Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Donate

Twitter Facebook YouTube Pinterest

RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

Keep me logged in
New? Register here
Forgot your password?

Latest Posts


Lindzen's Clouded Vision, Part 2: Risk

Posted on 9 May 2012 by dana1981

In Part 1 of this post, we examined the fundamental flaws in the last hope for climate contrarians - that the planet won't warm very much in response to rising greenhouse gas (GHG) emissions, because climate sensitivity is low, because clouds will act as a negative feedback and dampen future warming.  While it would be convenient if this picture (best embodied by Richard Lindzen) were accurate, the evidence is stacked heavily against it.

Nevertheless, as Part 1 concluded, there is a slim chance that Lindzen and company are correct, that climate sensitivity is low and global warming is not a major concern.  There is also a high probability that they are wrong, that future global warming will be substantial, and that the consequences will be bad if we don't do something about it.  How we choose to address these scenarios is a question of risk management, which happens to be a big part of my day job.  Unfortunately, as with his scientific positions, Lindzen's risk management arguments are ill-conceived.

Irrational Optimism

In the Gillis New York Times article, Lindzen summarizes his approach to this climate risk management question:

"If I’m right, we’ll have saved money...If I’m wrong, we’ll know it in 50 years and can do something."

There is a rather obvious flaw in Lindzen's logic here - it assumes that in 50 years we will be able to simply flip a switch and solve the climate problem.  Unfortunately, that is probably not the reality of the situation.  Figure 1 shows the projected atmospheric CO2 levels under various emissions scenarios.  If we listen to Lindzen, we will follow one of the higher emissions paths (currently we are on track with A2 [yellow]).  Figure 2 shows the resulting global warming based on climate model runs which, as Part 1 showed, have thus far been quite accurate.

Figure 1: Atmospheric CO2 concentrations as observed at Mauna Loa from 1958 to 2008 (black dashed line) and projected under the 6 IPCC emission scenarios (solid colored lines). (IPCC Data Distribution Centre)

Figure 2: Global surface temperature projections for IPCC Scenarios. Shading denotes the ±1 standard deviation range of individual model annual averages. The orange line is  constant CO2 concentrations at year 2000 values. The grey bars at right indicate the best estimate (solid line within each bar) and the likely range.  (Source: IPCC).

The big difference between the higher and lower emissions scenarios is that at mid-century, emissions in the higher scenarios are accelerating upwards, while in the lower scenarios they are flattening out.  It takes time to deploy the necessary infrastructure to reduce GHG emissions - there is no magical switch we can suddenly flip in 2050 when we realize that Lindzen and company were wrong.  As Figure 2 shows, the average global surface temperature difference between Scenario A2 (essentially business-as-usual advocated by Lindzen) and Scenario B1 (which involves serious action to reduce GHG emissions) in 2100 is close to 2°C.

What's Dangerous?

Internationally, 2°C warming above pre-industrial levels is generally accepted as the "danger limit" we should try to avoid exceeding.  This is not a hard and fast limit - there won't suddenly be a catastrophe if we reach 2.01°C; in fact, many experts believe even 2°C warming is too risky.  However, some of the impacts listed in the IPCC report for global warming of a Lindzen-level 3-4°C above pre-industrial levels include:

  • hundreds of millions of people exposed to increased water stress

  • 30–40% of species at risk of extinction around the globe

  • about 30% of global coastal wetlands lost

  • increased damage from floods and storms

  • widespread coral mortality

  • the biosphere – soils, plants etc – stops absorbing carbon and starts releasing it

  • reduced cereal production

  • increased death and illness from heat waves, floods and droughts.

In Scenario A2, we reach this level of warming in about 60 to 80 years - within a couple of decades of Lindzen's 50 year 'wait and see' target.  If he is wrong, by the time we're forced into taking action, it will be too late to avoid some really nasty consequences.

And of course let's not forget global warming's evil twin, ocean acidification.  Even if the contrarians are right about low climate sensitivity, the impacts of rising atmospheric CO2 on marine ecosystems will be severe, and a 50-year delay in reducing CO2 emissions could have dire consequences for those ecosystems.

In short, if Lindzen is wrong, future generations are in big, big trouble.  In fact, according to The Critical Decade report by the Australian Climate Commission, we've already burned through 30% of our allotted GHG emissions between 2000 to 2050 if we want to give ourselves a good chance to limit global warming to that 2°C limit.  Not only don't we have 50 years, we're already behind where we should be in terms of emissions reductions.

Risk Management 101

Humans are generally very averse to risk.  Everyone who drives a car purchases auto insurance.  Everyone who owns a house purchases homeowners insurance.  Most first world countries have implemented universal health care systems, and in the USA, virtually everyone who can afford it purchases health care insurance.  Personally I'm relatively young and in good health, I'm a safe driver, and I'm not worried that anything will happen to my home; yet I've purchased all three types of insurance.  Why?

Because if anything were to do substantial damage to my home, car, or health, it could impose a huge cost which I couldn't afford without insurance.  The probability of any of these things happening is relatively low, but the potential consequence is so bad that we all mitigate it by purchasing insurance to cover our most valuable assets in case the worst case scenario comes to fruition.

Yet when it comes to the climate, we are behaving in exactly the opposite manner.  It's hard to imagine a larger potentially diastrous scenario than a major climate change.  It could potentially impact every single living thing on Earth, and impose a huge cost on every person.  This is not just some slim possibility, as shown in Part 1, it's the most probable outcome!  And yet thus far we have utterly failed to mitigate this massive, highly probable risk.

This is the risk management approach I described in my entry in Why Are We Sure We're Right, and as Greg Craven has eloquently summarized in this video.  However, to adequately manage the risks posed by climate change, we should perform a cost-benefit analysis.

Mitigation Costs

The costs associated with mitigating climate change are relatively straightforward to evaluate.  Generally, estimates put the cost of reducing GHG emissions 80% by 2050 (which will approximately limit global warming to the 2°C 'danger limit') at around 1% of Gross Domestic Product (GDP).  Some estimates put the cost as low as a fraction of a percent of GDP, while others put it as high as 2 to 3%.  While this is a substantial cost, it is not an unmanageable one, and we already have all the technology necessary to accomplish this task.

It's also worth noting that the longer we wait, the larger the costs become.  Delays force emissions cuts to be steeper, and they also delay the development of cheaper emissions reductions technologies.  A study found that delaying significant investment in green tech by 5 years could cost the USA $2.3 to $3.2 trillion in GDP (Figure 3).

Google GDP

Figure 3: US GDP gains between 2010 and 2050 in three scenarios.  The green scenario includes a $30 per ton price on utility sector CO2 emissions and strong investment in green tech to develop "breakthroughs" (BTs).  the blue line depicts a scenario in which there is heavy investment in green tech without a carbon price.  The purple line is a 5 year delay before significant investment in green tech.  The red and orange area depicts the difference in GDP growth: $2.3 to 3.2 trillion lost in the 5 year delay scenario. Source: study

Mitigation Benefits

The benefits of climate mitigation are more difficult to estimate, because it depends who's right.  If Lindzen and company are right about low climate sensitivity, then reducing GHG emissions has some relatively small benefits.  For example, countries will produce more domestic energy and become more energy-independent.  National security will improve as oil-based wars become less likely.  The transition away from fossil fuels, which are after all non-renewable and limited substances, will be smoother and easier.  Air and water pollution and their associated adverse health impacts will be reduced.

Installing the necessary infrastructure would also create a lot of jobs and help alleviate the current unemployment problems around the world.  Right now, when there is a major surplus in the available work force, is arguably the best time for governments to invest in infrastructure projects like those which will be necessary to reduce GHG emissions.

So there are some definite benefits to reducing emissions even if the Lindzen low sensitivity crowd is right.  If they are wrong, which is the far more likely scenario, the benefits will outweight the costs several times over, by trillions of dollars (Figure 4).

Figure 4:  Approximate costs of climate action (green) and inaction (red) in 2100 and 2200. Sources: German Institute for Economic Research and Watkiss et al. 2005

'Fingers Crossed' is Poor Risk Management

Lindzen's suggested approach of waiting 50 years and hoping the consequences are not disastrous is one of exceptionally poor risk management.  The prudent approach would involve addressing the worst case scenario, particularly when that scenario has a significant probability of coming to fruition if we fail to prevent it.  This is particularly true when the mitigation costs, while not cheap, will certainly not cripple the economy, and when the benefits are also significant in any scenario, and may very well outweigh the costs several times over and by trillions of dollars.

From a risk management standpoint, there is no question that we should be ignoring Lindzen's ill-conceived approach and instead taking serious action to reduce our GHG emissions.  Unfortunately, for various reasons, we have thus far failed to take the prudent climate risk management approach, and if we continue to fail, future generations will suffer the consequences of Lindzen and his fellow contrarians' foolhardy approach.

0 0

Bookmark and Share Printable Version  |  Link to this page | Repost this Article Repost This


Comments 1 to 23:

  1. The other challenging part of this issue is that we are doing something that is somewhat unusual in terms of risk management. We are looking to insure future generations. It's one thing to pay for car insurance just in case you have a wreck. It's another thing entirely to say we should be paying auto insurance on our grand children's cars and homes.

    This is precisely why this has to be a governmental issue. Individuals have individual responsibilities that span their lifetimes, and to a lesser extent, their children's lives. Corporations are worse. They have to deal with quarter to quarter issues bordering with the span of time key executives are in charge. Governments operate in generational timeframes. They establish laws and structures that are intended to apply for the long term and ensure the security and prosperity for their people.

    The challenge is balancing the needs and responsibilities of corporations and individuals with the needs of nations over the course of generations. It's what makes this issue so incredibly challenging.
    0 0
  2. Good point Rob. People naturally have a harder time with risk management the further into the future the threat is posed.
    0 0
  3. To make matters worse, I wonder if the future cost estimate is drastically understated. As shown in the bullet points, several negative consequences of 3-4 ° warming are amplifiers that are only going to make matters worse. As Joe Romm and others have pointed out, 4 may be just a stopping point to even more warming. Am I correct in thinking that economic models don't account for that?
    0 0
  4. Right now the odds of future generations emerging from this global experiment are becoming lower with each year of inaction.

    Rob, makes some good points. The problem with governments is that they typically work on a four year election cycle. This is a problem that requires vision, prudence and being altruistic. Sadly, much of what I see at work is myopia and greed.

    For future generations to stand a good chance of not having to pay an even heftier penalty for our actions, we need two things to hold true:
    1) We need to reduce emissions as rapidly as possible.
    2) Climate sensitivity needs to be on the very low end of the IPCC range.

    Arguing that climate sensitivity is "low" as an excuse to delay taking action, or not take action at all, is foolhardy, as we may very well already be locked into dangerous warming.

    Moreover, if little or no further action is taken because of this false sense of security, we could be headed for over 1000 ppmv CO2 by 2100, and in that situation even if climate sensitivity is "only" 2 C, we would still be potentially looking at warming on the order of 4-5 C, perhaps more. And that does not include the potentially disasterous impacts of ocean acidification associated with CO2 levels > 1000 ppmv.

    So, from my perspective, the pros of taking meaningful and prompt action on reducing GHGs far outweigh the cons, regardless of the value of climate sensitivity.
    0 0
  5. BWTrainer @3 - I do think that accounting for all of the economic consequences of future climate change is a major challenge. It's hard enough to predict those changes, let alone their potential costs.

    Considering how risk averse people normally are, our cavalier attitute towards climate change is really uncharacteristic and bizarre. I think some of it is due to the fact that it's a long-term problem, as Rob noted. Some of it is just disbelief that the risk could be as high as it is. A lot of it is probably the effectiveness of the disinformation campaign as well.

    There's also the fact that most people do support reducing GHG emissions, but politicians are beholden to corporate interests, which are focused on their short-term profits. People don't see the problem as a high enough priority to force their representatives to act on it for the reasons noted above.

    There are a lot of factors behind our faiulre to mitigate this risk.
    0 0
  6. By coincidence, the Club of Rome just released a new report on mankind’s ability to deal with climate change.

    (Rotterdam, the Netherlands): 2052: A Global Forecast for the Next Forty Years, by Jorgen Randers, launched by the Club of Rome on May 7, raises the possibility that humankind might not survive on the planet if it continues on its path of over-consumption and short-termism.

    This new report is summarized in the article, “New Report issues a warning about humanity’s ability to survive without a major change in direction” posted on the Club of Rome’s website. The article also contains a video about the launch.

    To access the article and video, click here .
    0 0
  7. 6 - John

    That is so going to press all buttons the Conspiracy Theorists!!
    0 0
  8. Ies
    very true, sentences like "We need a system of governance that takes a more long-term view" will set conspiracy theorists on fire.
    0 0
  9. It's not so much sentences like that; but that they're a secret society - you knew that they're secret, right? - along with other secret societies like the Bilderberg group, the UN, EU, pan-dimensional shape-shifting lizards, Michelle Mann and my aunt Matilda; who are engineering the reduction of the world population by cutting off the oil supply, motivated by the AGW-hoax. Or something like that.
    0 0
  10. We just lost another month: April 2012 Mauna Loa CO2 now at 396.18 ppm

    One more month of rise before the seasonal peak is reached. This possibly puts 400 ppm within reach in May 2013...
    0 0
  11. DB@10,

    While clicking at your NOAA link, it's worth noting the growth from 4/2011 (393.28ppm) to 4/2012 was almost 3ppm thus well above the average 2ppmy-1 in the last decade (fig 3 in the link target). While the growth rate has "slowed down" (poor consolation) to just 1.5ppmy-1 in 1990-2000, now it seems to have accelerated to the levels likely unseen in the entire history of Planet Earth. Anyone wants to challenge this last statement?
    0 0
  12. One telltale sign to watch out for is the slipping of the seasonal pattern (6-7 month rise culminating in a May apex). If enough tropic, temperate and boreal forest degradation occurs, and if the oceanic sinks begin to lose effectivity as carbon sinks, then the sign to watch out for is the apex of the seasonal rise continuing on into June...

    Needless to say, that would be very bad. Almost "game-over" bad.
    0 0
  13. Dan, that raises a question: has anyone done a statistical analysis of the monthly CO2 readings in your post 10 ?
    0 0
  14. The annual CO2 rise was 2.9ppm. Increases up to 3.0ppm lasting for one or two months are not so unusual.
    A graph showing such rises in MLO data two clicks down here.
    However, what makes it a little more alarming is that ENSO has only just turned positive & it is ENSO that precedes these increased rates of CO2 rise. To add to that, RSS gives April a 0.333 deg C global temperature, again nudging up high before ENSO has even started.

    On a different note (& more 'on-topic'), the idea that Lindzen has ever given any thought to the impact that global surface temperatures is entirely farcical. It is realising his blasé attitude to rising temperature that has made me see what a buffoon Lindzen really is (or more correctly has always been. His comment I relate below is nothing new.)
    In his recent talk in London he compared the 0.7 deg C rise in global temperature over the last century to the temperature changes experienced in Boston. This is bar room gobby-git talk, but perhaps simply Lindzen doing propaganda.
    What convinced me he genuinely believes this tosh was his comment at the conclusion of this bit of his talk. “Say, at least so far, I mean if some day I see there are changes 20 times what I’ve seen so far, that would be certainly remarkable. But nothing so far looks that way.
    That's 20x 0.7 deg C or +14.0 deg C. Anybody who dismisses the prospect of such a rise in global temperatures in such a manner cannot be considered any sort of climatologist.
    0 0
  15. Really would be useful if we had a dletail analysis on why we came to agree on the 2C threshold.

    It is amazing that this was not challenged until around 2005 when Hansen started to look at it more closely.

    One gets the feeling that we are sticking to it because the 1-1.5C is now impossible and if we do accept that 2C is in fact way too much we will lose hope.

    Considering what is happening in the arctic and the acceleration of global extreme weather and climate events/changes, 2C is catastrophic. We are looking at around at least 3C and counting, depending on what action we take.

    The thing is once we get up to around 1C, climate disruption is going to ensure that our economic engine grids to a a halt. So interesting times....
    0 0
  16. John @ 6

    cant find any links to report....

    "Research last month by the University of Oxford and Princeton University said global warming was likely to be between 1.4 and 3 degrees by 2050, but that 3 degrees was at the upper end of what was likely."
    0 0
  17. Paul - we do have a fairly detailed analysis. Click the first link in the 'What's Dangerous?' section. A lot of it has to do with what's policitically feasible, since ultimately it's a policy goal. I think most groups would agree that zero additional warming would be the best goal, were it feasible to achieve.
    0 0
  18. @Paul Magnus #16

    The new Club of Rome report, 2052: A Global Forecast for the Next Forty Years, by Jorgen Randers is actually a 304 page book that will not be available until Jun 1, 2012.

    The report is summarized in the article, “New Report issues a warning about humanity’s ability to survive without a major change in direction” posted on the Club of Rome’s website.

    The article also contains information about its publication both as an e-book and as a traditional hard-copy book.

    To access the article, click here .
    0 0
  19. @les #7

    I personally endorse the strategy for communicating the reality of manmade climate change set forth by Bill Blakemore of ABC News (US) in his recent essay:

    ‘Hug the Monster’ for Realistic Hope in Global Warming (or How to Transform Your Fearful Inner Climate)
    0 0
  20. @ Paul

    Sokolov et al 2009 (blogged on by Romm here) shows all 400 model runs exceeding 2C by 2100. Fig 8b shows SAT exceeding 2C before 2050:

    (middle red line above is ensemble mean for Sokolov)

    Betts et al 2011 (blogged on by Romm here), published in the Royal Society A, details a 4C world by 2070...
    0 0
  21. If you listen via BBC iPlayer 'listen again' feature to 'Costing the Earth', BBC Radio 4, U.K. time 20.00 today (9th May), it will break your heart. It is all about coal, need I say more?

    I just hope that the denialati are called to account for their actions, especially Monckton.
    0 0
  22. Yes Dana, I agree it seems to have been politically influenced. I did see the links, but think it would be a good exercise to cover it more systematically to see how the concensus formed around it.

    @18 John, yes I saw the report. I meant I couldn't find any links to the Oxford/Princeton research that the reuters news item refered to.
    0 0
  23. This one is getting bookmarked. It is nice to have a collection of some of the economic analyses in one place. It seems many that disagree with the scientific stance have an issue with the solutions, so I make it a point to get straight to the point.
    0 0

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

The Consensus Project Website



(free to republish)



The Scientific Guide to
Global Warming Skepticism

Smartphone Apps


© Copyright 2014 John Cook
Home | Links | Translations | About Us | Contact Us