Monthly Archives: March 2008

Roger A. Pielke Sr.’s Perspective On The Role Of Humans In Climate Change

There continues to be misunderstandings on my viewpoint on the role of humans within the climate system. This weblog is written to make sure it is clear, and can be used whenever someone asks the question as to where does Pielke Sr. stand on this issue.

 As I have written in the Main Conclusions of Climate Science

“Humans are significantly altering the global climate, but in a variety of diverse ways beyond the radiative effect of carbon dioxide. The IPCC assessments have been too conservative in recognizing the importance of these human climate forcings as they alter regional and global climate.”

and that

“Attempts to significantly influence regional and local-scale climate based on controlling CO2 emissions alone is an inadequate policy for this purpose.”

These conclusions are different from those who claim that the global average radiative effect of carbon dioxide is by far the major human climate forcing, as well as from those who conclude that natural climate variations dominate climate change and that the human climate forcings are inconsequential.

My viewpoint is also well articulated 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

and you are encouraged to read the Executive Summary of that report [a report which whas been ignored by the media despite its broad base of authorship and its extensive review before it was published].

The reason that those who focus on the global average radiative forcing of carbon dioxide are missing the bulk of human climate forcings include the following:

1. Atmosphere and ocean circulations respond to regional forcings not a global average (e.g., see and see)

2. The other human climate forcings include

  • the diverse influence of human-caused aerosols on regional (and global)  radiative heating (e.g., see).
  • the effect of aerosols on cloud and precipitation processes (e.g., see)
  • the influence of aerosol deposition on climate (e.g., see and see)
  • the effect of land cover/land use on climate (e.g., see and  see)
  • the biogeochemical effect of added atmosopheric CO2 has a greater effect on the climate system than the radiative effect of added CO2 (e.g. see).

Natural climate variations and change, have also been underestimated (and are only poorly understood) based on examination of the historical and paleo-climate record (e.g., see and see).

Human climate forcings have a more significant role in altering the weather than does a global average increase in the radiative effect of an increase in the atmospheric concentration of CO2.  This does not mean that we should not work to limit the increase of this gas in the atmosphere, but it is not the dominant climate forcing that affects society and the environment.

Policies that focus on CO2 by itself are ignoring definitive research results (such as reported in the 2005 National Research Council report) that humans have a much broader influence on the climate system than was communicated in the 2007 IPCC report.  To neglect these other climate forcings represents a failure by policymakers (and the media) to utilize this scientifically robust information.

The neglect of including the diversity of human climate forcings indicates that the real objective of those promoting the radiative effect of the addition of atmospheric CO2 as the dominant human climate forcing is to promote energy and lifestyle changes. Their actual goal is not to develop effective climate policies. 

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Filed under Climate Science Misconceptions, Climate Science Reporting, RA Pielke Sr. Position Statements

A Short Tutorial On Global Warming

 Climate Science (and other weblogs) have posted detailed information on the issues associated with different methods to assess global climate system heat changes. Readers can access examples of these posts on Climate Audit, Watts Up With That, Hall of Record, ICECAP and The Blackboard.

 This current Climate Science weblog is intended to just summarize the issue as there are still individuals who perpeturate the claim that measuring near surface air temperature at irregularly spaced observation sites around the globe can accurately diagnose global warming.

As repeatedly emphasized on Climate Science, the use of surface air temperature is not a measure of climate system heat since it has almost no mass associated with it. Heat of the climate system requires that temperature change (and heat associated with the phase of water) ocurr over mass.  The relation of a change in global climate system heat change is dominated by ocean heat changes, as succincty summarized in Table 1 of

Levitus, S., J.I. Antonov, J. Wang, T.L. Delworth, K.W. Dixon, and A.J. Broccoli, 2001: Anthropogenic warming of Earth’s climate system. Science, 292, 267-269

where they write

“Our analysis of components of Earth’s heat balance quantitatively demonstrates that during the latter half of the 20th century, changes in ocean heat content dominate the changes in Earth’s heat balance.”

This heat change can be expressed as

ΔH = CΔT * Mass of the ocean where C is the specific heat capacity of sea water in units of Joules per degree per kilogram, T is temperature and M is the mass of the ocean in kilograms.

 Thus if  ΔH > 0, there is global warming.

No where is there a need to use a global average surface temperature trend to diagnose global warming, and, in fact, its use is misleading since there is an inconsequential amount of mass of the climate system involved.  Over the oceans, the sea surface temperatures are correlated with the upper ocean heat content, but over land there are a variety of serious problems with its use as reported in the paper

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.

Climate Science (and others; e.g. see) have been reporting on the shortcomings of the use of the global average surface average temperature trend to diagnose global warming, but this poor metric continues to be used by those advocating for particular policy actions on climate (e.g. see its inadequate and incomplete explanation in Wikipedia).

However, using the actual robust metric of global warming, ΔH, there has been none since 2004 (e.g. see), at least in the upper 700m of the ocean.

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Filed under Climate Change Metrics

Reality Check On Antarctic Sea Ice

The news reports on the breaking off of a portion of floating ice in Antarctica have received wide distribution (i.e. do a google search under news for Antarctic sea ice and hundreds of reports appear on this event). These news reports claim that this breaking is due to global warming. As just one example of the statements in the news, The Guardian wrote 

 “The collapsing shelf suggests that climate change could be forcing change much more quickly than scientists had predicted.

“The ice shelf is hanging by a thread,” said Professor David Vaughan of the British Antarctic Survey (BAS). “We’ll know in the next few days or weeks what its fate will be.”

The Wilkins shelf covers an area of 5,600 square miles (14,500 sq km). It is now protected by just a thin thread of ice between two islands.

Vaughan was a member of the team that predicted in 1993 that global warming could cause the Wilkins shelf to collapse within 30 years.”

This media reporting has become typical of the bias that many journalists have. Not reported in the media (but well reported on ICECAP by Joe D’Aleo)  the media has ignored in their reporting the increase in Antarctic sea ice cover in recent years, with, at present, a coverage that is well over 1 million square kilometers above average (see)!

In fact, over the globe, since the Arctic sea ice cover is not far below its average and the Antarctic sea ice coverage is well above average for this time of the year, the global coverage of sea ice is actually above average after being below last year (see). There is no way to know if this is just a short term perturbation, but at the very least the news media should have been honest and balanced in their coverage.

Unfortunately, it appears that most journalists just parrot the perspective of the first news release on these climate issues, without doing any further investigation. If this is inadvertent, they need to be educated in climate science. If deliberate bias, they are clearly advocates and the reporters should be clearly and publically identified as having such a bias. In either case, the public is being misinformed!

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Filed under Climate Science Misconceptions, Climate Science Reporting

Interesting Weblog On Hall Of Record Entitled “What is Normal”

There is an informative post on the website Hall of Record entitled “What is Normal”.  I recommend Climate Science readers read the contributions on that weblog on this subject.

With respect to the term “normal, there is an issue as to what it means in climate science.  In climate, “normal” is actually used to mean “average”, but it is misleading since a temperature that is above average is not abnormal unless it exceeds a threshold of deviation.

 We discuss this issue in our paper

 Pielke, R.A. and N. Waage, 1987: A definition of normal weather. Natl. Wea. Dig., 12, 20-22.

The abstract reads

“This paper clarifies the distinction between abnormal weather, and above and below average weather, using standard statistical analyses. Abnormal maximum and minimum temperatures are defined as requiring at least two standard deviations from the mean; otherwise even though they could be above or below average, the weather is still “normal”.  July and January maximum and minimum temperatures for Denver, New York, Los Angeles, Miami and Bismarck are presented as examples of this analysis.”

Thus when the media or weather broadcasters state that the maximum (or minimum)  temperature for a particular day is “above normal”, unless it is a large (e.g.  greater than 2 sigma) deviation from the average maximum (or minimum) temperature, it is not really above normal. 

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Filed under Climate Change Metrics

Meeting Announcement: AAWE Workshop in Vail August 20-22 2008

There will be a Workshop of the American Association of Wind Engineers on August 20-22 2008 in Vail Colorado. The meeting information can be found at AAWE Conferences. This is a world class organization and those who are working on this topc or otherwise interested in attending will find much of value. This organization is an essential player in the development of wind as an alternate energy source.

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Filed under Climate Science Meetings

Follow Up On News Article “Global Warming Rushes Timing Of Spring”

Richard Berler of the Laredo Morning Times has a very good follow up to the post on Climate Science in the post Comments On The News Article by Seth Borenstein entitled “Global Warming Rushes Timing of Spring”.  His article is titled “Global warming not always at fault” and can be found towards the bottom of the page. It is worth reading.

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A Proposed Test Suite for Atmospheric Model Dynamical Cores

There is an excellent proposal entitled  A Proposed Test Suite for Atmospheric Model Dynamical Cores by Christaine Jablonowski of the University of Michigan which Climate Science was alerted to from a February 3 2008 weblog on Climate Audit.

The idea for this test is described as

   “Tests of atmospheric General Circulation Models (GCMs) and, in particular, tests of their dynamical cores are important steps towards future model improvements. They reveal the influence of an individual model design on climate and weather simulations and indicate whether the circulation is described representatively by the numerical approach.
      Testing a global 3D atmospheric model is not straightforward. In the absence of non-trivial analytic solutions, the model evaluations most commonly rely on intuition, experience and model intercomparisons. In addition, GCM simulation statistics are typically compared to global reanalysis data while numerical weather forecasts are compared to local observations. Such approaches are not applicable to pure dynamical core assessments that isolate the dynamics package from the physical parameterizations. In general, three different sets of equations are most commonly used in dynamical cores. These include the hydrostatic primitive equations as well as the non-hydrostatic shallow-atmosphere and non-hydrostatic deep-atmosphere equation sets. As modeling groups now move towards the next generation of dynamical cores a standard test suite for hydrostatic and non-hydrostatic dynamics packages on the sphere if highly desirable. This webpage contributes to this effort. It suggests a collection of dynamical core test cases with varying complexity.”

Such evaluations of the global models used to make multi-decadal climate predictions are long overdue. In the paper

Pielke, R.A., 1991: Overlooked scientific issues in assessing hypothesized greenhouse gas warming. Environ. Software, 6, 100-107, I wrote

“The horizontal grid spacing of general circulation models is around 400 km. As shown by Pielke [the first edition of Pielke, 2002], as least four grid increments are required to reasonably represent an atmospheric feature, thus this grid resolution would only permit features 1600 km or larger to be reasonably represented in the models, Since extratropical cyclones often are observed to have horizontal wavelengths as small as 500 km or so, they are poorly represented in these models, Since these features provide the major physical mechanism for the exchange of heat, moisture, and momentum between the subtropics and the polar regions, the inability of GCM representations to adequately represent these exchanges is a serious shortcoming. Tropical cyclones, which also provide an important mechanism for exchanges between the tropics and higher latitude is even more poorly represented since its scales of important physical processes includes the eye wall which can be tens of kilometers in radial size.”

and

“Upwelling of deep, cold ocean waters occurs at a number of locations around the world including the equatorial Pacific, around Antarctica, and off the west coast of North America, northern South America, northwest Africa, southwest Africa, and elsewhere. Caused by the direction and speed of the wind at the ocean surface, these upwelled regions of cold surface waters usually have an extent in one spatial direction of 50km or so. Since atmosphere-ocean GCMs have spatial resolutions on the order of 400km, these important sinks for carbon dioxide are ignored.”

The test of the dynamical core fits into these evaluations and assessment of the global climate models as prediction tools. As a necessary condition, when configured to run in a multi-decadal predictive mode they should still be used to make short-term global weather predictions in order to asses their skill at simulating the development and movement of major high and low pressure systems, including tropical cyclones. Moreover, they should be run as seasonal weather predictions using inserted sea surface temperatures at the initial time in order to see if they can skillfully predict the development of El Nino and La Nina events, as well as other circulation patterns such as the North Atlantic Oscillation. If they cannot accurately predict these short term and seasonal weather patterns, they should not believed as valid and societally useful prediction tools on the regional (and even the global average) scale decades into the future.

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Filed under Climate Models