Climate-change deniers are everywhere. If you’ve ever had a conversation about global warming, you’ve probably heard their ‘arguments’. Despite the fact that they typically provide very little evidence to support their position, they can be distracting, so it’s helpful to have the facts at hand, to handle their rhetoric.

Here’s a collection of some of the more common claims I’ve encountered, along with the actual facts.

1) “The science is not nearly as settled as the wild zealots say”

This is an actual Tony Abbott quote:

(Sorry about the aspect ratio; it was the only video of the interview I could find.)

The facts: Those so-called zealots Abbott mentions? They happen to be the vast majority of the world’s climate scientists. According to NASA, 97% of climate scientists believe we are contributing significantly to climate change.

Ninety-seven percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities, and most of the leading scientific organizations worldwide have issued public statements endorsing this position.”

One of NASA’s sources for that claim was the US National Academy of Sciences. It reviewed the publications of 1,372 climate researchers, and found that:

97–98% of the climate researchers most actively publishing in the field surveyed here support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.”

Many other reviews have found the same thing. Here’s a handful:

• In 2004, Oreskes analysed the abstracts of papers published from 1993–2003 matching the search ‘global climate change’, and found that none of 928 papers disagreed with the consensus position on human-caused global warming.
• In 2008, Bray & Storch surveyed 2058 climate scientists from 34 countries, and 98.6% of respondents said they were at least somewhat convinced that climate change is or will be human-induced (34.6% very much agreed, 48.9% agreed to a large extent, 15.1% agreed to a small extent, and 1.35% didn’t agree at all).
• In 2009, Doran and Zimmerman asked 10,257 earth scientists if they think human activity is a significant contributing factor in changing mean global temperatures. Of the 3,146 who responded, 82% said yes. Importantly, 96.2% of the most specialised respondents said yes (i.e. those who were actually climate scientists with more than half of their peer-reviewed work in the field of climate science).
• In 2010, Anderegg et al analysed 1,372 peer-review climate articles and found that 97–98% of the climate researchers most actively publishing in the field surveyed here support the tenets of ACC [Anthropogenic or human-caused Climate Change] outlined by the Intergovernmental Panel on Climate Change.
• In 2011, Yale University & George Mason University surveyed 489 randomly selected members of either the American Meteorological Society or the American Geophysical Union and 84% of respondents said they personally believed human-induced warming was occurring.
• In 2013, James Powell analysed 10,885 peer-reviewed climate articles published in 2013, and found that only 2 rejected anthropogenic global warming! (Powell is  a former member of the National Science Board and current executive director of the National Physical Science Consortium.)
• In 2013, Powell also found that of a total of 25,182 scientific articles in peer-reviewed journals he’d analysed over the years, only 26 out of 25,182 rejected anthropogenic global warming. That’s just 0.1%!
• In 2013, John Cook et al analysed the abstracts of 11,944 peer-reviewed climate change articles from 1991–2011, and found that of those that actually expressed an opinion, 97.1% said humans were contributing to global warming. Cook et al also asked the authors of the papers whether their papers endorsed the consensus that humans are contributing to global warming. 97.2% of those who responded said they did.

Many other scientific organisations agree that there is consensus among client scientists, including:

• American Association for the Advancement of Science, 2006: “The conclusions in this statement reflect the scientific consensus represented by, for example, the Intergovernmental Panel on Climate Change, and the Joint National Academies’ statement.”
• US National Academy of Sciences: “In the judgment of most climate scientists, Earth’s warming in recent decades has been caused primarily by human activities that have increased the amount of greenhouse gases in the atmosphere. … On climate change, [the National Academies’ reports] have assessed consensus findings on the science…”
• Joint Science Academies’ statement, 2005: “We recognise the international scientific consensus of the Intergovernmental Panel on Climate Change (IPCC).”
• Joint Science Academies’ statement, 2001: “The work of the Intergovernmental Panel on Climate Change (IPCC) represents the consensus of the international scientific community on climate change science. We recognise IPCC as the world’s most reliable source of information on climate change and its causes, and we endorse its method of achieving this consensus.”
• American Meteorological Society, 2003: “The nature of science is such that there is rarely total agreement among scientists. Individual scientific statements and papers—the validity of some of which has yet to be assessed adequately—can be exploited in the policy debate and can leave the impression that the scientific community is sharply divided on issues where there is, in reality, a strong scientific consensus…. IPCC assessment reports are prepared at approximately five-year intervals by a large international group of experts who represent the broad range of expertise and perspectives relevant to the issues. The reports strive to reflect a consensus evaluation of the results of the full body of peer-reviewed research…. They provide an analysis of what is known and not known, the degree of consensus, and some indication of the degree of confidence that can be placed on the various statements and conclusions.”
• Network of African Science Academies: “A consensus, based on current evidence, now exists within the global scientific community that human activities are the main source of climate change and that the burning of fossil fuels is largely responsible for driving this change.”
• International Union for Quaternary Research, 2008: “INQUA recognizes the international scientific consensus of the Intergovernmental Panel on Climate Change (IPCC).”
• Australian Coral Reef Society, 2006: “There is almost total consensus among experts that the earth’s climate is changing as a result of the build-up of greenhouse gases… There is broad scientific consensus that coral reefs are heavily affected by the activities of man and there are significant global influences that can make reefs more vulnerable such as global warming…”
• The CSIRO and the Australian Bureau of Meteorology: ” It is extremely likely that the dominant cause of recent warming is human-induced greenhouse gas emissions and not natural climate variability.” (p.10)
• The Australian Meteorological and Oceanographic Society: “It is highly likely that those human activities that have increased the concentration of greenhouse gases in the atmosphere have been largely responsible for the observed warming since 1950.” (p.1)
• United States Environmental Protection Agency: “The Earth’s climate is changing. Temperatures are rising, snow and rainfall patterns are shifting, and more extreme climate events—like heavy rainstorms and record high temperatures—are already taking place. Scientists are highly confident that many of these observed changes can be linked to the climbing levels of carbon dioxide and other greenhouse gases in our atmosphere, which are caused by human activities.”
• The British Antarctic Survey: “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in human-induced greenhouse gas concentrations.”
• The Royal Meteorological Society: “…it is very likely that most of the global temperature rise observed since the middle of the last century has been caused by increasing greenhouse gases in the atmosphere from human activities such as fossil-fuel burning.”
• And many more…

2) “But this scientist said…”

I had a debate with a denier on Google+ the other day. He quoted 18 scientists to support his argument. But when I actually had a close look at them, they weren’t very persuasive. Of the 18, only 12 of the quotes were specifically denying man-made climate change. The rest were just peripheral. And of the 12 that specifically denied it, only 1 was from an actual climate scientist (Dr. Steven M. Japar). The others were from other scientific disciplines. One was a physicist who works on electron tunneling in superconductors. Two were geologists, another was an industrial chemist, and one was a paleontologist! The rest were mostly chemists and/or physicists, and there was also a civil and biosystems engineer, and a meteorologist (they study weather, not climate).

Now, I’m no scientist, so I’m certainly not going to debate the merits of Japar’s argument. But he’s just one scientist! And as discussed above, the vast majority of the rest of the scientific community disagrees with him. It would be irrational of anyone to take the word of one scientist when the weight of opinion contradicts him.

My point here is that climate-change deniers like to do a lot of copy-pasting from denial/conspiracy theory sites, and it can seem they have a valid argument, simply because they have a lot to say. But don’t be fooled. Take the time to tease apart their arguments, and I suspect you’ll find, as I did, that they’re largely hot air.

3) “But this study said…”

Occasionally a new study is released that appears to refute man-made climate change. But it’s important to look at these studies in context. Firstly, remember that 99.9% of peer-reviewed articles reviewed express the belief that we are contributing to climate change. And secondly, understand that just because a study is released, doesn’t mean it’s correct. Michael Mann, director of Penn State’s Earth System Science Center, explains it like this:

Every once and a while there’s some contrarian paper that gets published in a journal and immediately the climate change contrarians trumpet this new study and it gets air-time on Fox News and Rush Limbaugh, and inevitably — in almost every case that I can think of — the study turns out to have been fundamentally flawed. But it may take a year before a peer-reviewed article assessing that particular study is published. It takes time for scientists to independently look at the data, test the hypotheses, and either replicate or refute an analysis in a previously published article… But it becomes very easy for those looking to throw doubt and confusion into the picture to select some late-breaking study, take it out of context, milk it for all it’s worth and neglect the fact that there’s a much larger body of scientific research upon which our understanding is based.”

It’s also important to consider the source of these articles. In the US, for instance, the Heartland Institute commissions reports like this one that suggests carbon dioxide is not a pollutant, and climate change is good for us! But the Heartland Institute is sponsored by oil companies and other corporations that see climate-change science as a threat. Here’s a screenshot of a confidential Heartland document leaked by a Heartland donor:

In fact, one of America’s most high-profile deniers, Willie Soon, is funded by the fossil fuel industry. He received a total of $1.25m over 14 years from Exxon Mobil, Southern Company, the American Petroleum Institute (API) and a foundation run by the ultra-conservative Koch brothers. Yet despite this obvious conflict of interests, he’s been cited by US Senators, and was called to testify when Republicans in the Kansas state legislature tried to block measures promoting wind and solar power, and he received a courage award from the Heartland Institute.

In Australia, a similar thing happens. Right-wing think-tank, the Institute of Public Affairs (IPA), sponsors ‘studies’, writes articles and promotes climate change deniers to try to discredit genuine science. For example:

• This article that claims “Nobody knows whether global temperatures will rise, fall or stay the same. But there are multitudes of political entrepreneurs trying to persuade us they will rise and do so at alarming rate.”
• This fund-raising push for geologist, Ian Pilmer’s anti-climate change book.
• This $350,000 donation from a climate change sceptic, channeled through the IPA who wanted it to be spent on climate research.

But like Heartland, the IPA is sponsored by big businesses, including big mining companies. In fact, according to the Sydney Morning Herald:

About a quarter of its $2 million in annual funding comes from corporations with a direct stake in the climate change debate, not including contributions from its 1000 individual members, some of whom also have a personal interest in climate change.”

The IPA also has direct links to America’s Heartland Institute. One of the IPA’s ‘Emeritus Fellows’ and its Science Policy Advisor, Bob Carter, was being paid $1,667 per month by Heartland. Bob was also a speaker at one of Heartland’s climate science denial conferences in the US. Indeed, the IPA actually sponsored two of those conferences – once in 2009 and once in 2010. (You’ll note I’ve used archived copies of those pages… the originals have been taken down.)

Perhaps even more alarming is the fact that the IPA plays a big part in setting policy in Australia. It put together a wishlist of 100 policies it wanted our government to implement, and so far, the Coalition has adopted or endorsed, or is considering, more than a third of them!

4) “But the Wall Street Journal debunked the 97% consensus argument”

Well, no it didn’t. Many deniers point to this Wall Street Journal article which cites a study that allegedly found Cook’s original 97% findings were wrong. But you know what? The article was written by the Heartland Institute! The authors are none other than Joseph Bast, Heartland’s co-founder, president and CEO, and Roy Spencer, one of their official ‘Experts’.

And the study it cites? Surprise, surprise, it was conducted by Heartland too!:

• Willie Soon, Heartland Institute ‘Expert’, astrophysicist and geoscientist (not a climate scientist). Shown above to be directly on the take from the fossil fuel industry, Soon writes ‘research papers’ (he calls them ‘deliverables’) on behalf of the coal industry and even gives them “the right to review his papers and make suggestions before they’re published!
• David Legates, Heartland Institute ‘Expert’, who’s actually a professor of geography (not a climate scientist).
• William Briggs, Heartland Institute ‘Expert’, who’s actually a statistician (not a climate scientist).
• Christopher Monckton, Heartland Institute ‘Expert’ and conservative government policy advisor (not a climate scientist).

And the study itself counted only papers that explicitly quantified the human contribution to global warming. It assumed that every other paper is an outright rejection of the consensus! (i.e. They deceptively ignored the fact hardly any papers bother to state the obvious.) Oh, and it was published in an education journal, not a climate science journal. (Not quite the same thing…) If you want to learn how the article was wrong, here’s a rebuttal by one of the authors of the study it criticises.

Other deniers point to this Forbes article that quotes climate scientists allegedly mis-classified as supportive of global warming theory. And guess what? This article was written by the Heartland Institute too! The author was James Taylor, a Heartland ‘Senior Fellow’. And every single one of the researchers it quotes is a Heartland stooge!:

• Willie Soon, Heartland ‘Expert’, discussed above.
• Craig Idso, Heartland ‘Expert’.
• Nicola Scafetta, speaker at Heartland denial conventions.
• Nir Shaviv, Heartland ‘Expert’.
• Nils-Axel Morner, speaker at several Heartland denial conventions.
• Alan Carlin, Heartland ‘Expert’.

In other words, what these deniers are citing is a whole lot of guff written and paid for by the Heartland Institute. So let’s not pretend it even approaches scientific objectivity.

5) “But NASA, NOAA and the BOM doctored the data”

This is a denier favourite at the moment. Mostly because it requires a level of analysis to disprove, and some patience to understand the analysis. So a lot of people (particularly those who want to believe the conspiracy theory) find themselves wondering who to believe.

Essentially this conspiracy theory says that NASA, the National Oceanic and Atmospheric Administration (NOAA) and the Australian Bureau of Meteorology (BOM) have all doctored historical temperature data to make it seem like we’re experiencing a warming trend. This is a conspiracy theory promoted by Abbott’s chief business adviser, Maurice Newman (who, it should be noted, is a member of an organisation that’s paid to discredit climate science and which is associated with the Heartland Institute), as well as one of Abbott’s backbenchers, George Christensen (also closely associated with the Heartland Institute) and high profile scientist, Dr Jennifer Marohasy (who’s even spoken at at least one Heartland Institute event, and who worked at the IPA for 6 years).

So first let’s look at the BOM conspiracy theory. Yes, they’ve altered some data. But no, it wasn’t to exaggerate global warming. It was just to account for things like trees casting shadows, station relocation and changing measurement methods. This is a standard, peer-reviewed process called ‘homogenisation’ and it’s done to ensure there’s NO bias due to differences in data collection or analysis methods.

But if that’s not enough for you, there’s also the fact that it’s the only one of their data sets that’s been homogenised. In the BOM graph below (shared by the Guardian), you can see the homogenised data (the yellow line) looks pretty much the same as the unaltered data (the other lines).

Indeed, according to analysis of CLIMDEX data performed by UNSW (and shared by theconversation.com) the warming trend across the whole of Australia looks bigger when you don’t homogenise the data than when you do. The chart on the left below shows unadjusted data. The chart on the right shows homogenised data. As you can see, the adjusted data shows a cooling trend over parts of northwest Australia, which isn’t seen in the raw data.

The attacks on NASA and NOAA are pretty similar. For example, one particularly vocal conspiracy theorist, Steven Goddard, claims the NOAA doctored its figures to exaggerate global warming. Turns out, it was just homogenisation again. Here’s a NOAA chart published on deepclimate.org, showing the data before and after homogenisation. Although some of the altered data (red) indicates warmer temperatures, those warmer temperatures are spread across the entire century, so the trend remains the same.

If you click through to Goddard’s post, you’ll notice he includes an animated gif of the following 3 temperature charts (all without sources), allegedly illustrating how NASA has doctored global temperature data:

At face value, it looks like he’s right. But when you actually look more closely, you discover it’s part lie, part illusion.

Let’s start with the first chart (Hansen 1981). It turns out this is a version of the following chart from a study by Alan Robock (p.2). It shows northern hemisphere temperature variations, NOT global temperature variations, as Goddard claims. What’s more, the data is from a narrow latitude-longitude grid and records during that period covered only about 8% of the surface (p.39).

There are many, many other issues with this first chart, but I’ll leave you to read them for yourself in the original study (here’s the link again).

I haven’t figured out where he got graphs 2 and 3, because I stopped looking when I discovered he’d lied about the first. But there’s no need to find the originals. If you look closely, you’ll see that the seemingly significant differences in the circled bits can be attributed mostly to a difference in chart scale. Take the 1940 and 1980 circles, for instance. You’ll note that the 1940 circles highlight data values at around .1 in both the Hansen 1999 and GISS 2014 graphs. Similarly, the 1980 circles highlight data values at around .25 in both graphs. In other words, there’s very little, if any, difference, even though (to my understanding), the graphs are derived from different data sources or from data analysed by different people.

Oh, and for the record, Goddard is associated with the Heartland Institute too. He was a speaker at their Ninth International Conference on Climate Change.

6) “But it’s really cold where I live”

Weather and climate are two different things. Think of climate as your personality, and weather as your moods. Your mood changes from moment to moment, but your personality changes slowly over the years. It’s the same with climate. Just because someone’s experiencing a particularly cold winter doesn’t mean the temperature is not trending upwards, worldwide.

7) “It’s a conspiracy by the scientists”

We know the fossil fuel companies sponsor ‘think tanks’ like Heartland and the IPA. And we know Heartland and the IPA accuse scientists of making up climate change because scientists want more research grants. Who do you think is more likely to be making things up for profit?

Ironically, it’s more likely that the climate change deniers, themselves, are conspiracy theorists. This study certainly suggests they are:

Using established criteria to identify conspiracist ideation, we show that many of the hypotheses exhibited conspiratorial content and counterfactual thinking… The overall pattern of the blogosphere’s response… illustrates the possible role of conspiracist ideation in the rejection of science…”

8) “Solar and wind create just as much pollution”

This was something else my Google+ debating opponent said the other day: “A Coal plant produces Far Less Pollution per watt than either Wind or Solar…” But when I investigated, not surprisingly, I found he was wrong. According to the Union of Concerned Scientists (UCSUSA), an alliance of more than 400,000 citizens and scientists, coal-generated electricity produces 35-180 times as many global warming emissions as wind turbines.

Most estimates of wind turbine life-cycle global warming emissions are between 0.02 and 0.04 pounds of carbon dioxide equivalent per kilowatt-hour. To put this into context, estimates of life-cycle global warming emissions for natural gas generated electricity are between 0.6 and 2 pounds of carbon dioxide equivalent per kilowatt-hour and estimates for coal-generated electricity are 1.4 and 3.6 pounds of carbon dioxide equivalent per kilowatt-hour.”

9) “Windfarms slow down the wind which leads to global warming”

Yes, seriously. This was actually suggested by US congressman, Joe Barton. He said:

Wouldn’t it be ironic if in the interest of global warming we mandated massive switches to energy, which is a finite resource, which slows the winds down, which causes the temperature to go up?”

He was paraphrasing some researchers who found that wind farms may change the mixing of air near the surface, drying the soil near the site, and if this happened on a massive global scale, temperatures in some regions could go up by about 1 degree Centigrade.

So I looked into this one too, and it turns out it doesn’t have much merit either. NASA published results of a study that confirm wind farms may cause a localised warming effect by acting as a fan during the night, drawing warmer air to the surface, and drying the soil. BUT it went on to say:

The warming estimate applies specifically to this particular region, and covers a time when wind farms were expanding rapidly… The estimate should not be considered directly applicable for other regions and landscapes, nor should it be extrapolated over a longer period of time, as the warming would likely plateau rather than continue to increase if no new wind turbines are added. The warming is also considered a local effect, not one that would contribute to a larger global trend.”

10) “Wind turbines kill lots of birds”

Not true. According to a 2012 study by Danish researcher, Benjamin K. Sovacool:

wind farms killed approximately 20,000 birds in the United States in 2009 but nuclear plants killed about 330,000 and fossil fueled power plants more than 14 million.”

Similarly, a 2002 study by the U.S. Forest Service found wind farms killed approx 28,500 birds per year in the US, whereas buildings kill 550 million, power lines 130 million and cats 100 million!

A report by the U.S. Fish and Wildlife Service estimates that the figures are somewhat higher than the above studies. It says approximately 440,000 birds are killed by wind farms each year. And an approximate comparison by US News and World suggests a similar range (from 140,000 to 328,000 per year).

I generated a graph based on the worst figures for windfarms from the above sources, compared to deaths caused by other energy sources (click to zoom):

And for some perspective, here’s a graph from the same data showing a comparison of all major causes of bird deaths (click to zoom):

 

11) “Wind turbines make people sick”

In another Google+ discussion, a guy said of wind turbines: “Try living near one! The vibrations in the air will actually make you extremely ill. These cannot be used in areas inhabited by living creatures.” Again, bollocks. According to the National Health and Medical Research Council’s (NHMRC):

There is no reliable or consistent evidence that wind farms directly cause adverse health effects in humans.”

This finding is consistent with at least 19 other previous reviews…

Another study published by the University of Sydney explains claims that wind turbines cause health problems in communities:

In view of scientific consensus that the evidence for wind turbine noise and infrasound causing health problems is poor, the reported spatio-temporal variations in complaints are consistent with psychogenic hypotheses that health problems arising are “communicated diseases” with nocebo effects likely to play an important role in the aetiology of complaints.”

In other words, “wind turbine syndrome is spread by scaremongers”.

12) “You’re a communist!”

Communism is a socioeconomic system structured upon common ownership of the means of production and characterized by the absence of classes, money, and the state.

I just want my kids to inherit a healthy planet! Bit of a difference.

13) “Coal is the backbone of our economy”

Coal is NOT the backbone of the Australian economy. According to the Minerals Council of Australia, coal mining and related industries and services represent just 3.1% of Australia’s GDP (2011-12). I don’t have figures for other industries for that year, but I do have them from the previous year:

As you can see, more than half of our other industries contribute more to GDP than coal! And that’s just the start…

In reality, nearly all of the profits earned by the coal industry go directly overseas! (Foreign-owned coal revenue is still counted in the GDP, because GDP measures revenue earned within Australia, not BY Australians.)

14) “We can just make more coal”

Last, but not least, someone seriously asked me this question on Twitter once. Seriously!

The answer, of course, is that yes, we can make more coal. Here’s how…

STEP 1: Look at the ground.

STEP 2: Wait a few million years.