Global warming “deniers”: myth-conceptions abound
They’ve been compared to “flat earthers” and even “Holocaust deniers”. And, as the recent “Climategate” email scandal reveals, they have been blacklisted in certain professional circles. Scientists who disagree with the current consensus on Anthropogenic Global Warming (AGW) are dismissed by some colleagues and politicians as ignorant and irrelevant. Though there are certainly cranks out there who lend credence to this stereotype, not everyone who rejects the idea that global warming is a planetary crisis brought about by burning fossil fuels deserves to be vilified.
There are numerous myths surrounding those who are wrongly labeled “deniers”. Most of them can be distilled into six basic accusations:
1. “Deniers” believe the climate has not warmed.
No one questions that there has been a slight, but unmistakable increase in global temperature since the end of the “Little Ice Age” in the early nineteenth century. Global average surface temperature has risen approximately 0.9°C since 1850. But not all scientists attribute this change to the human addition of CO2 and other greenhouse gases to the air. Those who oppose the prevailing view on AGW point out that since temperatures began to increase well before CO2 levels were considered significant (c. 1940), a considerable part of this warming is due to natural variations in the climate. Such variations in the past have brought about abrupt climate changes with large swings in temperature.
Numerous articles have appeared in scientific journals over the last several years documenting a warm bias in official temperature measurements. This bias, which may account for up to half of the reported warming, is due largely to changes in land cover—especially the geographic expansion of cities which creates “urban heat islands.” An ongoing survey of over 1000 climate reporting stations in the United States, shows that 69% are poorly sited resulting in errors of 2°C to 5°C or more (www.surfacestations.org). Surface data has also been impaired from station dropout. Over two-thirds of the world’s stations were dropped from the climate network around 1990. Most of them were colder, high latitude and rural stations.
2. “Deniers” are not real scientists.
Some of the world’s foremost atmospheric scientists, physicists, astronomers, and geologists disagree with the current consensus on anthropogenic global warming. These include Richard Lindzen (Massachusetts Institute of Technology), Roger Pielke Sr. (University of Colorado), Roy Spencer and John Christy (University of Alabama), Willie Soon (Harvard-Smithsonian Center for Astrophysics), Robert Carter (James Cook University, Australia), Fred Singer (University of Virginia), Will Happer (Princeton University), and Nils-Axel Mörner (Stockholm University). In addition to these, there are hundreds of credentialed scientists at universities around the world who reject the hypothesis that CO2 induced warming dominates changes in earth’s climate system.
Though science is not based on authority, the inclusion of such high profile scientists should raise red flags when advocates claim that the “science is settled.”
3. “Deniers” are a tiny minority of scientists.
“Nay-sayers” are overshadowed by a vast majority of learned scientific bodies that support the consensus. But most scientific organizations, such as the American Meteorological Society, the American Physical Society, and the National Academies of Science, do not poll their members. Decisions and position statements are made by a small group of officials at the top of the organization. This has created sharp unrest within some professional societies.
The American Meteorological Society is a case in point. A recent survey of AMS broadcast meteorologists revealed that 50% of the respondents disagreed, and only 24% agreed, with the statement that, “Most of the warming since 1950 is very likely human-induced.” When asked if, “Global climate models are reliable in their projections for a warming of the planet,” only 19% agreed, while 62% disagreed (Bulletin of the American Meteorological Society, Oct. 2009).
As the number of those who oppose the consensus grows, it appears that the “deniers” are not a tiny minority as is often claimed.
4. “Deniers” are anti-environmental shills of Big Oil.
Only a small number of scientists who challenge the current consensus have direct ties to the fossil fuel industry. Most are funded by university departments, governments, or private institutions. Many receive no funding at all. Unfortunately, no amount of evidence can unseat the deeply held belief among some, that opposition to the AGW hypothesis is part of a conspiracy funded by big oil. The underlying fear is that any scientific research subsidized by big corporate money will be compromised.
But the blade cuts both ways. Climate research among those who espouse the prevailing view is supported by billions of dollars from government grants and green industries that have a vested interest in global warming. Why should research conducted or funded by environmental organizations and green energy be regarded as more reliable? Whether science is bought and sold by deep pockets, or made subservient to a political or philosophical ideology, the result is the same: Truth is compromised.
5. “Deniers” think CO2 is irrelevant.
The issue is not whether CO2 is irrelevant, but, rather, how relevant is it? The U.N.’s Intergovernmental Panel on Climate Change (IPCC) maintains that CO2 induced warming dominates the climate system. They project that increasing emissions will result in a 2°C to 6°C rise in global average temperature by the year 2100.
This has been widely misunderstood by the public to mean that energy absorbed and reradiated by atmospheric CO2 is the direct cause of the warming. In reality, the IPCC claims that CO2, acting alone, will result in only a 1.2°C rise in temperature. The rest depends on whether the climate amplifies (positive feedback) or diminishes (negative feedback) CO2 forcing.
This is where the real dispute lies. Climate “sensitivity” is based on numerous interactions that are poorly understood. Scientists who disagree with the IPCC’s conclusions are not contesting the fact that CO2 can cause atmospheric warming (.3°C according to more conservative estimates). They disagree with the science behind the water vapor feedback mechanisms that are said to amplify this warming on a global scale. The complex and chaotic processes underlying these mechanisms, especially as they relate to cloud formation and precipitation, exceed the limits of our knowledge. As a result, climate feedback is not simply the product of numerical calculations (“straightforward physics”) as is often supposed, but depends extensively on large scale estimates (parameterizations) by computer modelers.
“Deniers” demand empirical proof and are quick to point out that the water vapor feedback hypothesis is poorly supported by hard evidence, and even contradicted by the absence of warming in both the oceans and the atmosphere over the last several years. In fact, some scientists (Lindzen, Spencer, etc.) theorize that water vapor and cloud cover act like a thermostat (negative feedback) to maintain the earth’s temperature in approximate equilibrium.
6. “Deniers” believe humans have no impact on climate.
Scientists who challenge the status quo point out that we live in regional and local climates with vast differences in temperature and precipitation—differences that far outweigh changing global averages. Given these differences, the idea of “average global temperature” seems rather meaningless. More importantly, the human impact on climate is far greater at regional and local scales than it is on a global scale. These impacts include land use and land cover changes (e.g., deforestation, agriculture, urbanization) and aerosol pollution (e.g., soot, sulfur, reactive nitrogen, dust). Any one of these modifications can significantly alter temperature, evaporation, cloud cover, precipitation, and wind over a region—and perhaps beyond.
Though the global surface area of agricultural land alone is greater than the size of South America, the IPCC has largely ignored the influence of land cover and aerosols on regional climates. Moreover, climate models have shown no skill in projecting regional climate changes decades in advance.
But a wave of new research is forcing scientists to reevaluate the impact of these factors. Some have already concluded that the effect of CO2 has been overstated while regional changes in land use and aerosol pollution have been grossly underestimated. One recent study of U.S. climate has concluded that land use changes alone may account for 50% of the warming since 1950 (Environmental Science and Technology, December, 2009).
“Deniers” vs. the “Consensus”
Though “deniers” unanimously agree that CO2 is not the main driver of climate change, they represent a diversity of scientific viewpoints on issues of climate change, green energy, and the environment—perhaps a greater diversity than scientists who are in lock-step with the consensus. The Climategate scandal has exposed a concerted effort on the part of some IPCC scientists to enforce this consensus by denying access to crucial data and marginalizing anyone who questions the scientific basis of their conclusions. Stealthy tactics like this undermine scientific progress which depends on a robust exchange of information and ideas.
Skepticism is at the heart of the scientific method. So it is ironic that those who have challenged the prevailing orthodoxy are regarded as outcasts. Fortunately, science is not settled by popular vote or authority, but by empirical evidence. History has not always vindicated the majority view or justified the assumed authority of “official science.” Consequently, it may be the “deniers”, rather than their opponents, who have the last word on global warming.
Bill DiPuccio served as a weather forecaster and lab instructor for the U.S. Navy, and a Meteorological/Radiosonde Technician for the National Weather Service. More recently, he was the head of the science department for Orthodox Christian Schools of Northeast Ohio.