Tag Archives: skeptical science

Milestones

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You may have already heard that carbon dioxide concentrations have surpassed 400 ppm. The most famous monitoring station, Mauna Loa Observatory in Hawaii, reached this value on May 9th. Due to the seasonal cycle, CO2 levels began to decline almost immediately thereafter, but next year they will easily blow past 400 ppm.

Of course, this milestone is largely arbitrary. There’s nothing inherently special about 400 ppm. But it’s a good reminder that while we were arguing about taxation, CO2 levels continued to quietly tick up and up.

In happier news, John Cook and others have just published the most exhaustive survey of the peer-reviewed climate literature to date. Read the paper here (open access), and a detailed but accessible summary here. Unsurprisingly, they found the same 97% consensus that has come up over and over again.

Cook et al read the abstracts of nearly 12 000 papers published between 1991 and 2011 – every single hit from the ISI Web of Science with the keywords “global climate change” or “global warming”. Several different people categorized each abstract, and the authors were contacted whenever possible to categorize their own papers. Using several different methods like this makes the results more reliable.

Around two-thirds of the studies, particularly the more recent ones, didn’t mention the cause of climate change. This is unsurprising, since human-caused warming has been common knowledge in the field for years. Similarly, seismology papers don’t usually mention that plate tectonics cause earthquakes, particularly in the abstracts where space is limited.

Among the papers which did express a position, 97.1% said climate change was human-caused. Again, unsurprising to anyone working in the field, but it’s news to many members of the public. The study has been widely covered in the mainstream media – everywhere from The Guardian to The Australian – and even President Obama’s Twitter feed.

Congratulations are also due to Andrew Weaver, my supervisor from last summer, who has just been elected to the British Columbia provincial legislature. He is not only the first-ever Green Party MLA in BC’s history, but also (as far as I know) the first-ever climate scientist to hold public office.

Governments the world over are sorely in need of officials who actually understand the problem of climate change. Nobody fits this description better than Andrew, and I think he is going to be great. The large margin by which he won also indicates that public support for climate action is perhaps higher than we thought.

Finally, my second publication came out this week in Climate of the Past. It describes an EMIC intercomparison project the UVic lab conducted for the next IPCC report, which I helped out with while I was there. The project was so large that we split the results into two papers (the second of which is in press in Journal of Climate). This paper covers the historical experiments – comparing model results from 850-2005 to observations and proxy reconstructions – as well as some idealized experiments designed to measure metrics such as climate sensitivity, transient climate response, and carbon cycle feedbacks.

A Little Bit of Hope

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I went to a public lecture on climate change last night (because I just didn’t get enough of that last week at AGU, apparently), where four professors from different departments at my university spoke about their work. They were great speeches – it sort of reminded me of TED Talks – but I was actually most interested in the audience questions and comments afterward.

There was the token crazy guy who stood up and said “The sun is getting hotter every day and one day we’re all going to FRY! So what does that say about your global warming theory? Besides, if it was CO2 we could all just stop breathing!” Luckily, everybody laughed at his comments…

There were also some more reasonable-sounding people, repeating common myths like “It’s a natural cycle” and “Volcanoes emit more CO2 than humans“. The speakers did a good job of explaining why these claims were false, but I still wanted to pull out the Skeptical Science app and wave it in the air…

Overall, though, the audience seemed to be composed of concerned citizens who understood the causes and severity of climate change, and were eager to learn about impacts, particularly on extreme weather. It was nice to see an audience moving past this silly public debate into a more productive one about risk management.

The best moment, though, was on the bus home. There was a first-year student in the seat behind me – I assume he came to see the lecture as well, but maybe he just talks about climate change on the bus all the time. He was telling his friend about sea level rise, and he was saying all the right things – we can expect one or two metres by the end of the century, which doesn’t sound like a lot, but it’s enough to endanger many densely populated coastal cities, as well as kill vegetation due to seawater seeping in.

He even had the statistics right! I was so proud! I was thinking about turning around to join in the conversation, but by then I had been listening in for so long that it would have been embarrassing.

It’s nice to see evidence of a shift in public understanding, even if it’s only anecdotal. Maybe we’re doing something right after all.

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For a long time I have struggled with what to call the people who insist that climate change is natural/nonexistent/a global conspiracy. “Skeptics” is their preferred term, but I refuse to give such a compliment to those who don’t deserve it. Skepticism is a good thing in science, and it’s not being applied by self-professed “climate skeptics”. This worthy label has been hijacked by those who seek to redefine it.

“Deniers” is more accurate, in my opinion, but I feel uncomfortable using it. I don’t want to appear closed-minded and alienate those who are confused or undecided. Additionally, many people are in the audience of deniers, but aren’t in denial themselves. They repeat the myths they hear from other sources, but you can easily talk them out of their misconceptions using evidence.

I posed this question to some people at AGU. Which word did they use? “Pseudoskeptics” and “misinformants” are both accurate terms, but too difficult for a new reader to understand. My favourite answer, which I think I will adopt, was “contrarians”. Simple, clear, and non-judgmental. It emphasizes what they think, not how they think. Also, it hints that they are going against the majority in the scientific community. Another good suggestion was to say someone is “in denial”, rather than “a denier” – it depersonalizes the accusation.

John Cook, when I asked him this question, turned it around: “What should we call ourselves?” he asked, and I couldn’t come up with an answer. I feel that not being a contrarian is a default position that doesn’t require a qualifier. We are just scientists, communicators, and concerned citizens, and unless we say otherwise you can assume we follow the consensus. (John thinks we should call ourselves “hotties”, but apparently it hasn’t caught on.)

“What should I call myself?” is another puzzler, since I fall into multiple categories. Officially I’m an undergrad student, but I’m also getting into research, which isn’t a required part of undergraduate studies. In some ways I am a journalist too, but I see that as a side project rather than a career goal. So I can’t call myself a scientist, or even a fledgling scientist, but I feel like I’m on that path – a scientist larva, perhaps?

Thoughts?

General Thoughts on AGU

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I returned home from the AGU Fall Meeting last night, and after a good night’s sleep I am almost recovered – it’s amazing how tired science can make you!

The whole conference felt sort of surreal. Meeting and conversing with others was definitely the best part. I shook the hand of James Hansen and assured him that he is making a difference. I talked about my research with Gavin Schmidt. I met dozens of people that were previously just names on a screen, from top scientists like Michael Mann and Ben Santer to fellow bloggers like Michael Tobis and John Cook.

I filled most of a journal with notes I took during presentations, and saw literally hundreds of posters. I attended a workshop on climate science communication, run by Susan Joy Hassol and Richard Sommerville, which fundamentally altered my strategies for public outreach. Be sure to check out their new website, and their widely acclaimed Physics Today paper that summarizes most of their work.

Speaking of fabulous communication, take a few minutes to watch this memorial video for Stephen Schneider – it’s by the same folks who turned Bill McKibben’s article into a video:

AGU inspired so many posts that I think I will publish something every day this week. Be sure to check back often!

Climate Change Denial: Heads in the Sand

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I recently finished reading Climate Change Denial: Heads in the Sand by Haydn Washington and Skeptical Science founder John Cook. Given that I am a longtime reader of (and occasional contributor to) Skeptical Science, I didn’t expect to find much in this book that was new to me. However, I was pleasantly surprised.

Right from Chapter 1, Washington and Cook discuss a relatively uncharted area among similar books: denial among people who accept the reality of climate change. Even if a given citizen doesn’t identify as a skeptic/contrarian/lukewarmer/realist/etc, they hold information about global warming at arm’s length. The helplessness and guilt they feel from the problem leads them to ignore it. This implicit variety of denial is a common “delusion”, the authors argue – people practice it all the time with problems related to their health, finances, or relationships – but when it threatens the welfare of our entire planet, it is a dangerous “pathology”.

Therefore, the “information deficit model” of public engagement – based on an assumption that political will for action is only lacking because citizens don’t have enough information about the problem – is incorrect. The barriers to public knowledge and action aren’t scientific as much as “psychological, emotional, and behavioural”, the authors conclude.

This material makes me uncomfortable. An information deficit model would work to convince me that action was needed on a problem, so I have been focusing on it throughout my communication efforts. However, not everyone thinks the way I do (which is probably a good thing). So what am I supposed to do instead? I don’t know how to turn off the scientist part of my brain when I’m thinking about science.

The book goes on to summarize the science of climate change, in the comprehensible manner we have come to expect from Skeptical Science. It also dips into the site’s main purpose – classifying and rebutting climate change myths – with several examples of denier arguments. I appreciate how up-to-date this book is, as it touches on several topics that are included in few, if any, of my other books: a Climategate rebuttal, as well as an acknowledgement that the Venus syndrome on Earth, while distant, might be possible – James Hansen would even say plausible.

A few paragraphs are dedicated to discussing and criticizing scientific postmodernism, which I think is sorely needed – does anyone else find it strange that a movement which was historically quite liberal is now being resurrected by the science-denying ranks of conservatives? Critiques of silver-bullet approaches to mitigation, such as nuclear power alone or clean coal, are also included.

In short, Climate Change Denial: Heads in the Sand is well worth a read. It lacks the gripping narrative of Gwynne Dyer or Gabrielle Walker, both of whom have the ability to make scientific information feel like a mystery novel rather than a textbook, but it is enjoyable nonetheless. It adds worthy social science topics, such as implicit denial and postmodernism, to the discussion, paired with a taste of what Skeptical Science does best.

Who are the Skeptics?

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Part 3 in a series of 5 for NextGen Journal
Adapted from part of an earlier post

As we discussed last time, there is a remarkable level of scientific consensus on the reality and severity of human-caused global warming. However, most members of the public are unaware of this consensus – a topic which we will focus on in the next installment. Anyone with an Internet connection or a newspaper subscription will be able to tell you that many scientists think global warming is natural or nonexistent. As we know, these scientists are in the vast minority, but they have enjoyed widespread media coverage. Let’s look at three of the most prominent skeptics, and examine what they’re saying.

S. Fred Singer is an atmospheric physicist and retired environmental science professor. He has rarely published in scientific journals since the 1960s, but he is very visible in the media. In recent years, he has claimed that the Earth has been cooling since 1998 (in 2006), that the Earth is warming, but it is natural and unstoppable (in 2007), and that the warming is artificial and due to the urban heat island effect (in 2009).

Richard Lindzen, also an atmospheric physicist, is far more active in the scientific community than Singer. However, most of his publications, including the prestigious IPCC report to which he contributed, conclude that climate change is real and caused by humans. He has published two papers stating that climate change is not serious: a 2001 paper hypothesizing that clouds would provide a negative feedback to cancel out global warming, and a 2009 paper claiming that climate sensitivity (the amount of warming caused by a doubling of carbon dioxide) was very low. Both of these ideas were rebutted by the academic community, and Lindzen’s methodology criticized. Lindzen has even publicly retracted his 2001 cloud claim. Therefore, in his academic life, Lindzen appears to be a mainstream climate scientist – contributing to assessment reports, abandoning theories that are disproved, and publishing work that affirms the theory of anthropogenic climate change. However, when Lindzen talks to the media, his statements change. He has implied that the world is not warming by calling attention to the lack of warming in the Antarctic (in 2004) and the thickening of some parts of the Greenland ice sheet (in 2006), without explaining that both of these apparent contradictions are well understood by scientists and in no way disprove warming. He has also claimed that the observed warming is minimal and natural (in 2006).

Finally, Patrick Michaels is an ecological climatologist who occasionally publishes peer-reviewed studies, but none that support his more outlandish claims. In 2009 alone, Michaels said that the observed warming is below what computer models predicted, that natural variations in oceanic cycles such as El Niño explain most of the warming, and that human activity explains most of the warming but it’s nothing to worry about because technology will save us (cached copy, as the original was taken down).

While examining these arguments from skeptical scientists, something quickly becomes apparent: many of the arguments are contradictory. For example, how can the world be cooling if it is also warming naturally? Not only do the skeptics as a group seem unable to agree on a consistent explanation, some of the individuals either change their mind every year or believe two contradictory theories at the same time. Additionally, none of these arguments are supported by the peer-reviewed literature. They are all elementary misconceptions which were proven erroneous long ago. Multiple articles on this site could be devoted to rebutting such claims, but easy-to-read rebuttals for virtually every objection to human-caused climate change are already available on Skeptical Science. Here is a list of rebuttals relevant to the claims of Singer, Lindzen and Michaels:

With a little bit of research, the claims of these skeptics quickly fall apart. It does not seem possible that they are attempting to further our knowledge of science, as their arguments are so weak and inconsistent, and rarely published in scientific venues. However, their pattern of arguments does work as a media strategy, as most people will trust what a scientist says in the newspaper, and not research his reputation or remember his name. Over time, the public will start to remember dozens of so-called problems with the anthropogenic climate change theory.

Climate Change Communicator of the Year Award

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There’s just over a week left to vote in the Climate Change Communicator of the Year awards, run by the Centre for Climate Change Communication at George Mason University.

There are several familiar names among the nominees, including meteorology professor and frequent ClimateSight commenter Scott Mandia, the ever-brilliant Naomi Oreskes, and the growing organization of Skeptical Science.

Voting is quick and easy, and only requires an email address. Please be sure to cast your vote before April 15th and support the community!

“It’s Just a Natural Cycle”

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My second rebuttal for Skeptical Science. Thanks to all the folks who helped to review it! Further suggestions are welcome, as always. -Kate

“What if global warming is just a natural cycle?” This argument is, perhaps, one of the most common raised by the average person, rather than someone who makes a career out of denying climate change. Cyclical variations in climate are well-known to the public; we all studied the ice ages in school. However, climate isn’t inherently cyclical.

A common misunderstanding of the climate system characterizes it like a pendulum. The planet will warm up to “cancel out” a previous period of cooling, spurred by some internal equilibrium. This view of the climate is incorrect. Internal variability will move energy between the ocean and the atmosphere, causing short-term warming and cooling of the surface in events such as El Nino and La Nina, and longer-term changes when similar cycles operate on decadal scales. However, internal forces do not cause climate change. Appreciable changes in climate are the result of changes in the energy balance of the Earth, which requires “external” forcings, such as changes in solar output, albedo, and atmospheric greenhouse gases. These forcings can be cyclical, as they are in the ice ages, but they can come in different shapes entirely.

For this reason, “it’s just a natural cycle” is a bit of a cop-out argument. The Earth doesn’t warm up because it feels like it. It warms up because something forces it to. Scientists keep track of natural forcings, but the observed warming of the planet over the second half of the 20th century can only be explained by adding in anthropogenic radiative forcings, namely increases in greenhouse gases such as carbon dioxide.

Of course, it’s always possible that some natural cycle exists, unknown to scientists and their instruments, that is currently causing the planet to warm. There’s always a chance that we could be totally wrong. This omnipresent fact of science is called irreducible uncertainty, because it can never be entirely eliminated. However, it’s very unlikely that such a cycle exists.

Firstly, the hypothetical natural cycle would have to explain the observed “fingerprints” of greenhouse gas-induced warming. Even if, for the sake of argument, we were to discount the direct measurements showing an increased greenhouse effect, other lines of evidence point to anthropogenic causes. For example, the troposphere (the lowest part of the atmosphere) is warming, but the levels above, from the stratosphere up, are cooling, as less radiation is escaping out to space. This rules out cycles related to the Sun, as solar influences would warm the entire atmosphere in a uniform fashion. The only explanation that makes sense is greenhouse gases.

What about an internal cycle, perhaps from volcanoes or the ocean, that releases massive amounts of greenhouse gases? This wouldn’t make sense either, not only because scientists keep track of volcanic and oceanic emissions of CO2 and know that they are small compared to anthropogenic emissions, but also because CO2 from fossil fuels has its own fingerprints. Its isotopic signature is depleted in the carbon-13 isotope, which explains why the atmospheric ratio of carbon-12 to carbon-13 has been going down as anthropogenic carbon dioxide goes up. Additionally, atmospheric oxygen (O2) is decreasing at the same rate that CO2 is increasing, because oxygen is consumed when fossil fuels combust.

A natural cycle that fits all these fingerprints is nearly unfathomable. However, that’s not all the cycle would have to explain. It would also have to tell us why anthropogenic greenhouse gases are not having an effect. Either a century of basic physics and chemistry studying the radiative properties of greenhouse gases would have to be proven wrong, or the natural cycle would have to be unbelievably complex to prevent such dramatic anthropogenic emissions from warming the planet.

It is indeed possible that multidecadal climate variability, especially cycles originating in the Atlantic, could be contributing to recent warming, particularly in the Arctic. However, the amplitude of the cycles simply can’t explain the observed temperature change. Internal variability has always been superimposed on top of global surface temperature trends, but the magnitude – as well as the fingerprints – of current warming clearly indicates that anthropogenic greenhouse gases are the dominant factor.

Despite all these lines of evidence, many known climatic cycles are often trumpeted to be the real cause, on the Internet and in the media. Many of these cycles have been debunked on Skeptical Science, and all of them either aren’t in the warming phases, don’t fit the fingerprints, or both.

For example, we are warming far too fast to be coming out of the last ice age, and the Milankovitch cycles that drive glaciation show that we should be, in fact, very slowly going into a new ice age (but anthropogenic warming is virtually certain to offset that influence).

The “1500-year cycle” that S. Fred Singer attributes warming to is, in fact, a change in distribution of thermal energy between the poles, not a net increase in global temperature, which is what we observe now.

The Little Ice Age following the Medieval Warm Period ended due to a slight increase in solar output (changes in both thermohaline circulation and volcanic activity also contributed), but that increase has since reversed, and global temperature and solar activity are now going in opposite directions. This also explains why the 11-year solar cycle could not be causing global warming.

ENSO (El Nino Southern Oscillation) and PDO (Pacific Decadal Oscillation) help to explain short-term variations, but have no long-term trend, warming or otherwise. Additionally, these cycles simply move thermal energy between the ocean and the atmosphere, and do not change the energy balance of the Earth.

As we can see, “it’s just a natural cycle” isn’t just a cop-out argument – it’s something that scientists have considered, studied, and ruled out long before you and I even knew what global warming was.

New Year Gratitude

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A very happy 2011 to everyone. I thought I would write a New Year’s post like last year’s.

ClimateSight wouldn’t exist at all without my very best friend and partner, who, after listening for months to my rambles about climate science and policy, set me up with a blog. Since my first post, he has listened to my ideas and provided many of his own, even though he’s not particularly interested in climatology. He is also a source of balance in my life, keeping me sane when news reports and nasty comments start to overwhelm me.

Equally deep gratitude goes to the scientist who first sparked my interest in climate, and who continues to be both a mentor and a friend, as well as a library (I promise I’ll return those books sooner or later). You know who you are!

I have received advice on everything from my comment policy to my course selection from many wise climate bloggers, such as Steve Easterbrook, Michael Tobis, and Tamino, as well as countless others who prefer to read and comment than to write their own blogs – too many to name!

This year, I have become involved in Skeptical Science, a multi-faceted collaboration of scientists and science enthusiasts concerned about the state of climate change communication. It is an honour to be part of the supportive, enthusiastic community of authors, and the articles they write provide hours of fascinating reading and further research.

Last but not least, I must thank the readers and commenters over here. I feel that I get more out of this blog than I put in. My thoughts on a topic don’t end when I hit “publish” – that’s just the beginning, as insights and links to further reading invariably appear in the comments.

I am grateful for more than the people who helped to create this online community, though. I am grateful to live in the age of information when looking up the state of Arctic sea ice takes less than a minute. I am grateful to live in the age of climatology, where the field is expanding throughout virtually every discipline. Finally, strangely enough, I am grateful to live in the age of climate change, to witness this fascinating phenomenon unfold, and (hopefully) to be a part of the generation that stops it in its tracks.

Just Links for Now…

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I apologize for my relative silence recently. I am in the midst of studying for my first set of final exams. To tide you over until that has calmed down a bit, I will share some of the interesting pieces I have read and watched recently.

My study break today was spent watching a fantastic video that Peter Sinclair recently dug up. It’s an hour-long talk by Dr. Ben Santer (see my recent interview with him), with an introduction by the late Stephen Schneider and questions at the end. He tells a very troubling story about “science, non-science and nonsense”. Lots of great quotes in there – I highly recommend giving it a watch.

John Cook from Skeptical Science has compiled his articles and rebuttals into a gorgeous document about the evidence for anthropogenic climate change, written in accessible language with effective graphics on every page. It’s so effective, I would like to print out a few dozen of these booklets and hand them out at the university.

On RealClimate, Ray Pierrehumbert addressed the common policy option of focusing on cutting emissions of methane and soot in the short-term in order to “buy us time” to reduce carbon dioxide. In fact, because these emissions have such a short atmospheric lifetime, it doesn’t really matter whether we focus on them now or later – while concentrations of carbon dioxide, with a lifetime of centuries to millennia, highly depend on when we address it. Take a look at these projections comparing our options:

Michael Tobis, however, thinks that we should focus on non-CO2 emissions despite these realities. Short-term economic and population “crashes” due to sudden warming in the near term could conceivably be more damaging to human security, because it means that we won’t be able to afford any mitigation, further worsening the long-term emissions. Both articles are worth a read.

Well, off to go memorize organic functional groups. Enjoy!