Monthly Archives: June 2007

Error In The Economist On Their Coverage Of Climate Issues

The Economist is an excellent publication. However, as I have communicated before on Climate Science, it is occasionally inaccurate in its coverage. This occurs very clearly in the June 23rd-27th issue in an otherwise very good article.

The article is “Arnie’s uphill climb” and the error is in their insert “Where smog comes from”. The data that they present is “California’s greenhouse-gas emissions by end-use sector, 2004%”.

However, it is incorrect to refer to “greenhouse-gas” as “smog”! As defined by the American Meteorological Society’s Glossary of Meteorology, the definition is

“smog—As originally coined in 1905 by Des Voeux: a natural fog contaminated by industrial pollutants, a mixture of smoke and fog. Today, it is the common term applied to problematical, largely urban, air pollution, with or without the natural fog; however, some visible manifestation is almost always implied. Smogs are constituted in great variety, but a major dichotomy exists between the photochemical smogs of nitrogen oxides and hydrocarbons emitted mainly by automobile engines and, on the other hand, the sulfur-laden, sometimes deadly, smogs produced by the large-scale combustion of fuel oil and coal. Both types contain carbon monoxide, carbon dioxide, and a variety of particulates. See Los Angeles (photochemical) smog, London (sulfurous) smog.”

It is unclear if the author of this figure unintentionally used the wrong word, or if it was used to draw a greater attention to the figure. It either case, it is an error.

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More On The Suppresion Of Climate Change Views

There is an Online NewsHour interview entitled

“Oregon Global Warming Skeptic Finds Controversy”

with the header

“Oregon state climatologist George Taylor does not believe that global warming is due to human activity. Now, Oregon Gov. Ted Kulongoski wants him to stop using the state climatologist title. NewsHour correspondent Lee Hochberg reports from Oregon and Washington on the controversy.”

It is worth listening to (or reading the transcript) as it shows how politicians are seeking to usurp the ability of scientists to present the diversity of views on climate (thanks to Jim Angel to alerting us to it). George Young is certainly well qualified as a climatologist (he was President of the American Association of State Climatologists for two years and has been the state of Oregon NOAA recognized State Climatologist for years.

Whether one agrees or not with Mr. Taylor (or the other climatologists whose voices are being stifled), this is an inappropriate politicalization of climate science to promote a particular view.

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Important New Paper On The Urban Effect On Temperature And Other Climate Metrics

There is an important new paper that has appeared which adds significantly to the understanding of the role of urban areas within the climate system.. The paper is

Jin Menglin, J. Marshall Shepherd and Christa Peters-Lidard, 2007: Development of a parameterization for simulating the urban temperature hazard using satellite observations in climate model, Nat Hazards DOI 10.1007/s11069-007-9117-2 [subscription required].

The abstract reads,

“Abstract Urban surface temperature is hazardously higher than surrounding regions (so-called urban heat island effect UHI). Accurately simulating urbanization-induced temperature hazard is critical for realistically representing urban regions in the land surface- atmosphere climate system. However, inclusion of urban landscapes in regional or global climate models has been overlooked due to the coarse spatial resolution of these models as well as the lack of observations for urban physical properties. Recently, National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) observations illustrate important urban physical properties, including skin temperature, surface albedo, surface emissivity, and leaf area index, It is possible to identify the unique urban features globally and thus simulate global urban processes. An urban scheme is designed to represent the urban-modified physical parameters (albedo, emissivity, land cover, roughness length, thermal and hydraulic properties) and to include new, unique physical processes that exist in urban regions. The urban scheme is coupled with National Center for Atmospheric Research (NCAR) Community Land Model Version 2 (CLM2) and single column coupled NCAR Community Atmosphere Model CAM2/CLM2 to assess the mechanisms responsible for UHI. There are two-steps in our model development. First, satellite observations of albedo, emissivity, LAI, and in situ observed thermal properties are updated in CLM2 to represent the first-order urban effects. Second, new terms representing the urban anthropogenic heat flux, storage heat flux, and roughness length are calculated in the model. Model simulations suggest that human activity-induced surface temperature hazard results in overlying atmosphere instability and convective rainfall, which may enhance the possibility of urban flood hazard.”

Excerpts read,

“More importantly, although a single urban region may not result in a large impact on global climate, the collective impact of all urban regions on the global climate system is as yet unknown and unstudied. Jin et al. (2005a) show that zonal mean UHI has 1–3 degree warming over the Northern Hemisphere latitudes, implying that the collective UHI may be a significant contributing factor in the overall global warming signal.”


“The current urban scheme does not include potentially important urban land-atmosphere feedbacks, in particular, urban aerosols’ impacts on surface insolation and aerosol-cloud rainfall interactions over urban regions. Therefore, the presented urban impacts are limited to those resulting from changes in the urban surface only. Future model development on coupled urban land-atmosphere interactions is essential for fully understanding the extent of urban impacts.”

The role of urban areas within the climate system is yet another human climate effect whose role was minimized in the 2007 IPCC WG1 Report.

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New Paper On Exceptional European Heat – Another Example of Cherrypicking

There is a new paper that has just appeared that discusses the recent warm period in Europe in 2006 and 2007. It provides an excellent summary of an extreme weather event (and thanks to Juerg Luterbacher for sending to me!)

However, part of this paper is yet another example of following the IPCC policy, discussed yesterday, of ignoring inconvenient other peer reviewed research.

The paper is

Luterbacher, J., M. A. Liniger, A. Menzel, N. Estrella, P. M. Della-Marta, C. Pfister, T. Rutishauser, and E. Xoplaki (2007), Exceptional European warmth of autumn 2006 and winter 2007: Historical context, the underlying dynamics, and its phenological impacts, Geophys. Res. Lett., 34, L12704, doi:10.1029/2007GL029951. .

The abstract reads,

“Updated European averaged autumn and winter surface air temperature (SAT) timeseries indicate that the autumn 2006 and winter 2007 were extremely likely (>95%) the warmest for more than 500 years. In both seasons, the European SAT anomaly is widespread with anomalies up to three standard deviations from normal. The anomalous warmth is associated with strong anticyclonic conditions and warm air advection from south west. Phenological impacts related to this warmth included some plant species having a partial second flowering or extended flowering till the beginning of winter. Species that typically flower in early spring were found to have a distinct earlier flowering after winter 2007.”

An excerpt from the conclusions reads,

“As SAT [ seasonal surface air temperature] anomalies are expected to increase up to 5 (3) SD from 1961–1990 in autumn (winter) at the end of the 21st century [Scherrer et al., 2007], the AU06 and WI07 warmth discussed in this study may be seen as typical representation of upcoming climate change at continental scale.”

This paper, however, fails to recognize that regional predictive skill has not been shown on any multidecadal (or even yearly time scale) (e.g. see), nor whether in a global context, the warm period is unusual; see

Chase, T.N., K. Wolter, R.A. Pielke Sr., and Ichtiaque Rasool, 2006: Was the 2003 European summer heat wave unusual in a global context? Geophys. Res. Lett., 33, L23709, doi:10.1029/2006GL027470,

where we concluded

“We place the European summer heat wave of 2003 in the context of other extreme summer tropospheric temperature events from 22 N to 80 N since 1979, as well as globally using annual averages. The analysis is performed in terms of standard deviations (SD) exceeded and correlations between regional extremes and temperatures at larger spatial scales. As has been pointed out previously the heat wave was statistically unusual and was a deep tropospheric phenomenon. In this analysis we also find the following. (1) Extreme warm anomalies equally, or more, unusual than the 2003 heat wave occur regularly. (2) Extreme cold anomalies also occur regularly and occasionally exceed the magnitude of the 2003 warm anomaly in terms of the value of SD. (3) There is a correlation between global and hemispheric average temperature and the presence of warm or cold regional anomalies of the same sign (i.e., warmer than average years have more regional heat waves and colder than average years have more cold waves). (4) Natural variability in the form of El Nino and volcanic eruptions appear to be of much greater importance in causing extreme regional temperature anomalies than a simple upward trend in time. Extreme temperature anomalies in the wake of the1997–98 El Nino were larger than the anomalies seen in summer 2003 both in area affected and SD extremes exceeded. (5) Regression analyses do not provide strong support for the idea that regional heat waves are increasing with time.”

The Luterbacher et al paper also ignored the paper,

Fischer E. M., S. I. Seneviratne, D. Lüthi, C. Schär (2007), Contribution of land-atmosphere coupling to recent European summer heat waves, Geophys. Res. Lett., 34, L06707, doi:10.1029/2006GL029068. [see also].

That the Luterbacher et al paper chose to ignore these peer reviewed studies is another clear example of ignoring published work that raises questions about their conclusions. These papers should have been discussed even if the authors have reasons to refute them. They should have placed this recent very warm period in Europe in a global context if they are going to assert that this is the type of weather that should become routine in the coming decades.

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Documentation Of IPCC WG1 Bias by Roger A. Pielke Sr. and Dallas Staley – Part I

The 2007 Intergovernmental Panel on Climate Change (IPCC) Reports have the following stated goals:

“A comprehensive and rigourous picture of the global present state of knowledge of climate change”


“The Intergovernmental Panel on Climate Change (IPCC) has been established by WMO and UNEP to assess scientific, technical and socio-economic information relevant for the understanding of climate change, its potential impacts and options for adaptation and mitigation.”

However, the IPCC WG 1 Chapter 3 report failed in this goal.

This weblog illustrates this defect using the example of their assessment of the multi-decadal land near-surface temperature trend data, where peer reviewed papers that conflicted with the robustness of the surface air temperature trends are ignored. Later Climate Science weblogs will document this issue with other climate issues.

Readers of Climate Science are invited to present other important peer reviewed papers that were available to the IPCC that were ignored in their assessment as further evidence to document IPCC bias.

To evaluate the IPCC’s claim to be comprehensive, we cross-compared IPCC WG1 references on near-surface air temperature trends with the peer-reviewed citations that have been given in Climate Science. We selected only papers that appeared before about May 2006 so they were readily available to the IPCC Lead authors.

The comparison follows where the bold faced citations are in the IPCC WG1 Report:


Chase, T.N., R.A. Pielke Sr., J.A. Knaff, T.G.F. Kittel, and J.L. Eastman, 2000: A comparison of regional trends in 1979-1997 depth-averaged tropospheric temperatures. Int. J. Climatology, 20, 503-518.

Davey, C.A., and R.A. Pielke Sr., 2005: Microclimate exposures of surface-based weather stations – implications for the assessment of long-term temperature trends. Bull. Amer. Meteor. Soc., Vol. 86, No. 4, 497–504.

Davey, C.A., R.A. Pielke Sr., and K.P. Gallo, 2006: Differences between near-surface equivalent temperature and temperature trends for the eastern United States – Equivalent temperature as an alternative measure of heat content. Global and Planetary Change, 54, 19–32.

de Laat, A.T.J. and A.N. Maurellis, 2006: Evidence for influence of anthropogenic surface processes on lower tropospheric and surface temperature trends. International Journal of Climatology, 26, 897-913.

González, J. E., J. C. Luvall, D. Rickman, D. E. Comarazamy, A. J. Picón, E. W. Harmsen, H. Parsiani, N. Ramírez, R. Vázquez, R. Williams, R. B. Waide, and C. A. Tepley, 2005: Urban heat islands developing in coastal tropical cities. Eos Trans. AGU, 86(42), 397.

Hale, R.C., K.P. Gallo, T.W. Owen, and T.R. Loveland, 2006: Land use/land cover change effects on temperature trends at U.S. Climate Normals Stations. Geophys. Res. Lett., 33, doi:10.1029/2006GL026358.

Hanamean, J.R. Jr., R.A. Pielke Sr., C.L. Castro, D.S. Ojima, B.C. Reed, and Z. Gao, 2003: Vegetation impacts on maximum and minimum temperatures in northeast Colorado. Meteorological Applications, 10, 203-215.

Hansen, J., R. Ruedy, J. Glascoe, and Mki. Sato, 1999: GISS analysis of surface temperature change. J. Geophys. Res. 104, 30997-31022, doi:10.1029/1999JD900835.

Hansen, J.E., R. Ruedy, Mki. Sato, M. Imhoff, W. Lawrence, D. Easterling, T. Peterson, and T. Karl, 2001: A closer look at United States and global surface temperature change. J. Geophys. Res. 106, 23947-23963, doi:10.1029/2001JD000354.

Hansen, J., L. Nazarenko, R. Ruedy, Mki. Sato, J. Willis, A. Del Genio, D. Koch, A. Lacis, K. Lo, S. Menon, T. Novakov, Ju. Perlwitz, G. Russell, G.A. Schmidt, and N. Tausnev, 2005: Earth’s energy imbalance: Confirmation and implications. Science 308, 1431-1435, doi:10.1126/science.1110252.

Hansen, J., Mki. Sato, R. Ruedy, L. Nazarenko, A. Lacis, G.A. Schmidt, G. Russell, I. Aleinov, M. Bauer, S. Bauer, N. Bell, B. Cairns, V. Canuto, M. Chandler, Y. Cheng, A. Del Genio, G. Faluvegi, E. Fleming, A. Friend, T. Hall, C. Jackman, M. Kelley, N. Kiang, D. Koch, J. Lean, J. Lerner, K. Lo, S. Menon, R. Miller, P. Minnis, T. Novakov, V. Oinas, Ja. Perlwitz, Ju. Perlwitz, D. Rind, A. Romanou, D. Shindell, P. Stone, S. Sun, N. Tausnev, D. Thresher, B. Wielicki, T. Wong, M. Yao, and S. Zhang 2005. Efficacy of climate forcings. J. Geophys. Res. 110, D18104, doi:10.1029/2005JD005776.

Hansen, J., M. Sato, R. Ruedy, K. Lo, D.W. Lea, and M. Medina-Elizade, 2006: Global temperature change. PNAS, 103, 14288 – 14293.

He, J. F., J. Y. Liu, D. F. Zhuang, W. Zhang, and M. L. Liu 2007: Assessing the effect of land use/land cover change on the change of urban heat island intensity Theor. Appl. Climatol., DOI 10.1007/s00704-006-0273-1

Holder, C., R. Boyles, A. Syed, D. Niyogi, and S. Raman, 2006: Comparison of Collocated Automated (NCECONet) and Manual (COOP) Climate Observations in North Carolina. J. Atmos. Oceanic Technol., 23, 671–682.

Huang Y., R. E. Dickinson and W. L. Chameides, 2006: Impact of aerosol indirect effect on surface temperature over East Asia. Proc. Natl. Acad. Sci., 103, 4371-4376, doi: 10.1073/pnas.0504428103.

Hubbard, K.G., and X. Lin, 2006: Reexamination of instrument change effects in the U.S. Historical Climatology Network. Geophys. Res. Lett., 33, L15710, doi:10.1029/2006GL027069.

Jones, P.D., and A. Moberg. 2003: Hemispheric and large-scale surface air temperature variations: An extensive revision and an update to 2001. J. Climate 16, 206-223.

Kalnay E., and M. Cai, 2003a: Impact of urbanization and land-use change on climate. Nature, 423, 528-531;

Kalnay, E. and M. Cai, 2003b: Impact of urbanization and land-use change on climate – Corrigenda. Nature, 425, 102.

Kalnay, E., M. Cai, H. Li, and J. Tobin, 2006: Estimation of the impact of land-surface forcings on temperature trends in eastern United States J. Geophys. Res., Vol. 111, No. D6, D06106.

Karl, T.R., S.J. Hassol, C.D. Miller, and W.L. Murray, Eds., 2006: Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences. A Report by the Climate Change Science Program and the Subcommittee on Global Change Research, Washington, DC.

Lim, Y.K., M. Cai, E. Kalnay, and L. Zhou, 2005: Observational evidence of sensitivity of surface climate changes to land types and urbanization. Geophys. Res. Lett., Vol. 32, No. 22, L2271210.1029/2005GL024267.

Mahmood, R., S.A. Foster, and D. Logan, 2006: The GeoProfile metadata, exposure of instruments, and measurement bias in climatic record revisited. Int. J. Climatology, 26(8), 1091-1124.

Parker, D.E., 2004: Large-scale warming is not urban. Nature, 432, 290, doi:10.1038/432290a;

Peterson, T.C., 2003: Assessment of urban versus rural in situ surface temperatures in the contiguous United States: No difference found. J. Climate, 16, 2941–2959.

Peterson, T.C., 2006. Examination of potential biases in air temperature caused by poor station locations. Bull. Amer. Meteor. Soc., 87, 1073-1089.

Peterson, T.C. and R.S. Vose, 1997: An overview of the Global Historical Climatology Network temperature data base. Bull. Amer. Meteor. Soc., 78, 2837-2849,

Peterson, T.C., D.R. Easterling, T.R. Karl, P. Ya. Groisman, N. Nicholls, N. Plummer, S. Torok, I. Auer, R. Boehm, D. Gullett, L. Vincent, R. Heino, H. Tuomenvirta, O. Mestre, T. Szentimre, J. Salinger, E. Førland, I. Hanssen-Bauer, H. Alexandersson, P. Jones, D. Parker, 1998: Homogeneity adjustments of in situ atmospheric climate data: A review. Int. J. Climatology, 18, 1493-1517.

Robeson, S.M., 2004: Trends in time-varying percentiles of daily minimum and maximum temperature over North America. Geophys. Res. Letts., 31, L04203, doi:10.1029/2003GL019019.

Runnalls, K.E. and T.R. Oke, 2006: A technique to detect microclimatic inhomogeneities in historical records of screen-level air temperature. J. Climate, 19, 959-978

Schmidt, G.A., R. Ruedy, J.E. Hansen, I. Aleinov, N. Bell, M. Bauer, S. Bauer, B. Cairns, V. Canuto, Y. Cheng, A. Del Genio, G. Faluvegi, A.D. Friend, T.M. Hall, Y. Hu, M. Kelley, N.Y. Kiang, D. Koch, A.A. Lacis, J. Lerner, K.K. Lo, R.L. Miller, L. Nazarenko, V. Oinas, Ja. Perlwitz, Ju. Perlwitz, D. Rind, A. Romanou, G.L. Russell, Mki. Sato, D.T. Shindell, P.H. Stone, S. Sun, N. Tausnev, D. Thresher, and M.-S. Yao, 2006: Present day atmospheric simulations using GISS ModelE: Comparison to in-situ, satellite and reanalysis data. J. Climate, 19, 153-192,

Trenberth, K.E., 2004: Rural land-use change and climate. Nature, 427, 213, doi:10.1038/427213a. doi:10.1175/JCLI3612.1.

Vose, R.S., T.R. Karl, D.R. Easterling, C.N. Williams, and M.J. Menne, 2004: Impact of land-use change on climate. Nature, 427, 213-21

Vose, R., D.R. Easterling, and B. Gleason, 2005: Maximum and minimum temperature trends for the globe: An update through 2004. Geophys. Res. Letts.,. 32, L23822, doi:10.1029/2005GL024379

Vose, R.S., D.R. Easterling, T.R. Karl, and M. Helfert, 2005: Comments on “Microclimate Exposures of Surface-Based Weather Stationsâ€?. Bull. Amer. Meteor. Soc., 86, 504–506.

Zhou, L., R.E. Dickinson , Y. Tian, J. Fang , Q. Li , R.K. Kaufmann, C.J. Tucker, and R.B. Myneni, 2004: Evidence for a significant urbanization effect on climate in China. PNAS, 101, 9540-9544.

If the papers were neglected because they were redundant, this would be no problem. However, they are ignored specifically because they conflict with the assessment that is presented in the IPCC WG1 Report, and the Lead Authors do not agree with that perspective!

That is hardly honoring the IPCC commitment to provide

“A comprehensive and rigourous picture of the global present state of knowledge of climate change”.

Moreover, the conflict of interest that was identified in the CCSP Report “”Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences” is perpetuated in the IPCC WG1 Chapter 3 Report [where the Editor of this CCSP Report, Tom Karl, is also Review Editor for the Chapter 3 of the 2007 IPCC WG1 Report].

These comments were made with respect to this CCSP Report

“The process for completing the CCSP Report excluded valid scientific perspectives under the charge of the Committee. The Editor of the Report systematically excluded a range of views on the issue of understanding and reconciling lower atmospheric temperature trends. The Executive Summary of the CCSP Report ignores critical scientific issues and makes unbalanced conclusions concerning our current understanding of temperature trendsâ€?.

“Future assessment Committees need to appoint members with a diversity of views and who do not have a significant conflict of interest with respect to their own work. Such Committees should be chaired by individuals committed to the presentation of a diversity of perspectives and unwilling to engage in strong-arm tactics to enforce a narrow perspective. Any such committee should be charged with summarizing all relevant literature, even if inconvenient, or which presents a view not held by certain members of the Committee.”

The IPCC WG1 Chapter 3 Report process made the same mistakes and failed to provide an objective assessment. Indeed the selection of papers to present in the IPCC (as well as how the work of others that was cited was dismissed) had a clear conflict of interest as the following individuals cited their research prominently yet were also a Review Editor (Tom Karl), works for the Review Editor (Tom Peterson, Russ Vose, David Easterling), were Coordinating Lead Authors (Kevin Trenberth and Phil Jones), were Lead Authors (Dave Easterling and David Parker), or a Contributing Author (Russ Vose).

In fact, as stated above, the CCSP Report “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences“, with its documented bias, was chaired by the same person as the Review Editor of the IPCC WG1 Chapter 3 Report (Tom Karl)! Regardless of his professional expertise, he is still overseeing an assessment which is evaluating his own research. There cannot be a clearer conflict of interest.

The IPCC WG1 Chapter 3 Report clearly cherrypicked information on the robustness of the land near-surface air temperature to bolster their advocacy of a particular perspective on the role of humans within the climate system. As a result, policymakers and the public have been given a false (or at best an incomplete) assessment of the multi-decadal global average near-surface air temperature trends.

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A New Paper That Highlights the First-Order Radiative Forcing Of Black Carbon Deposition

A 2005 National Research Council Report, Climate Science, and our research studies have summarized studies that show that black carbon deposition on snow and sea ice is a major positive radiative forcing; e.g. see

Page 38 in

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.

What Fraction of Global Warming is Due to the Radiative Forcing of Increased Atmospheric Concentrations of CO2?

-Strack, J., R.A. Pielke Sr., and G. Liston, 2007: Arctic tundra shrub invasion and soot deposition: Consequences for spring snowmelt and near-surface air temperatures. J. Geophys. Res., accepted.

There is a new paper that provides further evidence on the major role of black carbon deposition on snow and sea ice as a positive radiative forcing.

The paper is

Flanner, M. G., C. S. Zender, J. T. Randerson, and P. J. Rasch (2007), Present-day climate forcing and response from black carbon in snow, J. Geophys. Res., 112, D11202, doi:10.1029/2006JD008003.

The paper was also reported in the media by Henry Fountain with the headline Warming in the Arctic? Blame the Snow. The Dirty Snow, That Is.

The abstract of the Flanner et al paper reads,

We apply our Snow, Ice, and Aerosol Radiative (SNICAR) model, coupled to a general circulation model with prognostic carbon aerosol transport, to improve understanding of climate forcing and response from black carbon (BC) in snow. Building on two previous studies, we account for interannually varying biomass burning BC emissions, snow aging, and aerosol scavenging by snow meltwater. We assess uncertainty in forcing estimates from these factors, as well as BC optical properties and snow cover fraction. BC emissions are the largest source of uncertainty, followed by snow aging. The rate of snow aging determines snowpack effective radius (re), which directly controls snow reflectance and the magnitude of albedo change caused by BC. For a reasonable re range, reflectance reduction from BC varies threefold. Inefficient meltwater scavenging keeps hydrophobic impurities near the surface during melt and enhances forcing. Applying biomass burning BC emission inventories for a strong (1998) and weak (2001) boreal fire year, we estimate global annual mean BC/snow surface radiative forcing from all sources (fossil fuel, biofuel, and biomass burning) of +0.054 (0.007–0.13) and +0.049 (0.007–0.12) W m-2, respectively. Snow forcing from only fossil fuel + biofuel sources is +0.043 W m-2 (forcing from only fossil fuels is +0.033 W m-2), suggesting that the anthropogenic contribution to total forcing is at least 80%. The 1998 global land and sea-ice snowpack absorbed 0.60 and 0.23 W m-2, respectively, because of direct BC/snow forcing. The forcing is maximum coincidentally with snowmelt onset, triggering strong snow-albedo feedback in local springtime. Consequently, the ‘‘efficacy’’ of BC/snow forcing is more than three times greater than forcing by CO2. The 1998 and 2001 land snowmelt rates north of 50 N are 28% and 19% greater in the month preceding maximum melt of control simulations without BC in snow. With climate feedbacks, global annual mean 2-meter air temperature warms 0.15 and 0.10 C, when BC is included in snow, whereas annual arctic warming is 1.61 and 0.50 C. Stronger high latitude climate response in 1998 than 2001 is at least partially caused by boreal fires, which account for nearly all of the 35% biomass burning contribution to 1998 arctic forcing. Efficacy was anomalously large in this experiment, however, and more research is required to elucidate the role of boreal fires, which we suggest have maximum arctic BC/snow forcing potential during April–June. Model BC concentrations in snow agree reasonably well (r = 0.78) with a set of 23 observations from various locations, spanning nearly 4 orders of magnitude. We predict concentrations in excess of 1000 ng g-1 for snow in northeast China, enough to lower snow albedo by more than 0.13. The greatest instantaneous forcing is over the Tibetan Plateau, exceeding 20 W m 2 in some places during spring. These results indicate that snow darkening is an important component of carbon aerosol climate forcing.”

Excerpts from the paper read,

“Global annual mean equilibrium warming resulting from the inclusion of BC in snow is 0.15 and 0.10 C for 1998 and 2001 central experiments, respectively. Annual arctic (66.5–90 N) warming, however, is 1.61 and 0.50 C. Arctic annual mean surface albedo for these two experiments is reduced by 0.047 and 0.017, relative to their control simulations without BC in snow. The 1998 and 2001 land snowmelt rates north of 50 N are 28% and 19% greater in the month preceding maximum melt of control simulations.”

“BC in snowpack can provoke disproportionately large springtime climate response because the forcing tends to coincide with the onset of snowmelt, thus triggering more rapid snow ablation and snow-albedo feedback. The model and methods we develop here could be applied to study snow forcing by other aerosols, including mineral dust, volcanic ash, brown carbon, and marine sediment in sea-ice [Light et al., 1998].”

In terms of the global radiative forcings, the fraction of attribution of observed warming to the radiative forcing of the well-mixed greenhouse gases is reduced by this large radiative forcing by black carbon, as Climate Science has been reporting; e.g. see slide 12 in

Pielke, R.A. Sr., 2006: Regional and Global Climate Forcings. Presented at the Conference on the Earth’s Radiative Energy Budget Related to SORCE, San Juan Islands, Washington, September 20-22, 2006.

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Comment on the Nature Weblog By Kevin Trenberth Entitled “Predictions of climate”

Our research has led us to conclude that

1. Climate prediction is an initial value problem; e.g. see

Pielke, R.A., 1998: Climate prediction as an initial value problem. Bull. Amer. Meteor. Soc., 79, 2743-2746


2. Multi-decadal skillful regional climate prediction is not yet been achieved; e.g see

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

There is a remarkable weblog on Nature from an unexpected source that supports these views. The weblog is presented by one of the Lead Authors of Chapter 3 the IPCC WG1 report [Kevin Trenberth] and is in direct conflict with statements that climate science is settled.

The Trenberth weblog reads’

Predictions of climate
Posted by Oliver Morton on behalf of Kevin E. Trenberth

I have often seen references to predictions of future climate by the Intergovernmental Panel on Climate Change (IPCC), presumably through the IPCC assessments (the various chapters in the recently completed Working Group I Fourth Assessment report ican be accessed through this listing). In fact, since the last report it is also often stated that the science is settled or done and now is the time for action.

In fact there are no predictions by IPCC at all. And there never have been. The IPCC instead proffers “what ifâ€? projections of future climate that correspond to certain emissions scenarios. There are a number of assumptions that go into these emissions scenarios. They are intended to cover a range of possible self consistent “story linesâ€? that then provide decision makers with information about which paths might be more desirable. But they do not consider many things like the recovery of the ozone layer, for instance, or observed trends in forcing agents. There is no estimate, even probabilistically, as to the likelihood of any emissions scenario and no best guess.

Even if there were, the projections are based on model results that provide differences of the future climate relative to that today. None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate. In particular, the state of the oceans, sea ice, and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models. There is neither an El Niño sequence nor any Pacific Decadal Oscillation that replicates the recent past; yet these are critical modes of variability that affect Pacific rim countries and beyond. The Atlantic Multidecadal Oscillation, that may depend on the thermohaline circulation and thus ocean currents in the Atlantic, is not set up to match today’s state, but it is a critical component of the Atlantic hurricanes and it undoubtedly affects forecasts for the next decade from Brazil to Europe. Moreover, the starting climate state in several of the models may depart significantly from the real climate owing to model errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialized.

The current projection method works to the extent it does because it utilizes differences from one time to another and the main model bias and systematic errors are thereby subtracted out. This assumes linearity. It works for global forced variations, but it can not work for many aspects of climate, especially those related to the water cycle. For instance, if the current state is one of drought then it is unlikely to get drier, but unrealistic model states and model biases can easily violate such constraints and project drier conditions. Of course one can initialize a climate model, but a biased model will immediately drift back to the model climate and the predicted trends will then be wrong. Therefore the problem of overcoming this shortcoming, and facing up to initializing climate models means not only obtaining sufficient reliable observations of all aspects of the climate system, but also overcoming model biases. So this is a major challenge.

The IPCC report makes it clear that there is a substantial future commitment to further climate change even if we could stabilize atmospheric concentrations of greenhouse gases. And the commitment is even greater given that the best we can realistically hope for in the near term is to perhaps stabilize emissions, which means increases in concentrations of long-lived greenhouse gases indefinitely into the future. Thus future climate change is guaranteed.

So if the science is settled, then what are we planning for and adapting to? A consensus has emerged that “warming of the climate system is unequivocalâ€? to quote the 2007 IPCC Fourth Assessment Working Group I Summary for Policy Makers (pdf) and the science is convincing that humans are the cause. Hence mitigation of the problem: stopping or slowing greenhouse gas emissions into the atmosphere is essential. The science is clear in this respect.

However, the science is not done because we do not have reliable or regional predictions of climate. But we need them. Indeed it is an imperative! So the science is just beginning. Beginning, that is, to face up to the challenge of building a climate information system that tracks the current climate and the agents of change, that initializes models and makes predictions, and that provides useful climate information on many time scales regionally and tailored to many sectoral needs.

We will adapt to climate change. The question is whether it will be planned or not? How disruptive and how much loss of life will there be because we did not adequately plan for the climate changes that are already occurring?

Kevin Trenberth
Climate Analysis Section, NCAR”

This is remarkable since the following statements are made

1. “In fact there are no predictions by IPCC at all. And there never have been.”

2. “None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate.”

3. “Moreover, the starting climate state in several of the models may depart significantly from the real climate owing to model errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialized.”

4. “The current projection method works to the extent it does because it utilizes differences from one time to another and the main model bias and systematic errors are thereby subtracted out. This assumes linearity. It works for global forced variations, but it can not work for many aspects of climate, especially those related to the water cycle.”

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

Kevin Trenberth’s weblog confirms what has been repeatedly emphasized on Climate Science that no regional predictive skill for decades into the futrue has been achieved (e.g. see).

Moreover, since the global variations and trends involve a summation of the regional variations and trends, Trenberth’s claim that the linearity works for global forced variations is more of a convenient assumption to justify his statements at the end of his weblog.

Except for his statement about the linearity of the climate on the global scale, Trenberth’s conclusion supports the main conclusions of Climate Science that

-The needed focus for the study of climate change and variability is on the regional and local scales. Global and zonally-averaged climate metrics would only be important to the extent that they provide useful information on these space scales.

-Global and zonally-averaged surface temperature trend assessments, besides having major difficulties in terms of how this metric is diagnosed and analyzed, do not provide significant information on climate change and variability on the regional and local scales.

-In terms of climate change and variability on the regional and local scale, the IPCC Reports, the CCSP Report on surface and tropospheric temperature trends, and the U.S. National Assessment have overstated the role of the radiative effect of the anthropogenic increase of CO2 relative to the role of the diversity of other human climate climate forcing on global warming, and more generally, on climate variability and change.

-Global and regional climate models have not demonstrated skill at predicting regional and local climate change and variability on multi-decadal time scales.

Policymakers should be made aware of this very significant admission by one of the Lead IPCC authors on the limitations of the IPCC report.

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