Wednesday, October 26, 2011

Climate in the era of humans

The latest episode of the radio show and podcast Big Picture Science is all about the idea that we have entered the "anthropocene" or era of man. The guests include William Steffan, talking about the anthropocene concept, and a host of others including yours truly discussing the evidence that humans are changing the climate, and how we can best describe that evidence to people.

On a related note, the Yale Climate Media Forum has a story up about whether culture matters in discussing climate change, based on my upcoming publication on belief and climate change. 


Thursday, October 20, 2011

Can we make the climate a part of the human world?

A new paper of mine, about to be published in the October issue of BAMS (Bulletin of the American Meteorological Society), looks at how the common, ancient human belief that the weather and climate are out of human control affects education and outreach about human-caused climate change. I outlined these ideas and my outreach message at a talk earlier this year. An early online version of the paper is available.

The article could really be a book, and, in fact, it may become one in a year or two. It grew out of several years of interdisciplinary research, involving everything from reading history and religious texts, to interviewing religious leaders, to participating in outreach programs, to donning a sulu and attending church in Fiji.

Here's the core argument:

Skepticism about anthropogenic climate change may therefore be reasonable when viewed through the lens of religion or the lens of history. In order to create a lasting public understanding of anthropogenic climate change, scientists and educators need to appreciate that the very notion that humans can directly change the climate may conflict with beliefs that underpin the culture of the audience.

I briefly trace the history behind this argument, and provide some modern evidence for the influence of belief on acceptance of the evidence for climate change. Despite what William Briggs, a critic of the early online release, my argument is not purely about religion, rather it is about the sense that the climate is to large to be affected by humans. This idea that we are small compared to the grand forces of nature and the atmosphere may be encoded in a structured belief system, or it may drive people's desire to climb mountains and stare at the view from the top.

Even in secular communities, a broad sense that forces beyond humans control the climate may partly explain the persistence of the argument that natural forcings like solar activity are the primary cause of observed 20th century climate change despite overwhelming scientific evidence to the contrary.

I conclude with two broad suggestions for reforming climate change education and outreach:

Climate change outreach efforts need to address the perceived conflict between the scientific evidence and deeply ingrained cultural perceptions of climate. First, the development of human beliefs about climate should be added to educational materials and lesson plans. Existing education and outreach efforts rarely acknowledge any thinking about climate or climate change prior to the Svante Arrhenius’ 1896 study on atmospheric carbon dioxide and temperature....

Second, educators and scientists should take lessons from approaches used in teaching of evolution, another subject where science can appear to conflict with pre-existing beliefs. Pedagogical research on evolution finds that providing the audience with opportunities to evaluate how their culture or beliefs affect their willingness to accept scientific evidence is more effective than attempting to separate scientific views from religious or cultural views.

The paper concludes with a message that I am regularly repeating at scientific forums, and will continue to write about at Maribo:
Climate scientists, for whom any inherent doubts about the possible extent of human influence on the climate were overcome by years of training in physics and chemistry of the climate system, need to accept that there are rational cultural, religious and historical reasons that the public may fail to believe that anthropogenic climate change is real, let alone that it warrants a policy response. It is unreasonable to expect a lay audience, not armed with the same analytical tools as scientists, to develop lasting acceptance during a one hour public seminar of a scientific conclusion that runs counters to thousands of years of human belief.


Tuesday, October 18, 2011

Climate change debates and flags of convenience

One of the perverse thrills of paddling in Vancouver is cozying up to the massive container ships parked out in English Bay (right). A little while back, I paddled past one rusting behemoth with the word "Monrovia" painted in white on the red hull. Each letter was about the size of my little kayak.

Monrovia is the capital of Liberia, the country where that vessel is registered. There is no thriving trade between Liberia and western Canada. Merchant ships merely register in Liberia in order to avoid regulations and to reduce costs. Liberia is the flag of convenience.

As a scientist, I sometimes find the challenge of communicating about climate change similar to that of operating a ship according to the rules of your native country while the "competitors" take advantage of the lawless wilds of other nations.

People opposing the basic science of climate change in the public sphere need not adhere to the slow, rigorous method of hypothesis testing or build coherent arguments over time based on the balance of published evidence. That provides the rhetorical advantage of adopting whatever "flag" or argument is convenient that week, whether about sunspots, an error in an IPCC report, or temperature trends on Mars. If the argument is proven false in the court of public opinion, you adopt another flag. The sequence of arguments does not have to be logically consistent. The goal of the organized sceptic movement* is simply to keep the ship sailing.

The temptation for scientists to adopt the practices of the opponents in the debate is what the late Steve Schneider described called the "double ethical bind" in a famously mis-used quote:

On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but – which means that we must include all doubts, the caveats, the ifs, ands and buts. On the other hand, we are not just scientists but human beings as well. And like most people we’d like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climate change. To do that we need to get some broad based support, to capture the public’s imagination. That, of course, means getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have. This “double ethical bind” we frequently find ourselves in cannot be solved by any formula. Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both

The response to that honest, clear assessment of the communications challenge says enough. For years, that one line about offering up "scary scenarios" was itself a Liberia to many of Schneider's opponents.

It can be challenging to stay level-headed about communication in the face of often unscrupulous opposition. That's why I find that the keys to communication about climate change are not the usual suspects of technical expertise, passion, ability to drop jargon, etc. etc. In my experience, successfully communicating about climate change takes, more than anything else, patience and humility.

* Note: It's important to separate the funded movement from individual people's doubts about the science of climate change, which can be grounded in science, culture, religion, politics, moral values, you name it. And there are vocal sceptics who rely on a consistent line of argumentation; perhaps Lindzen's earlier arguments about the water vapour feedback could fall in this category, though it's fair to say that ship has since migrated to other shores.


Sunday, October 02, 2011

Nutrient limitation missing from an otherwise good NY Times story on forests and climate change

The NY Times published a lengthy article about the climate implications of the forest diebacks and fires. It is, on the whole, a great and all-too-rare example of longform science journalism.

The article does miss one important point about CO2 fertilization, the increase in plant growth thought to come from adding more CO2 to the air.

Climate-change contrarians tend to focus on this “fertilization effect,” hailing it as a boon for forests and the food supply. “The ongoing rise of the air’s CO2 content is causing a great greening of the Earth,” one advocate of this position, Craig D. Idso, said at a contrarian meeting in Washington in July.

Dr. Idso and others assert that this effect is likely to continue for the foreseeable future, ameliorating any negative impacts on plant growth from rising temperatures. More mainstream scientists, while stating that CO2 fertilization is real, are much less certain about the long-term effects, saying that the heat and water stress associated with climate change seem to be making forests vulnerable to insect attack, fires and many other problems.

The CO2 fertilization effect is limited, because plants require more than just CO2 to do their job:  photosynthesis. Water is certainly a limiting factor, but nutrients are just as important. In experiment after experiment, scientists find that the CO2 fertilization effect is short-lived without additional inputs of nutrients, particularly nitrogen.

One of the reasons CO2 fertilization may have accelerated plant growth in parts of Europe and North America over the past few decades may be the fact that we've inadvertently been fertilizing the plants with nitrogen, as well as CO2. We'll actually be talking about this in GEOB400 in a couple weeks. For the 6.7 billion or so of you who were unable to register this semester - yes, yes, the class is too small, I hear that all the time - I wrote about this on Maribo a few years ago, in a cross-post with Eli and Tamino:

One culprit is carbon’s chemical sibling nitrogen, that’s #7 on your periodic table if you’re scoring at home. Like many siblings, carbon and nitrogen are quite co-dependent, and, one might argue, a bit resentful about the whole thing. Carbon fixation - photosynthesis, plant growth – is limited by the availability of nitrogen. Though only up to a point. If there’s too much nitrogen, things get saturated, and the carbon-based plants pout and refuse to grow more.

You might find it strange that nitrogen is limited, given that N2 or di-nitrogen gas makes up the majority of the atmosphere. However, N2 is unreactive. It only becomes available to plants when converted to reactive form by microbes. In the process of making fertilizer and burning fossil fuels, we not only have increased the rate at which this conversion happens, leaving more nitrogen in our soils and waterways, we've emitted nitrogen in other reactive, gaseous forms, like nitrogen oxides or NOx