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The most popular deceptive climate graph

The “World Climate Widget” from Tony Watts’ blog is probably the most popular deceptive image among climate “skeptics”.  We’ll take it under the microscope and show what it would look like when done properly.

So called “climate skeptics” deploy an arsenal of misleading graphics, with which the human influence on the climate can be down played (here are two other  examples deconstructed at Realclimate).  The image below is especially widespread.  It is displayed on many “climate skeptic” websites and is regularly updated.


The “World Climate Widget” of US “climate skeptic” Anthony Watts with our explanations added.  The original can be found on Watts’ blog

What would a more honest display of temperature, CO2 and sunspots look like? More »

Recent global warming trends: significant or paused or what?

As the World Meteorological Organisation WMO has just announced that “The year 2014 is on track to be the warmest, or one of the warmest years on record”, it is timely to have a look at recent global temperature changes.

I’m going to use Kevin Cowtan’s nice interactive temperature plotting and trend calculation tool to provide some illustrations. I will be using the HadCRUT4 hybrid data, which have the most sophisticated method to fill data gaps in the Arctic with the help of satellites, but the same basic points can be illustrated with other data just as well.

Let’s start by looking at the full record, which starts in 1979 since the satellites come online there (and it’s not long after global warming really took off).

trend1Fig. 1. Global temperature 1979 to present – monthly values (crosses), 12-months running mean (red line) and linear trend line with uncertainty (blue) More »

New developments: Climate services for health

Filed under: — rasmus @ 13 October 2014

I recently received a joint email from the World Meteorological and Health organisations (WMO & WHO) which I like to bring to the attention of our readers. Both because it shows the direction of some new developments, but also because the WMO and WHO are inviting people to share their experience with health and climate. We wrote a post on the subject climate and health in 2011, based on a book by Paul Epstein (who sadly pased away in November 2011) and Dan Ferber (Health on a Changing Planet), and are glad to see an increased emphasis on this topic. The call from WMO/WHO goes as follows:

Guest commentary from Joy Shumake-Guillemot

Climate Services for Health
Enhancing Decision Support for Climate Risk Management and Adaptation

Climate services for health are an emerging technical field for both the health and climate communities. In 2012, WHO and WMO jointly published the Atlas on Climate and Health, drawing attention to the key linkages between climate and health, and how climate information can be used to understand and manage climate sensitive health risks. A new follow-up publication of Case Studies on Climate Services for Health is in preparation, and will take a next step to outline with greater detail how a wide range of health applications can benefit from using climate and weather information; what steps and processes can be used to co-develop and use climate and weather information in the health sector; and showcase how such partnerships and services can really make a difference to the health community. 

Submission Guidance – Deadline October 31, 2014
We invite you to share your experiences and call attention to the increasing opportunities to solve health problems with climate service solutions. Case studies should highlight existing partnerships and good practices that demonstrate the broad range of possible applications and the value of using climate information to inform health decisions. Case studies from across health science and practice are welcomed, including examples of climate services for integrated surveillance, disease forecasting, early warning systems, risk mapping, health service planning, risk communication, research, evaluation, infrastructure siting, etc. Additionally, the publication aims to highlight the full range climate-related health issues and risks (i.e. nutrition, NCDs, air pollution, allergens, infectious diseases, water and sanitation, extreme temperatures and weather, etc.) where health decision-making can benefit from climate and weather knowledge at historic, immediate, seasonal, or long-term time scales.

Case studies should be short (~600 words, 2 pages incl. images/diagrams and references) and designed to highlight the added-value that climate services have made for managing climate risks to health. Please find additional guidance on the structure and four elements to be included at  

For questions and submission please contact
Dr.Joy Shumake-Guillemot
WHO/WMO Climate and Health Office, World Meteorological Organization, Geneva, Switzerland

On arguing by analogy

Filed under: — gavin @ 2 September 2014

Climate blogs and comment threads are full of ‘arguments by analogy’. Depending on what ‘side’ one is on, climate science is either like evolution/heliocentrism/quantum physics/relativity or eugenics/phrenology/Ptolemaic cosmology/phlogiston. Climate contrarians are either like flat-earthers/birthers/moon-landing hoaxers/vaccine-autism linkers or Galileo/stomach ulcer-Helicobacter proponents/Wegener/Copernicus. Episodes of clear misconduct or dysfunction in other spheres of life are closely parsed only to find clubs with which to beat an opponent. Etc. Etc.

While the users of these ‘arguments’ often assume that they are persuasive or illuminating, the only thing that is revealed is how the proposer feels about climate science. If they think it is generally on the right track, the appropriate analogy is some consensus that has been validated many times and the critics are foolish stuck-in-the-muds or corporate disinformers, and if they don’t, the analogy is to a consensus that was overturned and where the critics are the noble paradigm-shifting ‘heretics’. This is far closer to wishful thinking than actual thinking, but it does occasionally signal clearly who is not worth talking to. For instance, an article pretending to serious discussion on climate that starts with a treatise about Lysenkoism in the Soviet Union is not to be taken seriously.

Since the truth of falsity of any scientific claim can only be evaluated on it’s own terms – and not via its association with other ideas or the character of its proponents – this kind of argument is only rhetorical. It gets no-one closer to the truth of any particular matter. The fact is that many, many times, mainstream science has survived multiple challenges by ‘sceptics’, and that sometimes (though not at all often), a broad consensus has been overturned. But knowing which case is which in any particular issue simply by looking for points of analogy with previous issues, but without actually examining the data and theory directly, is impossible. The point being that arguments by analogy are not persuasive to anyone who doesn’t already agree with you on the substance.

Given the rarity of a consensus-overturning event, the only sensible prior is to assume that a consensus is probably valid absent very strong evidence to the contrary, which is incidentally the position adopted by the arch-sceptic Bertrand Russell. The contrary assumption implies there are no a priori reasons to think any scientific body of work is credible which, while consistent, is not one that I have ever found anyone professing in practice. Far more common is a selective rejection of science dependent on other reasons and that is not a coherent philosophical position at all.

Analogies do have their place of course – usually to demonstrate that a supposedly logical point falls down completely when applied to a different (but analogous) case. For instance, an implicit claim that all correct scientific theories are supported by a unanimity of Nobel Prize winners/members of the National Academies, is easily dismissed by reference to Kary Mullis or Peter Duesberg. A claim that CO2 can’t possibly have a significant effect solely because of its small atmospheric mixing ratio, can be refuted as a general claim by reference to other substances (such as arsenic, plutonium or Vitamin C) whose large effects due to small concentrations are well known. Or if a claim is made that all sciences except climate science are devoid of uncertainty, this is refuted by reference to, well, any other scientific field.

To be sure, I am not criticising the use of metaphor in a more general sense. Metaphors that use blankets to explaining how the greenhouse effect works, income and spending in your bank account to stand in for the carbon cycle, what the wobbles in the Earth’s orbit look like if the planet was your head, or conceptualizing the geologic timescale by compressing it to a day, for instance, all serve useful pedagogic roles. The crucial difference is that these mappings don’t come dripping with over-extended value judgements.

Another justification for the kind of analogy I’m objecting to is that it is simply for amusement: “Of course, I’m not really comparing my opponents to child molesters/food adulterers/mass-murderers – why can’t you take a joke?”. However, if you need to point out to someone that a joke (for adults at least) needs to have more substance than just calling someone a poopyhead, it is probably not worth the bother.

It would be nice to have a moratorium on all such analogical arguments, though obviously that is unlikely to happen. The comment thread here can assess this issue directly, but most such arguments on other threads are ruthlessly condemned to the bore-hole (where indeed many of them already co-exist). But perhaps we can put some pressure on users of these fallacies by pointing to this post and then refusing to engage further until someone actually has something substantive to offer. It may be pointless, but we can at least try.

The most common fallacy in discussing extreme weather events + Update

Filed under: — stefan @ 25 March 2014

Does global warming make extreme weather events worse? Here is the #1 flawed reasoning you will have seen about this question: it is the classic confusion between absence of evidence and evidence for absence of an effect of global warming on extreme weather events. Sounds complicated? It isn’t. I’ll first explain it in simple terms and then give some real-life examples.

The two most fundamental properties of extreme events are that they are rare (by definition) and highly random. These two aspects (together with limitations in the data we have) make it very hard to demonstrate any significant changes. And they make it very easy to find all sorts of statistics that do not show an effect of global warming – even if it exists and is quite large.

Would you have been fooled by this?

More »

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