Analysis of &quot;The Phony War Against CO2&quot;

Professor, Directeur de Recherche, Mediterranean Institute for Biodiversity and Ecology (IMBE)

The article speaks about scientific questions under an “opinion” banner—as if questions about the role of CO₂ in the Earth system could be a matter of opinions. Virtually every single point in the article can be easily proven wrong by referral to standard textbook knowledge. For the major final conclusion “With more CO₂ in the atmosphere, the challenge [to feed additional 2.5 billion people] can and will be met.“, there is absolutely no scientific credibility, nor support in the scientific literature—it is pure fantasy.

REVIEWERS’ OVERALL FEEDBACK

These comments are the overall opinion of scientists on the article, they are substantiated by their knowledge in the field and by the content of the analysis in the annotations on the article.

William Anderegg

Associate Professor, University of Utah

The opinion article makes sweeping assertions that are not in line with the scientific understanding. The conclusions on CO₂ uniformly benefiting agriculture are simply misleading—yes, CO₂ can help plants but higher temperatures and more drought and pests with climate change also hurt plants.

Timothy Osborn

Professor, University of East Anglia, and Director of Research, Climatic Research Unit

The article presents a biased view by understating the degree and impacts of global warming while overstating or simplifying the benefits of CO₂ fertilisation.

Professor, Victoria University of Wellington

The article is full of half-truths, untruths, and red herrings. Casting increased CO₂ as a benefit to humankind, without considering the impacts and risks associated with a changing climate, is dangerous and irresponsible.

Assistant Professor, University of Virginia

The lack of distinction between the role of solid particulates and greenhouse gases in the atmosphere makes many of the authors’ claims false and misleading. The article does not present a complete or accurate discussion of climate change, its causes, and its societal influence. The authors state that readers should ‘check the facts’ regarding climate change, but have presented us with little scientific support for their own claims.

Victor Venema

Scientist, University of Bonn, Germany

This has nothing to do with science.

Notes:
[1] See the rating guidelines used for article evaluations.
[2] Each evaluation is independent. Scientists’ comments are all published at the same time.

Key Take-aways

The statements quoted below are from Harrison Schmitt and Rodney Nichols; comments and replies are from the reviewers.

1. The negative impacts of continued CO₂ emissions are significant and serious. The authors only find human emissions of CO₂ beneficial by ignoring all the reasons it is harmful.

“Unlike genuine pollutants, carbon dioxide (CO₂) is an odorless, colorless gas. Every human being exhales about two pounds of CO₂ a day, along with a similar amount of water vapor. CO₂ is nontoxic to people and animals”

Timothy Osborn

Professor, University of East Anglia, and Director of Research, Climatic Research Unit

This is a diversionary tactic: the concern about CO₂ is not about its smell, its colour or its direct toxicity; instead it is about its effect on the Earth’s climate. So it is a strawman statement that may be easily demolished but not relevant to the concern about CO₂ and climate change.

Victor Venema

Scientist, University of Bonn, Germany

There are many toxic gases that are odorless and colorless. The best known one is, like CO₂, also related to combustion: carbon monoxide (CO).

“But a myth persists that is both unscientific and immoral to perpetuate: that the beneficial gas carbon dioxide ranks among hazardous pollutants. It does not.”

Professor, Victoria University of Wellington

This is semantics. Some call carbon dioxide a “pollutant” and others don’t. What is relevant is that the huge amount of CO₂ that humanity has put into the atmosphere is changing the climate significantly. The hazard comes from changes to precipitation and extremes, leading to reduced food security and water availability. No wonder the Pentagon rates climate change as a critical threat to US national security. Just look at what’s happening in Syria and north Africa, on the back of a severe drought and a spike in food prices.

Reference:

Kelley et al (2015) Climate change in the Fertile Crescent and implications of the recent Syrian drought. Proceedings of the National Academy of Sciences

“[CO₂] is also a greenhouse gas which helps maintain earth at a habitable temperature.”

Professor, Directeur de Recherche, Mediterranean Institute for Biodiversity and Ecology (IMBE)

While the presence of CO₂ has warmed the atmosphere to “habitable” temperatures, the additional increase of it will bring temperatures way outside habitable ranges in many regions including the oceans, as well as disturbing the water cycle and acidifying the oceans.

“But observations, such as those on our CO₂ Coalition website, show that increased CO₂ levels over the next century will cause modest and beneficial warming—perhaps as much as one degree Celsius (1.8 degrees Fahrenheit)”

Professor, Victoria University of Wellington

That [1 °C warming] is an absolute best-case scenario, if significant mitigation action is taken urgently. Increased CO₂ leads to warming, which leads to increased atmospheric water vapor, less ice, and other feedbacks. A doubling of CO₂ concentrations would lead to about 3 °C warming.

Timothy Osborn

Professor, University of East Anglia, and Director of Research, Climatic Research Unit

Projections of future warming can’t be made from observations alone: we need understanding of the mechanisms and physical processes. Neither of these are provided by the quoted website, which instead contains inaccurate articles about supposed adjustments to temperature data and claiming a new ‘little ice age’ is already here—both of which have been shown to be incorrect by scientific research. (For example, section 1.3.2 of the Fourth Assessment Working Group I IPCC report compared global temperature records from various vintages and found broad consistency.)

“The costs of emissions regulations, which will be paid by everyone, will be punishingly high and will provide no benefits to most people anywhere in the world.”

Assistant Professor, University of Virginia

This is simply not accurate. Global warming is a global issue that, for example, affects global coastal populations, marine ecology, crop stability, and the area of habitable land. Humans, especially in countries with the largest carbon emissions, have been successfully altering the entire Earth system; therefore, climate change is currently the most global issue that we face and will continue to face in the coming centuries.

Professor, Directeur de Recherche, Mediterranean Institute for Biodiversity and Ecology (IMBE)

It is unclear what costs are referred to here. The regulations themselves cost nothing. The reductions of emissions will avoid huge damage costs and also produce economic benefits in other than the fossil-fuel dependent economic sectors. It is the damage costs that will be “paid by everyone”, not the emission reductions.

2. Continued CO₂ emissions will not improve future crop production. The IPCC report concludes that the net result of further climate change will be to hinder global crop yields.

“In 2013 the level of U.S. farm output was about 2.7 times its 1948 level, and productivity was growing at an average annual rate of 1.52%. From 2001 to 2013, world-wide, global output of total crop and livestock commodities was expanding at an average rate of 2.52% a year[…] Along with better plant varieties, cropping practices and fertilizer, CO₂ has contributed to this welcome increase in productivity.”

G Philip Robertson, Professor, Michigan State University:
In general, CO₂ has had a positive effect on crop growth, but it’s impossible to separate historical effects from the greater effects of genetics and nitrogen and other inputs. However, it’s generally considered to be a fraction of those. We know better future effects because we have CO₂ fertilization experiments in the field comparing present to future CO₂ levels. Those experiments suggest that corn may have about a 1% gain [because of increased CO₂] and soybeans 3-4 times that. However, these gains will almost certainly be offset by yield declines associated with the temperature increases caused by elevated CO₂, which are well known.

Historically, it’s worth noting that we had elevated CO₂ long before we had the green revolution, and crop yields didn’t increase much until the green revolution. You can see this in graphs of average US corn yields from 1900.

Source: University of Nebraska-Lincoln

“With more CO₂ in the atmosphere, the challenge [feeding 2.5 billion more people] can and will be met.”

Professor, Directeur de Recherche, Mediterranean Institute for Biodiversity and Ecology (IMBE)

There is absolutely no scientific study that would support such a conclusion. And even if there was no climate effect of CO₂, a simple speculative growth enhancement by CO₂ could not produce such an effect.

Professor, Victoria University of Wellington

This is very naïve. Many factors control food production. If further large changes in climate come to pass, no amount of extra CO₂ will improve food security.

“Feeding these people and assuring them a comfortable living standard should be among our highest moral priorities.”

Assistant Professor, University of Virginia

Climate change and poverty go hand in hand, as developing countries are disproportionately affected by climate change.

“When someone says, ‘climate science is settled,’ remind them to check the facts.”

Professor, Victoria University of Wellington

The basic radiation physics has been well known for 150 years. The details will always be under discussion, but we are already seeing very clearly the expected patterns of climate change.