By Willie Soon, Robert Carter and David Legates

This is a response to “Why Can’t We Innovate Our Way To A Carbon-Free Energy Future?”, a “Perspective” by Bjorn Lomborg that ran in this space a week ago.

Bjorn Lomborg, author of “The Skeptical Environmentalist” and “Cool It,” is right about the need to focus on critical health and economic priorities. But he is wrong about human carbon dioxide emissions causing what is now being called “global climate disruption.”

By demonizing the gas of life, in league with Al Gore and Bill Gates, Lomborg commits several serious scientific errors. As independent scientists, with broad training in mathematics, physics, chemistry, geology and geography, we know CO2 is not a pollutant, and the notion of “carbon-free” or “zero-carbon” energy is inherently harmful and anti-scientific.

If nitrogen, oxygen, hydrogen, helium or any other nontoxic gas is pumped into a chamber containing air and a growing plant, the response is barely measurable. By contrast, if more CO2 is added, the plant and its root system benefit enormously, displaying enhanced growth and more efficient use of available water and nutrients.

Far from having detrimental effects, carbon dioxide has decidedly beneficial impacts on plants, aquatic and terrestrial alike, and a new study connects enhanced plant productivity to greater bird species diversity in China. How, therefore, can anyone conclude that human carbon dioxide is a pollutant that must be eradicated?

These facts erect a formidable barrier for “zero-carbon” advocates. By insisting that no human CO2 should be emitted, they are promoting continued suboptimal growth of food plant species in the face of impending global food shortages — and poorer functioning and less diversity in the global ecosystem.

Zero-carbon activists respond to these facts by asserting that human CO2 emissions cause “dangerous global warming.” They are wrong about this, too.

If rising atmospheric CO2 levels drive global temperatures upward, as they insist, why is Earth not suffering from the dangerous “fever” that Al Gore predicted? Instead, after mild warming at the end of the twentieth century, global temperatures have leveled off for the past decade, amid steadily rising carbon dioxide levels.

Lomborg’s claim that we need to “cure” so-called “unchecked climate change” is thus fallacious and contradicted by reality. Reducing human CO2 emissions will likely have no measurable cooling effect on planetary temperatures.

His insistence that we prioritize expenditures is spot-on when applied to genuine environmental and societal problems. However, it is irrelevant when the problems are mythical - or devised to advance ideological agendas. Moreover, even if human impacts on the global climate can actually be measured at some future date, humans currently lack the scientific and engineering understanding and capability to deliberately “manage” Earth’s constantly changing climate for the better.

Most certain of all, atmospheric carbon dioxide is not the “climate control knob” that anti-hydrocarbon alarmists assert, and it is irresponsible for Lomborg to claim his socio-political agenda will provide a low-cost solution for the global warming “problem.”

The scientific reality is that even the United Nations Intergovernmental Panel on Climate Change has been unable to demonstrate a cause-and-effect scientific connection between rising human CO2 emissions and dangerous warming. To support global limits on CO2 emissions, in the absence of real-world data showing clear cause and effect, is scientific and policy incompetence on the highest order.

Imagine a drug company seeking FDA approval for a new drug, based on an analysis that says simply: “Our supercomputers say the drug is safe and effective. We have no clinical data to support this, but can think of no reason actual results would contradict what our computers predict. Moreover, failure to license the drug will be disastrous for patients suffering from the targeted disease.” Failing to demand actual dose-and-response studies, before licensing the drug, would be gross negligence on FDA’s part.

Between 2007 and 2009, U.S. carbon dioxide emissions dropped approximately 10%, to their lowest level since 1995, largely because of reduced energy consumption during the recession. Similar CO2 emission reductions occurred in Britain, Germany, France and Japan.

Have their climates gotten better or less dangerous? Are they now a better place, for having a lower intensity carbon energy diet? Have global temperatures been statistically unchanged since 1995 because, or in spite of, Chinese and Indian carbon dioxide emissions increasing far more than the aforementioned countries reduced theirs?

These are practical, not rhetorical questions. As far as we can see, the only direct effect of decreasing CO2 levels via expensive renewable energy programs has been to cost more American and European jobs than would otherwise have been the case during the global economic recession.

The central issue is not whether rising CO2 levels will cause a warmer planet. The fundamental concern is whether globally warmer temperatures are factually worse (or better) for human societies - and more (or less) damaging to the environment - than colder temperatures (like those experienced during the ice ages and Little Ice Age).

Bjorn Lomborg, Al Gore and Bill Gates need to consider the likelihood that, driven by changes in solar activity and ocean circulation, Earth will cool significantly over coming decades. Damaging the global economy with ineffectual carbon dioxide controls, in a futile quest to “stop global warming,” looks stupid now.

Viewed later, with hindsight, it will be judged outrageously irresponsible.

• Soon studies sun-climate connections at the Harvard-Smithsonian Center for Astrophysics.

• Carter is an emeritus fellow of the Institute of Public Affairs and chief science advisor to the International Climate Science Coalition.

• Legates is a hydroclimatologist at the University of Delaware and serves as the state climatologist of Delaware.

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