The Climate in Emergency

A weekly blog on science, news, and ideas related to climate change


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Dead Biome Walking?

A photo of a man apparently reading a newspaper that is on fire. The man is dressed in dark, simple clothing and is seated on a stool with his legs crossed. The background is plain, gray, and somewhat dark and dingy looking. The view of the man is from the front and he is holding the paper at an angle that obscures his face and upper body. The newsprint is too small for the viewer to read it and its content does not appear to be important for the image.

Photo by Elijah O’Donnell on Unsplash

So, about those Australian fires….

It’s high time I wrote a post about them, as the disaster constitutes one of the most dramatic climate-related catastrophes today, and it’s likely to keep getting worse for a while, yet. While some people have complained that climate change didn’t start the fires, that’s a bit like saying that jumping off a sky-scraper wouldn’t kill you–technically true, but more deeply false (with the sky-scraper, it’s the sudden stop at the end that gets you). Climate change helped create the circumstance where hitherto-unheard-of fires are possible.

I’ve written before about the links between climate change and fire with respect to California. The situation in Australia is broadly similar.

I’m not going to rewrite those articles  with an Australian focus–other people are covering the topic already. What I want to know is how bad are these fires, other than “really bad”? How big are they, really? It’s easy enough to look up the numbers of acres burned, number of people killed, and so forth, but it’s hard to really put that information in context. How much of Australia burns in a typical year? How well will Australia be able to recover, ecologically or economically? Is anything being lost that can’t be regained?

Putting the Australian Fires in Context

There are several questions I want answers to:

  • How much of Australia is burning or has burned?
  • How much damage has been done to the specific biomes involved?
  • How do the 2019/2020 fires compare to historical fires in Australia, both in extent and in intensity?
  • In what ways besides climate change have human activities made the fires worse?
  • How well can Australia recover, either ecologically or economically?
  • Will Australia have more fires like this in the future?
  • Could other countries see similar disasters in the near future?

Some of those questions are easy to find answers for, others would require a major research project if they could be answered at all. For now, let’s just explore some of these issues.

How Bad Are the Fires?

Several questions involve the severity of the current disaster. As I said, it’s easy to look up the acreage burned, and it is just as easy to look up maps that show the extent of the fires relative to Australia’s land mass overall. These are pretty arresting images, but they don’t tell the whole story.

The issue is that the part of Australia that is not on fire is mostly uninhabited–both flammable vegetation and humans cluster in the well-watered coastal regions. If we could calculate the proportion of Australia’s inhabited area that has burned over the past year, the resulting fraction would be even more arresting and give outsiders a much more accurate picture of what Australians are going through right now.

Unfortunately, I have not been able to find a figure for the size of Australia’s inhabited area. In fairness, it is difficult to define such an area, because there is no black-and-white distinction between “inhabited” and “uninhabited.” Rather, the population just gets thinner and thinner.

A steep slope with long, dry grass in the foreground and a forest of tall, dead conifer trees in the background. In the very far distance, mountains and a hazy blue sky are visible.

Photo by Meritt Thomas on Unsplash (stock photo, not necessarily recent or Australian)

At the moment, the best I can do is eyeball a comparison between a map of Australia’s population distribution and the various maps of the fires (here’s one; an image of the cumulative light of a month of fires)

Those well-watered coastal areas are also ecologically distinct from the arid interior. A map of Australia’s major biomes (a biome is an ecologically defined region) shows that the region where many of the fires have been clustered are also within a relatively small biome, the Temperate Broadleaf and Mixed Forest. Another cluster of fires overlaps with much of an even smaller biome, the Tropical and Subtropical Moist Broadleaf Forests. As you’ll see if you click on the links, I have not actually found a map that shows biomes and fires, I’m doing more eyeball comparisons. To my eyeball, it looks like a significant chunk of both biomes must have gone up in smoke this year.

Wildfire is usually not the disaster it appears to be, since the burned-over areas are re-colonized with vegetation and animals from unburned areas–and while the burn zone is recovering, it provides habitat to various species that specialize in the different stages of recovery. However, if an entire biome were to burn completely, recovery would not be possible because the organisms able to live in that biome would all be dead–and most of them would be extinct, since it is unusual for a species to occupy multiple, radically different habitats. Real wildfires seldom burn completely (there are usually un-burned pockets, and the less-intense fires spare the roots of plants, burrowing animals, and even some trees) but disaster need not be complete to be decisive–and Australia has already suffered widespread deforestation and habitat fragmentation. There’s not a lot left to burn.

Could we be witnessing the loss of two biomes right now?

Are the Fires a Cause or an Effect?

A forest of black tree trunks on blackened ground. Smoke drifts eerily through the forest, partially obscuring the orange flames coming up from the ground.

Photo by Joanne Francis on Unsplash (A stock photo, not necessarily depicting a recent Australian fire)

Can Australia recover? I have found several articles on economic and cultural recovery, and while everyone seems to acknowledge that recovery will be difficult, no one seems to doubt it will happen. There is some worry that there may indeed be permanent ecological change.

What I wonder is whether the permanent change has already happened. In other words, is fire (exacerbated by climate change) the agent of an ecological shift, or merely a symptom of a shift that has already occurred?

To choose an example of what I mean that is closer to my home, the Southwest of the United States is famous for its deserts, but actually much of the region is dry forest dominated by several species of pines. There are those who think much of that forest will be lost with climate change–and in fact, some parts of it have been lost already. One might be tempted to think the loss will be gradual, since climate change, while very fast, is gradual (that is, it is more like a gradient than a step), but that’s unlikely.

Living systems, whether individual organisms or whole ecosystems, resist change the same way a spinning top is harder to push over than it looks like it should be. Dying people can sometimes hold their own far into grave illnesses, looking and sounding almost normal until very close to the end. Unfortunately, I’ve seen this recently, as those who know me are aware. Dying forests work much the same way, the trees hanging on in the face of heat and drought that isn’t really drought but rather a new regional normal. Then there is a fire or an infestation of bark beetles or both. The beetles are not new, but in the past the trees could fight the beetles off with sticky sap. In a bad drought, the trees can’t make enough sap. There are more beetles, too, after warm winters. I’ve seen this–almost twenty years ago, I watched almost every pinyon pine in one forested area die from beetles in just a few months. That year I saw pictures of places where similar beetles had killed whole hillsides of ponderosa pines, turning them a pretty red-brown that looked like autumn. Sooner or later, those dead and dying forests will burn. When they do, I doubt trees will grow in their place.

The climate that made the forests possible will have moved.

There are thus at least two scenarios by which Australia’s forests might be permanently changing as we speak. One is that so much of the already-fragmented forests are burning that there won’t be enough left for effective recovery. Species could be extinguished through habitat loss, or through the loss of ecological partners, or simply by too many individuals, plant or animal, burning to death. Relict populations might be too small and too scattered to be self-sustaining. I don’t actually know, there is a lot of information I don’t have, but it seems at least possible that fires exacerbated by climate change are radically altering the ecological map of a country.

But the other scenario is that the alteration has already happened, that these forests were dead ecosystems walking even before the fires started, that the climate has changed and the fires are simply a form of belated adjustment to a new normal that began years ago.

Time for Hope?

As I said, I don’t know that the situation is as dire as it seems–it may not be. Real-life worst-case scenarios are rare.

Perhaps more to the point, even if the worst case is upon us, things are never so bad that they can’t get even worse, and that also means things are never so bad that we can’t avoid them getting worse.

Even if part of Australia’s forest is now doomed, it’s likely part of it still retains a climate conducive to forests. If conservationists scramble, and if they get the public and private help they need, it may be possible to create relicts that are large enough and interconnected enough to be self-sustaining.

And perhaps more to the point, if we all do something about climate change, maybe it won’t get much worse.

No situation is ever so bad that there is no reason to help.

 


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Are Koalas Extinct?

A close-up of a koala whose facial expression appears vaguely amused yet accusatory. The koala, like all koalas, has gray fur, a round, teddy-bear-like head, and a large but flat black nose.

Photo by Laura Barry on Unsplash

A few weeks ago, scary links spread across social media to the effect that koalas are “functionally extinct” as a result of the recent catastrophic fires in Australia. Of course, reality is often more nuanced than Facebook posts, and “functionally extinct” is a technical phrase that doesn’t necessarily mean what it seems to.

So are koalas really just about extinct now?

The short answer is no, they’re not, although the species may indeed be in bad shape and climate change is largely to blame.

Koalas and Functional Extinction

The scary social media posts either referred to, or actually linked to an article in Forbes that quoted the Australian Koala Foundation as saying the species may be “functionally extinct,” and that 1000 koalas may have died in the fires and that 80% of the animal’s habitat may be gone. Since its initial publication, the article has been edited to sound less alarming and to reflect the fact that some experts think the situation with koalas might not be as bad. Several other publications have also issued articles on the subject (such as this, in the New York Times) that attempt to walk back the panic a bit and provide some additional context.

But what does “functional extinction” mean, and is it really correct to calm down about koalas?

What Does “Functional Extinction” Mean?

The original Forbes article defines “functional extinction” as meaning a population no longer plays a role in its ecosystem and is no longer viable. These are actually two, ecological irrelevancy and non-viability, very different situations, and while they can obviously occur together, they can also occur separately–and neither means that the species is “basically gone,” as in a hopeless situation or a foregone conclusion.

Functional Extinction

Properly speaking, “functional extinction” refers only to the first problem described in the Forbes article; that a species can no longer participate ecologically. In fact, a species can be functionally extinct even when its population is still big enough that its existence is not seriously threatened–instead, functional extinction means that other species in the same ecosystem react as though it is already gone and they die out.

A large, round seed or nut sitting in the top of a glass containter that has a round body and a long, thin neck. The container is partly filled with water and sits on a whitish table top. The seed has sprouted, and has a long, thin root reaching into the water and a few small green leaves coming out the top. It is difficult to be sure, but it looks as though it could be the seed of a chestnut tree.

Photo by Daniel Hjalmarsson on Unsplash

A good example of functional extinction is the American chestnut*, which is by no means extinct, but which was devastated by an accidentally introduced disease some decades ago. Some trees proved resistant, and the root systems of young trees often survived and still send up shoots that sometimes manage to produce a few nuts before succumbing to the disease again. There are also well-organized efforts underway to breed blight-resistant American chestnuts, and I have in fact seen a blight-resistant seedling (it was given as a retirement gift to a noted naturalist at a party I attended). The species is likely to survive–but anything dependent on American chestnut forests is likely already gone.

Insects and birds and bears and whoever else once ate parts or products of this species must now do without.

So not only does “functionally extinct” not mean “almost extinct,” the concept is important precisely because it applies to species that may still be relatively abundant–and yet its decline is causing other extinctions around it.

Koalas themselves are not currently listed as “endangered,” or even “threatened,” only “vulnerable,” and although that assessment was conducted in 2014 and may now be outdated, it’s also possible it’s still accurate–the current status of koalas is apparently a matter of debate, since they are difficult to accurately count in the wild. But that doesn’t mean the species isn’t functionally extinct, nor does it mean that Australia is not in the process of losing something important.

What depends on koalas?

Population Viability

A large flock of small, dark birds flies against a blue sky. The birds are mostly in the bottom third of the image, clustered around a bright spot that might be the sun, so the blue is visually dominant. The birds are hard to see, being very small, but an expert birder would be able to tell they are not passenger pigeons; they may be rock pigeons, the familar bird of cities.

Photo by Rowan Heuvel on Unsplash

“Population” doesn’t necessarily mean “species.” Most species consist of multiple populations that interbreed with each other to greater or lesser degrees, and one population can become non-viable or even extinct and leave the rest of the species doing just fine–or, a species can go extinct one population at a time, or all at once if one population is all there is.

The study of population dynamics is a whole branch of conservation science and I’m not going to get into most of it here (I don’t know most of it!). The relevant point is you can have a species that still has living members but is almost certainly going to go extinct. In fact, the species could actually still look quite large and yet be non-viable. For example, passenger pigeons could only breed in very large colonies. The phrase “hunted to extinction” evokes images of heartless gun-toters searching out every last member of a dying species, but that’s not what happened to the pigeons. Instead, they were so ridiculously abundant that no one saw any reason not to harvest them freely, and then they were slightly less abundant, and then all of a sudden there just weren’t any more–because the still-huge flocks had dropped below the threshold necessary for the birds to breed. Another, perhaps more common, scenario is that habitat loss fragments a species into lots of little, genetically isolated populations, each of which is too small to sustain itself. The species might have tens of thousands of members, but if they are scattered across hundreds of tiny refuges able to breed only with their cousins, the situation is dire.

They are like a person falling from the top of a sky-scraper. In one sense, they are fine until they hit the ground, but in another sense they are obviously not.

Extinction can take a long time, especially in species where individuals are long-lived, and a few individuals can persist, unable to breed at replacement, for decades or more, and yet their loss is more or less assured. The concept of the non-viable population is another important one for conservationists to pay attention to, for it, too, points to a type of catastrophe-in-progress.

An yet “non-viable” doesn’t mean “doomed” or “hopeless.” Species have been pulled back from the brink before. Sometimes the falling man is rescued.

Are Koalas Functionally Extinct or Non-viable?

A koala clinging to a tree with a baby koala sitting in her lap. The mother is curled up so her face is hidden, but the baby is looking towards the viewer. Both have mostly gray fur and large, round ears. The baby is a miniature of the mother.

Photo by David Clode on Unsplash

Are koalas functionally extinct? The Australian Koala Foundation says that they are, but it’s important to recognize that the group made the announcement in a press release (calling for political action to protect the species) back in May. So no, the fires probably haven’t pushed koalas to the brink–they were there already. As to what the fire has done to them, we really don’t know. It’s too soon for anyone to have done a real assessment.

The leader of the Foundation, Deborah Tabart, appears to conflate functional extinction with non-viability, but from her statements quoted in the New York Times (the same article I linked to earlier) it is clear she considers both to be true.

Both the Forbes article and the piece in the NYT make clear that some experts disagree with the Foundation’s assessment, apparently due to a perceived lack of data on the subject. I’m not in a position to weigh in either way–though I will say that “hey, there MIGHT be more koalas than you think, they’re hard to count!” is not really a comforting argument.

In any case, the Foundation has put the results of their assessment online for public review. Here is the link.

The real reason (again, based on the NYT piece) that Ms. Tabart’s assertions are controversial is not that she might be wrong but that she might be misunderstood, that people might think the koalas’ case is hopeless and stop fighting for them. Public perception is an important issue, but if koalas ARE either functionally extinct or non-viable as a species, then we do need to know so we can do something about it.

Koalas and Climate Change

That koalas are in trouble is not in any serious doubt, despite their not being officially listed as endangered. There are several reasons. First, millions were shot for their fur in the few decades before and after 1900. More recently, habitat loss has become the critical factor as more and more of Australia’s native eucalypt forests are cleared. More than 80% of their original habitat has been lost. And deforestation not only limits the total amount of space where the animals can live (and hence limits the total number who can live), but also fragments the survivors into increasingly isolated small populations. Living near human development also leaves the animals vulnerable to being hit by cars or attacked by dogs.

But koalas are also considered one of the world’s ten species most vulnerable to climate change; not only are they very specialized animals (specialists categorically handle environmental disruption badly), but Australia’s climate is among the fastest-changing in the world.

The clearest danger is from heatwaves and drought. One area lost a quarter of its koalas in one heatwave in 2009 alone. Drought and heat together stress the trees and reduces the moisture content of their leaves; koalas not only depend on eucalypt leaves for food, but also for moisture (though the animals will drink if water is available). Heat-induced water stress is the primary factor that will shrink koalas’ range in the coming decades. Some conservationists are arranging supplemental drinking stations for koalas and other wildlife, and the animals do use the stations, but it isn’t known yet whether the extra water will help with survival.

But then there is fire. Fire can kill koalas directly, and the animals can also starve to death in the time it takes a burned-over forest to green up again. Eucalypt forests do burn sometimes, and koalas evolved with fire, but several things are different now. First, the badly-fragmented nature of koala habitat means that now if an area loses its koalas due to fire, koalas from other places can’t come in and repopulate the forest as it grows back. But the other new thing is climate change; by allowing much larger, more devastating fires, it has increased the scale of destruction to where a single fire event could become an existential threat to an entire species–this year alone, Australia’s north coast has lost a third of its koala habitat. That’s not the only region that has burned, either. Where will the animals who survived those fires go? What will they eat until the forest grows back?

About Those Scary Posts….

It’s easy to get panicked seeing those social media posts, which seem to imply that this year’s fires have burned up so many koalas and so much of their habitat so as to suddenly doom them. The truth, as always in more nuanced, and panic does not help. But while a careful reading of the situation is always helpful, it is not necessarily very encouraging in this case.

Koalas are not doomed, and it is far from clear how bad their situation is, but it is clear it’s dire, not least because the threats to the species are complex and can’t be solved with a single stroke of a pen (as might be possible if hunting were still the primary threat).. We’re talking climate change, land use policy, economic development, human lifestyle issues, all of which depends on the principled cooperation of many, many people for any hope of progress. And if koalas are in danger, than so is everything else that depends on the same habitat and anything that depends on koalas.

And as of today, Australia continues to burn.

 

*The chestnut example and several other un-cited portions of this post are based on material I learned in grad school.


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Annual Reading of Names

Here is a slightly edited version of a post I’ve used every year at this time for several years running. The link for my original source for the list isn’t working. Here is another.

Hallowe’en is coming up. A rollicking, morbid carnival, a celebration of the mortal flesh through sugar, alcohol, sex, and fake blood (if you don’t believe me about the sex, look at the women’s costumes available in stores), a blurring of identity and the thrill of things that go bump in the night.

I could write about the impact of the holiday on global warming, but that’s been done. I could write a scary story about our possible future, but that’s been done, too.

But, basically, I’m not all that interested in Hallowe’en anymore. I’ve grown out of trick-or-treat and I’m not frightened by blood, fake or otherwise. I’m more interested in the older traditions of taking a day to honor and remember the dead. This is therefore a Day of the Dead post, a Samhain post. I want to mark and honor the dead of climate change–not as a scare tactic or a self-flagellation of guilt, but simply as an act of witness. Because it is the right thing to do.

There are several possible ways to go with this. I could focus on individuals who have died of climate change, but linking global warming to particular deaths is very difficult. The result would also be too similar to my post comparing the mortality rates of climate change and Ebola. Instead, I want to honor whole species that have died. I’ve often thought that reading a list of recently extinct species names, the way the names of individuals lost to some accident or disaster are sometimes read, would be a powerful way to add an ecological dimension to Samhain. I’ve never done it, in part because finding such a list is difficult. Compiling a list of the extinct is hard, since we don’t always know a species exists before it stops existing again, and because it’s hard to be sure a whole species is really gone and not holding on in some remnant population somewhere. What lists exist seldom turn up whole on Internet searches, perhaps because many of the species on the list are plants and animals most people have never heard of.

Still, I intend to observe the Day of the Dead by formally noticing our planetary losses.

Looking for Smoking Guns

Which species, if any, have gone extinct because of climate change is a bit complicated.  I addressed the question in some depth in an earlier post, but it comes down to the difference between ultimate cause and proximate cause; if you fall off a cliff, the ultimate cause of your death is your poor footing, while the proximate cause is your impact with the ground. The problem is that the connection between those two causes is rarely as obvious or straight-forward as in that example.

Climate change as the ultimate cause of extinction might be linked with any number of proximate causes. Some of them are: drought; habitat loss (think polar bears and sea ice); the extinction or relocation of an ecological partner; and new competitors, pests, or diseases that take advantage of warmer weather. Of course, most of these problems can have other ultimate causes as well. Climate change is not likely to be the species’ only major problem–consider the paper birch, which is dying out in parts of New England because of a combination of exotic diseases, climate change, and probably the advanced age of the relevant stands (the species requires bare soil to sprout, such as after a fire or logging, and there happened to be a lot of that in New England decades ago–hence, a lot of aging birches). Against this complex backdrop, it is hard to say for certain which extinctions actually belong at global warming’s door.

Some years ago, scientists announced the extinction of the Seychelles snail, the first species known to go extinct because of climate change. Fortunately, a previously unknown population of the snail turned up recently–it’s not extinct at all (though presumably still in grave danger). Many writers have treated the snail’s resurrection as some kind of embarrassing “oops” for climate scientists, which of course it is not; the species took a huge hit because of global warming, and the fact that it’s still hanging on is great news. Confirming an extinction is very, very hard–a bit like looking for the absence of a needle in a haystack. Mistakes are inevitable, and welcome.

The golden frog and the Monteverde harlequin frog are sometimes cited as victims of climate change as well. The proximate causes of the golden frog’s demise were habitat loss due to drought and also the chytrid fungus, which could be exacerbated by climate change. Chytrid has extinguished or gravely endangered many other amphibians world-wide, so at least some of them might be considered victims of climate change as well–as could various non-amphibians, including some no one knows about yet.

But there is another way to look at all of this.

Climate change itself has a cause, and that cause has other effects. As I explained in another previous post, our burning fossil fuel has destabilized the biosphere as a whole by altering how energy flows through the system. Climate change is one consequence of that destabilization, but systemic biodiversity loss is another. That is, no matter what the proximate cause of an extinction is (whether climate itself is directly involved), the ultimate cause of this entire mass-extinction event is fossil fuel use.

We know what to do about it. You know what to do about it. If you’re an American citizen, VOTING is a major and necessary step. But this is the festival to honor the dead, and we should take a moment to do that–to remember that these are not just numbers, political statements, arguments, but actual animals and plants, whole ways of being, that will never exist again.

I did find a list of historical extinctions. You can look up the whole thing here. It is far from comprehensive, but even so it’s still too long for me to copy over all of it. I’ll just focus on those from the list that have been lost since my birth.

Pinta Island Tortoise

Chelonoidis abingdoni

Last seen, 24 June 2012

Vietnamese Rhinoceros

Rhinoceros sondaicus annamiticus

Last seen, 29 April 2010

Christmas Island Pipistrelle

(a bat)

Pipistrellus murrayi

Last seen, 27 August 2009

Chinese Paddlefish

Psephurus gladius 

Last seen, 8 January 2007

Yangtze River Dolphin

Lipotes vexillifer 

Last seen, before 2006

Po’o-uli

(a bird in Hawaii)

Melamprosops phaeosoma

Last seen, 28 November 2004

Saint Helena Olive

Nesiota elliptica

Last seen, December 2003

Vine Raiatea Tree Snail

Partula labrusca 

Last seen, 2002

Pyrenean Ibex

Capra pyrenaica pyrenaica 

Last seen, 6 January 2000

Sri Lanka Legume Tree

Crudia zeylanica

Last seen, 1998

Nukupuu

(a bird in Hawaii)

Hemignathus lucidus

Last seen, 1998

Western Black Rhinoceros

Diceros bicornis longipes

Last seen, 1997

Aldabra Banded Snail

Rhachistia aldabrae

Last seen, 1997

Zanzibar Leopard

Panthera pardus adersi

Last seen, 1996

Swollen Raiatea Tree Snail

Partula turgida

Last seen, 1 January 1996

Golden Toad

Incilius periglenes

Last seen, 1989

Antitlan Grebe

Podilymbus gigas

Last seen, 1986

Alaotra Grebe

Tachybaptus rufolavatus

Last seen, September 1985

Eungella Gastric-brooding Frog

Rheobatrachus vitellinus

Last seen, March 1985

Kaua’i ‘O’o

(a bird in Hawaii)

Moho braccatus

Last seen, 1985

Christmas Island Shrew

Crocidura trichura

Last seen, 1985

Ua Pou Monarch

(a bird in Polynesia)

Pomarea mira

Last seen, 1985

Amistad Gambusia

(a fish, in Texas, USA)

Gambusia amistadensis

Last seen, 1984

Conondale Gastric-brooding Frog

Rheobatrachus silus

Last seen, November 1983

San Marcos Gambusia

(a fish, in Texas, USA)

Gambusia georgei

Last seen, 1983

Kama’o

(a bird in Hawaii)

Myadestes myadestinus

Last seen, 1983

Guam Flycatcher

(a bird in Guam)

Myiagra freycinet

Last seen, 1983

Aldabra Warbler

Nesillas aldabrana

Last seen, 1983

Galapagos Damselfish

Azurina eupalama

Last seen, 1982

Marianas Mallard

Anas oustaleti

Last seen, September 1981

Southern Day Frog

Taudactylus diurnus

Last seen, 1979

White-eyed River Martin

(a bird in Thailand)

Eurychelidon serintarea

Last seen, 1978

Little Hutia

(a rodent in Honduras)

Mesocapromys minimus

Last seen, 1978


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A Prospect Less Sweet

A friend of mine wants to know whether anyone is doing anything about sugar maples and climate change.

The issue, succinctly, is that sugar maples are a cold-climate species that only grow well in the cooler parts of North America. As climate change shrinks those areas, the range of the maples will shrink, too. That’s a problem most obviously because this is the tree that gives us maple syrup, but it also provides much of the fall color for which New England is famous–and leaf-peeping is a major driver of the tourist economy of the region. And beyond economics, sugar maples (like the also-climate-stressed paper birch) are part of the regional identity of New England (and doubtless of other regions I’m less personally familiar with).

Maple sugar sap production is already starting to drop in some areas, though the economic burden is being countered to some extent by improvements in collection methods. We’re not talking about some vague warning about the future; this is happening now.

So, my friend wants to know, are there any efforts underway to breed climate change-resistant sugar maples, just as there are efforts to breed disease-resistant American chestnut trees?

A good question.

Introducing the Sugar Maple

Let’s start by taking a look at the star of the show, the sugar maple, Acer sacharum, from whose unusually sweet sap maple syrup and maple sugar candies are made. The sap comes from the tree as sweetish water and must be concentrated by boiling (or freezing) in order to produce syrup. Further concentration allows crystallization into candy. The tree itself is large and long-lived, with furrowed bark and distinctive leaves with U-shaped sinuses (if a maple leaf is a hand, the sinuses are the parts between the fingers).

Those who aren’t plant geeks might be surprised to learn that not all maples are sugar maples, and that while some of the others also provide sweet sap, others don’t. The maples are a large group of trees native to North America, Asia, and Europe. In New England there are six native species (sugar, red, silver, mountain, striped, and ash-leafed), and at least two exotic species are also common (Norway and Japanese). The American maples all produce clear, sweet sap, though none as sweet as the sugar maple, but the Norway maple produces white, inedible sap.

The sweet sap runs in the early spring, when the plant mobilizes stores sugars in order to power the growth of leaves. It would be interesting to compare how quickly different species leaf out; is the sugar maple faster (less time fro bud-break to full leaf-out) than other trees because its sap delivers more fuel for growth?). It’s important to recognize that the sugar is food the plant stored for its own use; tapping trees stresses them, and there is a limit to how much sap a tree of a given size can spare. The sap flow itself is triggered and maintained by changes in temperature. If the winter is too warm, or if the spring does not include an extended period when nights are below freezing and days are above, the tree won’t produce. What effect reduced sap flow has on the tree’s own physiology, I haven’t learned–I don’t imagine it’s healthy.

Sugar maples are not only valuable to humans. Across much of Eastern North America, they are one of the two dominant species in older forests (the other being American beech). The trees collect calcium and concentrate it in their leaves, enriching the soil as the leaves fall and decompose, thus feeding other plants. Many animals depend on sugar maples; some are insects that feed on no other species (these insects go on to feed birds), while others are mammals and birds that use maples at certain times of year. Most charmingly, squirrels tap the trees for sugar by biting through the bark. The sap leaks out and evaporates, leaving behind sugar which the squirrels lick. Porcupines eat the leaves and buds in the early spring, when little else is available to them. Sugar maple seeds feed songbirds, squirrels, chipmunks, and mice, while the bark provides emergency food for deer, rabbits, and mice in winter. The list could go on.

Much of the above information comes from the wonderful The Book of Forest and Thicket, by John Eastman. Curiously, the author also states that sugar maple is in a decline across the southern part of its range, in part due to climate change–a striking assertion, given that the book was published in 1992.

Sugar Maples and Climate Change

A few years ago, I wrote an article imagining the climate through the lifetime of my nephew into his old age. Towards the end of the piece, I imagined him taking a vacation in Vermont with his wife and talking to a waitress who complains about the economy because the sugar maples are dying. While researching for the piece I did not find any actual discussion of sugar maples, but I did notice that the range of the sugar maple is essentially bounded by certain USDA zones, and that zones that do not currently support wild sugar maples are predicted to move north into New England by century’s end. I drew the logical conclusion.

I should have known better.

Trees, in general, have narrower germination niches than growth niches, meaning that mature trees can survive circumstances that would kill seedlings–I learned that in grad school. In practice the narrower germination niche means that species can often be grown as specimen trees in lawns and parks in places where they can’t grow in the wild. Wild trees must start from seed, whereas those growing in lawns were usually sprouted in controlled environments in nurseries, then grown for years before being balled and burlapped for sale. By the time the tree is installed in a lawn, it’s already strong enough to withstand the local conditions.

Sugar maple will grow as a specimen tree well to the south of its current range (there is one in my mother’s back yard), so climate change alone is not likely to kill New England trees–but it could prevent a new generation of maples from establishing. Neither I nor my nephew are likely to see a Vermont without its classic autumnal red and orange, but he could well live to see the last generation of wild Vermont sugar maples sprout. Three hundred years later, those few lonely trees will die of old age without heirs, if things continue as they are now.

Research supports that second, corrected vision as closer to the truth.

In Michigan, where climate change is making the growing season drier, sugar maples are growing much more slowly than they used to. The lead researcher of that study was quoted by NPR as saying that under some climate change scenarios, that region would lose its sugar maples entirely; the new climate won’t kill mature trees, but no new young trees will survive to replace them. In the meantime, trees that don’t grow well don’t produce much sap, either.

A warm spring can cut the season short, and did so in 2012, when much of New England produced dramatically less maple syrup than in previous years because of heat waves in March. Climate change promises more heat waves, and just as trees that don’t grow well don’t produce a lot of sap, it’s hard to imagine that non-productive maple trees are growing much.

A study in Vermont found that climate-related stress has, over the last several decades, been equal in severity to pests and other more well-known problems; the authors note that 50 years from now, half the state’s sugar maples could be experiencing “moderate to severe climate stress.” I’m not sure what that means in practical terms, but some dieback combined with widespread declines in productivity and a general failure to breed (except in isolated refugia with colder climates) would seem to fit the bill.

In general, climate change could lead to widespread habitat loss for sugar maples, especially under the more dire warming scenarios.

Perhaps counter-intuitively, the loss of American sugar maples won’t necessarily translate into a lot of dry pancakes, despite many headlines to the contrary. For one thing, even in New England, a lot of pancakes are already being eaten with artificially-flavored “pancake syrup.” For another, according the the paper linked in the previous paragraph, most sugar maple trees that are large enough to be tapped currently are not, and as long as we avoid the most extreme warming, it should be possible to keep production up–while the number of sugar maples will decline, producers can tap a greater proportion of those that are left.

Of course, neither pancake syrup nor expanded tapping operations will help songbirds, squirrels, or porcupines very much.

Doing Something

My friend’s question is actually two or three questions, and they don’t necessarily have the same answers.

Is anyone developing sugar maples that can survive climate change and save New England’s forests? The most obvious way to answer that question is to look at whether anyone is developing cultivars or hybrids that can tolerate the new climate now moving towards them. But if the goal is indeed to save the maple forests–and that does appear to be my friend’s interest–we must also ask whether any of these cultivars could be released into the wild and whether they would indeed do all of the things we rely on sugar maples for. The possible third question hiding behind the other two is whether trying to propagate such a cultivar on a broad scale is even a good idea.

Breeding Sugar Maples

Is anyone developing a climate-proof sugar maple? The short answer is yes.

These are difficult questions to research because of the way search engines work–the information you get is not necessarily what you want but rather what the search engine’s algorithm thinks you want, and in this case breathless articles about dry pancakes tend to shoulder conservation genetics out of the way. I am therefore unable to say definitively whether there is a program that has as its stated goal rescuing the sugar maple from climate change.

However, there are cultivars that have different habitat requirements than wild sugar maple does: Crescendo, and Green Mountain are each both heat and drought tolerant; Bonfire is heat-tolerant; Legacy is resistant to drought; and Majesty is resistant to frost cracking–since climate change is causing increased frost cracking in paper birch (there are more freeze-thaw cycles in the spring, now), I’m guessing it could be a problem for maples, too. There are probably other cultivars with useful properties offered from other sites. Whether any of these were developed with climate change in mind I’m not sure, but they certainly fit the bill.

And there are plant breeders working on sugar maple with climate change in mind. The US Forest Service and various state agencies have been working on “improving” the sugar maple–meaning, developing domestic cultivars with commercially desirable traits–since the 1960’s at least. Their primary goal has been to increase sugar content in the sap (they have succeeded), but state agencies in New York are also continuing the research with the aim of storing sugar maple germplasm in case of catastrophic loss due to invasive insects or disease–possibilities they acknowledge are made more pressing by climate change since the trees are stressed and less resilient than they once were. Some of the same researchers are also looking at how climate change is impacting the tapping of sugar maples.

So the research is being done, more or less.

Saving Maple Forests

Curiously, I have not been able to find anyone discussing using sugar maple cultivars on a large scale to save either the American syrup industry or American sugar maple forests–of course, for me not to find something is no proof it doesn’t exist, but the lack of results is interesting. What I’m finding instead are discussions of using improved technology and improved forest management techniques to preserve the industry, possibly coupled with the use of red maple sap as an alternative source of maple sugar. Red maples are much more heat tolerant and is being used for syrup already. The syrup is said to taste a little different, but it’s quite good and suitably maply.

If indeed the climate-change-tolerant cultivars are not part of an organized push to save the forests, why not? I’m just speculating here, but it’s possible the issue is economic; changing management practices and using some red maple syrup are adequate stopgaps for now, and have the advantage of using trees that already exist. People do plant maples, including high-sugar cultivars and hybrids, with an eye towards sugaring, but a young maple won’t be ready to tap for 20 years or more. A major investment in a new cultivar might not be very attractive when there are options with a more immediate return.

Saving Maple Forests?

OK, you mind if I speculate a bit?

I can think of two reasons why mass propagation of the cultivars might not be a good idea. First, unlike the American chestnut, which has bee taken out by disease everywhere, wild-type sugar maple could hang on in parts of its range. That means that if cultivars are naturalized, they could end up competing with the wild type. What if the cultivars win?

A domestic cultivar could have all the marketable advantages of the original, but it’s not the same tree. And depending on what the differences are, the switch, if it happens, could matter a lot, especially given that sugar maple is a dominant species in many areas. Changing it, even slightly, could have vast consequences. For example, according to some remarkable research by Dr. Doug Tallamy, many herbivorous insects are highly specialized–even plants closely related to their host species are inedible to them, such that replacement of natives with exotics causes insect populations to crash–followed by songbirds, who need insects to feed their chicks. Last time we spoke, Dr. Tallamy didn’t yet know whether cultivars are typically also inedible to specialized insect herbivores–but since some cultivars are marketed for superior pest resistance, it is clear palatability for insects suffers sometimes. And wild-type sugar maples, remember, support huge numbers of insects.

Second, if wild-type sugar maple loses its habitat to climate change, so will a lot of the other species that inhabit the same forests. Perhaps a sugar maple cultivar could save some of them, but not all. Many aspects of how the forest functions will change. Arguably, the sugar maple-American beech forests we know will be gone from certain areas, replaced by something else. If the “something else” includes a sugar maple cultivar, I don’t see how that would be a problem (the danger is in the cultivar spreading to places where the wild type persists)–but I don’t see how that’s really a victory, either. At best, it would be a lessened scope of loss.

Realistically, our best hope lies in saving as much of the wild-type sugar maple forest as we can, and that means stopping climate change now.

 

 


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World on Fire

The Amazon is burning.

Social media appeared to suddenly take note of the fact last week, followed by mainstream news coverage a few days later. Personally, I found the whole thing too depressing and frightening for words, which is why I resolved not to read up on the subject until I was in a position to do a full investigation of the subject, including reading up on steps I could take to do something about it. Writing this post has become the occasion of my reading.

At least part of the reason for my panic is that I’ve read this story before–a novel I picked up some years ago covered the future of climate change in frighteningly plausible detail and included scenes in which the entire Amazon burned. As in, the rainforest there simply went out of existence, taking human lives, human cultures, endemic species, and a major carbon sink with it. Could something like that happen for real? Maybe: I’ve written before of how a positive feedback loop could make deforestation suddenly become self-sustaining; And Brazil’s president, Jair Bolsonaro, is building a reputation for himself as a rabid anti-environmentalist. Is the nightmare actually happening as we speak? Maybe.

But maybe not. And while something is clearly going very wrong in Brazil, knee-jerk panic is unlikely to do anything to help. We need to educate ourselves.

Clearing the Smoke to See the Fire

Let’s start by looking at what the news media are saying about the fires, what the current story actually is. Then, let’s look at some varying voices of commentary. Finally, let’s take a quick look at the complex background against which this fiery drama is playing out.

Just the Facts

There is an excellent article on Al Jazeera’s website summarizing the story. Let me summarize their summary, supplemented by other sources as noted.

Fires are normal in the Amazon at this time of year, although most of them are set deliberately by humans to clear land for crops and pasturage. Not all the fires are in the forest; farmers often burn agricultural stubble after harvest. Even the forest fires are not necessarily instances of large-scale deforestation; slash-and-burn agriculture is a very old technique in which a small area is cut and burned and then farmed for several years until the soil becomes nutrient-poor. Then the people start over with a new plot and the old one regrows. Whether slash-and-burn is a problem, ecologically, depends on other factors, and fire can also be used to clear large areas of land permanently. Deforestation in the Amazon is not new, either, unfortunately.

The unusual thing this year has been the extent of the burning which has been much higher than in years past since June at least. This, coupled with the anti-environment, pro-business leaning of Brazil’s president, has led to wide-spread worry that we could indeed be looking at catastrophe.

Many people are now raising their voices against the fires internationally, including celebrities and European leaders. President Bolsonaro has seemed slow to respond to the fires and has recently rejected international aid, citing his concern for his country’s sovereignty.

Some of the Facts May or May Not Be Wrong

I found an article in Forbs, that made some interesting counterclaims about these fires.

  • The images of fire being shared by celebrities and on social media are mostly not pictures of the current fires in the Amazon.
  • The Amazon rain forest is not a major source of the planet’s oxygen and while it is a carbon sink, so are the agricultural lands that are replacing it.
  • Most of the fires are not burning rain forest but rather brush and scrub.
  • Deforestation in the Amazon is currently declining and most of the remaining forest is protected.
  • The current mainstream coverage of the fires ignores political, economic, and cultural realities on the ground. Much of the international pressure is actually counterproductive because it ignores that reality.

Now, I question the veracity of parts of this article. Notably, while mature rain forest does use most of the oxygen it produces, it’s a mistake to use that factoid to downplay the planetary importance of the forest. And while cattle pasture and soy farms do hold carbon and produce oxygen, there is no way they can hold as much carbon as forest does because they have much less biomass. Biomass is made out of carbon compounds, remember. It’s also worth noting that cattle release much of the carbon they consume as methane rather than as carbon dioxide–and methane is a more powerful greenhouse gas.

However, the part about political and economic reality rings true. While I know very little about Brazil specifically, environmental conservation has a long history of foundering through willful ignorance of actual people. These fires are being set by people, and the people have reasons for setting the fires. They either need what the fires can give them, or think they do. While the fires themselves are unquestionably a problem, charging in (metaphorically or literally) without regard to the needs that drive the fires will be ineffective at best.

So while I do not regard the Forbs article as a reliable source of information, it raises some interesting points that certainly bear further research–and the call to avoid knee-jerk, under-informed reactions is almost certainly spot-on.

More than the Facts

I’m not going to present myself as an expert, here. I have a good deal of knowledge of conservation issues generally, and some aspects of the current crisis have been familiar to me for a while, but other things I’m just reading about today. Doubtless there are things, even important things, that I’ve just missed so far. What I’m trying to do is get the information I do have into a manageable, accessible form so that I and my readers can do something productive instead of running around wringing our hands in a panic.

There are a couple of pieces here that deserve careful attention.

Politics

What we’re looking at is the latest iteration of a complex, long-term political problem. Mr. Bolsonaro, remember, was elected. A large part of the issue is something that crops up in virtually all international discussions of climate change: fairness.

Europe and the United States and certain other countries have grown rich and powerful largely by two mechanisms: liquidating our own environmental capital and exploiting the resources of other countries through a combination of force and unbalanced trade. When we rely on historically poorer countries, like Brazil, to leave their wildlands intact as a means of buffering the planet against our excesses, resentment and suspicion are predictable. Arguably, we’re just trying to exploit their resources again, though this time it’s intact forest we want to take–Brazilian nationalism is not necessarily a matter of paranoia or jingoistic pride but is, rather, an understandable reaction to actual foreign bullying.

Doubtless the situation is complicated by moneyed interests and internal cultural disputes. It’s not that Brazil should get a free pass to do whatever its people want in the name of understandable anger–legitimate grievance is doubtless not the only factor in play, nor is there any guarantee that legitimate grievance automatically leads to legitimate response. The rise to power of the Nazis, fueled as it was, in part, by a truly tragic economic crisis, provides a dramatic example of the principle.

But the international response could easily prove counterproductive if it is not lead by people with a deep understanding of what’s actually happening in Brazil.

The People and the Peoples of Brazil

Massive protests against the fires are underway worldwide–but also within Brazil. So while some Brazilians may feel pushed around by foreigners, others are doing their own pushing to protect what they see as their heritage–and demanding help and support from outside. Many of these protestors are indigenous, and indigenous communities are being hit hard by both smoke and the loss of forests and crops to fire. Bolsonaro’s policies generally have been bad for them.

A reasonable question, when we talk about what the people of Brazil want, is who are the people of Brazil? Which viewpoint should outsiders regard as legitimate? It’s an age-old question, one that applies equally well to many other countries.

Are These Wildfires?

If these are wildfires, than how can the government be blamed for them? If these are intentional burns, then how and why are the fires damaging private property? Are the fires legal or illegal–and, if legal, are the laws supporting them just? I’m seeing a variety of answers to these questions. I suspect the real answers depend on which individual fire you’re talking about and when you are talking–a deliberately-set fire can escape to burn out of control.

I have no answers, yet, but it’s worth noting that tackling these questions could be the only way to make sense of the disagreements among editorial slants we see regarding the fires.

What Can We Do?

We may or may not currently be facing catastrophic nightmare–but at the very least, this year represents a surge in the ongoing crisis of deforestation in the Amazon. Something needs to be done.

We can start by saying what not to do.

  • Nothing. Do not do nothing.
  • Panic and make assumptions. Riding in, guns blazing, without a full understanding of the situation, is likely to make a bad situation worse.
  • Demand complete perfection immediately. I’ve seen some people claim that the whole world needs to go vegan because meat production for export is a major driver of deforestation in the Amazon. Probably some are calling for an end to capitalism as well. It’s not that such ideas are bad–they’re not. But these to-do list items are not likely to be accomplished this week, and meanwhile the Amazon is burning.

So, what should we do?

The Guardian (a British publication that does good work) recommends political action in favor of forest protection, financial support of non-profits active in the region, and boycott of products that are derived unsustainably from the Amazon, such as Brazilian beef. It sounds like good advice, but it’s a little vague. Let me elaborate.

Political Pressure

Bolsonaro is showing signs of responding to international pressure, even as such pressure also sometimes seems counterproductive. The solution is to identify the political leaders who seems to be getting results and support them both politically and, if possible, financially. Call your representatives and ask them to block trade deals with countries that are environmentally destructive–and to offer support to those that protect their forests. Might be a good idea to show appreciation for leaders of other countries who seem to be getting results, too. Notice that all this is bigger than Brazil.

Above all, focus your support on political leaders who are doing the well-informed, nuanced work the situation needs.

I suspect the most immediate solutions will be political and are, in fact, underway and in need of support. The other two options are more long-term.

Non-Profits?

The Guardian recommends supporting the following groups (though this is clearly not meant to be an exhaustive list):

I plan to focus on groups that specifically champion the rights of people who live in the forest; protect the people who protect the land. Respond to the S.O.S. messages that have been sent.

Consumer Activism

Yes, cutting back on meat consumption, especially beef consumption, is a good idea, since the global meat industry relies heavily on both pasture and feed production in areas that used to be rain forest. Boycott unsustainably-produced products generally. But don’t stop there. Brazil and other heavily-forest countries do need to make a living somehow, and if cutting down the forests is the only way to do it, then the result is predictable and possibly unavoidable.

Both as a consumer and as a voting citizen, support sustainable economic activity by countries whose forests we want to preserve.

The Guardian recommends The Rainforest Alliance as a source of information on what to buy and what to avoid.


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Groundhog’s Day!

The following is a slightly re-edited version of an older, but clearly seasonal post. I’ve always liked this time of year–it feels optimistic, when optimism can be hard to come by.

-C.

This weekend was Groundhog Day, the day when, supposedly, a groundhog in Pennsylvania predicts the weather by seeing or not seeing his shadow. It’s the closest we have to a climate-related holiday.

It’s an odd holiday–never mind how a groundhog could predict the weather, how can one groundhog give a single prediction for the entire country? And why six weeks? We can explore these questions briefly and then I’ll get back to talking about climate.

Groundhog Day itself goes back to Europe, where a group of interrelated traditions had various animals–hedgehogs, bears, badgers, perhaps even snakes–breaking hibernation in February to predict the remaining length of winter. The underlying idea is that clear weather in early February is, counter-intuitively, a sign of a late spring. And that association may well hold, at least in parts of Europe, for all I know.

February 1st or 2nd is also a cross-quarter day, one of the four days per year mid-way between a solstice and an equinox (the solstices and equinoxes are the quarters). The other three are May 1st, August 1st, and November 1st. All four were holidays in at least some of the pre-Christian European religions and all four survive as folk traditions and Christian holidays. All four are also holidays within the modern religion of Wicca. So today or yesterday is not just Groundhog Day but also Candlemas, Brigid, or Imbolg, depending on your persuasion, and all involve the beginning of spring. I have always heard that in European pagan tradition, the seasons begin on the cross-quarters, not the quarters–thus, spring begins not on the Spring Equinox but on the previous cross-quarter, in February. I’ve always wondered if perhaps “six more weeks of winter” is a remnant of cultural indecision as to which calendar was correct–whether spring should begin in February or six weeks later, in March.

In any case, we in America got Groundhog’s Day when German immigrants in Pennsylvania adapted their tradition to the New World–Germans looked to hedgehogs as prognosticators, but hedgehogs don’t live in America (porcupines are entirely unrelated). Groundhogs do. In the late 1800’s, the community of Punxsutawny announced that THEIR groundhog, named Phil, was the one and only official groundhog for everybody, thus utterly divorcing the tradition from any concern with local weather. There are rival Groundhog’s Day ceremonies, but Phil is still the primary one.

Groundhogs (which are the same thing as woodchucks) do sometimes take breaks from hibernation, though they don’t necessarily leave their burrows. There are various theories as to why, but most involve the need to perform various bodily processes that hibernation precludes–including, perhaps, sleep. Hibernation is not the same as sleep, after all. But there is evidence that male groundhogs spend some of their time off in late winter defending their territories and visiting females. They actually mate after hibernation ends for the year, but apparently female groundhogs don’t like strangers. Thus, it is actually appropriate that Phil is male–the groundhogs who come out of their holes in February are.

Anyway, underneath the silliness at Gobbler’s Knob in Punxsutawny, Groundhog’s Day is about a cultural awareness of weather patterns and animal behavior. Certain times of the year are cold and other times are not, dependably. If we pay attention, we can know what to expect and we can organize holidays and cultural observances around that knowing. In this sense, then, Groundhog’s Day is not about weather but about climate. Climate is the roughly stable pattern that makes it possible for ordinary people who don’t have supercomputers or satellites to predict the weather simply by watching the world around them.

We’re losing that, now. It’s fifty degrees outside, where I live. In February. And while warm, springlike weather is pleasant and I intend to go out in it as soon as I’m done writing this, there’s always something unnerving about unseasonable conditions. But the patterns our cultural traditions are build on–climate–are eroding. The world is getting less reliable, less like home.

It’s a little thing, as consequences from climate go, but one likely to have a profound effect on us psychologically. There is still time to do something about it. Get involved politically, support climate-sane candidates.

Now.


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The Carbon Footprint of a Beagle

So, we just got a beagle.

We already had one beagle, but after the death of her co-dog (a Lab/pit mix) last month, she’s been lonely, so we got her a companion. His name is Reilly, and he is sweet and affectionate and already causing trouble in his distinctively charming and beaglish way.

This seems like a good time to cover a topic I’ve been interested in for a while, the relationship between climate change and pets

The Carbon Footprint of Pets

Turns out, there have been serious scientific studies of the carbon footprint of dogs and cats. Results vary, but the general consensus tends to be that pets, collectively, have a large carbon footprint because there are a lot of them and dogs and cats eat mostly meat, which is a carbon-intensive food.

There are a couple of interesting points, here.

First, these studies may be studies of the carbon footprint of pet food, not pets. One research team is quoted as having looked at dog food only, based on the assumption that other aspects of dog care have minimal impact. Their assumption may be correct, but personally I’d like to see a study that examined all aspects of dog (and cat) care so we could check the accuracy of that assumption. I’m also amused by their conclusion, that big dogs have a larger carbon footprint than small dogs, since big dogs eat more. Personally, I’m not sure why anyone would assume the non-food aspects of dog care have minimal impact (a complicated question involving lots of data most of us don’t have) but then perform and publish a formal study on whether big dogs eat more than small dogs do.

Second, sorting out the carbon footprint of food may be trickier than it appears. For example, pet food is often made, in part, from meat by-products, which humans can’t eat. By-products are essentially waste for which a market has been created, stuff that would not exist if the primary product (muscle meat for human consumption) were not being produced. So is it really fair to assign the carbon footprint of the meat by-product to the dog who eats it rather than to the human whose demand for steaks created that steer in the first place?

The carbon footprint of food can vary a lot, as we know from studies of human diets. For example, beef and lamb are much more carbon-intensive than chicken. I’d like to see a detailed break-down of several different kinds of pet food and the different aspects of their production.

To Pet or Not to Pet

What does the question “what is the carbon footprint of a pet?” really mean? We could ask about the carbon footprint of Reilly and what we, his guardians, can do to make him a “greener” dog. Alternatively, we could be asking about our own carbon footprint and whether not having Reilly would make my husband and I “greener” people.

And since Reilly’s personal impact on the climate would presumably be about the same no matter who had him, the latter question really boils down to the draconian “should Reilly be alive?”

In a similar spirit we might debate, or refuse to debate, the lives of human children. Indeed, since humans have huge carbon footprints, especially in the so-called “developed” world, some list “having a child” as the worst thing a person can do to the planet, even worse than airplane travel, car travel, or eating meat.

My husband and I don’t have children, and environmental impact is part of the reason, but phrasing the decision as a measurable reduction of our carbon footprint as a couple seems very wrong.

What if the child in question were the next generation’s Rachel Carson?

The very idea of reducing a child to a carbon footprint is offensive. Reducing Reilly in such a way is less so, but still pretty bad.

But Haven’t There Always Been Dogs?

There is an argument to be made for having fewer dogs and cats in total. Their collective environmental impact is not negligible, and most humans could get along without them quite well (I said most, not all). But if all dogs and cats suddenly vanished, would the carbon footprint of humanity really shrink? Or would some other use be found for meat by-products?

Perhaps more to the point, would climate change really slow?

This whole line of questioning reminds me of cows. There is an argument to be made for having fewer head of cattle, too, after all, since their environmental impact is quite large, and we can eat other things. But when I brought up such an argument a while back, a friend of mine posed an interesting question; haven’t there always been cows?

And yes, cows are not new. I’m fairly sure there are a lot more now than there used to be, but surely before the modern mountain of moo there were other ungulates, bison and caribou, antelopes and takhi and quagga, to take up the slack.

Ok, those last two aren’t exactly ruminants, but you get the point. The only way large herds of cattle could actually change the climate would be if the total number of ruminants, domestic or otherwise, had grown–and how would such increased stock find enough to eat if something else hadn’t changed?

The same question applies to dogs and cats. If these animals have not simply replaced their wild counterparts but actually exist now in excess of the total historical animal mass, where did the excess food come from and why isn’t it accounted for in the historical carbon balance, where the carbon each animal releases came ultimately from plants and returned to plants again for no net change?

Some other source of energy must be fueling the swelling populations, something from outside the old balance–fossil, presumably, in one way or another. In other words, if the total population of dogs (or cattle or humans) has grown too large for the planet, it is a symptom, not a cause, of our problem.

As useful as carbon footprint calculation can be, it’s possible to get lost in the weeds here and miss the larger picture, which is that the climate is changing because the concentration of greenhouse gasses is rising, period.

Reilly can’t introduce additional carbon to the system. He just can’t. If he is alive because of such an introduction, his death at some shelter would not begin to solve the problem.

Take Home Messages

Yes, certainly it makes sense to feed pets the most climate-friendly diet possible. And people who are bound and determined to buy a pet from a breeder might seriously consider a little vegetarian, like a rabbit, instead of a big carnivore, like a retriever–shift the market in a more climate-friendly direction.

But you are not going to fight climate change by not getting that beagle from the shelter.

Let’s keep our collective eye on the ball, the ball being to get off fossil fuel completely as soon as possible. Only then can we fix the problem that causes all the other problems.