The Climate in Emergency

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


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Reading of Names

I’m re-posting this one from last year (n the yer before), with minor edits. I have not found any new species to add to the list, though unfortunately that doesn’t mean there aren’t more that belong on it. There is a leak in the world and life is running out of it…

Tomorrow is Hallowe’en, of course. 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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Falling

I was going to write about solar ovens in Africa this week, but I’m still waiting for an interviewee to get back to me. So instead I’m going to talk about… leaves.

Here in Maryland, the forests still look surprisingly green. Now that we’ve had a few cold nights, some of the trees are “trying to turn,” as my husband puts it, but it doesn’t really look like fall, yet. The Weather Channel confirms that the delayed color is both regional and weather-related. That is, it’s not just my autumn that has been delayed, and the delay in foliage is, indeed, because of the extended warm weather.

But I’ve noticed that the leaves are falling.

They’re not falling heavily, yet, though at this point in the year they wouldn’t be. It’s just a few dead leaves accumulating on the sides of the roads and the edges of the sidewalk. But the funny thing is, the fallen leaves are mostly green. The trees they are falling from are also mostly green, but it is a strange green, an altered hue. I wonder–have the leaves changed after all?

“Brown-down,” the technical term for it, is a multifaceted process initiated when shortening day-length triggers the growth of the “abscission layer,” a corky section in the leaf petiole (its stem) that interferes with the flow of water and nutrients. Eventually, the cork gets thick enough to cut off the leaf entirely so it dies, and the petiole breaks neatly at the abscission layer. The leaf falls off. But before all that happens, before the cut-off is complete, the leaf continues to function. But chlorophyll breaks down as it’s used. It has to be continually replaced. With the leaf partly cut off, the chlorophyll can’t be replaced. The green fades from the leaf, revealing yellow and sometimes red pigments. Eventually, those pigments, too, break down, and the color fades.

Temperature changes help determine the speed and intensity of the color changes, even though the growth of the abscission layer itself is governed by day length.

Does this sound familiar?

Years ago, I wrote a post about spring, and how different aspects of spring (leaf-out, hatching of caterpillars, arrival of migratory songbirds) are cued by different factors. As climate change speeds up some of those factors but not others, the entire progression of spring gets out of sync. I’m wondering if the same thing is happening with fall.

If leaf-fall is triggered by day length, and the color change is triggered by temperature, then as climate change shifts the seasonal cooling later and later–and the timing of shortening days can’t change–it stands to reason autumn should get out of wack. Specifically, the leaves will fall more or less on time, but there will be little to no fall color.

Is that what we’re seeing?

I’m engaging in speculation, here, but it seems plausible. The ecological cost of climate change, and ultimately most important (that includes human ecology, FYI), but there’s a psychological cost, too. Personally, I find the weirdness of this non-fall very disturbing.


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Independence Day

I’m re-posting this from last year, as it’s still quite timely. -C.

Happy American Independence Day.

The best of America has always been an ideal to which reality aspires in an irregular and sometimes ambivalent way. Our principle of equality has always been marred by racism, sexism, and various other interrelated isms, and yet the principle itself is valuable as a stated goal—and for much of our history, we have enjoyed a more egalitarian, and more participatory political and legal system than much of the rest of the world. It is not true that anyone can be anything if only they work hard, but hard-working people do have more latitude here than they might, as the flow of economic refuges to our borders attests. We are not the bastion of democracy that we should be, but we are the imperfect bastion that we are.

Anyone who thinks that the United States is the greatest and most perfect country on Earth has not been paying attention. But anyone who cannot tell the difference between the US and a third-world dictatorship hasn’t been paying attention either.

So, with that caveat, I’ll get to my point: the US is not currently independent.

Russia did try to get Donald Trump elected. Whether their involvement was decisive is debatable—it’s possible he would have been elected anyway. That Candidate Trump himself actually cooperated with Russian interference on his behalf has not been proved and might not be true. Yes, his public joking, during the campaign, to the effect that Russian hackers should help him is not, by itself, a smoking gun that he actually expected him to do so, or that any quid pro quo arrangement was made between the American oligarch and any Russian counterpart. That other people connected to the campaign were actively working for, or trying to work with, foreign entities during the campaign is also not proof, nor is the fact that President Trump has some odd financial ties to foreign entities (the extent of which we don’t know because he won’t release his taxes) proof. The whole thing is suspicious as all get-out, but we don’t actually know.

But the fact remains that by attempting to pull out of the Paris Climate Agreement, President Trump is acting in the interests of Russia (and Saudi Arabia) and not those of the United States. Maybe he’s doing it out of the “goodness” of his own heart, a spontaneous volunteerism with no prior planning or thought of reward, but he is acting in the interests of a foreign power.

I’ve argued previously that pulling out of Paris, and otherwise minimizing or reversing American action on climate, is the primary reason for Mr. Trump’s presidency, the true central plank of his personal platform. His rhetoric on the subject of the economy and American security, his dog-whistles to white nationalists, his consistent vocal abuse of women both individually and collectively, all of that can be chalked up to either personal proclivity or empty campaign promise. A wall on the border with Mexico would do nothing whatever to protect his constituents’ job prospects or personal safety, even if Mexico did pay to have it built. Getting out of Paris, though, is the one campaign promise he’s acted on and the only one that will actually help anyone.

It will help the owners of the fossil fuel industry.

I said that part already. What I did not point out before was the way in which acting on behalf of that industry constitutes selling out American interests in favor of those of other countries. It is true that Russia has powerful interests in oil, but so does the United States. While transnational corporations are, in some ways, independent of any country, Exxon, for example does have an American origin and the US still produces substantial amounts of coal, oil, and natural gas. It’s possible to tell this story as one of private, corporate interest, and many of the interested parties are Americans.

But the United States doesn’t need the fossil fuel industry. We have a fairly diversified economy, a highly diversified resource base, and we’re a net exporter of food. There is huge economic opportunity for us in a properly managed transition, and we’ll likely survive, or even come out ahead, as fossil fuel prices drop due to lessened demand. Russia is simply not as well prepared for the shift. Oil is its primary source of national wealth.

While I haven’t looked into what climate change will do for Russia, I don’t imagine that a rapidly warming planet is actually good for that country. And Russia did, in fact, sign the Paris Climate Agreement. But even if they don’t have less to lose that we do to a changing climate, certain elements within Russian society do have more to gain from hanging on to fossil fuel a little longer.

And we do have a lot to lose. Most of our major cities are coastal and thus vulnerable to sea level rise and a possible increase in hurricane activity. Much of our landmass is already capable of experiencing killer heat waves, and thanks to air conditioning, many of our most vulnerable citizens live in places that get dangerously hot (like Arizona and Southern Florida)—a problem that will only get worse. Increased drought and increased flooding will likely interfere with our agriculture. In many areas, our use of irrigation water is already unsustainable. The United States already gets more tornadoes than any other country on Earth, and while there is no way to tell whether climate change is increasing tornadic activity (there’s no reliable baseline data), it is a fair bet that it will. Political and economic instability in other countries caused by climate change represents a major threat to American security.

Mr. Trump is willing to risk all that for the sake of short-term economic gain—by people other than us.

I want to make very clear that I do not have anything against Russians as a people. Russia is not, at present, a free democracy, so I don’t hold its people accountable for what their leaders are doing. I also want to make clear that I’m not blaming Russia for America’s troubles. While it does seem clear we are under attack, our vulnerability to such attack is entirely home-grown. I’m only pointing out that our laws and government institutions are currently being used to protect a foreign government’s revenue stream at our expense.

242 years ago today, we told the world we weren’t going to let that happen anymore.


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Tick, Tick, Tick, Tick, Tick

When I was little, the appearance of a tick itself was reason for alarm.

“So-and-so found a tick the other day!” Mom would announce. “Be careful!” I think I had one on me–just one–my entire childhood. I’m not sure whether there were really so few ticks, or if we were simply bad at finding them. I do know that when I moved to Maryland, I didn’t have to be good at finding the little parasites. Huge numbers of them found me.

Seriously, go for a walk in my neighborhood in the summer, and you’re likely to pull off ten or twenty just while you’re walking. When you get back to the house, strip off your clothes and find a dozen more. They won’t have had time to embed, yet, so it’s not a big deal. You just get in the habit of routine regular tick checks.

Incidentally, I don’t find the standard advice of long pants and so forth very useful. Sure, fewer ticks will make it to skin that way, but some will, and they’ll be impossible to find without taking your pants off, which the neighbors tend to frown on. So the ticks get more time in which the crawl into someplace inaccessible and bite.

My advice?

  • Wear as little clothing as possible and then investigate every tickle and itch immediately–it might be a tick.
  • Do a thorough tick check and take a shower immediately upon returning home.
  • If you walk through a tick-hatch and get zillions of the tiny things on you, don’t panic. They can’t give you any diseases because they’re babies and don’t have any diseases yet. Remove them as best you can, stick them on a length of tape so they can’t escape and bite you again, then invest in a large supply of anti-itch cream.
  • Don’t bother learning to identify different species of tick. They can all give you SOMETHING, so just avoid getting bitten by any of them, and if you get sick, go see your doctor.
  • Look up the proper way to remove an embedded tick. NEVER put anything on the tick to make it let go, because that makes the tick vomit into you first and then you’ll definitely have whatever it was was carrying.

I’m not a doctor, this is just my personal approach to the problem.

The reason I bring all this up is to make clear I am personally familiar with the density of the tick population in the mid-Atlantic region of the United States, and I am equally aware that New England has fewer of them. Don’t get me wrong, New England does have ticks–Lyme disease is named after a town in Connecticut, after all–but the problem is simply not on the same scale.

That could be changing.

There are reasons other than climate change. Tick population dynamics and the epidemiology of tick-borne illnesses are complex, inter-related topics with a lot of variables. For example, modern land-use practices, which has converted vast areas of the United States into mosaics of tiny forested patches with houses mixed in, favors white-footed mice, which are the primary hosts of deer ticks–which transmit Lyme disease. The mice, after all, can use tiny habitat patches (and houses) just fine, but their predators can’t. No foxes, no bobcats, no black snakes, no owls, etc., all adds up to oodles of mice and oodles of ticks. So, some kinds of ticks would be a bigger problem than they used to be, even without climate change.

But yes, the climate is helping.

The story is a complex one, because not only do factors other than climate influence tick populations, but the response of ticks to climate is not straight-forward. For example, ticks of the same species may become active at different temperatures in different parts of their range. All these different variables working together mean that predictions of what climate change will do to different species of ticks can disagree with each other widely. But some increases in tick-borne illnesses have been traced to climate change–so we don’t know what’s going to happen in the future, but in the present, the ticks are worse in some places already because of climate.

For example, the two species responsible for infecting people I actually know, deer ticks and lone star ticks, are both expanding their range because of climate change. Both can transmit multiple illnesses. Lone stars, named for the white spot on their backs, can give you a (possibly life-long) allergy to red meat. Without giving away any individual’s medical history, I can say I’ve seen this one, it’s quite real. And lone stars are now in all New England states, though they didn’t used to be.

(By the way, the article that I’ve linked to above describes lone stars as “hunting in packs.” I’ve seen the behavior the article is describing, and the phrase is misleading. The ticks aren’t acting cooperatively, like mini-wolves. But, unlike deer ticks, they can and do walk towards potential hosts. In my neighborhood, population densities are often high enough that half a dozen might be near enough to notice the same person, and if you stay still for a few minutes they’ll converge on you. They’re easy to avoid or remove, but it’s creepy to watch.)

And then there’s the winter ticks, which have always been in New England, but warming climates are letting their numbers surge so high that they’re literally bleeding moose calves to death.

All of which is to say that if you head north in the summer, as we do, and you notice more ticks on yourself and your pets than you used to, as we have, it’s not your imagination.


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Last

The world’s last male northern white rhinoceros is dead.

His name was Sudan. He liked people, and was liked by them, and spent most of his 45 years in captivity. He was very old, very ill, and, recently, in a lot of pain. He was euthanized yesterday by a team of veterinarians who loved him.

He leaves behind just two other members of his subspecies, both female relatives of his, both unable to reproduce. His death doesn’t actually change the picture for his kind; recovery is not quite impossible–some of his sperm remains in storage, and one of the females, though unable to gestate, can produce eggs, which could be harvested–but it is an extreme long shot, and it was equally a long shot yesterday before he died. The death of the last member of a species or subspecies is a technicality.

The northern white rhino is part of the same species as the southern white rhino, which is not in quite such dire straights, but the distinction between the two matters. The northern white rhino may have been capable of ecological relationships that its southern counterpart can’t replace. Anyway, things are bad for rhinos in general, these days. We can’t take any subspecies’ survival for granted.

Periodically, someone questions whether we really need all these species and subspecies, whether the heroics enacted for the likes of Sudan are really worth the effort. Such questions ignore the fact that we almost certainly don’t know what we’re losing when a species dies. We don’t know how far the web of its relationships in the world went.

Climate change did not kill Sudan, not directly. But species loss is another symptom of the collapse that is causing climate change. As long as our species insists on using more resources than our planet actually has–something that is only possible with the use of fossil fuel–progressive biosphere collapse is inevitable. Climate change did not kill Sudan, but it’s possible that climate sanity could have saved him. What might climate sanity now still save?

Talk about climate change. Talk to your friends, your neighbors, your co-workers, your Congresspeople. Don’t let the issue be ignored.


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BOEM, Again

Remember the BOEM scoping process from a few years ago?

Basically, every five years, the Federal government decides which Federal waters will be available for oil and gas exploration. The process is supervised by the Bureau of Ocean Energy Management, or BOEM, and is somewhat drawn out. In the beginning, all areas that will be considered are included in a proposed map, and public and expert comment is sought. Based on those comments, some areas may be removed from consideration, before the creation of another map and another round of comments. At each stage, the area potentially available to oil and gas extraction can grow smaller, but never bigger. When the final plan comes out, energy companies can lease small areas within those regions made available under the plan, but not every square mile within those regions is ever offered for lease, and not every possible lease is ever exploited. Although BOEM explicitly allows and facilitates oil and gas exploitation, its job is to make sure that such exploitation happens in as safe, as environmentally responsible, and as fair a way as possible.

As possible given the scale of oil and gas exploitation demanded by the economic and political will of the American people.

That last is the key–although BOEM’s job is to say “yes” to people who really should not be said “yes” to, that approval has already been issued by many other entities, including the collective weight of all the American people who buy petroleum products. BOEM’s job is to say a negotiated “yes,” to minimize harm. The BOEM personnel I’ve spoken to have all seemed friendly, helpful, sincere, and genuinely interested in environmental values and fair due process. They depend on us to give them the political cover they need to do the right thing, and they want to help us provide that cover.

BOEM is not our enemy.

Two years ago, parts of the Atlantic were initially considered for exploration, a problem, both because even the safest practices do not reduce the risk of an oil spill to zero, and because the process of locating oil and gas deposits involves sonic testing that is so loud it can kill marine life that happens to be in the way. A lot of us organized and gave public comment, passed local resolutions, and even lobbied Congress. And it worked. Most of the areas originally under consideration, including the entire Atlantic, were removed from the plan. We won! Yay!

And then Present Trump decided to start the whole process over again.

Starting Over

A new presidential administration has the option to re-examine certain decisions of its predecessor, including which areas are available for oil and gas exploitation. Mr. Trump has exercised this option, so we have to go over all of it again.

The obvious motivation for the Trump Administration to re-start the process is a desire to open up more seabed to resource extraction, especially since now, for the first time, almost all American Federal waters are under consideration. But if the process goes as it should, the results should be close to the same as they were last time–most areas should again be excluded.

But even if we win this time, too, there is still a problem, because this process requires quite a lot of work on the part of BOEM personnel–and while they are working on collecting and analyzing comments and making recommendations, they are not doing other things. While discussing the matter with BOEM personnel at a public outreach meeting yesterday, I asked what these other duties are.

Turns out, when not wrangling public comments, many BOEM personnel are involved in conducting environmental impact assessments, identifying gaps in the scientific knowledge used for those assessments, and hiring scientists to fill those gaps. Right now, those duties are still being carried out, but by fewer people. To some extent, this temporary personnel reassignment slows research for some months. More seriously, few people doing the work means fewer minds available to figure out how to solve problems and how to ask research questions.

Do you suppose interfering with research in this way could be the point of this massive do-over?

What to Do?

This is a call to action. Although not directly related to climate change, there are a lot of indirect connection, as I’ve described in previous posts.

The action is fairly simple and user-friendly–make a comment.Obviously this especially addressed to you if you live in the US somewhere coastal, but if you simply care about these areas, please get involved. And remember, we’re talking about almost the entire US coastline and adjacent offshore waters and all the animals and human economic activity (tourism, seafood, etc.) that depend on them.

Feel free to read my earlier posts (like this one) for more information, the issue and the process haven’t changed. There are a number of organizations that have also agreed to provide talking points and links; I’ll update this post when they do so. You can also go to BOEM’s website for more information on the process, a virtual version of the public informational meetings BOEM is holding, as well as how to comment.

BOEM personnel suggest that your comment involve more than “please don’t drill off my beach.” If you have any detailed information on ecological vulnerabilities of specific oceanic areas and coastlines, give those details. If you or someone you know has a strong personal connection to a given area, or if your livelihood depends on the water in some way, say so, and provide details, numbers, data, stories.

Here’s the link to comment again–you have until March 9th.

 


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Dead Zones?

In previous years I have written New Years’ retrospectives, recapping notable climate-related news stories from over the past twelve months.

This year, a retrospective of the past few weeks might be in order.

While I’ve been occupied writing holiday posts–for Yule, for Christmas, for New Years’ Day–and generally being distracted by family obligations, we’ve seen California’s worst wildfire ever (followed by a deadly mudslide just today, which is not unrelated), a rather startling case of Extreme Winter, and a new and really frightening report on marine dead zones. And there have been various political issues. Let’s pick one of these stories and catch ourselves up, shall we?

Please note that where I make statements of fact without linking to a source, it’s because I’m using a source I already linked to.

Dead Zone

The term, “dead zone” is, unfortunately, not a metaphor. These are areas, usually along the coast, but sometimes out at sea, where there is so little oxygen in the water that animals can’t live. It’s a horrifying idea. Imagine minding your own business, living as you usually do, and all of a sudden breathing does no good. Dead zones aren’t spontaneous. They are caused when flushes of nutrients (usually runoff from over-fertilized farm fields or lawns, or from sewage treatment plants) trigger massive algae blooms in the water. Although algae itself make oxygen, when the supply of fertilizer is exhausted, the algae die off and decompose and bacteria go through a population explosion. While not all bacteria breathe oxygen, these do, and there are so many of them that they use up the local supply, causing a dead zone.

In some circumstances, a dead zone can also be caused by algae directly, since algae, too, must breathe (I mean “breathe” loosely here, since all this happens under water)–it is a misconception that plant breathing is the reverse of animal breathing, that plants breathe in carbon dioxide and breathe out oxygen. Instead, plants breathe in oxygen just as we do, and for the same reason–to “burn” sugars for energy. The difference is that we get our sugars by eating, whereas plants make sugars by photosynthesis. Free oxygen is a byproduct of photosynthesis, and fortunately for us, plants make more of it than they need. But in warm, shallow water, a super-abundance of algae can sometimes run short of oxygen at night, when of course photosynthesis stops but breathing doesn’t. In Mobile Bay, in the summer, if the wind and tide are just right, this type of dead zone can move towards the shore, driving anything capable of fleeing before it. Long about dawn, anyone on the right stretch of shoreline can scoop up as much seafood as they want. Before the reason for this influx was discovered, it seemed like magic, an unearned gift from the sea. It’s called the jubilee.

Jubilees occur, less predictably, in other areas, too, such as the Chesapeake Bay, anywhere a dead zone can develop and then move towards shore. The size, shape, and duration of a dead zone depends on many factors, including, temperature, salinity, and wind direction. Dead zones are often low-down in the water column, leaving oxygenated water near the surface, which is why jubilees involve bottom-dwelling species, such as flounder or crab.

Dead zones occur in certain areas every summer, but their shape and size vary from year to year. Evidence of dead zones has been found in sediments going back at least to the late 1800’s, but the same study shows a worsening of the problem since 1950. It may be possible for a dead zone to form without human help, but humans unquestionably cause most of them.

In any case, the problem is less that individual animals die in the short-term, and more an issue of habitat loss. Because of dead zones, the places where marine life can exist are now smaller.

It’s worth noting that there are parts of the ocean where very little lives, and very little has ever lived because there is not much in the way of nutrients for various reasons. These are not dead zones. By definition, a dead zone is a place where life would occur if something had not used up so much of the oxygen.

Ok, Where Does Climate Change Come In?

Dead zones are mostly a story about pollution and land use–the factors that send excess nutrients downstream and into the sea. As such, the problem is sort of a cousin to climate change; the two have causes in common. But climate change also has a direct influence, most obviously because the warmer the water is, the less oxygen it can carry–and the less oxygen must be used up before a dead zone occurs. Also, warmer water raises the metabolisms of the animals that live in it, meaning that they need more oxygen, using the precious stuff up faster–and possibly also making dead zones occur at higher oxygen saturation levels.

Also, remember that salinity and wind direction are also factors in dead zones–and climate change can alter both.

The mechanisms here are a little complex, and I’m not going to describe all of them. Fresher water is lighter than saltier water, which means the two tend to resist mixing. River water flowing into the Chesapeake Bay, for example, or raining onto it, tends to float on top of saltwater flowing in  from the ocean. This resistance to mixing is not absolute–the surface waters of the Bay get brackish pretty quickly–but it is enough that the water on the bottom has trouble getting oxygen from the air. If the algae and sea grass in the water can’t produce enough of their own oxygen, a dead zone develops. The salty water is effectively under an air-tight lid, unless wind blows and stirs the layers.

Well, as sea level rises, more saltwater flows into the Bay. As the deeper waters get saltier, the resistance to mixing gets stronger, and dead zones get more likely.

In fact, although the dead zones of the Chesapeake Bay are now shrinking (thanks to concerted efforts in the Chesapeake watershed to limit nutrient run off), the amount of excess nutrient in the Bay water is shrinking faster. That is, the Bay has been dying more easily now than it used to, and the problem is getting worse. No one is exactly sure why, and various feedback loops and long-term ecological changes  (water dies easier if it’s been sick for a while?) could be in play, but sea level rise could be part of the answer, as could rising temperatures. Changes in wind direction may also play a role, as winds from the south have become less common since the early 1980’s, in favor of winds from the west. Since the Chesapeake is large, north to south, and skinny east to west, the change in wind direction has meant less wave action, and thus less mixing in Bay waters. I don’t know that the change in wind direction has anything to do with climate change–but I don’t know that it doesn’t, either.

As often happens, there are other factors that could be involved, some of which could actually mean climate change reduces the size of dead zones, long term. No one knows for sure.

But so far, as climate change progresses, dead zones have been getting worse. I suppose that could be a coincidence….

What’s the Story?

The reason I’m bringing all of this up now is that a study has just come out showing that although the Chesapeake dead zones are shrinking, dead zones elsewhere are getting much worse–and dead zones are even occurring and worsening in the open ocean, which is generally much more resilient.

Each area’s dead zone has its own history and its own context. How long has the zone been occurring, which industries cause it, who gets hurt by it, what is the relative political power of each, what details of local geography and ecology make the situation worse or better, what stresses other than low oxygen levels might be bothering marine life…. I’m reluctant to make generalized statements without first looking into the rabbit hole of information on each zone. Climate change may be a factor in some zones but not others.

But these zones are worth watching. Is there one near you? Does something you do, or don’t do, help cause a dead zone down stream? Are your state, local, and Federal representatives aware of the problem and concerned about it?

There are zones in the water that kill fish and many of them are growing.