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SkS Analogy 1 - Speed Kills: How fast are we going?

Posted on 25 January 2022 by Evan

This is an updated version of Analogy 1, which illustrates the impact of the rate of increase of CO2 on the natural world's ability to adapt. The original version is here.

Tag line

Speed Kills

Elevator Statement

Deceleration from 60 mph to 0 in …

  • 30 seconds (base rate): Normal exit from a freeway; no drinks spilled; life goes on.
  • 3 sec (10 times base rate): Slam on the brakes. Loose items end up on dashboard. Those not wearing seat belts do ungraceful face plants. Survivable injuries.
  • 0.3 sec (100 times base rate): Like running into a parked car. Crumple zones in both cars absorb much of the energy, but people are seriously injured, some mortally.
  • 0.03 sec (1000 times base rate): Like running into a brick wall. You get the point.

Climate Science

Increasing atmospheric CO2 concentrations cause global warming. Global warming drives climate change. The rate of increase of CO2 concentration is important, because it determines the rate of global warming, and therefore the rate at which natural systems must adapt. Figure 1 shows CO2 concentrations from the end of the recent ice age to the present. Think of Fig. 1 as the Keeling Curve with historical context, illustrating how rapidly CO2 is rising relative to the most recent deglaciation rate. If we limit the rate of increase of CO2 to that experienced during a deglaciation cycle, we expect nature will adapt; the further away we move from this base rate the more difficult it is for nature to adapt, because rapid rises of temperature are often associated with extinction events.

CO2 Concentration from before last deglacition up to the present

 Figure 1. Rate of increase of CO2 relative to the rate during the recent deglaciation. The animals running up the CO2 "hill" indicate that nature can adapt to this rate of change. A stable CO2 level provided a relatively stable climatic base for the development of modern civilization. Can modern civilization surmount the CO2 cliff in front of us? (Clipart licensed from iStock/skalapendra (car), iStock/blueringmedia (herd), Getty Images/zaricm (caveman), and 123RF/Lorelyn Medina (chariot))

Is it a coincidence that during the rise of modern civilization that CO2 concentrations have been remarkably stable?

Although the natural world has successfully navigated many deglaciation cycles, will the natural world successfully adapt to the current rate of change?

Will modern civilization successfully adapt to the deglaciation cycle we are forcing?


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Comments 1 to 16:

  1. Perhaps it's "rah-rah" from the team but I really like this analogy.

    Not least because it neatly addresses the "climate's always changed" confusion.

    I stop and start my car every time I drive. The velocity of my car constantly changes when it's in normal use. Running into a brick wall is a change of velocity. Even while the ultimate kinetic result of a brick wall is identical to using brakes, running into a brick wall results in destruction. 

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  2. I think it's a terrible analogy!

    Many if not most semi-deniers seem to think that by slowing down the rate of emissions everything is hunky-dory. They have no conception of the fact that it's the TOTAL amount, not the RATE of emissions that matters, given the glacial rate of sequestration of CO2.

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  3. Wol@2 Actually, it is both the total (as you correctly point out) and the rate that matter.

    I agree that rate is not important in the sense that emission rates are important in a city (high rates are associated with smog alert days). But rate is important in that it determines how rapidly the natural world must adapt. Sea  level rise of 1ft/100 years is doable: 1ft/10 years is a  challenge.

    Please take a look at SkS Analogy 10: Bathtubs and Budgets, where we discuss the aspect of emissions that you point out. Analogies usually only deal with a single aspect of what is a large, complex problem, so it is normal that we will not deal with all aspects in a single analogy.

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  4. Evan @3,

    I would say it is unethical to state that "Sea level rise of 1ft/100 years is doable".

    It is unethical to suggest that a portion of the current population should be allowed to benefit from a harmful activity that, from their perspective, appears to be an acceptable imposition of harm on others and all of the future of humanity. There are already island nations that have had centuries of sustainable living be ruined by the small sea level rise that has already occurred. And many other low lying areas are already harmfully impacted. And the sea level rise is only a part of the total climate change impact problem.

    A potentially justified version of that thinking is:

    The least fortunate can 'exclusively' be helped to live better, at least decent, lives by a short-term transition involving understandably unsustainable and harmful activity.

    The fuller understanding of that version is that the people who are not less fortunate should be helping the least fortunate and ensuring that no lasting negative consequences are produced. That would involve the current day wealthy, all of them - not just the ones who care, doing whatever is required to neutralize the negative impacts of the short-term actions taken to help the least fortunate live decent lives. That would mean 'not accepting' a level of harm done to future generations, because excusing harm done is an ethically slippery slope to 'no future for humanity'.

    That is also an ideal. But the understanding needs to be that anything short of that ideal is 'understandably unacceptable, not excusable'. And everybody needs to appreciate that reality and the constant need to investigate and correct what has developed to limit, and correct for, harm done.

    The challenge of today is the reality that a lot of what has developed is harmfully over-developed, especially in the supposedly superior nations on this planet. Undoing all that harmful over-development, and repairing the damage done, is required for humanity to have a sustainable improving future.

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  5. OPOF@3 The World (as embodied by the IPCC and the COPs) has declared that the ideal is holding the line at 1.5C. At that level, we will certainly have 1 ft/100 years for a long time. If not more. If not much much more.

    Meltwater Pulse 1A saw sea level rise of 1 ft/10 years when CO2 rose at 1 ppm/100 years and had only risen 10's of ppm. Even if we hold to 400 ppm (1.5C), that represents 120 ppm CO2 added much much faster than during Melwater Pulse 1A. Do we really think that we can limit sea-level rise to any better than 1 ft/100 years?

    I care about the plight of others and I share your sentiment. It is well stated. But we are in a situation now where the developed countries need to adapt quickly enough and stay strong enough to help those who will be affected by climate change. At 1 ft/100 years we can probably do that, although there is still the question if we have the will to do that. At 1 ft/10 years it is questionable if developed countries will even have the resouces to help themselves, much less anyone else.

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  6. OPOF said: "I would say it is unethical to state that "Sea level rise of 1ft/100 years is doable".

    I disagree. Look at it this way. If burning fossil fuels and so global warming was only going to cause at worst 1 foot of sea level rise per century, and for example mild effects on our weather I wouldn't be too worried. We could adapt easily enough. Therefore its hard to see an ethical issue of any substance. And apply some reductio ad absurdum and consider if it was only one inch of sea level rise per century. Would anyone seriously argue this is unsustainable or unethical? 

    The big issue to me is this. The advantages of using fossil fuels would arguably outweigh that small 1 foot level of sea level rise per century. The one argument against all this is loss of land area building up over time. It would probably depend on just how extensive that was, but everything humans do affects the environment, so we have to make these unpleasant trade offs.

    The point I'm making is there is likely to be a level of anthropogenic sea level rise per century and also in total over time that is essentially insignificant. And a level that is seriously problematic.

    Of course thats all somewhat academic in the sense we are likely to cause much more than 1 foot per century of sea level rise per century, and for several centuries, and  this is unsustainably fast and certainly unethical to try to justify it.

    Normally I do tend to mainly agree with OPOFs views.

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  7. Evan and nigelj,

    All I am saying is that the current reality is the result of the unethical lack of action by the wealthy and powerful, especially through the past 30 years.

    1ft of sea level increase per 100 years needs to be declared to be the future disaster that it is. That is the way to strengthen the argument that more harm done is even less acceptable. It also leads to the understanding that current day humanity needs to be aggressively implementing CO2 removal technology (and making sure that it is harmless) even if that is not popular or profitable (and doing that while sustainably improving the lives of the least fortunate).

    An Ethical Perspective requires developed perceptions of wealth and prosperity (and superiority) today to be understood to be the destructive unsustainable reality that they are.

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  8. OPOF @7

    "All I am saying is that the current reality is the result of the unethical lack of action by the wealthy and powerful, especially through the past 30 years."

    Fine agreed.  Its certainly in large part due to that.

    "1ft of sea level increase per 100 years needs to be declared to be the future disaster that it is."

    I just dont see 1 foot of sea level rise per 100 years as a future disaster. Its not great, but it would be possible to adapt to. And we have had about 1 foot of sea level rise last century. Anything above 1 foot per century becomess very hard to adapt to.

    I'm assuming here we get enough control over the climate problem that 1 foot per century doesn't go on for millenia and create hugely significant loss of land. 

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  9. FWIW, here is an interview with Eric Rignot, an expert on SLR.

    The lower end currently discussed is 3 ft/100 years, with 1 ft/10 years a distinct possibility. At this point we may just be passengers on a lumbering freight train. It's taken us this long to get it rolling. We are not likely to stop it very quickly.

    Although I agree with you OPOF that even 1 ft/100 years is too much for some people, I think that at this point we are talking semantics. What your point really clarifies is the delicate balance that defines so much of life on this blue marble, the great care that is needed to protect it, and our responsibility to help each other.


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  10. OPOF Thank you for your comments. As a result of this discussion, I am going to modify the text in an upcoming post. I think the essence of what you're saying is that whereas many are fearing the arrival of catastrophic effects of climate change, what you are saying, I think, is that catastrophic effects have already arrived for many, because even a "modest" sea level rise of 1 ft/100 years, which we've already experienced, represents a catastrophe for many. For those who have not yet felt the effects of climate change, we need to emphasize that others have already been affected, that we need to acknowledge that fact, and to provide assistance to those already affected.

    Catastrophic climate change in the sense of a global response will be when the catatrophe already felt by many spreads to a critical fraction of the global population so as to limit the ability of the global community to provide meaningful assistance to those with the greatest needs. In this sense, we are already experiencing catastrophic climate change. The real question might be how much we can tolerate before our ability to properly respond as a global community is severely impaired.

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  11. Evan,

    The interview of Eric Rignot is sobering reading.  Don't buy land near the ocean if you want it to retain value in the future.

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  12. Funny you should say that Michael. 25 years ago we bought a large wetland area in Minnesota. At the tiime it was cheap because wetlands were considered one step above a garbage dump. Now we realize the value of wetlands for absorbing large quantities of water. Even though we are planning to build a house just 5 ft above the normal high-water mark, we have no concerns about current or future flooding.

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  13. More sobering than the interview with Eric Rignot is something that Richard Alley said. Up to 20 ft SLR is possible by 2100. Richard Alley is as professional and careful as climate scientists come. So when he says something like that. Well, er, what can you say.

    We sit and drink coffee and have picnics and go on about our lives, pretty much as normal, while CO2 rises 250 times faster than the most recent deglaciation. Just numbers. Just data. But each year the rate continues to increase. We are not wired to comprehend such a non-linear system. We would be wise to listen to people like Profs Rignot and Alley, who are tuned into what might be a very nasty non-linear response.

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  14. Evan,

    I am surprised that you found ocean front land in Minnesota ;-)!!  Future flooding will be different for you than for me in Florida.

    I agree with you completely.  Pictures of ocean front condos in Miami with people wading to their cars tell me that sea level rise is already a big problem.  Developers have just not acknowledged it yet. I live in Tampa, Florida.  The newspaper just ran a story of how many billions of dollars of real estate will be endangered by the next category 1 hurricane (we do not need a category 5 to do great damage).  Every centimeter counts when you are wading to your car.

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  15. Michael, we have two ponds. If you get tired of wading/swimming/surfing to your car, come join us. We'll build by one pond, you by the other.

    Just bring lots of bug spray and warm clothes. :-)

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  16. Evan @10

    That presentation of thoughts is indeed aligned with my current thinking, which I openly admit is ‘not the norm’, and which is open to improvement.

    The following may be more than needs to be presented as further clarification. It should not change your understanding. But it leads to other thoughts related to nigelj’s point @8 and your comment @9 about the magnitude of impacts that are presented in the newer version of the SkS Analogy 1. I plan to make comments about that there.

    The basis for my thoughts is what I would call ‘idealized ethics’. My thinking is based on Professional Engineering Ethics which are fairly thoroughly presented in the APEGA Guideline for Ethical Practice, supplemented significantly by the more fundamental ethical considerations developed and shared by Derek Parfit in his effort to develop a secular understanding of ethics that he presented in his 1984 book Reasons and Persons (and lots of other ethics related reading – including the basis for the Sustainable Development Goals).

    I would clarify ‘idealized ethics’ to be: An ideal governing objective for human thoughts and actions in order to develop sustainable improving conditions for the diversity of humanity and its diversity of civilizations living as sustainable parts of the robust diversity of life on this planet now and into the distant future. That understandably includes the correction of harmful developed systems and activity and making amends for the harm done.

    And I would currently briefly express the best way to achieve that ‘ideal objective’ as: Pursuing increased awareness and improved understanding in order to constantly learn to: Do No Harm and Help Others, especially helping those who have been or are being harmed.

    I consider the ‘current norm’ discussions of ethics and related ‘development and application of rule of law’ (and the history of ethics and rule of law discussion) to have been harmfully compromised by the developed systems or ‘games of pursuit of personal benefit and perceptions of superiority relative to Others’. That competition can lead people to evaluate the Greater Good for current living humans without proper consideration of future humans (refer to the ways that people like Lord Monckton tried to justify more harm being done to future generations by significantly discounting, and underestimating, the future harm), and with harm being done to portions of the current population (see the ways that many people try to argue against ‘the more fortunate being obliged to help the less fortunate’). And the harm being done is also poorly justified, including claims that the perceived benefits obtained by those who benefit outweigh the perceptions they have of the harm done. The people who benefit most from the harmful activity can also be seen to misleadingly claim that people who are harmed are also benefiting so it is All is for the Greater Good (from the perspective of the people who benefit the most).

    A key Ethical understanding is that Do No Harm means that no Person is to be ‘net-harmed’ by an action. Medical ethics are a clear example of that understanding.

    Also note that future humans, and many less fortunate current day humans, have little or no influence. They lack legal standing, cannot vote, and cannot effectively question or challenge what is being done that alters the conditions or environment that the people being harmed have to deal with.

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