Monthly Archives: July 2010

Comment On The Denial of Petitions for Reconsideration of the Endangerment and Cause or Contribute Findings For Greenhouse Gases Under Section 202(a) Of The Clean Air Act”

There is a news release titled July 29, 2010 EPA Rejects Claims of Flawed Climate Science.

It is based on

Denial of Petitions for Reconsideration of the Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act

I am going to comment here on just one of the EPA findings in the rejection. In EPA Rejects Claims of Flawed Climate Science they write

“…the IPCC report… provided a comprehensive and balanced discussion of climate science.”

The EPA, however, in contrast to what they write,  chose to ignore the conclusion of such reports, peer reviewed papers, and testimony as

National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp.

Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell,  W. Rossow,  J. Schaake, J. Smith, S. Sorooshian,  and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union

Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229.

Pielke, R.A. Sr., 2008: A Broader View of the Role of Humans in the Climate System is Required In the Assessment of Costs and Benefits of Effective Climate Policy. Written Testimony for the Subcommittee on Energy and Air Quality of the Committee on Energy and Commerce Hearing “Climate Change: Costs of Inaction” – Honorable Rick Boucher, Chairman. June 26, 2008, Washington, DC., 52 pp.

as well as documentation of the deliberate successful attempt to exclude viewpoints in the CCSP and IPCC reports which differ from the EPA findings; e.g.

Pielke, R.A. Sr., 2005: Public Comment on CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences”. 88 pp including appendices.

The EPA claim that

“After months of serious consideration of the petitions and of the state of climate change science EPA finds no evidence to support these claims”

is absurd.

It is almost trivial to show that the EPA is not properly considering peer reviewed research that differs from their findings.

As just one example, they write

“The global warming trend over the past 100 years is confirmed by three separate records of surface temperature, all of which are confirmed by satellite data.”

There are not three independent records of surface temperatures trends as we reported in our Pielke et al 2007, i.e.

“The raw surface temperature data from which all of the different global surface temperature trend analyses are derived are essentially the same. The best estimate that has been reported is that 90–95% of the raw data in each of the analyses is the same (P. Jones, personal communication, 2003).

They also ignored  peer reviewed research that shows a discrepancy between the surface and lower tropospheric temperature trends; i.e.

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841.

This EPA Denial is yet another perpetuation of the group think that was so evident in the released CRU e-mails.

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An Excellent Paper That Focuses On The Vulenerabiltiy of Water Resources

There is an excellent paper that presents the much needed broader view of a bottom-up, resource-based vulnerability perspective (in this paper with respect to water resources) than the IPCC dominated literature which focuses on a top-down multi-decadal global climate model driven focus on impacts.

The paper is

Harou, J. J., J. Medellín‐Azuara, T. Zhu, S. K. Tanaka, J. R. Lund, S. Stine, M. A. Olivares, and M. W. Jenkins (2010), Economic consequences of optimized water management for a prolonged, severe drought in California, Water Resour. Res., 46, W05522, doi:10.1029/2008WR007681.

If abrupt climate change has occurred in the past and may be more likely under human forcing, it is relevant to look at the adaptability of current infrastructure systems to severe conditions of the recent past. Geologic evidence suggests two extreme droughts in California during the last few thousand years, each 120–200 years long, with mean annual streamflows 40%–60% of the historical mean. This study synthesized a 72 year drought with half of mean historical inflows using random sampling of historical dry years. One synthetic hydrological record is used, and sensitivity to different interpretations of the paleorecord is not evaluated. Economic effects and potential adaptation of California’s water supply system in 2020 to this drought is explored using a hydroeconomic optimization model. The model considers how California could respond to such an extreme drought using water trading and provides best‐case estimates of economic costs and effects on water operations and demands. Results illustrate the ability of extensive, intertied, and flexible water systems with heterogeneous water demands to respond to severe stress. The study follows a different approach to climate change impact studies, focusing on past climate changes from the paleorecord rather than downscaled general circulation model results to provide plausible hydrologic scenarios. Adaptations suggested for the sustained drought are similar for dry forms of climate warming in California and are expensive but not catastrophic for the overall economy but would impose severe burdens on the agricultural sector and environmental water uses.

This paper applies the emphasis that was presented in the post

The Vulnerability Perspective

where I wrote

There are 5 broad areas that we can use to define the need for vulnerability assessments : water, food, energy, health and ecosystem function. Each area has societally critical resources. The vulnerability concept requires the determination of the major threats to these resources from climate, but also from other social and environmental issues. After these threats are identified for each resource, then the relative risk from natural- and human-caused climate change (estimated from the GCM projections, but also the historical, paleo-record and worst case sequences of events) can be compared with other risks in order to adopt the optimal mitigation/adaptation strategy.

The Harou et al 2010 is an excellent example of this approach.

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Meeting Announcement – “AMS Annual Meeting: Land-Atmosphere Interactions And The Role Of HydroEcology On Climate

I have received an announcement of an upcoming meeting that examines the role of land surface processes within the climate system.  It reads

Call for papers: Land-Atmosphere Interactions and the Role of HydroEcology on Climate at AMS Annual Meeting, Seattle, Jan 23-27, 2011

We are pleased to announce that the American Meteorological Society’s annual meeting, held January 23-27 in Seattle, WA, USA, will include a session on Land-Atmosphere Interactions and the Role of HydroEcology on Climate as part of the 25th Conference on Hydrology. This session seeks contributions from the research and operational forecasting communities on recent advances in quantifying the role of land surface processes on atmospheric dynamics from short-range to interannual time scales and at spatial scales from plot studies to regional assessments. We are particularly interested in studies addressing the roles of complex terrain, vegetation, snow and soil moisture dynamics, as well as ecosystem disturbances, on model predictability or skill. Efforts that study one-way or two-way interactions through observational, modeling or reanalysis techniques, or their integration, are encouraged. This session will help advance our understanding of the importance of land surface properties and ecosystem disturbances on local to regional weather, hydrology and climate.

We have invited a number of speakers to offer invited talks. Dr. Ruby Leung from the Pacific Northwest National Laboratory will speak on land-atmosphere interactions within regional climate models.

We encourage you to submit an abstract by August 9, 2010 (The deadline of August 2 that is currently listed on the AMS abstract submission tool will be changed.).  For online abstract submission go to the AMS annual meetings page: http://www.ametsoc.org/MEET/annual, select “Submit Abstract”, and select the “25th Conference on Hydrology”.  A topic list will follow; select “Land-Atmosphere Interactions and the Role of HydroEcology on Climate “.  Submitting your abstract to this session assures that the session organizers will see it.

Speaking presentations are limited due to the tremendous array of topics covered at the Annual Meeting.  Therefore, please indicate during the online submission process if you would be willing to accept (or would prefer) a poster presentation.  We will do our best to accommodate all submissions, particularly those of our international participants.

There is a $90 USD abstract submission fee charged by AMS which must be paid at the time of submission.  Conference organizers are not allowed to accept submissions without advance payment.  For additional details, see the Call for Papers from the AMS annual meetings homepage.  You may also contact me or the other conveners if your questions are not answered by the online resources.

We appreciate your consideration of the meeting and hope that you can join us in Seattle!

Regards,

Enrique R. Vivoni, Arizona State University, vivoni@asu.edu
David J. Gochis, National Center for Atmospheric Research, gochis@ucar.edu
Jessica D. Lundquist, University of Washington, jdlund@u.washington.edu

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A Misleading News Report – “Northern Colorado Water Reserves Safe From Climate Change”

There is a misleading news article in the Fort Collins Coloradoan (h/t to Steve Geiger) that reads

Larimer County’s water supplies – and those of most of the state’s mountain counties – are at little risk of diminishing in the face of climate change because Northern Colorado could see more precipitation as the Earth warms, not less.

That conclusion was spelled out in a report issued Tuesday by California-based Tetra Tech and the Natural Resources Defense Council, which looked at climate change’s effects on water supplies across more than 1,500 counties nationwide.

Some of the most devastating effects on water supplies will be felt up and down the Great Plains, including Weld County and Denver, according to the report.

The authors of the report created a “Water Supply Sustainability Index,” which shows, county by county, the threats climate change pose to water supplies.

The report uses public water data and climate projections from the Intergovernmental Panel on Climate Change to show that 14 states face a high risk of having their water supplies diminish as temperatures rise and water demand exceeds availability by 2050.

Climate change might pose moderate to extreme risk to water supplies in Jackson, Mesa, Delta, Montrose, Montezuma, La Plata, Alamosa, Rio Grande, Moffat and Saguache counties in addition to those in the Eastern Plains, according to the report.

The study’s lead author, Tetra Tech principal engineer Sujoy Roy, said Tuesday that Colorado’s Eastern Plains are at high risk of seeing their water diminish by mid-century because of the region’s heavy use of groundwater, which could begin to dry up.

Groundwater use for agriculture in the Great Plains, Texas and the Southwest already exceeds water supply, according to the report.

Roy said a region’s risk of seeing its water supplies disappear with the advent of climate change depends on how much it relies on stored water during the summer. If water demand exceeds what’s falling from the sky or flowing down from the mountains, the higher the risk of diminishing water supplies.

Larimer County is expected to see more precipitation as temperatures rise, lowering the risk to the county’s water supplies, Roy said.

This article perpetuates the scientifically unsupported claim that there is skill in predicting regional climate decades into the future. Kevin Trenberth, one of the IPCC authors wrote in 2007 (Predictions of climate)

“However, the science is not done because we do not have reliable or regional predictions of climate.”

We need regional predictive if droughts decades into the future are going to be correctly forecast, as is claimed in this news article.  However, this level of forecast skill does not exist.

Policymakers are being lulled into a false sense of confidence that we understand where water resource threats exits and where they do not. The reality is that natural climate variations have produced multi-decadal droughts in the past (e.g. see) even without human intervention into the climate system.  The adoption of a bottom-up resource-based vulnerability perspective (see) is a much more robust approach for policymakers to apply than the use of the top-down IPCC predictions.

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“The Greenhouse Effect – Part II” by Ben Herman and Roger Pielke Sr.

Update #2 John Nielsen-Gamon has alerted us to more information on the Moon’s radiative temperature. John e-mailed

 I read your blog post on Greenhouse Part 2.  I also recently came across the Science of Doom web site; it seems to be of very high quality.  You might want to link to http://scienceofdoom.com/2010/06/03/lunar-madness-and-physics-basics/ [on] your post to direct the reader to further details on the radiative temperature of the Moon.

Update – corrected text (underlined) h/t to Gerald E. Quindry

We have received a further question on our post

“The Greenhouse Effect” by Ben Herman and Roger Pielke Sr.

The question is summarized by the following text

Anyway my question refers to the common example of taking away the atmosphere and observing a cold surface. But as I understand it, the mean daytime surface temperature on the moon is over 100 C, with no  greenhouse effect. The mean nighttime temp drops to -150 C. http://www.solarviews.com/eng/moon.htm

This is important to note, because encouraging a popular picture in which the presence of the atmosphere only warms the surface takes all the convection and fluid dynamics out of the discussion, and that’s where all the important complexities are.

Isn’t it more the case that the atmosphere both warms and cools the surface, depending on circumstances? The IR absorption of H2O and other GHG’s warms the surface relative to what it would otherwise be, but as the lunar case shows, convection and turbulent mixing cools the surface relative to what would happen without an atmosphere. Take away the atmosphere and you take away both warming and cooling mechanisms.

We have reproduced the substance of our follow up answer below.

Predicting the surface temperature indeed involves the interaction of the atmospheric and ocean turbulent sensible and latent fluxes, long- and short- wave radiative fluxes and interfacial fluxes between the surface and the atmosphere. I have been urging for years to move away from the surface temperature to characterize global warming and cooling (and replace with ocean heat content changes in Joules) because the surface temperature is such a limited sample of the heat content changes of the climate system as well as involving these complicated feedbacks.

 On the Moon, there is, of course, no atmosphere, so its surface temperature results from the difference between the surface long wave radiative emissions, the amount of solar radiation absorbed and reflected, and the conduction of heat into and out of the surface. The effect of the atmosphere on Earth is to mute the diurnal (and seasonal) temperature range as a result of the turbulent fluxes, and other effects (such as clouds and precipitation). These atmospheric effects, for example, result in lower daytime and higher nighttime temperatures from what they otherwise would be. I presume this is the cooling and warming effects that you refer to. However, even with these effects, the surface is clearly warmer than it would be without the CO2 and water vapor IR absorption bands.

But the reasons are that the atmosphere scatters back to space some sunlight, and takes up some of the surface heating through conduction, and mixes it it by convection and turbulence. Also, the relatively rapid rotation of the earth on its axis  does not permit the daytime side to reach equilibrium before it starts nighttime cooling. As a result, daytime temperatures on earth are cooler than they would be with no atmosphere, and warmer at night than with no atmosphere.

Of course, the Moon, with no atmosphere, still  has to have basically the same effective radiating temperature as does the Earth. This should be

[sigma *Tmd**4 + sigma* Tmn**4]/2 = sigma*Te**4  where Tmd is the daytime temperature of of the Moon, Tmn is the night time temperature of the Moon, and Te is the effective radiating temperature of the Earth.

The fact that the daytime time temperature is warmer than the Earth’s temp is simply a result of the fact that the Moon is not in an equilibrium state – it warms up during the daytime and cools down at night, just as does the Earth. However the warming during day and cooling at night must balance each other or the Moon ( and the Earth) would be steadily heating up or cooling down over time.  The daytime warming occurs because the outgoing IR cannot balance the absorbed solar during the day. The nighttime cooling occurs because the outgoing IR is greater than the non-existing solar at night. The existence of a partially absorbing atmosphere does, as you stated, keep days cooler and nights warmer.

Also, the length of a day on the Moon is 29.5 earth days, almost a full Earth month. Therefore the daylight side of the Moon heats due to solar radiation, for half a month. Then when it’s night, it cools for another half month. Thus the daytime and nighttime temperatures are much more extreme. There is no greenhouse effect on the Moon, of course, and if the Moon’s day was the same 24 hours as an Earth day, its day and night temperatures would not vary  as much but its  radiative equilibrium temperature would be the same.

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Three Papers On The Role Of Surface Landscape Albedo On Radiative Forcing

There are three interesting papers on the role of the land surface in human caused climate change (h/t to Anthony Watts’s post Cooler white roofs – no complaints there).  In this case, the focus is on urban albedo.

The importance of this paper is that if such a significant effect on radiative forcing can be achieved by altering the urban albedo, a much larger radiative effect also occurs with other land use/land cover change!

The papers are

1. Surabi Menon, Hashem Akbari, Sarith Mahanama, Igor Sednev and Ronnen Levinson, 2010: Radiative forcing and temperature response to changes in urban albedos and associated CO2 offsets. Environ. Res. Lett. 5 (January-March 2010) 014005 doi:10.1088/1748-9326/5/1/014005.

The abstract reads

“The two main forcings that can counteract to some extent the positive forcings from greenhouse gases from pre-industrial times to present day are the aerosol and related aerosol-cloud forcings, and the radiative response to changes in surface albedo. Here, we quantify the change in radiative forcing and land surface temperature that may be obtained by increasing the albedos of roofs and pavements in urban areas in temperate and tropical regions of the globe by 0.1. Using the catchment land surface model (the land model coupled to the GEOS-5 Atmospheric General Circulation Model), we quantify the change in the total outgoing (outgoing shortwave + longwave) radiation and land surface temperature to a 0.1 increase in urban albedos for all global land areas. The global average increase in the total outgoing radiation was 0.5 W m–2, and temperature decreased by ~ 0.008 K for an average 0.003 increase in surface albedo. These averages represent all global land areas where data were available from the land surface model used and are for the boreal summer (June–July–August). For the continental US the total outgoing radiation increased by 2.3 W m–2, and land surface temperature decreased by ~ 0.03 K for an average 0.01 increase in surface albedo. Based on these forcings, the expected emitted CO2 offset for a plausible 0.25 and 0.15 increase in albedos of roofs and pavements, respectively, for all global urban areas, was found to be ~ 57 Gt CO2. A more meaningful evaluation of the impacts of urban albedo increases on global climate and the expected CO2 offsets would require simulations which better characterize urban surfaces and represent the full annual cycle.”

2. Oleson,K. W., G. B. Bonan, and J. Feddema (2010), Effects of white roofs
on urban temperature in a global climate model,
Geophys. Res. Lett., 37, L03701, doi:10.1029/2009GL042194.

The abstract reads

“Increasing the albedo of urban surfaces has received attention as a strategy to mitigate urban heat islands. Here, the effects of globally installing white roofs are assessed using an urban canyon model coupled to a global climate model. Averaged over all urban areas, the annual mean heat island decreased by 33%. Urban daily maximum temperature decreased by 0.6 C and daily minimum temperature by 0.3 C. Spatial variability in the heat island response is caused by changes in absorbed solar radiation and specification of roof thermal admittance. At high latitudes in winter, the increase in roof albedo is less effective at reducing the heat island due to low incoming solar radiation, the high albedo of snow intercepted by roofs, and an increase in space heating that compensates for reduced solar heating. Global space heating increased more than air conditioning decreased, suggesting that end-use energy costs must be considered in evaluating the benefits of white roofs.”

3. The third paper is

Hashem Akbari, Surabi Menon and Arthur Rosenfeld, 2010: Global cooling: increasing world-wide urban albedos to offset CO2. Climatic Change DOI 10.1007/s10584-008-9515-9

The abstract reads

“Increasing urban albedo can reduce summertime temperatures, resulting in better air quality and savings from reduced air-conditioning costs. In addition, increasing urban albedo can result in less absorption of incoming solar radiation by the surface-troposphere system, countering to some extent the global scale effects of increasing greenhouse gas concentrations. Pavements and roofs typically constitute over 60% of urban surfaces (roof 20–25%, pavements about 40%). Using reflective materials, both roof and pavement albedos can be increased by about 0.25 and 0.15, respectively, resulting in a net albedo increase for urban areas of about 0.1. On a global basis, we estimate that increasing the world-wide albedos of urban roofs and paved surfaces will induce a negative radiative forcing on the earth equivalent to offsetting about 44 Gt of CO2 emissions. At ∼$25/tonne of CO2, a 44 Gt CO2 emission offset from changing the albedo of roofs and paved surfaces is worth about $1,100 billion. Furthermore, many studies have demonstrated reductions of more than 20% in cooling costs for buildings whose rooftop albedo has been increased from 10–20% to about 60% (in the US, potential savings exceed $1 billion per year). Our estimated CO2 offsets from albedo modifications are dependent on assumptions used in this study, but nevertheless demonstrate remarkable global cooling potentials that may be obtained from cooler roofs and pavements.”

The text of the third paper includes the text

“Equal-area sinusoidal projection of the 30-arc-sec urban extent mask indicates that of the Earth’s 149 million km2 of land area, 128 million km2 is rural and 3.5 million km2 is urban. The 3.5 million km2 of urban land represents 2.4% of global land area and 0.7% of global surface area. Most of the 17.5million km2of unclassified land lies in Antarctica (14 million km2) or Greenland (2.2 million km2). The GRUMP estimate of 2.4% is twice the estimate of 1.2%.1 Furthermore, the analysis from McGranahan et al. (2005) shows that the urban areas account for 2.8% of the land area.”

“Rose et al. (2003) have estimated the fractions of the roof and paved surface areas in four U.S. cities. The fraction of roof areas in these four cities varies from 20% for less dense cities to 25% for more dense cities. The fraction of paved surface areas varies from 29% to 44%.Many metropolitan urban areas around the world are less vegetated than typical U.S. cities. For this analysis, we consider an average area fraction of 25% and 35% for roof and paved surfaces, respectively.”

“The albedo of typical standard roofing materials ranges from 0.10–0.25; one can conservatively assume that the average albedo of existing roofs does not exceed 0.20. The albedo of these surfaces can be increased to about 0.55 to 0.60.”

“In our analysis, we have estimated that available urban surfaces for potential increase of their albedo are about 1% of the land surface of the earth.Any under or over-estimation in this estimate directly scales our results.”

“Using cool roofs and cool pavements in urban areas, on an average, can increase the albedo of urban areas by 0.1. We estimate that increasing the albedo of urban roofs and paved surfaces will induce a negative radiative forcing of 4.4×10−2 Wm−2 equivalent to offsetting 44 Gt of emitted CO2. A 44 Gt of emitted CO2 offset resulting from changing the albedo of roofs and paved surfaces is worth about $1,100 billion. Assuming a plausible growth rate of 1.5% in the world’s CO2- equivalent emission rate, we estimate that the 44 Gt CO2-equivalent offset potential for cool roofs and cool pavements would counteract the effect of the growth in CO2- equivalent emission rates for 11 years.”

Clearly, a message from their paper is that if a landscape albedo change of  +0.1 in urban areas, which cover ~1% of the Earth’s surface, has such a significant effect on the global radiative forcing, than a landscape albedo change of 10% of the Earth’s landscape by +0.01 would result in the same the radiative forcing effect.

As documented in Table 11-4 (page 408) in

Pielke, R.A., Sr., 2002: Mesoscale meteorological modeling. 2nd Edition, Academic Press, San Diego, CA, 676 pp.

albedo values for different landscapes are quite different. For example, a leaved deciduous forest has an albedo of about 0.20 while a cereal crop has an albedo of  about 0.25.  Thus the conversion of this type of forest for just 0.2% of the Earth’s surface would have the same radiative impact as the white roof conversion that is examined in the these papers.

Clearly, these papers provide much deserved recognition of the major role of the human management of landscape as a first order component in the climate system.

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Brian Hoskins Interview By The Economist

I was alerted to an interview of Brian Hoskins, Head of the Grantham Institute for Climate Change, in the post on Die Klimazwiebel titled

Brain Hoskins and Camilla Toulmin, drinking tea with The Economist

The interview is titled

Brian Hoskins on climate change

His candid comments on the ability of models and their limitations later in the interview, in response to excellent questioning by the Economist reporter, is quite informative.

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“The Greenhouse Effect” by Ben Herman and Roger Pielke Sr.

Post By Ben Herman and Roger A. Pielke Sr.

During the past several months there have been various, unpublished studies circulating around the blogosphere and elsewhere claiming that the “greenhouse effect” cannot warm the Earth’s atmosphere. We would like to briefly explain the arguments that have been put forth and why they are incorrect.  Two of the primary arguments that have been used are

  1. By virtue of the second law of  Thermodynamics, heat cannot be transferred from a colder to a warmer body, and
  2. Since solar energy is the basic source of all energy on Earth, if we do not change the amount of solar energy absorbed, we cannot change the effective radiating temperature of the Earth. 

Both of the above statements are certainly true, but as we will show, the so-called  “greenhouse theory” does not violate either of these two statements. (we use quotation marks around the  words “greenhouse theory” to indicate that while this terminology has been generally adopted to explain the predicted warming with the addition of absorbing gases into the atmosphere, the actual process is quite a bit different from how a greenhouse heats).

With regards to the violation of the second law, what actually happens when absorbing gases are added to the atmosphere is that the cooling is slowed down. Equilibrium with the incoming absorbed sunlight is maintained by the emission of infrared radiation to space. When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates. 

Going to the second statement above, it is true that in equilibrium, if the amount of solar energy absorbed is not changed, then the amount of IR energy escaping out of the top of the atmosphere also cannot change.  Therefore the effective radiating temperature of the atmosphere cannot change. But, the effective radiating temperature of the atmosphere is different from the vertical profile of temperature in the atmosphere. The effective radiating  temperature is that T that will give the proper value of upward IR radiation at the top of the atmosphere  such that it equals the solar radiation absorbed by the Earth-atmosphere system.

In other words, it is the temperature such that 4 pi x Sigma T4 equals pi Re2 Fso, where Re is the Earth’s radius, and Fso is the solar constant. Now, when we add more CO2, the absorption per unit distance increases, and this warms the atmosphere.  But the increased absorption also means that less radiation from lower, warmer levels of the atmosphere can escape to space. Thus, more of the escaping IR radiation originates from higher, cooler levels of the atmosphere. Thus, the same effective radiating temperature can exist, but the atmospheric column has warmed.

 These arguments, of course, do not take into account feedbacks which will  kick in as soon as a warming (or cooling) begins.

 The bottom line here is that when you add IR absorbing gases to the atmosphere, you slow down the loss of energy from the ground and the ground must warm up. The rest of the processes, including convection, conduction, feedbacks, etc. are too complicated to discuss here and are not completely understood anyway.  But the radiational forcing due to the addition of greenhouse gases must result in a warming contribution to the atmosphere. By itself, this will not result in a change of the effective radiation temperature of the atmosphere, but it will result in changes in the vertical profile of temperature.

The so-called “greenhouse effect” is real. The question is how much will this effect be, and this is not a simple question. There are also questions being raised as to the very sign of some of the larger feedbacks  to add to the confusion.  Our purpose here was to merely point out that the addition of absorbing gases into the atmosphere must result in warming, contrary to some research currently circulating that says to the contrary.

For those that might still question this conclusion, consider taking away the atmosphere from the Earth, but change nothing else,  i.e., keep the solar albedo the same (the lack of clouds would of course change this), and calculate the equilibrium temperature of the Earth’s surface. If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of  the atmosphere.

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Guest Post “Calculating Moist Enthalpy From Usual Meteorological Measurements By Francis Massen

Francis Massen, in response to the posts,

Comment On The Northeast Heat Wave

Further Information On The Role Of Water Vapor In Measuring Heat By Francis Massen

has graciously prepared a write up of how to compute the moist enthalpy of surface air. Francis websites include http://meteo.lcd.lu/; http://computarium.lcd.lu/; and http://bmb.lcd.lu/

Calculating Moist Enthalpy From Usual Meteorological Measurements By Francis Massen

Abstract: This short article shows how to compute the moist enthalpy from usual meteorological measurements of dry temperature, air pressure and relative humidity. The result is used to add a plot of moist air enthalpy to the other near-live graphs shown by meteoLCD, the meteorological station of the LCD, Diekirch, Luxembourg

1. Sensible heat of dry air

The sensible heat of dry air is defined as Ha = Cp*T [ref. 3] with Cp usually taken as 1.005 when Ha is given in [kJ/kg] and temperature T in [°C].

Here we will use for Cp the following expression, valid for temperatures higher than 0 °C and lower than 60 °C, as given by PADFIELD [ref.2]

Ha = 1.007*T – 0.026          0 °C < T < 60 °C                                                         [eq.1]

2. Heat content of water vapor at temperature T

The heat content of water vapor is the sum of the latent heat of vaporization and the sensible heat of water vapor:

Hv =  q*( L + 1.84*T) [ref. TET]                                                                               [eq.2]

Where L = heat of vaporization = 2501 kJ/kg at 0°C

and 1.84*T = sensible heat of water vapor in kJ/kg

The sensible heat term of eq.3 (1.84*T) is very often considered negligible and omitted. 

Note:L is a function of temperature, becoming slightly smaller with increasing T; for values between 0°C and 50°C one can use the linear interpolation L(T) = 2502 – 2.378*T computed by the author from a table with enthalpy values given by YHCHEN [ref.4]: The linear fit is excellent with R2 = 0.9998.

Combining eq.2 with L(T) gives:

Hv = q*(2502 – 0.538*T)    with Hv in kJ/kg and T in °C                [eq.3]

3. Total enthalpy of moist air

Total enthalpy of moist air is the sum of Ha and Hv:

H = Ha + Hv = (1.007*T -0.026) + q*(2502 – 0.538*T)                       [eq.4] 

with H in kJ/kg, T in °C and specific humidity q in kg/kg

The problem with this formula is that the specific humidity q is usually not measured by a standard meteorological equipment which commonly measures relative humidity.

4. Finding q from measured dry bulb temperature, relative humidity and atmospheric pressure

PIELKE [ref.3] and the AOMIP website [ref.1] give the following formula for the specific humidity q:

                                          [eq.5]

where ea = vapor pressure in [Pa] and pa = atmospheric pressure in [Pa].
Attention: pa is the true air pressure, not the barometric pressure reduced to sea level!

Dividing numerator and denominator by ea gives:

                                                               [eq.6]

Relative humidity is the fraction of water vapor pressure to saturated water vapor pressure, usually multiplied by 100 to give a percent value:

RH = 100* ea/esat  →  ea = RH/100*esat

There are many different formulas relating esat to temperature. We will use the expression given in AOMIP [ref.1] and valid up to 40°C:

       [eq.7]

with saturated water vapor pressure esat in [Pa] and temperature T in °C.

Equations 4, 6 and 7 contain only T, RH and pa, which are parameters measured by practically every standard weather station. Together they can be used to calculate the enthalpy of moist air by a single (albeit unwieldy) formula:

          [eq.8]

This expression is valid for temperatures 0°C < T < 40°C. Units: H[kJ/kg], T[°C], pa[Pa] 

5. A practical example

The author has used eq.8  in GNUPLOT to display near-live plots of the moist enthalpy at meteoLCD, Diekirch, Luxembourg (see http://meteo.lcd.lu/today_01.html). The following figure shows the situation for the week from 10 to 16th July 2010. Sensible heat is shown by the blue bottom curve; the difference between the upper red curve ( = moist enthalpy) and the blue curve corresponds to the latent heat.

Technisolve Software has a website with an online moist air calculator, which is very handy for a quick validation check of individual values: http://www.coolit.co.za/airstate/airmoistobject.htm

References

[1] AOMIP: Atmospheric Forcing Data – Humidity

http://efdl.cims.nyu.edu/project_aomip/forcing_data/atmosphere/humidity.html

[2] PADFIELD, Tim: Conservation Physics

 http://www.conservationphysics.org/atmcalc/atmoclc1.php

[3] PIELKE, Roger, Sr., WOLTER, Klaus: The July 2005 Denver Heat Wave: How unusual was it ?. National Weather Digest, vol.31, no. 1, July 2007

http://pielkeclimatesciencesci.files.wordpress.com/2009/10/r-313.pdf

[4] TET (The Engineering Toolbox)

http://www.engineeringtoolbox.com/enthalpy-moist-air-d_683.html

[5] YHCHEN: Calculation of Enthalpy Changes

www.ntut.edu.tw/~yhchen1/Chap.%2023.pdf

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Presentation In Golden Colorado July 22 2010 By Susan Solomon “Climate Change: A Challenge For Our Times”

I was alerted to a presentation by Susan Solomon tomorrow in Golden, Colorado (thanks to Mark Kutchenreiter for alerting us to this!).

The presentation is sponsored by CRES – Colorado Renewable Energy Society. The announcement reads

You Are Invited

CRES Membership Meeting & Webcast

DATE: Thursday, July 22
TIME: 7:00 p.m.
LOCATION: Jefferson Unitarian Church
14350 W. 32nd Avenue, Golden
Map & Location
FREE This Month Only!
There will be no cover charge at the July meeting. If you haven’t attended one of our events, this is the month to check us out!

A reception with drinks, light snacks, and networking will follow this meeting. This Meeting is Also Available Via Live Webcast! Click here for details and Instructions.

Climate Change: A Challenge for Our Times

Dr. Susan Solomon

Dr._Susan_Solomon

Our planet is warmer today than it was a century ago. Understanding how temperatures are increasing around the world, how ice is melting at the poles, and how rain is decreasing in key regions are among the critical issues attracting the attention of the public, scientists, and policymakers worldwide. Recent work has also shown that man made warming, that takes place due to increases in carbon dioxide concentration, is nearly irreversible for more than 1000 years after emissions stop. Human choices in the next several decades can be expected to have an enduring impact on our planet. Join us to discuss how our and why our climate is changing, some of its impacts on humans & natural systems, and how it is expected to change in the future.

Guest Speaker: Dr. Susan Solomon
Co-Chair of the Science Working Group I of the Intergovernmental Panel on Climate Change

Dr. Susan Solomon has altered the course of atmospheric research through her pioneering role in the international scientific community’s efforts to discover the cause of depleted atmospheric ozone in the Antarctic, known as the ozone “hole.” Her research has also helped institute a global ban on chemicals that destroy atmospheric ozone and threaten human health worldwide. (Read more on Dr. Susan Solomon)
CRES – Colorado Renewable Energy Society
www.CRES-Energy.org
Join Today!

Her presentation provides valuable insight into the perspective that will be reported in the next IPCC report. She, unfortunately, continues to perpetuate the view that the dominate human climate forcing is the radiative effect of human added carbon dioxide.  While I cannot attend her seminar, if anyone does, please ask her regarding the broader perspective that we present in our paper

 Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell,  W. Rossow,  J. Schaake, J. Smith, S. Sorooshian,  and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union.

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