Last week, Matt Ridley and Benny Peiser took to the pages of The Wall Street Journal to offer a “complete guide to the climate debate” this week in Paris.  Our friends over at Climate Feedback  assembled a group of 12 scientists to examine their claims; claims that are, unfortunately, rather omnipresent on the Right.  We repost their response in full below:

12 scientists contributed to analyzing the article and estimated its overall scientific credibility to be ‘Low’ to ‘Very Low’[1].


The opinion piece in the WSJ by Matt Ridley & Benny Peiser contains numerous false statements, cherry-picked evidence, and misleading assertion about climate science. It attempts to surround the hard facts about climate change with clouds of uncertainty, even though these facts are agreed to by the scientific academies of every major country in the world and the vast majority of the world’s climate scientists.

Facts and/or studies are cherry picked or placed out of context to support the main claim that global warming is not as bad as we feared. For example the assertion that 1.5C of warming would be “beneficial” is one that very few scientists or economists agree with, and is contradicted by the overwhelming weight of evidence in the IPCC’s reports showing that the adverse impacts from climate change will far outweigh the benefits from carbon-dioxide induced greening and other heat-related effects.

See below for a list of scientists’ comments on the article’s statements.

See all the scientists’ annotations in context

Guest comments:

Steven Sherwood, Professor, University of New South Wales

This article peddles the usual false statements masquerading as opinion that we have been seeing for years, and would not be published by a reputable publisher. Most of the scientific statements in the article are false or misleading.

Mark Z. Jacobson, Professor, Stanford University

Misleading article with cherry-picked information placed out of context.

Eric Wolff, Professor, University of Cambridge

The article starts with an obvious logical fallacy: that because people attend a long-planned meeting on climate change, they must think this issue is more important than terrorism.

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.
See who the scientists quoted are.

Alexis Berg (Alexis_b)
The authors cherry-picks facts and/or studies to try to make the claim that, essentially, global warming is not as bad as we feared. It is a very biased and misleading presentation of the science.

Twila Moon (twilamoon)
This article is full of convenient cherry-picking and misleading statements. The level of information provided suggests the author is aware of the actual scientific findings that clearly demonstrate the severity of the climate change, but is building false conclusions by cherry picking or making false or unspecific statements.

Emmanuel Vincent (emvincent)
The authors omit to mention all the evidence that go against his narrative, this is cherry picking. For instance, the claim that extreme events are not increasing as a response to the ongoing warming of the climate can only be made by not considering the fact that we clearly observe an increase in the severity of  both heat waves and heavy rainfall events for instance.

William Anderegg (anderegg)
The article contains rampant cherry-picking, misleading statements, and flawed logic. Its presentation of the science is highly biased and inaccurate.

Rasmus Benestad (rasmus)
The article makes a number of false claims, such as the planet has been warmer during the last 10000 years. The claim that there has been no increase in frequency/intensity of storms/floods/droughts is misleading. There has been increases in extreme precipitation. It’s wrong that the climate sensitivity is “likely to be anything from 1.5 to 4.5 degrees Celsius” – the most likely value is in the central parts of this range, and the fringe values are less probable.

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


List of Statements commented on by scientists

Below is a list of statements made by Matt Ridley and Benny Peiser in their Wall Street Journal article along with comments and replies made by scientists.

What precisely makes these world leaders so convinced that climate change is a more urgent and massive threat than the incessant rampages of Islamist violence?

Dr Julien Emile-Geay, University of Southern California:
Studies like this one: Climate change in the Fertile Crescent and implications of the recent Syrian drought.

It is one of many examples illustrating how climate stressors may bring societies into conflict over scarce resources. The exact number of future climate victims is impossible to compute, but even by the most conservative estimates it is many orders of magnitude greater than the hundreds (or conservatively) thousands of people killed yearly by terrorist acts.

Prof. Eric Wolff, University of Cambridge:
The article starts with an obvious logical fallacy: that because people attend a long-planned meeting on climate change, they must think this issue is more important than terrorism.

Dr Alexis Berg, Columbia University:
False dichotomy. Climate change and terrorism both can and should be addressed – no matter how one ranks them. By the author’s logic, there couldn’t be a summit on anything else than terrorism right now.

Prof. Mark Z. Jacobson, Stanford University:
I think the authors are ignorant of the fact that combustion of fossil fuels and solid biofuels today kills between 4-7 million people worldwide EACH year due to the air pollution impacts alone, and these deaths are preventable. This is referenced here.

Prof. Anthony Barnosky, University of California, Berkeley:
Climate change has now been shown to be a contributing cause to the rise of the Islamic State in Syria and a chief national security concern. Happening now are the current refugee crisis and international terrorism spawned by ISIS—a legacy of how climate change helps precipitate conflict as a threat multiplier. Past examples include the Arab Spring uprising (major contributor was a failed crop in Egypt from intense drought), riots in Pakistan and attacks on government officials when drought meant choosing between water to drink and water for hydropower. See recent comments by National security adviser Susan Rice.

…world temperatures, because they have gone up only very slowly, less than half as fast as the scientific consensus predicted in 1990…

Prof. Steven Sherwood, University of New South Wales:

This statement is false. The IPCC predicted that warming between 2015 and 1990 would be within about 0.35 and 0.60C; the actual temperature in 2015 will be about 0.5C above the average of years around 1990, so a bit above the middle of the range originally predicted by the IPCC.

…the world is barely half a degree Celsius (0.9 degrees Fahrenheit) warmer than it was about 35 years ago…

Dr Alexis Berg, Columbia University:

This kind of statement seems to imply that 0.5 C change in global temperature is negligible. For reference, readers unfamiliar with the order of magnitude of changes in global temperature should be reminded that the difference between today’s global temperature and that of the the Last Glacial maximum (around 20,000 years ago), when ice sheets extended over northern North America and Northern Europe/Asia, is estimated to be only around 4-5 C (e.g., Annan, J. D. and Hargreaves, J. C.: A new global reconstruction of temperature changes at the Last Glacial Maximum) A warming of a few degrees C globally, as projected today under a business-as-usual scenario, is thus something of geological magnitude.

Prof. Anthony Barnosky, University of California, Berkeley:

Global temperature rise has of course been almost double what this article implies if you compare it to preindustrial rather than just the past 35 years. Which means warming has accelerated, not slowed, contrary to the presentation in this article.

Also, it is increasingly clear that the planet was significantly warmer than today several times during the past 10,000 years.

Dr William Anderegg, Princeton University:

In addition to likely wrong, this has absolutely no bearing on current human-caused warming. The projections of current warming will greatly exceed temperatures of the past 10,000 years and, more importantly for society and ecosystems, the rate of anthropogenic warming already greatly exceeds any temperature changes in the past 10,000 and even several million years. This rate of warming can have massive societal consequences and will be exceptionally hard for ecosystems and societies to adapt.

Prof. Eric Wolff, University of Cambridge:

This is incorrect. It is notoriously hard to estimate a global average temperature, even today, let alone in the past. However the most comprehensive attempt to do so was by Marcott et al (A reconstruction of regional and global temperature for the past 11,300 years, Science) They found that early Holocene (10,000 to 6,000 years ago) warmth was followed by a slow cooling of about 0.7 degrees in the last 5,000 years. The warming of the last century has taken global average temperature just above the maximum of the early Holocene – albeit so far only for a short period of time. However, it is clear that as warming continues we are entering a prolonged period that is significantly warmer than any period in the last 10,000 years.

…there has been no increase in frequency or intensity of storms, floods or droughts, while deaths attributed to such natural disasters have never been fewer…

Prof. Steven Sherwood, University of New South Wales:

This statement is not justified as several studies are now reporting increases in severe rains and in storm damages even when non-environmental factors are accounted for. Moreover the authors ignore heat waves which show the clearest increase and kill more people than the ones they mention.

Dr Alexis Berg, Columbia University:

The authors seem to carefully select the types of climate extremes for which, despite projections of increased frequency/intensity of such extremes, observations over recent decades do not allow us to say if present trends are consistent with projections (e.g., droughts).

Note that for other types of climate extremes, like temperature extremes, heat waves, or high-intensity rainfall, observations are in agreement with projections and show an increase attributable to human influence- e.g., Fischer and Knutti, 2015, Anthropogenic contribution to global occurrence of heavy-precipitation and high-temperature extremes, Nature Climate Change.

Antarctica is gaining land-based ice, according to a new study by NASA scientists published in the Journal of Glaciology…

Dr Twila Moon, University of Oregon:

This study examined Antarctic ice sheet mass changes until 2008 and presents a single study of Antarctic ice mass. Also, the mechanism indicated for mass change – increased snowfall – is actually a result of a warming atmosphere and an understood change that is consistent with scientific understanding. Perhaps more pertinent, however, is that other studies, including of more recent changes have suggested overall ice loss and, most important, large future ice loss. Recently published articles (Joughin et al. 2014, Rignot et al. 2014) looking at changes on coastal Antarctic ice shelves shows that we have likely already entered a period of major ice shelf retreat, with no mechanisms in sight to stop this retreat over the next 100s of years. The implication of ice shelf and glacier retreat around the Antarctic coast is increased ice loss over the next 10s to 1,000s of years. There is a very large body of scientific work examining Antarctic ice sheet mass trends and there is community agreement that future ice loss is expected and will be worse if global temperatures increase more.

Prof. Jonathan Bamber, University of Bristol:

West Antarctica has been losing mass at an increasing rate since the 1990s and, irrespective of what is happening further East, that trend looks set to continue. Going to the other end of the Earth, the Greenland ice sheet has also been losing mass at an accelerating rate since around 1995. Greenland is now the single biggest source of mass to the oceans. These trends at both poles are huge signals that are unequivocal and uncontested.

“Sea level continues its centuries-long slow rise—about a foot a century—with no sign of recent acceleration.”

Dr Emmanuel Vincent, University of California, Merced:

‘Recent’ is not a precise term. On climate relevant scale, evidence shows that sea level rise has been accelerating. See for instance the figure below from Jevrejeva et al

sea level rise

see also: Church (2008) Understanding global sea levels: past, present and future

But scientists disagree: They say there is great uncertainty,

Dr William Anderegg, Princeton University:

This is highly misleading. Uncertainty is a fixture of life and is absolutely no reason for not taking policy action. There will always be uncertainty in science (in the form of standard deviations around estimates, for instance), but the scientists fundamentally do not disagree that: 1) humans’ emissions of greenhouse gases are the primary cause of climate change of the past 50-60 years, and 2) consequences are likely to be significantly harmful. See here and here.

It projects that temperatures are likely to be anything from 1.5 to 4.5 degrees Celsius (2.7 to 8.1 degrees Fahrenheit) warmer by the latter part of the century…

Dr Victor Venema, University of Bonn, Germany:

This is the range for the Equilibrium Climate Sensitivity, not for the temperature in 2100. This temperature depends on how much we will mitigate climate change for which there are no predictions.

This is a wide range of climate sensitivities, but not a sign of disagreement in the scientific community as the op-ed suggests. This range is a fair summary of the evidence for most scientists.

Prof. Steven Sherwood, University of New South Wales:

The authors confuses the “sensitivity” (which they correctly notes ranges from 1.5-4.5C) with the actual warming that we’d have by 2100 (which ranges from 3-6C). There is no way that 3C of warming would be beneficial, and there is no way that we would get away with less than 3C of warming on a business-as-usual emissions pathway. 4C or more of warming would probably render some regions of the planet uninhabitable due to heat stress and cause massive disruption to all societies; 3C might even be enough to do that, we don’t know.

…that is, anything from mildly beneficial to significantly harmful.

Dr Alexis Berg, Columbia University:

This sentence is very misleading. Even assuming that 1.5 C would be mildly beneficial – which is an unsubstantiated claim at this point – this sentence omits to mention that this more modest warming implies strong and rapid human action to limit greenhouse gas emissions – it is not at all an equally likely outcome of a business-as-usual scenario!

A large part in the uncertainties from IPCC projections for the end of the 21st century is due to human behavior, e.g., mainly how much of fossil fuels we will burn (RCPs on the figure below).

Note as well that for a business-as-usual scenario (RCP8.5), warming does not stop in 2100, but goes on after that.


Prof. Steven Sherwood, University of New South Wales:

The assertion that 1.5C of warming would be “beneficial” is one that very few scientists or economists would agree with other than Richard Tol. It is true that CO2-induced greening will be beneficial, but how beneficial compared to the problems from greater heat and shifting rainfall patterns is dubious at best.

…a new study by a leading climate economist, Richard Tol of the University of Sussex, concludes that warming may well bring gains, because carbon dioxide causes crops and wild ecosystems to grow greener and more drought-resistant.

Dr Victor Venema, University of Bonn, Germany:

It is a good idea to check the source. In this case the link goes to an unpublished manuscript.

The manuscript only cites one study with positive impacts. The one of Dr. Tol himself for a 1°C temperature rise, which is a point we have just reached. That impacts for this study become statistically significant only at 3.5°C is because the economic uncertainties are so large. Uncertainties go both ways.

Dr William Anderegg, Princeton University:

This is an old and largely debunked idea. The best available evidence suggests that while carbon dioxide concentrations do help some crops in some regions, the increases of temperature and drought stress are non-linear and have and will mostly overwhelm positive effects. In fact, climate change has probably driven declines in crop production of 2 of the 4 largest global crops even in the past 30 years.

A key study published in the Journal of Climate this year by Bjorn Stevens of the Max Planck Institute for Meteorology in Hamburg, Germany, found that the cooling impact of sulfate emissions has held back global warming less than thought till now…

Dr Victor Venema, University of Bonn, Germany:

That clouds and aerosols are an important reason for the large confidence interval for the climate sensitivity is generally accepted. However, it is an exaggeration to claim that Bjorn Stevens found this. He presented limited evidence that makes a case for future research into this topic. More in general, one should never judge the state of the art based on single papers, especially new papers.

Scientific skeptics are now routinely censored, or threatened with prosecution.

Dr Britta Voss, U.S. Geological Survey:

This is misleading as it implies that climate skeptics are being threatened with prosecution because of their skeptical views. In reality, the questions of legality directed at climate skeptics (or, more significantly, fossil fuel companies) are based on concerns of conflict of interest, as scientists and others expressing views on climate science that are contradictory to mainstream consensus have in some cases been found to derive significant funding from fossil fuel companies and other groups that stand to profit from delaying climate policies. The recent example of Willie Soon, the Harvard-Smithsonian researcher who neglected to disclose his funding from fossil fuel companies when publishing research skeptical of established climate science, is a prime example of such a conflict of interest.