The "Pause" - A Review of Its Significance and Importance to Climate Science 77

[rconnor]

----------Introduction---------
A comparison of recent temperature trends in isolation of earlier data, say 1998-present, to long(er)-term temperature trends, say 1970-present, reveals that more recent temperature trends are lower than long-term temperature trends. This has led many, including many prominent climate scientists, to refer to the recent period as a “pause”, “hiatus” or “slowdown”. While in isolation of any other context besides two temperature trends, the term “pause” or “hiatus” may be quasi-accurate, much more context is required to determine whether these terms are statistically and, more importantly, physically accurate.

It should be noted that most times when these terms are used by climate scientists, they keep the quotation marks to indicate the mention-form of the word and are not implying an actual physical pause or hiatus in climate change. The subsequent research into the physical mechanism behind the “pause” has continually demonstrated that it is not indicative of a pause in climate change nor does it suggest a drastic reduction in our estimates of climate sensitivity. However, this fact appears to be lost on many who see the “pause” as some kind of death-blow to the anthropogenic climate change theory or to the relevancy of climate change models.

While this subject has been discussed repeatedly in these forums, it has never been the focus but rather used as a jet-pack style argument to change the conversation from the subject at hand to the “pause” (“Well that can’t be right because the Earth hasn’t warmed in X years!”). Revisiting past threads, I cannot find an example of where someone attempted to defend the “pause” as a valid argument against anthropogenic climate change. It is brought up, debunked and then not defended (and then gets brought up again 5 posts later). The hope is to discuss the scientific literature surrounding the “pause” to help readers understand why the “pause” is simply not a valid argument. While some points have been discussed (usually by me) before, this post does contain new research as well as 2014 and 2015 temperature data, which shed even more light on the topic. The post will be split into three parts: 1) the introduction (and a brief discussion on satellite versus surface station temperature data sets), 2) Does the “pause” suggest that climate change is not due to anthropogenic CO2? and 3) Does the “pause” suggest that climate models are deeply flawed?

------Why I Will Be Using Ground-Based Temperature Data Sets-------
Prior to going into the meat of the discussion, I feel it necessary to discuss why I will be using ground-based temperature data sets and not satellite data sets. Perhaps one of the most hypocritical and confused (or purposefully misleading) arguments on many “skeptic” blogs is the disdain for all ground-based temperature data sets and the promotion of satellite temperature data sets. The main contention with ground-based temperature data sets is that they do not include raw data and require homogenization techniques to produce their end result. While I am not here (in this thread) to discuss the validity of such techniques, it is crucial to understand that satellite temperature data sets go through a much more involved and complex set of calculations, adjustments and homogenizations to get from their raw data to their end product. Both what they measure and where they measure it are very important and highlights the deep confusion (or purposeful misdirection) of “skeptic” arguments that ground-based temperatures are rubbish and satellite-based temperatures are “better”.

[ul][li]Satellites measure radiances in different wavelength bands, not temperature. These measurements are mathematically inverted to obtain indirect inferences of temperature (Uddstrom 1988). Satellite data is closer to paleoclimate temperature reconstructions than modern ground-based temperature data in this way.[/li]
[li]Satellite record is constructed from a series of satellites, meaning the data is not fully homogeneous (Christy et al, 1998). Various homogenization techniques are required to create the record. (RSS information)[/li]
[li]Satellites have to infer the temperature at various altitudes by attempting to mathematically remove the influence of other layers and other interference (RSS information). This is a very difficult thing to do and the methods have gone through multiple challenges and revisions. (Mears and Wentz 2005, Mears et al 2011, Fu et al 2004)[/li]
[li]Satellites do not measure surface temperatures. The closest to “surface” temperatures they get are TLT which is an loose combination of the atmosphere centered roughly around 5 km. It is also not even a direct measurement channel (which themselves are not measuring temperature directly) but a mathematically adjustment of other channels. Furthermore, due to the amount of adjustments involved, TLT has constantly required revisions to correct errors and biases (Christy et al 1998, Fu et al 2005).[/li]
[li]See the discussion on Satellite data sets in IPCC Report (section 3.4.1.2)[/li]
[li]Satellite data and the large amount of homogenization and adjustments required to turn the raw data into useful temperature data are still being question to this day. Unlike ground-based adjustments which lead to trivial changes in trends (from the infamous Karl et al 2015), recent research shows that corrections of perhaps 30% are required for satellite data (Weng et al 2013 .[/li][/ul]

None of this is meant to say the satellite temperature data is “wrong” but it very clearly highlights the deep-set confusion in the “skeptic” camp about temperature data sets. If one finds themselves dismissing ground-based temperature data sets because they require homogenization or adjustments while claiming satellite temperature data sets are superior have simply been lead astray by “skeptics” or are trying to lead others astray. Furthermore, it clearly demonstrates that any attempt to compare satellite data (which measures the troposphere) to the surface temperature output of models is completely misguided (*cough*John Christy *cough*). It is for these reasons that I will use ground-based data in the rest of the post.

Again, I would like to state that I do not wish this to be a focal point of this discussion. I am merely outline why I will be using ground-based temperature data sets and my justification for that as, undoubtedly, someone would claim I should be using satellite temperature datasets. In fact, I appear to be in pretty good company; Carl Mears, one of the chief researchers of RSS (and the same Mears from all the papers above), stated:

My particular dataset (RSS tropospheric temperatures from MSU/AMSU satellites) show less warming than would be expected when compared to the surface temperatures. All datasets contain errors. In this case, I would trust the surface data a little more because the difference between the long term trends in the various surface datasets (NOAA, NASA GISS, HADCRUT, Berkeley etc) are closer to each other than the long term trends from the different satellite datasets. This suggests that the satellite datasets contain more “structural uncertainty” than the surface dataset

If this is a topic of interest to people, perhaps starting your own thread would be advisable as I will not be responding to comments on temperature data sets on this thread. Now, onto the actual discussion…

 

[hawkaz]

My point was not about the science- but about perception. If you don't win the perception battle, the science is meaningless.

People like Al Gore are the face of climate change whether you like it or not. When he exaggerates, it discredits the whole movement.
With Climategate- Everyone (especially scientists) need to know that e-mails are forever- and they need to write them with the thought that they will go public- and how will they be interpreted. They also need to know that sarcasm doesn't work well in e-mail form. They sent out some very poorly worded and easily misinterpreted e-mails. We have probably all made mistakes like this (I know I have)- but theirs went public.

Regarding your question, I believe my response is clear from above- although I wouldn't necessarily call it ideological. Clearly laymen don't rely on scientific justifications. They rarely do. As you stated above,the public will generally get their info from blogs or 10 second sound bites.
At the same time, I know enough about history to know that just because 97% agree on something- that doesn't make it true.
I would guess that 97% thought he world was flat and that the sun revolved around the earth.
I would guess that 97% believed Einstein's and Hawking's theories that are now in question

I'm not saying that the 97% are wrong or conspiratorial, I just saying that I just don't know yet. The science is clearly still evolving. I'm still looking for the magic bullet that will convince me- but I don't have time to read every scientific journal, or research this myself- so I wind up reading blogs (like this one) too.

 

[rconnor]

If you don't win the perception battle, the science is meaningless.

No, this is so wrong. As Neil DeGrasse Tyson said, "The good thing about science is that it's true whether or not you believe in it". To Nature, our perception of science is truly meaningless. Climate change is happening, regardless of what Lamar Smith thinks about it.

People like Al Gore are the face of climate change whether you like it or not.

The only people that believe Al Gore is the face of climate change are the people that don't believe in climate change. It is a straw man that is used to attack climate change - that was my point.

With Climategate- Everyone (especially scientists) need to know that e-mails are forever- and they need to write them with the thought that they will go public- and how will they be interpreted...They sent out some very poorly worded and easily misinterpreted e-mails. We have probably all made mistakes like this (I know I have)- but theirs went public.

I agree. So what's your point? Write emails like they could be hacked, stolen and made public? Possibly that's good advice but how does that relate to "climategate" being misrepresented by blogs?

At the same time, I know enough about history to know that just because 97% agree on something- that doesn't make it true.

Agreed but it is ridiculous to think that because something is so strongly scientifically supported that it's more likely it's not true. It's even more ridiculous to use the fact that something is so strongly scientifically supported as a reason to not believe in it.

All in all, your argument seems odd to me. Similar to rb1957 talking about the irrational human response, you seem to be saying that people's perception of science is sometimes off. I completely agree. But you seem to be using this as an excuse to justify not supporting mitigation measures, which is absurd.

If your argument is that we need to correct people's perception, then I agree. However, when people choose to go to "skeptic" blogs for their climate news then they are not honestly looking for information on climate change; they are looking for anything to support their preferences. In this case, the issue lies with the individual, not science communication.

I'm not saying that the 97% are wrong or conspiratorial, I just saying that I just don't know yet. The science is clearly still evolving. I'm still looking for the magic bullet that will convince me- but I don't have time to read every scientific journal, or research this myself- so I wind up reading blogs (like this one) too.

This is fair. What, may I ask, is the "magic bullet" you are looking for? Or perhaps more appropriate, what causes you to not be convinced that mitigation measures are required?

However, if you choose to go to WUWT or Huffington Post over climate.nasa.gov, then you're being disingenuous in your open-mindedness. I'm not accusing you of doing this, just stating that point.

 

[snarkysparky]

Nothing will be done about climate change. Your as likely to herd cats as
get the public to agree to self regulate consumption.

Hey the Earth wasn't meant to last forever. It's our destiny in this phase of society to
use it up.

I just nod and grin at the lack of change all around me, pick up my guitar and play.....

 

[rconnor]

Hey the Earth wasn't meant to last forever. It's our destiny in this phase of society to use it up.

Your grand children (or their children) might think differently.

Apathy and ignorance.

[Edit: I misread this statement, see the clarification below]

 

[rb1957]

"Nothing will be done about climate change." unfortunately, IMHO, plenty will be done because the political battle has been won, to a very large extent; because the perception battle has been won. I predict a bunch of 1/2 measures will be forced on us, that a small group will get wealthy, that most of us will pay a small cost (something keenly judged not to make us revolt), and that it won't make a significant difference in the long run. Maybe we'll be a little more efficient in our use of FFs, and that'd be a good thing. Maybe we'll sacrifice our economy in trying to achieve CC goals (eg reduce CO2 emissions to 1990 level by 2030 ... why? what difference will that make to the outcome ? what's the gain ?) and just hasten the inevitable change in the world economic picture (and, in parallel, the world political picture).

another day in paradise, or is paradise one day closer ?

 

[ornerynorsk]

"As Neil DeGrasse Tyson said, "The good thing about science is that it's true whether or not you believe in it"."

A classic "I'm taking my toys and going home" statement if there ever were one. The science is settled.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[IRstuff]

"a small group will get wealthy, that most of us will pay a small cost"

Wow, we agree, but for different reasons. Note that a small group is already wealthy and getting more so by denying climate change, although not in the last 6 months or so, since oil prices tanked. In either case the rest of us suffer.

TTFN
I can do absolutely anything. I'm an expert!
homework forum: //

http://www.engineering.com/AskForum/aff/32.aspx

faq731-376 forum1529

 

[snarkysparky]

I am certainly guilty of a little apathy about the issue. Ignorance, yes also guilty as charged. I am not a climate scientist so yeah.

From what little I do know my opinion is in the "we should do something now" camp. I don't believe 97% of the scientists are in on the same conspiracy or they are all uniformly wrong.

The problem comes from some characteristic in people that at some level just refuse to accept the high likelihood that we are changing our planet for the worse.

Case in point here on this board with the irrational and seemingly magical thinking manifest by many of those who deny the science. Otherwise rational and intelligent people see only the facts that support their wishes and will form their theories about why it isn't happening with every known logical fallacy available. I realize they can't help doing so because something in the concept of a dying Earth is too terrible for them to comprehend, maybe religion plays a part. And so it goes with a significant portion of the population, enough to prevent solutions while democratic government is the ule.

There will always be deniers no matter how extreme the climate becomes and they will always attract a sizable following.

 

[ornerynorsk]

Here lies the problem folks. Bear with me, please.

If it were truly science, which in itself can be a very ambiguous and poorly defined term (it's relative to the speaker, not the listener), I would be on my soapbox and shouting it from the rooftops like many of the near-religious adherents in this forum. Ask yourselves, what facts do we really have? Does anyone know . . . and I use the word "know" in its proper and rightful definition so don't twist it . . . . and fully understand, the mechanisms, the real numbers in saturation points, where equilibrium resides, the range where change goes past the tipping point, the real cause and effect? Do you? The honest answer is "NO", and a very hearty and resounding NO, at that.

Facts are facts. Belief, conjecture, circumstantial evidence, popular science, and coincidental observation all do not bear the same weight as fact.

Before the zealots drag humanity once again into further bondage of taxation, regulation, and more government over-reach, let's at least establish facts.

I agree wholeheartedly that we pollute too much. Earth IS finite. There is much we can do as good stewards of the resources we have been charged with. Is more governance, Marxist penalties, and arcane "sin" credit markets the answer? Rarely.

The problem is that the policy makers (UN et al)hold little credibility as problem solvers, often employ "solutions" which are exclusive to elite and privileged committees all too happy to act on the behalf of us poor drooling cretins who cannot hold our lives together , and frankly, are not often in the best interest to all involved, wrought with corruption and thuggery. Not to mention, that many of the players are criminals.

Enough is enough. Get off your damned soapboxes and start doing something about it. Start with your own communities. Grassroots and groundswell may not be as attractive to some as having Big Brother step in to save the day, but bottom up has better potential for humanity than top down dictatorial tactics do. rconnor, it's obvious you are a well-read and highly intelligent person. People like you are the ideal candidate for such grassroots actions. You certainly have the passion. Just please don't lead us into fascism with misdirected fervor.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[rconnor]

Snarkysparky, I really misread your first post. I thought you were happy about the situation (I took “destiny” to mean “desired goal”) but your reply clears that up. My apologies.

There is a part of me that completely agrees with your second post. The magical thinking by otherwise rational people is disheartening and at times I can become pessimistic that we will have the societal will to make the changes necessary. However, one thing you need to keep in mind, as do I, is that while the rejectionists may be loud and vocal, they are not the majority. The best thing we can do is offer the best information to help educate the general public and minimize the anti-science rhetoric.

 

[IRstuff]

"Facts are facts. Belief, conjecture, circumstantial evidence, popular science, and coincidental observation all do not bear the same weight as fact. "

Sure, but that's as moot an argument as saying that unless you personally see and feel global warming, it's not real. Global warming cannot be a "fact" until it's obvious to everyone that the game is already over. So, we wait until we're neck deep in water and living at the now-temperate poles and then say, "Gee, now we know AGW is real."

You don't "know" that you're going to get into an accident, yet you prudently put on your seat belt and don't disable or remove your airbags. You don't "know " the exact failure point of a particular batch of steel, yet one can design and build 1300-ft tall buildings based solely on the FEM analysis with 2x and 3x safety factors. Why not design to 10% safety factors? Because you don't "know" the exact failure point, and you don't "know" the exact magnitude of the largest possible earthquake.

It's so easy to paint anyone who disagrees with, "fascist, criminal, popular science, dictatorial" isn't it? Yet, seat belts and air bags were, in fact, mandated by law before everyone had them and were made to wear them, and have saved thousands of lives. And, given that there are those with absurdly deep pockets willing and able to obfuscate the arguments, demonize the opponents, who's really the fascists?

TTFN
I can do absolutely anything. I'm an expert!
homework forum: //

http://www.engineering.com/AskForum/aff/32.aspx

faq731-376 forum1529

 

[ornerynorsk]

Apples and oranges, IRstuff. Seatbelts and airbags had observable results prior to enactment. AGW mitigation does not. Warming is not disputed, causality is.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[rb1957]

personally i put on my seat belt to avoid the fine, and to avoid giving the police an invitation to stop me and look for more things ... "oh, your ownership is just a photocopy, not a notarised copy ..."

another day in paradise, or is paradise one day closer ?

 

[rconnor]

personally i put on my seat belt to avoid the fine, and to avoid giving the police an invitation to stop me and look for more things ... "oh, your ownership is just a photocopy, not a notarised copy ..."

So do you only buckle in an infant (say your child or grandchild) to avoid the fine and possible hassle of getting pulled over? The kid flying through the windshield isn't a huge concern for you but that damn ticket...

 

[rb1957]

i said "i put on my seatbelt" ... nothing else. A child is a slightly different matter, in that they can't anticipate the motion of the car well, probably won't react to sudden changes in the same manner as an adult, ...

for me, in 30+ years of driving I've had 1 accident when I needed a seatbelt, and 1 when it would've made no difference ... ie the chance of a serious accident occurring is very small.

of course, over the population there are lots of serious accidents, and seat belts have saved an enormous number of lives.

it's similar to flying ... do you refuse to fly because of the risk of a fatal accident, or do you accept the risk ?

another day in paradise, or is paradise one day closer ?

 

[rconnor]

i said "i put on my seatbelt" ... nothing else. A child is a slightly different matter

My point exactly. Climate change doesn't just impact you. You have to factor in others.

The Indonesian islands might need a seat belt from sea level rise. Central Africa might need a seat belt from drought. Bangladesh might need a seat belt from extreme heat. And they aren't the ones doing the majority of the driving.

do you refuse to fly because of the risk of a fatal accident, or do you accept the risk ?

I base the level of risk on the probability and severity of failure. Air travel deaths per billion km is 0.05 (for comparison, car travel is 3.1 deaths per billion km). So, I can accept that risk.

The IPCC states in AR5 WGII SPM:

Some risks of climate change are considerable at 1 or 2°C above preindustrial levels (as shown in Assessment Box SPM.1). Global climate change risks are high to very high with global mean temperature increase of 4°C or more above preindustrial levels [which is well within our "do nothing" emission scenario] in all reasons for concern (Assessment Box SPM.1), and include severe and widespread impacts on unique and threatened systems, substantial species extinction, large risks to global and regional food security, and the combination of high temperature and humidity compromising normal human activities, including growing food or working outdoors in some areas for parts of the year (high confidence).

and

Heat stress, extreme precipitation, inland and coastal flooding, landslides, air pollution, drought, and water scarcity pose risks in urban areas for people, assets, economies, and ecosystems (very high confidence). Risks are amplified for those lacking essential infrastructure and services or living in poor-quality housing and exposed areas.

and

By 2100 for the high-emission scenario RCP8.5, the combination of high temperature and humidity in some areas for parts of the year is projected to compromise normal human activities, including growing food or working outdoors (high confidence).

(I suggest reading through WGII SPM for more examples of the probability of various issues)

That's like the airline saying they have high confidence that the plane will experience serious technical issues if preventative maintenance measures aren't done.

That's a flight I'm not willing to take. That's a flight I'm sure as hell not willing to take everyone on the planet on.

 

[cranky108]

The problem with climate change regulation, is the same problem there is with migrotory bird regulation, or western water regulation. They unfairly benifit some, and adversely effect millions.

The taxes won't affect the rich, and the poor will be exempt, and so most of the impact will be felt by the middle class and people in rural areas.

This will place more stress on people, and may push a few more over the edge.

 

[IRstuff]

"They unfairly benifit some, and adversely effect millions."

Perhaps, but how is that different than anything else in the world? Can we honestly say everyone was equally affected by the "Great Recession?" I think the only reason there's such a big hoopla is that the people that would normally benefit are bitching because they know someone else will get the spoils.

TTFN
I can do absolutely anything. I'm an expert!
homework forum: //

http://www.engineering.com/AskForum/aff/32.aspx

faq731-376 forum1529

 

[rconnor]

and I use the word "know" in its proper and rightful definition so don't twist it

I’m not sure you are. The entire existence of the field of philosophical epistemology is due to the search for the “proper and rightful definition” of knowledge. So unless you’ve solved the prime question of epistemology, then I don’t think you can say you are using the “proper and rightful definition”.

But let’s get to the question (and then extend that to talk about the real world utility of our knowledge of climate science), “what facts do we really have”? CO2 causes a greenhouse effect that warms the planet is a fact (note: not the magnitude, especially including feedbacks, is not). Atmospheric CO2 concentrations are rising is a fact. The planet is accruing energy (warming, melting ice, rising OHC, etc.) is a fact.

You take these facts and you begin to build competing theories that explain and are consistent with the facts. Many people like to take “it’s natural” as the null hypothesis. However, climate doesn’t magically change, even “it’s natural” has a physical mechanism that drives the change. So you begin to examine the possible drivers. Solar activity is working in the wrong direction and, furthermore, the magnitude of the change in solar activity is too small to account for the magnitude of change in the climate. Volcanic activity has been too short-term and too weak to explain the magnitude of the changes. We haven’t had a major bolide impact that could explain it. Orbital cycles are about 50,000 to 100,000 year too early and the wrong sign (they would cool instead of warm), the previous warming cycle ended about 10,000 year ago and the rate of warming is completely inconsistent with orbital cycle forcing. Geothermal activity is far too weak and far too consistent to explain the rate and extent of warming (Stein and Stein 1992, Davies and Davies, 2010). Heat redistribution from the oceans is just that heat redistribution and cannot explain why the atmosphere, land and oceans (at all depths) are accruing energy without violating the conservation of energy. Any other non-magically drivers you can think of?

So then you look at non-natural drivers. The heat by-product of anthropogenic activities is orders of magnitude too weak to explain the changes. Land use changes do play a part in the changes but represent a small portion of the changes. Anthropogenic aerosol emissions have the wrong sign but do have an impact (this further emphasis the existence of a warming driver). Anthropogenic CO2 emissions correlate well with the changes, is consistent with the physics (that has been around since the 19th century) and can explain the magnitude of the changes.

The next step is to determine if that hypothesis is consistent with past changes. Looking back at the Earth’s history, major climatic changes coincide with major shifts in CO2 concentrations. CO2 concentrations fall, so do temperatures. CO2 concentrations rise, so do temperatures. But CO2 concentrations don’t magically change, so how did the CO2 get released/stored? At each major climatic shift, we can identify a driver that would cause a shift in CO2 concentrations – volcanic activity, orbital tilts, bolide impacts changing topology (note: see my discussion on whether CO2 leads or lags temperature changes at 24 Apr 15 20:24 – short answer, both). Try explaining paleoclimate using “skeptic” science where the planet is not sensitive to CO2 concentrations; it simply cannot be done. Low climate sensitivity is inconsistent with past and present changes.

Like any other scientific issue, when a hypothesis shows to have extremely good explanatory power of current and past changes and is consistent with other scientific facts and theories, it becomes the leading theory. As far as I’ve read (and that’s quite a bit), there is simply no other credible competing theory (at least none that past the first litmus tests described above). Here, some will jump out and say “we don’t need a competing theory, we just need to disprove the leading theory”. That certainly is true – but where is that scientific dagger in the side of the anthropogenic CO2 theory? It certainly isn’t the “pause” (see Part 1) and it certainly isn’t “models are wrong” (see Part 2). As I continually state, there is no credible* scientific evidence that casts serious doubt on the theory. (*note: blog science is not credible scientific evidence and has been repeated shown why that is – because it’s flawed)

This is actually a very important point – if climate science is so obviously wrong, where is the scientific explanation on why it’s wrong? Given the billion, if not trillion, dollar impact climate change has on oil companies, surely they could finance a model or study to conclusively demonstrate the error of climate science. These companies include some of the smartest people on the planet, surely they'd be able to see through the "tricks" of climate scientists. Exxon’s own internal scientists heavily researched climate science but their results agreed with the scientific consensus. The fact that they then proceeded to fund rejectionist “think-tanks” and made public statements to muddy the water now has them in some hot water. Even people like Willie Soon’s “deliverables” to energy companies have resulted in little more than a handful of largely discredited papers that were weak to begin with. When they actually did the science properly, their findings agreed with the scientific community (imagine that!), so they decided to fund institutions to push out Gish Gallop and unscientific drivel to seed doubt. At the end of the day, for me, the ethical (and legal) questions of this tactic are secondary to the fact that there simple is no conclusive, consistent and credible scientific argument against the current theory despite an enormous self-interest to find one. That is the most telling point.

Climate change has some very real and very significant consequences to our daily lives, so projecting the possible impacts becomes an extremely important societal concern. As we don’t have a crystal ball and the interdependent feed-back effects are not as simply to apply as Newtonian laws of physics, this becomes a risk assessment exercise where models are an important tool.

Models are not designed, nor could they be, to predict an exact dollar amount of damages at a specific time. Instead, they project the possible range of impacts, given a particular emission path. No single model nor the ensemble mean is expected to give the exact right answer but it offers crucial insights in order to be able to perform the risk assessment. That insight is clear – increasing atmospheric CO2 concentration greatly increases the risk and extent of future damages. Limiting the increase in atmospheric CO2 concentration limits the risk and extent of future damages. Mitigation, even at the “better” end of the uncertainty range, is beneficial and becomes even more imperative at the “worse” end. This is on top of the fact that the probability distribution function is right-skewed (i.e. it is more likely to be “worse” than we expect than “better” than we expect). So while the uncertainty is still large, it does not significantly impact the message.

Like any risk assessment exercise, we need to deal with and account for the uncertainty, not use it as a reason to stop doing risk assessment. Furthermore, like we engineers know, uncertainty is not your friend in risk assessment. We don’t get to focus on the “positive” end and ignore the “worse end”. We certainly don’t get to ignore the cost of the possible damages while hyperbolizing the cost of mitigation measures. That would be absurd but is repeatedly done by “skeptics”.

The rebuttal is often “we need to know more before we act”. However, the evidence demonstrates that the longer we wait to act, the worse it will get and the more drastic our emission reductions need to be. It’s been 50 years since President Johnson was warned about the impact of global warming and since that time the planet has continued to warm, ice has continued to melt, sea level rise has accelerated and the early signs of stresses on the biosphere are showing. Perhaps, a more appropriate response would be, “what more do you need to know?” Their reply, as IRstuff pointed out, seems to be “we need to wait until the consequences of climate change are dire before we’ll support action”. This of course is like saying, “I’ll support seatbelts after I go flying through the windshield.” It is, again, utterly absurd risk assessment.

Any claims that “I’m just not convinced” are pure appeals to ignorance or purposeful misdirection. The science is strong and the science is clear – we need to reduce CO2 emissions as much as possible and as quickly as possible. How we go about accomplishing that is still an ongoing debate. As I said before, I’d more than welcome those with an ideological resistance to government intervention to the table to join in this conversation. However, the conversation on mitigation measures follows the rules of rational discourse; “Pigeon rules chess” doesn’t fly. Statements require credible supporting evidence. The more fantastic the claim, the more tight the evidence has to be (i.e. to appeal to some ridiculous global conspiracy involving nearly every scientist and government colluding to invent a environmental crisis for personal gain needs support or you get shown the door). Logic, reason and science trumps politics, conspiracy and ideology.

(To your comment about working at the grassroots level, I do. However, while you can have a slight positive impact, the problem is grassroots is not effective enough. The best use of our effort is through educating those around you, cleaning up misinformation when it is peddled and pushing your politicians to support action. High level action is required to address climate change and that requires public and political support. Public and political support requires proper education on the subject and combating misinformation.)

 

[BiPolarMoment]

@rconnor: Do you have any idea as to why the popular media doesn't latch onto energy accumulation (radiative energy imbalance) instead of 'global' temperature more readily (or for that matter, even the more science oriented articles)? The latter doesn't even seem to me as a rational approach even if temperature is a fairly well understood concept to the person experiencing it (i.e. the public). If anything, taking the approach of talking about the temperature specifically creates the atmosphere (pun intended) for people to spout inane arguments such as "well it's not hot here right now so where's all this global warming!?"