There continues to be a lack of clarity as to the distinction between changes in the heat content of the climate system (global warming and cooling), and climate change, in the media and by the presidential candidates. There are erroneous views on the climate issue being presented.
As an example see the Washington Post article on August 19 2011 by Joel Achenbach and Juliet Eilperin titled
The article includes the text [highlight added]
“Four years ago in New Hampshire, campaigning for the Republican presidential nomination, John McCain said to voters, “I do agree with the majority of scientific opinion, that climate change is taking place and it’s a result of human activity, which generates greenhouse gases.” He made global warming a key element of every New Hampshire stump speech.
This week in New Hampshire, the governor of Texas and newest presidential contender, Rick Perry, said scientists have manipulated data to support their “unproven” theory of human-influenced global warming. He said increasing numbers of scientists have disavowed the theory altogether.”
The text of their article contains this statement [which is accurate but seriously incomplete]
“McCain’s 2007 description remains the scientific consensus: Human activity, including the burning of fossil fuels, is pumping carbon dioxide and other greenhouse gases into the atmosphere and warming the planet.”
Michael Bachman is quoted as
Rep. Michele Bachmann (R-Minn.), who suggested Wednesday that “manufactured science” underpins what a questioner called the “man-made climate-change myth.”
Other candidates are stated as
The nominal GOP front-runner, Mitt Romney, drew sharp fire from conservatives when he said in June that he accepts the scientific view that the planet is getting warmer and that humans are part of the reason. Former Utah governor Jon Huntsman Jr. (R) on Thursday tweeted: “To be clear. I believe in evolution and trust scientists on global warming. Call me crazy.”
There is a fundamental misconception in some of the views of the candidates. There are correct statements, such as from Mitt Romney that “the planet is getting warmer and that humans are part of the reason”, except the warming has halted in recent years (e..g. see Figure 7). John McCain is correct that “Human activity, including the burning of fossil fuels, is pumping carbon dioxide and other greenhouse gases into the atmosphere and warming the planet” since added greenhouse gases exert a radiative warming effect. However, he stops there and ignores the diversity of other human climate forcings which affect global warming and cooling, and more broadly, human caused climate variability and change.
However, the fault really lies with certain members of the climate science community who are misrepresenting the distinction between global warming and climate change. The article contains such a misrepresentation in the text
“The full impact of the greenhouse gases that we’ve already added to the system today won’t be felt for 20 or 30 years,” said Bill Chameides, dean of the Nicholas School of the Environment at Duke University and co-author of a recent National Academy of Sciences report, “America’s Climate Choices.”
When Chameides and his colleagues began their research in 2008, they assumed they’d have to rush to finish before the government took action on climate change. Instead, they watched the political landscape change as “Climategate” and other controversies incited public doubts about climate science. They delayed their report to take a fresh look at the research in its totality.
Their conclusion is stated in the report’s first sentence: “Climate change is occurring, is very likely caused by human activities, and poses significant risks for a broad range of human and natural systems.”
Bill Chameides, however, uses the term “climate change” when he really means global warming! His view, and that of several of the candidates, is that the addition of CO2 and a few other greenhouse gases is the dominant human climate forcing such that it is the dominate driver of climate change.”
However, in our article
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
and in the books
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.
Kabat, P., Claussen, M., Dirmeyer, P.A., J.H.C. Gash, L. Bravo de Guenni, M. Meybeck, R.A. Pielke Sr., C.J. Vorosmarty, R.W.A. Hutjes, and S. Lutkemeier, Editors, 2004: Vegetation, water, humans and the climate: A new perspective on an interactive system. Springer, Berlin, Global Change – The IGBP Series, 566 pp.
Cotton, W.R. and R.A. Pielke, 2007: Human impacts on weather and climate, Cambridge University Press, 330 pp.
it is shown that the role of humans in the climate system is much more than CO2 and a few other greenhouse gases, and, indeed the other human climate forcings may be more important (e.g. see with respect to the spatial gradient of radiative aerosols).
To clarify this issue and to correct the erroneous presentation of what is global warming and what is climate change, I have reposted below
This post reads
As discussed often in my posts; e.g.
there is lack of clarity in how these terms are defined……I offer the following short definitions:
Global Warming is an increase in the global annual average heat content measured in Joules.
Climate Change is any multi-decadal or longer alteration in one or more physical, chemical and/or biological components of the climate system.
The figure below (from NRC, 2005) schematically illustrates the Earth’s climate system
Thus climate change includes, for example, changes in fauna and flora, snow cover, etc which persists for decades and longer. Climate variability can then be defined as changes which occur on shorter time periods.
Global warming involves the accumulation of heat in Joules within these components of the climate system, which is predominantly the oceans, as shown in Table 1 in Levitis et al 2001. The current use of the global average annual surface temperature trend to diagnose global warming involves only the two dimensional land, cryosphere and ocean surface.
As I wrote in
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.
“Unlike temperature at some specific depth in the ocean or height in the atmosphere, where there is a time lag in the response to radiative forcing, no time lags are associated with heat changes, since the actual amount of heat present at any time is accounted for. Moreover, because the surface temperature is a massless two-dimensional global field while heat content involves mass, the use of surface temperature as a monitor of climate change is not accurate for evaluating heat storage changes. “
My recommendation is that the next IPCC assessment adopt these definitions for global warming and climate change.
The media and presidential candidates also need to be better educated that global warming is just a subset of climate variability and change. They also need to be informed of recent research that documents a large role of natural climate variability and longer term change, including with respect to global warming and cooling (e.g. see).