Guest essay By Roger A. Pielke Sr.
My son and Kevin Trenberth did an interview for Colorado Public Radio on February 17th. The entire interview is worth listening to, but here I want to comment on a specific statement that Kevin made that is scientifically inaccurate.
The entire interview (well worth listening too) is titled
Is climate change causing extreme weather? Experts disagree – click the listen button at http://www.cpr.org/news/story/climate-change-causing-extreme-weather-experts-disagree for the interview
In the discussion on added heat during droughts that is due to the increase of atmospheric CO2, Kevin Trenberth said
“You can add up how much of that heat there is and over a six month period it’s equivalent to running a very small microwave over every square foot at full power for about ½ hour”.
The interviewer [Ryan Warner] seemed to be impressed by this analog. The analog of a microwave is an effective image, but it is scientifically wrong for several reasons. Public Radio listeners and Mr. Warner were misled by this analog.
· First, the reduction of long wave radiation emitted to Space due to the added CO2 occurs over the six month time period, not in a short duration burst. Clearly, a short ½ burst of such heat would have a very different effect than when this heat is distributed across a six month time period.
· Second, the effect of long wave radiative flux divergence on surface temperatures from added CO2 (or other greenhouse gas including water vapor) is much larger at night. This is because during daylight, most of the time, vertical turbulent mixing dominates. The atmospheric boundary layer is typically much deeper during the daytime, so that added heat from the increase of CO2 is distributed through a much deeper depth. While the effect on nighttime minimum temperatures can be significant as we showed in our paper
McNider, R.T., G.J. Steeneveld, B. Holtslag, R. Pielke Sr, S. Mackaro, A. Pour Biazar, J.T. Walters, U.S. Nair, and J.R. Christy, 2012: Response and sensitivity of the nocturnal boundary layer over land to added longwave radiative forcing. J. Geophys. Res., 117, D14106, doi:10.1029/2012JD017578. Copyright (2012) American Geophysical Union. http://pielkeclimatesci.files.wordpress.com/2013/02/r-371.pdf
the effect on daytime maximum temperatures (and thus on increasing the heat stress in a drought) will be much less. Kevin did not properly inform the audience how the added heat would be processed differently during the day and night.
· Third, we examined this issue for a seasonal time scale in our paper
Eastman, J.L., M.B. Coughenour, and R.A. Pielke, 2001: The effects of CO2 and landscape change using a coupled plant and meteorological model. Global Change Biology, 7, 797-815 http://pielkeclimatesci.files.wordpress.com/2009/10/r-229.pdf
We concluded based on our model sensitivity runs that the radiative forcing effect of doubled atmospheric concentrations of CO2 on regional temperatures over a growing season are minimal (e.g. see Tables 8 and 9). This is especially true for daytime temperatures. Indeed, the biogeochemical effect on the regional weather from added CO2[which Kevin did not mention] was a much larger effect, as was land use change.
The ½ hour of added heat from the microwave forcing that Kevin presented, when properly input over the entire growing season would only result in a trivial effect on maximum temperature (ie. The hottest part of the day)!
Thus, while added CO2 and other human and natural climate forcings certainly can have an effect on large scale circulation features which could exacerbate droughts and fires, the analogy to a microwave that Kevin presented to convince the audience regarding the importance of added surface heating from the radiative effect of the increase of atmospheric CO2 is scientifically incorrect.
Indeed, when we perform model sensitivity experiments, we find that biogeochemical effect of added CO2 on plants (and the feedback to weather) and of land use change are much larger effects on this time and spatial scale.
My problem is that, for example, the Sahara desert can vary by 35C over a day. It will have just as much CO2 as elsewhere, and other GHGs. To say CO2 may affect this by a fraction of a degree seems meaningless. What is lacking is water, which is not a GHG.
I would say that the Sun and water on Earth [in all its’ forms] determines 99% of the climate, For example there is the 60 year cycle of warming and cooling caused by the Sun and the oceans, on top of a warming trend from 1800. So 1910-1940 [warming] 1940-1970 [flat/slight cooling] 1970-2000 [warming 2000-2030 [flat/ slight cooling].
This well established cycle is responsible for ‘the pause’ and it seems totally incredible that climate ‘scientists’ refuse to acknowledge it exists! Okay, I appreciate that 97% of climate ‘scientists’ realise they couldn’t get a job elsewhere if the money stopped flowing so they may be desperate to keep the meme going [although I suspect quite a few don’t have a clue about the real climate anyway!]
Could someone translate this into the number of atomic bombs per Manhattan so that we ordinary people can understand. While you are at it, how many cuddly polar bears will it kill?
Well I think Dr Kevin Trenberth’s 1/2 hour microwave goosing, is right on the mark; for him.
He after all is the one who thinks that the sun shines on the earth at 342 Watts per square meter, which doesn’t have a snowball’s chance in hell of heating the surface, even to the alleged mean global Temperature of 288 K, for which the black body total emittance is about 390 W/m^2.
Try 1366 W/m^2 Kevin, and a light will go on in your head, as to why tropical deserts can easily warm up to 60 deg. C in a few hours.
I add as a footnote, that WATTS is a unit of power, such as a RATE at which energy is supplied or processed, or in any other way accounted for. It is not the average of anything, it is instantaneous.
Tropical storm / hurricane Sandy really didn’t do much; on average, during its visit from Africa across the Atlantic ocean. It’s only if you cherry pick some data, while it was in the vicinity of some frail structures too near the US coast, that much of anything happened. And, if such things, can take down the coast itself, then why would one expect flimsy structures to survive.
If Kevin believed; as I do, that “climate” is the integral of weather, instead of the average of weather, then it would all be clear to him.
According to Kevin Trenberth’s CV he is a
“Nobel Laureate (shared) for Nobel Peace Prize 2007 (as part of IPCC)”
http://www.cgd.ucar.edu/staff/trenbert/cv.html
It doesn’t say much for a person who has to pretend to be a Nobel Laureate! Such a travesty! Someone should be fired!
So:
i) The effect of our emissions would be too small to notice compared to natural changes in energy flows.
ii) Any effect would be mostly or if not entirely cancelled by negative system responses.
iii) If there were any net effect it would result in air circulation changes which would be too small to measure compared to naturally induced variations from sun and oceans.
iv) The hydrological cycle is far more powerful than CO2 and helps to effect the negative system response (not the positive system response assumed by AGW theory).
The implication of all that is that the negative system responses, being able to work against the effects of non condensing GHGs such as CO2, must be working back towards a basic system energy content that is NOT significantly changed by those GHGs.
What sets that basic system energy content towards which the negative system responses always work back towards ?
If one excludes GHGs what is left ?
Ignoring an inconvenient truth never has stopped a true CAGW believer. In fact, as M. Mann demonstrated, covering up the truth is the preferred method.
The other misleading part of the microwave analogy is the we all know microwave radiation is dangerous to like. It cooks meat and vegetables. (See: woman puts poodle in microwave to dry it off)
LWIR is a lot less dangerous at an equivalent power density.
Why refer to “a microwave [oven]” instead of a simple electric oven. Because it’s intended that the listener will see it as dangerous.
Kevin Trenberth is well aware of basic physics, so that is further indication of his knowing intent to mislead the listener.
dangerous to _life_
Who comes up with these bizarre analogies like a microwave, or the ridiculous Hiroshima metric. I work in science everyday and analogies like these imply nothing to me. Do the general public really understand these meaningless comments, seriously?
It looks like they have changed there heading.
has changed to
See the old headline in Google cache
I meant
“It looks like they have changed their heading.”
We also saw this in spades during the last ~11,000 years of the Holocene. There was “persistent drought” in California lasting for over 200 years before AD 1300! I have many, many other examples of extreme climate change and mine are actually CLIMATE and not the weather. They made it very clear some years back that the weather is NOT THE SAME AS THE CLIMATE!
Like I said before they are getting so desperate they now point to weather events to back there climate getting worse because of man claims. Why is it that the great authority, the IPCC, does not come to such conclusions? How Trenberth ever made it to be an IPCC author is beyond me. This is sad to watch, the desperation.
hitting yourself on the head constantly with a mallet can be bad for you. To put it in context, it’s as bad as listening to Trenberth for half an hour every six months
Mike Tremblay says:
February 19, 2014 at 7:55 pm “When you start involving radiative forcing in …….are the main contributing factors to why deserts have such a variation between night and day temperatures.”
Thank you. I’ve been saying that for years. It’s the reason why Swamp Coolers worked well in Arizona but not to well in Florida.
For those, like Trenberth, who insist on seeing climate change in the weather here are many examples of floods, droughts, storms etc. from 1709 to 1989. As you may know there are plenty more between, and before those dates.
Show me the trends then show me it’s not caused by natural climate changes, then show me it’s not caused by land use changes, soot and other non-greenhouse gases then I might listen to the likes of Trenberth. This is the sceptical position I believe and very reasonable indeed.
Imagine a promoter of AGW misrepresenting the facts of the case in order to sell more fear. /sarc off
The consistent pattern of AGW opinion leaders misleading the public is a compelling insight into their quality of work.
@anticlimactic
Water is not a GHG but water vapour is. I think your post needs a couple of edits. A desert floor heats rapidly because there is little to block the incoming sunlight. At night it cools rapidly because if the low water vapour concentration overhead.
In a real desert like the Sahara, there are months when the sun cannot be clearly discerned because of the large amount of dust in the air, yet it gets quite hot anyway and still cools a lot. Water vapour is the most important insulator we have.
@timetochooseagain
“Seems to me like mankind’s real enemy is entropy.”
A friend of a friend used to consistently throw rocks uphill. When my friend asked why he did that, he replied, “I am staving off the heat death of the universe.”
True, that, in a philosophical way.
Where is the peer reviewed evidence showing a) it is happening, b) it’s caused or made ‘worse’ by man’s greenhouse gases? Is Trenberth now asking his fellow Warmists to break with IPCC findings / or lack thereof and believe his claims? Does he realise what he is actually saying here?
So the challenge from Trenberth is “ … can you prove there is not an effect?” Spoken like a true climate scientist, one who really understands the very essence of science.
From Hiroshima bombs to microwave ovens.. Next they’ll be using Google searches as an analogy – all fake and distracting anyway. All it has to do is make headlines as their religion rots around them.
Dr. Trenberth misuses the null hypothesis. He relies on magical explanations to find missing heat. He offers a filibuster to explain the pause. And now he needs to deceive us by way of microwaving the Earth for an analogy. A pattern seems to emerge…..
If the Earth’s surface was receiving EM radiation in the microwave spectrum or the gamma-ray/x-ray/infrared spectrum of nuclear explosions, then Trenberth’s analogy would be a good one.
Since the Earth’s surface sees extremely, extremely small amounts of this type of radiation emitted from deep space and absolutely none from CO2 in the atmosphere, then it is a very poor analogy.
If the Earth’s surface was receiving microwave radiation at 2,450 megahertz, the oceans wouldn’t be around very long. They would boil away in a short time and get even hotter in the atmosphere. Its how your microwave oven works.
Its like those shady salesmen who tell you that you’ll only be paying the equivalent of a cup of coffee a day or some analogy to create the illusion of not paying a lot. The reality when confronted by such spin is that you are being conned.
Can we call Trenberth a troll now?
At the end of the day, it matters not what Trenberth says because he’s a ‘CO2 man’ rather than a ‘solar man’. I think Trenberth needs to read “The Neglected Sun” (by Fritz Vahrenholt & Sebastian Luning) and learn about the solar cycles and effects that correlate nicely with weather and climate events. Truth is, people like Trenberth have always overly exaggerated the role of CO2 on weather and climate.