survives. Maybe not mammals…

  5. Bret says:

    This only illustrates how dangerous and ill-conceived is Obama’s decision to forego any meaningful regulation of CO2 at this time. Obama is a Republican in disguise.

  6. popeyesmotto says:

    My last post some months ago was to identify myself as not a climate hawk but rather a climate sparrow. Upon the hot winds of a future 1000ppm CO2 future will I be blown. Really I don’t possibly see a realistic response in the USA to climate change. The RIGHT still views the curtailment of FREON as bullshit. Reminds me of a little song by the lost planet airmen ‘Lost In The Ozone Again’. Status quo is the current plan. Our current president is working as hard as he can to maintain it. Not only climatologically. Folks just want to remain in ignorant bliss. Americans, and probably all humans are most at ease when they have to make NO effort to change the lifestyle. Tweet tweet goes this sparrow. Wonder what’s gonna hatch outta the egg we laid.

  7. Dr.A.Jagadeesh says:

    Outstanding article on Global warming impacts
    Joe Romm.While Global Warming is the Cause,Climate Change is the Effect. Are we not witnessing calamities in the form of earthquakes and floods? It is time Nations take it seriously the measures to tackle global warming.

    Dr.A.Jagadeesh Nellore(AP),India

  8. Joe Romm says:

    Yes, that was March 2009. Hard to believe those were the good old days of media coverage of climate.

  9. Joan Savage says:

    “It will be a cornerstone of the Climate Progress archive I promised.” Yay!

    “Please add links to more studies in the comments.”
    Regarding Unexpected impacts — the fearsome “unknown unknowns” — a reference
    Christopher D.G. Harley and Robert T. Paine “Contingencies and compounded rare perturbations dictate sudden distributional shifts during periods of gradual climate change” PNAS, July 7, 2009, 106:27

  10. Interesting Times says:

    Think this post can’t possibly get more depressing? Here, let me help:

    You left out one unpleasant surprise – massive wars over whatever dwindling resources are left. Possibly (or even probably) nuclear.

    So…are there are models that look at how a regional nuclear war (either between India/Pakistan or both those countries plus China) would affect these future scenarios?

  11. Mike Roddy says:

    Hard to top that summary, Joe, thanks. I’m not sure if we have 15 years to stop the ship, so it’s rapidly becoming a matter of adaptation and survival for our descendants.

    Everybody should read this book: Green Carbon, by Brendan Mackey of Australia. It’s a systematic analysis of the carbon cycle in old growth eucalyptus forests in Australia, and their huge potential for sequestration. The same applies in the US, and much more so, since our potential forests are bigger.

    It used to be available online for free, and is a great read. Friends who know my email address can ask and I’ll send them my copy of it.

  12. Joe Romm says:

    Yes, but the speed and scale of these changes make it all but impossible to do a worthwhile study.

  13. Paul Magnus says:

    “We can’t let this happen. It is indeed humanity’s self-destruction. We must pay any price or bear any burden to stop it.”

    Well done joe. The language has to reflect the consequences.
    Everyone needs to start talking like this.

    There are so many around who just dont appreciate the risk and the consequences. The main reason is because the resultes of a 2C warming has not sunk in. And they dont think its worth taking the pain because of this.

    One thing we should do is drop probability trimmings like …
    ” twenty times more like like that its getting worse….”

    to communicate this to the public its simply “it is going to get worse”. The condition of 20x is probably not accurate and just seems to means that there is a reasonable chance that it might not get worse.

  14. jyyh says:

    I’m pretty sure a nuclear war wouldn’t lead to this:

    but after a couple of years of eating radioactively polluted crops, if the war was for agricultural resources (=land), I’d guess there would be less people eating the radioactively polluted crops, such a war would likely not have any long term effect on the GHG effect, as it’s already difficult to find tracers from the atmospheric nuclear tests of the 1960s.

  15. Interesting Times says:

    So you think nuclear winter scenarios are overblown?

  16. Paul magnus says:

    SLR…. Arent we definitely on for a 2c temp rise.
    I thought that from the latest science this means we will be getting at min at least a 1m rise by around 2100 what ever we do….

  17. Interesting Times says:

    Or try to frame the consequences in terms of real-life, right-now things people can relate to (e.g. “think this Texas drought is bad? It’s only -6 on the Palmer scale. In 20-30 years we could be looking at -15!”)

    Something else I think would be very effective (not sure if it’s already been done) – use CGI to its fullest to create ultra-realistic “before and after” pictures of important things and places (e.g. great barrier reef as it would look bleached, dying, and breaking apart, whole forests burned out, reservoirs dried out)

    In other words, stay away from technical language and abstractions as much as possible. Make it feel real.

  18. John Tucker says:

    You know of course people have been eating mercury, cadmium, lead, pesticide, PAH, Dioxin etc laden crops for 50 years and the amount of radiation from nuclear power doesn’t really compare to natural sources of radiation.

  19. sally says:

    What we really need to do is put out scenarios for 2020 and 2030. 2100 is too far away, people don’t see it as a problem.

  20. Andy G says:

    You’ve recently posted “what questions would you like CP to ask,” and I say you should update and republish this piece quarterly or semi-annually. With each iteration, add the latest science and focus the language, creating and evermore hard-hitting and accurate depiction of where we’re heading with our present “what me worry” attitude.

  21. EDpeak says:


    Can someone create a Fahrenheit version of the MIT graphic (two ‘pie chart’ probability circles) at the top?

    Not to replace it (since Celsius is what the scientists use) but to be a supplement shown besides it…(also helps with reading other stories like “M.I.T. doubles its 2095 warming projection to 10°F — with 866 ppm and Arctic warming of 20°F” on ClimateProgress which use F)

    Good/quick hands with graphics software? Please create and send to Joe and/or maybe post a url (like to redirect to the image) TIA!

    As an aside, if the green arrows are to be believed, and if one concludes the “early and rapid decline” just Ain’t Gonna happen, we’re at 2.9C or above…we’ll soon need new probability circles, with even the “with policy” wheel (due to all the delaying tactics still going on in 2011 and probably in 2012 and 2013..?) even that one will have to be made “worser”

  22. Paul Magnus says:

    yes, as well…
    Its already looking grim and we havent even broken through 1C…

  23. Paul Magnus says:

    Climate Portals
    The Silent Summer!
    It’s a Hard-Knock Butterfly’s Life
    Can a Lady Monarch Provide a Role Model?
    Like · · Share · 2 seconds ago
    Climate Portals This year we were missing earthworms and slugs for some reason… bird population grew early but then subsided.

  24. Hadley center link doesn’t work…

  25. Denis Frith says:

    The article provides insight into the dire consequences of the irreversible rapid climate change caused primarily by industry letting the fossil fuel genie out of its box. Reducing the global rate of emissions is a necessary mitigation measure that should become obligatory for all industrialized countries. Adapting to the predicted consequences should have a high priority in all countries.
    The acidification of the ocean by these emissions is another deleterious consequence that will have to be faced because of its impact on the marine ecosystem.

  26. Edith Wiethorn says:

    Here’s some good media coverage of good news – every word of interest:

    September 19, 2008
    Chicago Unveils Multifaceted Plan to Curb Emissions of Heat-Trapping Gases

    “… Ron Burke, a director with the Union of Concerned Scientists, which helped shape the plan, said it was “more robust and quantitative than those in any other city.”

    Like hundreds of other cities, Chicago has pledged by 2020 to reduce the emissions of heat-trapping gases 25 percent from the levels in 1990, the baseline established by the Kyoto Protocol, an international climate treaty. Mr. Burke said the Chicago plan offered much more specific ways than other cities’ plans to measure and cut the emissions.

    The mayor, who called the plan a “model for the rest of the nation,” has already won praise among environmentalists for a program that promotes rooftop gardens to conserve energy.

    The city plan, which draws on the work of climatologists, warns that the failure to act will produce dire consequences …”

  27. Edith Wiethorn says:

    Here are a few more good words >

    “…Sadhu Johnston, the chief environmental officer for the city, said that perhaps the most ambitious part of the plan was retrofitting low-cost housing complexes to reduce water and energy use.

    But getting the cooperation of the private sector for some of the more costly initiatives may be difficult.

    “Make no mistake,” Mr. Johnston said, “we’re facing huge challenges, especially with the credit crunch.”

    The Chicago initiative included consultation with business and labor leaders, as well as scientists and environmentalists, and involved 18 months of research and discussion. Mr. Johnston said the initiative came “despite the lack of federal support.” …

  28. Colorado Bob says:

    Paul –
    A week ago I saw just 3 monarchs. All headed south. There was 1,000 miles of drought in front of them. It the past here in Texas, I have seen them in the hundreds.

  29. Colorado Bob says:

    Joe –
    You’re going to need some people who follow life here.
    Life is clearly on the move.

  30. Colorado Bob says:

    Life can’t hear American AM Radio, it doesn’t give a fig about it. Every bit of it is moving to this new warmer world. From the the smallest plant, to the smartest mammal.

  31. C. Vink says:

    ‘We must pay any price or bear any burden to stop it.’

    Thanks again for a thourough survey, Joe. Yes, the situation is very, very alarming and more people need to realize this and act and vote accordingly. And yet, perhaps it’s preferable not to use phrases like your closing line. ‘Pay any price’ and ‘bear any burden’ would not include (suffering the consequences of) violent means, I’m sure you agree. Still, words like this can be interpreted like that by individuals who are not as wise en peacefully political as you are, imho.
    Just a thought.

  32. Calamity Jean says:

    Good idea. Predictions like “the North Pole will be ice-free in summer by 2020” would help the pollutocrats understand that they or their children will suffer personally for what they are doing now.

  33. jyyh says:

    No, but if the plants would die for the nuclear winter they could decompose afterwards throwing a bit more GHGs to the atmosphere. Full scale nuclear war would be the fastest way to destroy the civilization for sure. I’ve read next to nothing of smaller scale nuclear wars, so I’m not very confident on these matters.

  34. Peter Mizla says:

    Most here understand the dire situation we face. If I live another 20 years, in my old age I will probably experience a precarious life my parents never dreamed of. The Generations under me- will have it increasingly more difficult.

    The American Public by a larger margin still seem disinterested and distracted (probably because of the 100 million funded misinformation campaign) by the Koch subsidiaries and others over the last few years that has been remarkably effective.

    I see no hope in the short term for any change. The media has been secured by the vast denier money strings- and the politicians from both parties are incredibly timid & afraid to mention the word ‘climate change’.

    Of course this could all change- and quickly. Extreme weather events are happening far sooner then most have predicted. The planet is in fact far more sensitive to rising GHG then the scientific community suggested just a few years ago.

    As macabre as this sounds- is wishing for more climate catastrophes a ‘bad thing’?

    The media cannot hide forever the visual suffering of people and massive infrastructure destruction of homes, businesses, crops and highways repeatedly, without an explanation other then ‘strange weather’.

    We will have to accept a 3 degree rise C in global temperatures, by mid century and hope it stops there.

  35. Raul M. says:

    Saw a report about the aftermath of bad weather up along the east coast. Seemed as though fancy homeowners are subject to not having had flood style ins. And are wanting more fed. aid. Years ago my granddads place along a river was flooded , back then there was no such thing as fed. aid. It was bad news for them for sure to find their place flooded.
    They tried to have it back as closely as they could to before the flood, thinking that flooding didn’t happen often. For them, back then, they were right.
    Basement storm windows could be fitted with magnetic seals that cling to metal strips of the house window frames to help protect against water intrusion.
    Those cute and conveniently low placed outdoor elec. Outlets could be just disconnected and sealed up.
    Some changes could save a great deal of inconvenience.

  36. Joan Savage says:

    Colorado Bob, Let me throw in a keyword or two about “life” and climate change to at least activate us volunteers.

    Phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate. (wiki def.)

    The title of the citation I put in earlier has some keywords as well. (Harley and Paine had studied 30 years of data on intertidal algae in the Pacific Northwest.)

    Christopher D.G. Harley and Robert T. Paine (2009) “Contingencies and compounded rare perturbations dictate sudden distributional shifts during periods of gradual climate change”

  37. Mike Roddy says:

    Joe, how about Teach Ins, like we had in 67-68? They helped turn the tide of public opinion in those days, partly because they succeeded in shaming the media for not doing its job.

    Nowadays, there are no more Walter Cronkites in MSM, and no Fulbrights in the Senate, either.

    The new Teach In model would have to be ongoing and relentless, taking place at universities and in public places throughout the country. With a sophisticated effort, including handouts, press releases, and quality speakers, it could just succeed.

    What say you? I would guess that plenty of your loyal readers and commenters would jump to volunteer- including this one.

  38. Joan Savage says:

    I’m itching to translate graphics from the kind that are do-able with standard software to ones that use the knowledge of social science and advertising to communicate. This is not my forte, technically, so I’ll give some conceptual examples.
    In a financial graph, “up” is “good.” We can invert the carbon ppm so it hangs like a gloomy thickening cloud at the top of the graph. For 390 ppm, up is not good, it’s a downer.
    In two pie charts of equal size, bright color often indicates a preferred outcome. Not this time.
    Three-D graphs can be grasped by the public, a graph can show percentage in one plane and the temperature spiking into a third dimension.
    As I protested about the otherwise very useful map about days over 100 degrees, that gives a false impression that climate change stops around 100 degrees, without a sense of the 110 and 120 degree days that have already appeared.

  39. John McCormick says:

    RE # 22

    Peter, you said “The Generations under me- will have it increasingly more difficult.”

    That is saying it mildly, and too mildly. They are going to suffer and die.

    Joe has layed out their future in certain terms. We can debate degrees of suffering they will endure but we know it will happen.

    So, do we really believe Joe’s post? If we do, can we look into the faces of children and very young children and not feel despair for them? I cann’t.

    I wave and smile at children because their innoces captures me. But, I have the same feeling when they pass by. Deep regret.

    Why do we only talk about climate chaos in adult terms….wheat production, sea level rise, ocean acidification? How about using the Gerber baby as our frame of reference and morph that clid’s image into a youngster, teenager, young adult and superimpose some of the projections Joe has provided.

    Lets let parents of young children see and imagine how their children’s lives will be affected by actions for which children have no responsibility. Make parents feel guilty as hell that they are not acting in every way possible to avert the disaster we are bringing to children. Make Bachmann squirm.

    If it is really about the children, then why aren’t we campaining with them as the focus?

  40. Lou Grinzo says:

    Good point, sally. I’ve had numerous conversations with climate newcomers who, when presented with just a fraction of what Joe described, instantly ask, “But, will this happen in my lifetime?” When I say it’s already starting — Arctic melt, seasonal shifts, etc. — and will get steadily worse, they inevitably ask, “When will it get really bad? Not until after I’m dead, right?”

    The screaming immorality of that world view makes me wonder why it’s worth fighting this fight. If people are so myopic and self-centered that they don’t even care about their own kids(!!!), then perhaps we deserve nothing better than hell or high water.

    And then… and then I think, once again, about my personal motivation, my three nieces and all the other kids in this world who deserve so much better than the flaming train wreck we’re handing them. And it becomes clear that surrender to circumstances is not an option.

  41. David Smith says:

    Shouldn’t there be a “worse than business as usual” scenario shown above? The plunderers are making serious attempts to dismantle safeguards and oversight that are currently in place.

  42. Lewis Cleverdon says:

    Bill –
    I’d agree that Business As Usual is no longer useful as describing the status quo. There is no ‘Usual’ any more.

    Yet ‘No Action’ just doesn’t cut it as an effective alternative – there’s lots of action, including pretty roofgardens in Seattle, but most of it is neither remotely commensurate with the problem nor even on a credible path to becoming so.

    We need a term that expresses the human reality of the outcome, that arouses the sense of solidarity and outrage rather than merely self-interested fears, and that focusses attention on business conduct and the White House failure to address that conduct, particularly via the international agreement of an equitable and efficient climate treaty.

    To this end I’d suggest that BAU be replaced with BAG – ‘Business As Genocide’.

    I guess we’d agree that with rising climatic destabilization of farm yields (plus the immoral diversion of those yields to fuels) already causing unprecedented food insecurity globally, within a decade we may well see global crop failures occuring that cause unprecedented serial famines with genocidal outcomes. I’d suggest that under present policies we are pretty well certain to do so by 2040.

    BAG – ‘Business As Genocide’ is thus not an emotive or innaccurate charge – it is a dispassionate description of where current business practice and national climate policy is taking us. So I wonder if we may agree that it is in part a reluctance to date to properly describe that destination that has allowed our ongoing drift towards it ?



  43. Lou Grinzo says:


    One way to avoid the “up is good” issue with carbon is to plot it not as yearly or cumulative emissions, but to plot our remaining carbon budget. In general, I think people are very comfortable with the notion of a fixed amount of something that declines with use — money in a checking account, gasoline in their car’s tank, etc. Presenting carbon this way would tap into that leaning.

  44. Marie says:

    I’ll join the chorus concurring that this post (and regular updating of it) is so important and needed. What about methane releases though, Joe? How much worse could that make the rest of this? Is this getting less discussion/attention by scientists worldwide, and if so, why?
    Is the next IPCC report going to include estimates in all these areas they failed to include last time?

  45. Spike says:

    A tour de force Joe although apocalyptic in implications.

    I remember one study suggesting the Southern Ocean may reach critical acidity even earlier at around 450ppm Co2 by 2030 to 2038.

  46. Interesting Times says:

    “When will it get really bad? Not until after I’m dead, right?”

    My reply: “No, it could get even worse, long before then, if World War III takes place over dwindling resources”. And follow that up with real-life, right-now examples of brutal wars over arable land, water, etc.

    Speaking for myself, I don’t have children and never will, but I could still be around in the 2060s and would rather not spend my old age watching the world figuratively (and literally) burn down all around me.

  47. Interesting Times says:

    I wish there were more studies on this issue. Pakistan is soon poised to become the 4th-most populous country. Think about that: 3 of 4 of the world’s most populous nations – China, India, Pakistan – all nuclear powers, and all sharing borders and desperately shrinking food and water supplies. It says an awful lot, and none of it good :(

  48. Lewis Cleverdon says:

    Bret – you could be right. What’s a highly intelligent conservative black kid with ambitions for high office to do ? Join his Uni’s chapter of the GOP ?

    But – large But – this doesn’t explain his inaction on climate. With the polls showing over 80% of democrats and just over half of republican voters wanting action on climate, the core of the GOP is plainly fully aware of the issue, as are the controllers of the fossil corporations.

    The plausible motivations for blocking action fall into three general groups:

    – Callous Profiteering – no doubt some fit into this class, but, as a ruinous short termism that ignores ones own childrens’ welfare, we see nothing like the US circus of denial in Europe and many other regions, so this motive cannot explain more than a fraction of the obstructionism.

    – Reinforce US hegemony – by means of encouraging the climatic destabilization of China’s growing economic challenge via an undeclared “Brinkmanship of Inaction”, thus giving the bizarre appearance of the White House seeing additional global warming as being in the US national interest. (E.g. the Copenhagen snub, Stimulus funds priorities, subverting the Senate Bill, EPA delays, Keystone 1 & 2, etc).

    – Securing US plutocrats’ access to strategic resources – by means of serial climate-driven famines imposing a cull of a substantial fraction of global population – to prevent its rapid ongoing consumption of increasingly scarce finite commodities – e.g. oil, copper, phosphates, rare earth minerals, etc. – While most nations’ populations include some small fraction of fascists, sadly in the US they seem exceptionally well funded.

    Which of these three motives should be ascribed to Obama’s culpable negligence over climate is of course a matter of individual judgement. Personally I’m pretty certain its neither the first nor the third.



  49. Paul Magnus says:

    If we are honest then we have a GHG debt crisis because we should really be down below 350ppm….

  50. Joan Savage says:

    That is stimulating..
    At first I thought you meant the total global reserves, graphs of which have contributed to a lulling sense of non-emergency – so many centuries of coal left, tar sands, and the like.
    But I take your drift about familiar models, so we could graph a carbon budget like a controlled diet plan, identifying Gt carbon like allowable calories on the path to slimming down. It can have complementary line of what improves.
    This is a bit over the top, but what could make America shout for joy, “We shrank six carbon ‘dress sizes’!”

  51. Paul Magnus says:

    This is very relevant. We are not going to survive as a civilization past 2020 with the current rate of outlandish extreme weather events now happening.

    The cycle now seems to be around 3-7years and will surely be accelerating and intensifying with each few years as the temp rise starts to accelerate.

    There is no way that food security, health and just living conditions in many city and urban areas can stay afloat beyond 2020. Especially with peak oil and to some extent, peak other things like fisheries etc.

    THis is the message that we need to drive home to get the adaptation planing going for survival. As part of that adaptation GHG drawdown is the first priority!

    This is why I believe that we need emergency action now.

    Its looking like we will have another record hot year before the end of 2015 I think that will instigate this action as the extreme evens with be unprecedented and normall life for most of us wont continue. Developed and developing nations alike.

    Of course all this becomes a negative feedback forcing reducing GHGs. As our economies collapse, emissions will plumet.

    So one reason we will probably not have BAU scenarios is because of this. However, the unstoppable 2C-3C in the pipeline will be enough to reset humanity.

  52. Lewis Cleverdon says:

    – Well said !

    I don’t have an annual carbon footprint, I have almost 60 years of carbon debt.

    My livestock are doing what they can to build soil depth and recover that carbon, as are the trees I’ve planted, but much more is needed, and to be relevant it needs to be a collective action rather than just a matter of personal virtue.

    Therefore I’m campaigning for the UK to acknowledge its liability for historic emissions still retained in the atmosphere, and to commence their formal quantified recovery by native afforestation optimized for carbon sequestration – via biochar and its syngas energy coproduct.

    The example of a nation taking responsibility for its carbon debt is potentially seminal in its impacts on other nations’ conduct and, critically, on unblocking the North-South log-jam over the essential climate treaty.

    Whether at national, state or county level, the example of undertaking to recover the carbon debt is perhaps one of the most potent campaigns we can pursue, so I hope others will take it on board.



  53. Kevin says:

    I’d believe the MIT scenarios incorporated in the roulette wheel has stabilization at 550 ppm? If I recall correctly, they tend to believe 450 is already in the rear view mirror due to inertia in the global energy system. Certainly this is not a no risk pathway, though it can be argued it is much better than the “do nothing” scenario.

    From a political standpoint, it might be more helpful to try to build mechanisms that begin serious reductions — then, as they prove to be less painful than opponents claim, tighten. [I think arguing for 350 makes it harder for us to do anything in the political space.]

  54. lasmog says:

    I’m trying to understand the rate of CO2 increase predicted by the MIT study. If we are at 866 ppm of CO2 in 2095, wouldn’t that mean an increase of 5.65 ppm/year from where we are today? I think that we are currently increasing at a rate of about 2 ppm/year of CO2. Where does this dramatic increase in rate come from? Does everyone in China and India acquire an air-conditioned home? Is it positive feedback loops? Both?

  55. Joan Savage says:

    Lou, Paul and Lewis,

    Pay down the debt, balance the budget, it’s payback time. Oh yeah.

    Cumulative “carbon debt” can be shown in graphics.

  56. Lewis Cleverdon says:

    Kevin – given that mega-feedbacks including wildfire, tundra-melt, and cryosphere decline are already accelerating due to the timelagged warming from the mid-1970s’ ~335ppmv CO2,
    I’m not clear how a target of “stabilization at 550ppmv” can be presented as better than “do nothing.” Surely the target is actually an oxymoron ?

    On that pathway, how soon would you expect the interactive feedbacks’ CO2e output to exceed the natural carbon sinks’ annual intake, and thus establish an uncontrollable self-reinforcing acceleration of their output regardless of anthro-emissions’ control ?



  57. Paul Magnus says:

    It might be harder but its the reality.

  58. Michael T says:

    James Hansen just posted a new discussion on global warming on his website:

  59. Joan Savage says:

    I get your drift, but an ice-free Arctic by 2020 is not frightening to the millions with shares of Mobil-Exxon in their retirement plan or their child’s college fund.

    We need to draw attention to other climate changes, either present or forthcoming, that have more understandably negative impacts.

  60. Sasparilla says:

    Good point Bob.

    Virtually the entire Monarch population is migrating down through Texas (right now) and need water and nectar to make it through (and Texas is in that unprecedented drought). Boy, I sure hope enough make it through, it was a small crop of them this year anyways.

  61. Sasparilla says:

    As a related issue, Chicago and the surrounding suburbs are installing over this current year 270+ public Level 2 plug-in chargers and 70+ public Level 3 quick chargers (80% capacity of a Nissan Leaf in 30 min) resulting in the most comprehensive EV plug-in infrastructure in the US – and they did it all in a year.

  62. Sasparilla says:

    Unfortunately the answer to that one is no. IPCC 2013 will be much more updated from 2007, alot more bad news of course, but it will not include some of the really important feedbacks that are already starting to warm up (I believe arctic permafrost melt emissions is one that won’t be included) – serious bummer on this (seems like we’ll be living those things before the IPCC gets them in their bloody report).

  63. Sasparilla says:

    lasmog, do some reading on this site in particular and you’ll find your answers. The short is once we warm things up enough, mother nature will take over (multiple positive feedback loops) and we will not be running this experiment anymore – we’re already seeing glimpses of that happening.

  64. Sasparilla says:

    Thank you for putting this together Joe.

    Its wrenching to read, I’m sure its tougher to put together – excellent conclusion and final 3 sentences.

    Thank you for your work, blood, sweat and tears in all this.