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Category: biodiversity
New Study on Extinction Elicits the View from Somewhere
Before climate change took center stage, the most hotly contested environmental debate was over how many species there were in the world and how fast they were going extinct. A new review paper in the journal Science returns us to the subject. How this study has been filtered and interpreted in the media is interesting. Before I get to that, though, let the paper speak for itself. From the abstract:
Some people despair that most species will go extinct before they are discovered. However, such worries result from overestimates of how many species may exist, beliefs that the expertise to describe species is decreasing, and alarmist estimates of extinction rates.
Robert May, one of the world’s premier ecologists, is an author of the paper. He’s been at the center of the species debate for decades. In this latest stab, as the magazine Conservation summarizes,
researchers estimate that Earth houses 2 to 8 million species, and 1.5 million have been described. Other studies have suggested a species count of 30 to 100 million, but such estimates “seem highly unlikely,” the authors write.
The title of the new paper is curious: “Can we name species before they go extinct?” The authors say the answer is yes, “but we may have to hurry,” one of them cautions in The Conversation.
If the title of the Science paper seems oddly discordant with its thrust, that may owe to the high political stakes of the subject and the controversy stirred up by a 2011 Nature paper, which was titled: Read More
The Cost of a New Environmentalism
Last week, my Slate piece on environmentalism was read by many people who care (and write) about green issues. Some (okay, many of them) didn’t particularly like what I wrote. I felt the rumblings on Twitter and elsewhere. And I had planned on responding, but then the horrific tragedy on Friday happened, and I just didn’t have it in me to wade back into the nitty gritty of eco-narratives that still dominate our discourse.
I still plan on responding in full to the main rebuttals. Look for that in this space near the end of the week.
Meanwhile, I see that Bryan Walsh of Time magazine has just published a really thoughtful take on my piece. Which doesn’t surprise me, because it was Walsh’s thoughts on Twitter last week (in reaction to the essay) that got me thinking the most. He articulated implications of my argument that I hadn’t addressed (or much considered) and I’ve been brooding over them since.
In his Time piece, Walsh talks about the refreshing new strain of environmentalism modern greens have created. But he also wonders about the tradeoffs that come with eco-pragmatism. Go read his piece.
I’m pretty sure I’ll have it in the back of my mind today, as I wander around the American Museum of Natural History with my 8 year old son and his classmates during a school field trip. His class is currently learning about ecology, so we’ll be looking at exhibits on ecosystems and biodiversity.
Overplaying the Climate Fear Card
In her recent Mother Jones story, Julia Whitty mentions that “destruction of nature” has become a “dominant meme” in environmental discourse and politics. Her excellent piece does not follow this familiar script. Rather it chronicles the extraordinary conservation successes of a few unsung individuals.
Anyone who follows environmental writing knows that Whitty’s article bucks a long established theme. As Michelle Nijhuis noted in an essay last year:
Environmental journalists often feel married to the tragic narrative. Pollution, extinction, invasion: The stories are endless, and endlessly the same.
In her Mother Jones piece, Whitty references a 2011 paper by two conservation biologists in the journal Trends in Ecology and Evolution. Here’s the section in the paper that jumps out:
Relentless communication of an impending mass extinction is, self-evidently, having insufficient impact on politicians, policy makers and the public, and could eventually even be counterproductive for improved conservation. Instead, we contend that there is ample evidence from other disciplines, such as medicine, public health, and road safety, to show that achieving political support and lasting behavioral change requires ‘bad news’ to be balanced by empowerment. Berating people about biodiversity decline ignores fundamental human behaviors. In broader society, people ignore delivery of bad news because it reflects badly on the deliverer. Indeed, denial of major biodiversity loss might intensify in the wider public, even as scientific evidence accumulates, because of the way in which people respond to threats of this nature.
Sound familiar? Just substitute climate change for biodiversity and the same applies.
A lot of people have lauded Bill McKibben’s recent Rolling Stone article, titled “Global Warming’s Terrifying New Math.” In the Huffington Post, Neil Wagner said it
is probably (pound for pound) the best piece ever written about the dire straights anthropogenic climate change has presented the human race.
- Read the first couple of paragraphs
- Feel sick to your stomach
- Continue reading while curled up in a fetal position.
A recent video by Peter Sinclair connecting climate change to this summer’s heat waves, wildfires and extreme weather in the United States was called, “Welcome to the Rest of Our Lives.” Translation: Global warming has arrived and this is what it looks like. I think there might be some quibbles with that (in terms of the implied linkages), but no matter. If you don’t pay attention to the details, then watch the video and weep. If it doesn’t inspire utter helplessness in the average person, I’d be surprised.
Along those lines, I’ll be curious to see how the emerging climate movement motivates people to act while they are curled up in a fetal position.
What Values Inform Our Ecological Debates?
In the not so distant past, before there was a “collective fixation on global warming as the mother of all environmental problems,” as Jon Foley lamented in 2009, biodiversity was the poster child for environmental crises. It was an issue that captivated journalists, scientists and greens alike–much as climate change does today. Indeed, concern over the loss of biodiversity and how that impacted the overall health of the planet was once a frequent topic of discussion in leading scientific journals. For example, here is the summary overview of a review article for Nature in 2000 by a group of biologists:
Human alteration of the global environment has triggered the sixth major extinction event in the history of life and caused widespread changes in the global distribution of organisms. These changes in biodiversity alter ecosystem processes and change the resilience of ecosystems to environmental change. This has profound consequences for services that humans derive from ecosystems. The large ecological and societal consequences of changing biodiversity should be minimized to preserve options for future solutions to global environmental problems.
At this time, there was a lively debate within the field of ecology as to what extent species richness (i.e., diversity) contributed to productive (and resilient) ecosystem function. (This debate pivoted off a 1972 paper by Robert May, published in Nature, that suggested ecosystems with higher diversity actually tended to be less stable; the mathematical formula that May used–which upended a long-held assumption in ecology– was revisited last year.) In 2010, Michel Loreau published an excellent essay on the state of this debate, tracing its history, underlying tensions, and connection to global environmental policy. He noted:
The relationship between biodiversity and ecosystem functioning has emerged as a central issue in ecological and environmental sciences during the past 15 years. The idea that greater plant diversity allows greater plant biomass production dates back to Darwin (McNaughton 1993; Hector & Hooper 2002), but it was only in the 1990s that the interest in the effects of biodiversity on ecosystem functioning penetrated experimental and theoretical ecology. This interest spread very rapidly, leading to an entire new research field at the interface between community ecology and ecosystem ecology (Schulze & Mooney 1993; Tilman 1999; Chapin et al. 2000; Loreau 2000; Kinzig et al. 2001; Loreau et al. 2001; Loreau et al. 2002b; Hooper et al. 2005; Balvaneraet al. 2006; Cardinale et al. 2006; Cardinale et al. 2007).
Loreau goes on to discuss the experimental field and laboratory research that “has now clearly established that biodiversity does indeed affect ecosystem processes.” But the final verdict was not exactly ironclad, as he sort of admits here:
Although rigorous empirical support for the new diversity”“stability theory is scantier than for the effects of diversity on biomass and production, a few experiments that have manipulated species diversity have provided clear evidence for its stabilizing effect on ecosystem properties in both plant communities (Tilman et al. 2006) and aquatic food webs (Steiner et al. 2005).
In any case, the biodiversity = robust ecosystems train had already left the station, as Loreau explains:
Because its initial impetus was provided by the societal relevance of the issues it was addressing, biodiversity and ecosystem functioning research also impacted on social sciences and environmental management. The results of this research supported the work of the Millennium Ecosystem Assessment (2005) on the links between biodiversity, ecosystem services and sustainable development. The value of biodiversity as insurance against the uncertain provision of ecosystem services is being incorporated formally in ecological economics (Armsworth & Roughgarden 2003; Baumgärtner 2007).
Meanwhile, in a 2009 historical overview of ecological paradigms, Matt Chew observed that “different concepts of stability, diversity, and complexity” have, over time, shaped the studies that have sought to identify the most essential properties of ecosystem function.
Regardless, a new review paper just published in Nature coronates biodiversity as the winner of this long-simmering debate. Among the paper’s key findings:
There is mounting evidence that biodiversity increases the stability of ecosystem functions through time.
Diverse communities are more productive because they contain key species that have a large influence on productivity, and differences in functional traits among organisms increase total resource capture.
Coincidentally, and just before I saw the latest Nature paper, I had inquired on twitter about the status of the biodiversity/ecosystem function debate. “Which side came out on top,” I asked? One scientist responded, “Neither.. it was a theoretical vs. non-theoretical ecologists debate.” Another said, “It’s a subjective question, b/c it asks what we value about ecosystems.”
Precisely. The debates we’re now having over planetary boundaries and tradeoffs between development and conservation are based, in large part, on subjective notions, so asking what we value (and why) seems like something that should be a big part of the discussion.
About Those Tipping Points
Last week, we received this scary bulletin out of Berkley, California:
A prestigious group of scientists from around the world is warning that population growth, widespread destruction of natural ecosystems, and climate change may be driving Earth toward an irreversible change in the biosphere, a planet-wide tipping point that would have destructive consequences absent adequate preparation and mitigation.
Since the warning was featured in a prominent journal, many in mainstream media (and the enviro-blogosphere) dutifully treated it as the latest sky-is-falling alert.
The New York Times, taking the sober, detached approach, asked:
Are we nearing a planetary boundary?
That headline is a nod to a much-discussed concept laid out in Nature several years ago (you can read the expanded version here), which made the case for “a safe, operating space for humanity” by identifying thresholds for climate change, ozone depletion, ocean acidification, biodiversity, freshwater use, the global nitrogen and phosphorus cycles, and land use change.
While the main essay got gobs of attention, it’s worth recalling that Nature also hosted separate commentaries (seven of them) on the planetary boundaries thesis. In its introduction, Nature asked:
But do we understand the Earth system well enough to know the real limits to environmental degradation? And if we can define them, even roughly, would doing so ultimately help or hinder efforts to protect the planet?
Those questions have now been taken up by the Oakland-based Breakthrough Institute, in a blunt critique of the planetary boundaries framework, which they consider to be “a misleading guide to global environmental challenges.”
Here’s the thrust of Breakthrough’s report:
The Earth has entered the Anthropocene, a time in which humans are the dominant force shaping all Earth systems. All of the nine systems and processes identified by Rockström et al. are important determinants, albeit in complex ways, of human welfare “” indeed, they enable life on this planet to exist. They all need to be managed wisely and consciously. The planetary boundaries concept was suggested as a framework for doing so, and it makes several important contributions worth highlighting. It brings resilience thinking and complex systems theory to the center of the debate, and draws attention to the many interrelated elements and processes of the Earth system . However, our review of the framework has identified some serious flaws, which together make planetary boundaries a poor, even misleading, answer to the challenge of planetary stewardship. The implications of this review apply not only to the planetary boundaries concept in itself, but to Earth Science as a whole, especially as regards the way it interfaces with policy making.
In two follow-up posts that will appear tomorrow, I’ll delve more deeply into the specific criticisms made by the Breakthrough Institute, including elaboration from the report’s lead author. Meanwhile, Jon Foley, an earth scientist at the University of Minnesota, and a contributing author of the 2009 planetary boundaries paper in Nature, has responded to Breakthrough’s critique on twitter and to reporters in email, of which this is an excerpt:
Their entire report is based on two or three straw-man arguments. Sadly, there is nothing substantive here. And this isn’t sour grapes, believe me. I would welcome a useful critique of the Planetary Boundaries concept! In fact, the original publication in Nature included a half dozen sharply worded comments and critiques, and many were extremely useful in improving our collective ideas…I appreciate many of the points they [the Breakthrough Institute] have raised over the years — especially from their original “Death of Environmentalism” essay. But I think this report fails to raise anything very new or interesting. Too bad: I wish they had. This concept deserves more scrutiny and challenges.
Foley, in an email exchange, has made a more detailed rebuttal. So I’ll be pulling from that in the second post that will look more closely at the Breakthrough Institute’s critique. A third, related post will specifically examine how biodiversity has come to fit into the planetary boundaries concept.
Nature's Urban Melting Pot
Last week, Carl Zimmer’s NYT science article began this way:
To study evolution, Jason Munshi-South has tracked elephants in central Africa and proboscis monkeys in the wilds of Borneo. But for his most recent expedition, he took the A train.
To those of you unfamiliar with the NYC subway, this would be the A train to upper Manhattan. Zimmer notes:
Cities attract only a small fraction of evolutionary biologists, who often work in lusher places like the Amazon. But urban evolution is attracting more research these days, because cities are fast-growing, and the urban environment is quickly taking over large areas of the Earth’s surface.
As I recently discussed, this trend is part of an evolution in ecological thinking. And it’s long past due. After all, if neighborhood gardens and green markets can thrive in cities, then so can all manner of wildlife. The unruly biodiversity of society at large is also reflected in the urban landscape, a point unintentionally made in Zimmer’s article:
Biologists find a mixture of native and non-native in all the life forms they study in New York, from the trees in Central Park to the birds of Jamaica Bay.
Speaking of Jamaica Bay, here’s a great article in yesterday’s NYT about “the city’s largest open space”:
A giant salt water puddle, pooled over 20,000 acres beneath the leaky eaves of southern Queens and Brooklyn, the bay lies at the far end of the Rockaways A line. And to ride that line from Times Square to Canal Street to Broadway Junction, and then through Ozone Park to Howard Beach and Broad Channel, where suddenly there are marshes offshore and ibises and egrets in the sky, is to understand that with a simple 90-minute trip one can find a wilderness within the city limits.
The notion that “wilderness” can exist within a metropolis–something that probably would have been deemed nuts several decades ago–suggests that our views of nature have matured and expanded, just like those of the scientists now discovering and cataloguing urban biological diversity.
The Engineered Earth
The issue of human-manufactured biodiversity is controversial. After all, if humans are overrunning nature and degrading the vital ecosystem services that we depend on, isn’t it rather beside the point if we also inadvertently boost biodiversity on some landscapes?
I don’t think so. More environmentalists need to realize that the boundaries between pristine nature and civilization grow fuzzier by the day. The latest example is a new, intriguing study on pre-Columbian agriculture in the Amazon, published last week in PNAS.
This is the kind of stuff that makes my geeky heart flutter: interdisciplinary research on how ancient farmers engineered their environment in a part of the world that most people today consider primordial nature. Additionally, these findings hold important contemporary ecological lessons, as the study’s abstract explains:
The profound alteration of ecosystem functioning in these landscapes coconstructed by humans and nature has important implications for understanding Amazonian history and biodiversity. Furthermore, these landscapes show how sustainability of food-production systems can be enhanced by engineering into them fallows that maintain ecosystem services and biodiversity. Like anthropogenic dark earths in forested Amazonia, these self-organizing ecosystems illustrate the ecological complexity of the legacy of pre-Columbian land use.
In a nice write-up of the study, New Scientist interviews Doyle McKey, the lead researcher, who says:
Human actions cannot always be characterised as bad for biodiversity. Some might be good.
That’s one of those inconvenient truths that purists who subscribe to the human/nature dualism don’t like to hear. But science has come a long way since the publication of George Perkin Marsh’s seminal text. The increasing collaboration between archaeologists and ecologists is revealing an ancient world that discomfits doctrinaire environmentalists. (In the American Southwest, I’ve written about one such collaboration here.)
Moreover, as the New Scientist article puts it:
The new study is bound to further fuel the debate over whether most of the Amazon rainforest and the associated savannahs are pristine ecosystem. “To my mind, the debate has been too black-and-white,” says McKey. “Nature and culture are interacting to produce interesting things, and maybe that is the way this debate should go.”
Seems like good advice to me.
The Killer MacGuffin
Several days ago, this story at Slate, by Brendan Borrell, argued that habitat destruction posed a more immediate threat to wildlife and biodiversity than climate change. That makes obvious sense. Until recently, ecological degradation, be it from deforestation or overfishing, was the pre-eminent environmental concern of our time.
“Now, writes Borrell, “being green is all about greenhouse gases:
Neighborhood moms are more apt to fret over food miles than felled forests; organic cattle farmers are more interested in offsetting the methane coming from cow burps than pondering squished tadpoles in hoof prints. Even scientists have grown bored with question of habitat loss, tweaking their grant proposals to emphasize the climate angle no matter how tenuous the connection. Saving the Amazon is so 1980s.
So far, so good. Borrell then moves on to his essential point:
Climate change has the potential to displace the most impoverished human populations and bring about food shortages, flooding, and drought. But from the perspective of saving species, it’s a MacGuffin: a plot device that may impel the tired conservation narrative forward but is hardly a pragmatic strategy for preserving biodiversity.
Now them’s fightin’ words–not to me–but to many environmentalists who want the larger debate about ecological destruction to revolve around climate change. I happen to think that Borrell is right, that greenhouse gases pose a less immediate and near-term threat to ecosystem services and biodiversity than that of habitat destruction.
But Carl Zimmer, who I have immense respect for, makes a good case that Borrell underplays the ecological fallout from climate change. In fact, Zimmer has written a cogent counter-argument that is a model of respectful criticism. I wish more bloggers who take issue with climate-related stories in the press were as classy as Zimmer, instead of resorting to name calling and ad hominem attacks.
I’ve also noticed a disturbing trend in comment threads that encourages a kind of politically correct policing. For example, this commenter at Zimmer’s blog, feels compelled to point out that the comments to Borrell’s article at Slate
are dominated by anti-global warming types and Al Gore bashing. We should keep our eye on Borrell; he may be an embryonic Lomborg.
What the hell is that? Could there be any more blatant and perverse example of guilt by association? Yeah, keep a stink eye on Borrell, because you have problems with some of the people who read his article and commented on it. What’s even more disturbing is that this sort of thinking comes from a scientist and university professor. I’m hoping he was being inartfully sarcastic.
But this is not an isolated sentiment, though it is the only type of its kind to appear at this particular post by Carl Zimmer. I’ve seen many similar comments on other envirornment and climate-related blogs, including variations of that, which call on people to not read certain bloggers because of their supposed association with climate deniers or “delayers,” (this last term being a favorite of Joe Romm’s, which he uses to flog anyone he disagrees with).
That sort of close-mindedness–willfully disregarding other viewpoints–demeans the progressive spirit of environmental thinking.
Now, as to the merits of Borrell’s argument, I’m inclined to think, after reading Carl Zimmer’s critique, that Borell gets some of his details wrong. But I happen to think he gets the bigger picture right, which is that environmentalists, in their zeal to view everything through a climate change lens, are losing sight of a more tangible and truly urgent ecological crisis. As Borrell puts it,
while climate change remains a legitimate concern for wildlife””particularly on isolated mountaintops and in species-poor polar regions””it does not come close to the immediate, irreparable damage caused by the destruction of habitat. Our ecosystems are not just getting warmer or colder or wetter or drier. They’re disappearing.
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