The Climate in Emergency

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


Leave a comment

Retrospective

Hello. Sorry this post is a few days late.

I set out to write a retrospective of the year, as I have for at least some of the other years of this blog. But I noticed something funny, when I looked over my writings of 2016. In brief, there wasn’t a whole lot to retrospect.

Most of my posts this past year were opinion pieces, science explainers, or climate fiction–or politics. There was a lot of politics. I covered very few actual events.

Of course, there was weather. Remember that hurricane in January? The cyclone that literally blew around in the Pacific (as in its track made a circle)? The terrible flooding in Britain and then the rest of Europe? The fires? No, I did actually write about fire last year, but I remember the fires in the Smokies, anyway. Yes, fire counts as weather in the same way that flooding does, for one is a symptom of too much rain and the other a symptom of too little. But increasingly, I’m getting reluctant to write about weather here, because it’s always the same story. Climate change increases the frequency and severity of extreme weather, here is extreme weather happening, please stop causing climate change. Over and over again. And again.

There was the California methane leak, which I wrote about in January. It was finally sealed towards the end of February, a little earlier than some experts had feared. Two months later, some area residents still had not returned, worrying about lingering contamination. Some still had health problems, probably caused by poisoning from some combination of mercaptan, heavy metals, and benzene, all of which were present in the gas plume from the leak (methane itself is not toxic, but it is a dangerously powerful greenhouse gas). I don’t know what has happened since, how the lawsuits have turned out or if there have been any policy changes involving methane storage, because the newsmedia seem to have totally lost interest.

There was the oil and gas exploration policy process, which we more or less won. Not only was the Atlantic excluded from oil and gas exploration, so was the Arctic. How long any of that will last in the new political climate seems unclear, though.

There was the Dakota Access Pipe Line, which I’ve mostly avoided writing about because it’s not my story to tell, but it is an important and ongoing issue.

And there was the disaster that is Donald Trump and the new Republican Congress.

Look, people, we’re going the wrong way. We need a climate-sane government and we don’t have one yet. We don’t even have much of a popular movement in that direction. The pushback against Mr. Trump seems largely organized around women’s rights, LGBT rights, the civil rights of racial and cultural minorities, especially immigrants…but what no one is saying that if Mr. Trump disassembles President Obama’s climate legacy, members of all those groups will be directly and terribly affected. Climate change is a women’s rights issue. It’s a civil rights issue. It is an economic issue. There is no way to win on any of those other fronts if we lose on climate change.

And yet 2015 gave us a series of climate marches last year to which virtually nobody showed up. Not surprisingly, 2016 gave us an election cycle in which the issue was hardly  raised. We now have a Congress who has no particular reason to believe there is any political will to support climate action.

I am more than ready for 2017 to pleasantly surprise me.

Advertisements


Leave a comment

Climate Change and Food: Red Meat

I have talked about climate and food before in terms of how climate change influences the food supply, but what about the other way around? How does our eating influence the climate? As many readers are probably aware, a significant amount of our collective carbon footprint (about one quarter) comes from our food system and meat-based foods have a larger footprint than plant-based foods. But how much difference between foods is there? What is the best way to cut carbon emissions out of one’s personal diet? Does it matter whether the meat is local or free-range?

I didn’t know either. So I’ve done some reading.

The numbers don’t look good for meat

The short answers are that the difference is huge, the best way to cut emissions is to eat less meat, and free-range and local do matter but, as far as the climate goes, not very much. There are some complications and nuances, of course.

I found an article that includes a graphic showing the carbon footprints of various food types (chicken, beef, eggs, lentils, etc.) expressed in kilograms of carbon dioxide equivalent (CO2e) per kilogram of food. “Carbon dioxide equivalent” means all greenhouse gasses taken together and expressed in terms of their impact on climate. So these figures include methane. Logically, the numbers would be exactly the same with any other measure of weight–the point is there is a ratio between amount of food and amount of emissions.

The simplest thing is to read the article, which you should do anyway because it’s fascinating. Here is the link. But I’ll summarize the most striking parts–for simplicity, I’ll give a single numbers for this; instead of writing “5kg of CO2e per kg of food,” I’ll just write “five.”

Lamb is the most carbon-intensive meat by far, at 39.2. Less than five of that is transportation and processing, which presumably means that if you raised your own lamb in your back yard, killed it yourself, and then had a carbon-neutral barbecue, it’s number would still be around 36. The next-closest competitor is beef, at 27, and then the other animal-based foods on the list cluster between 13.5 and 4.8. In contrast, the various plant-based foods on the list all cluster between just under three and just under one. The importance of transportation and processing varies, but only in potatoes is it the majority of the total figure.

I can think of several possible complications (besides grass-fed vs. grain-fed, which I’ll get to later).

  • What if the animal is a by-product of another industry? For example, if a flock of sheep are managed for milk and wool as well as meat, so that only excess ram lambs are slaughtered, then the carbon footprint of the flock is the same as it would be if those excess animals were not eaten (letting them live as pets would actually increase the carbon footprint of the operation, aside from the other ethical questions involved). In such a case, the same kilogram of CO2e has to share meat, milk, and fiber,and the whole operation is much more efficient than it might seem, right?
  • Do the figures for animals include emissions from transporting animal feed?
  • Why is the footprint of cheese six times that of yogurt given that most of them are processed milk?
  • The study focused on food in Britain; are these numbers different in other countries, such as the United States?
  • What is the footprint of highly processed foods, such as candy or fast food?
  • Since different kinds of food have different nutritional profiles, how would this comparison work if the unit of comparison were nutritional value, rather than weight? Nutrition is complex, so it might be impossible to do that kind of study, but the issue could still be important.

I do not have answers to those questions.

In any case, clearly generally similar diets, such as two different versions of mostly-plant-based omnivory, might have extremely different carbon footprints. The study that released these numbers found that while the difference between eating a lot of meat and eating a little is huge, the different between eating a little meat and none is small.

What is so bad about meat?

The clear take-home message here is that giving up beef and lamb (except possibly where these are byproducts of dairy production?), and cutting way back on other animal-based foods, is one of the most powerful steps a person can take to address climate change (aside from voting!). So, why are meats so bad for the environment? We have to be very clear, here; this is not about animal rights, which is an important but separate issue.

I have not seen this issue addressed directly, but the Second Law of Thermodynamics, not to mention public tastes in food, is almost certainly relevant.

The Second Law states, in essence, that every time energy moves or changes form, some of it is lost. This is why, for example, a ten pound house cat needs to eat more than ten pounds of meat in its life. This is also why ecosystems always have more plant-eaters than carnivores and more plants than plant-eaters. Most of what an animal eats does not become meat–what happens to it? Some of it becomes bone or other tissues we don’t want to eat. Some of it is never digested and simply passed as feces–which decomposes into carbon dioxide or methane–or as flatulence, which is also methane. But most of that missing food is exhaled as carbon dioxide.

One way to think about this is that all carbon that is taken up by plants is ultimately either interred in long-term storage as fossil fuels, or released again to the atmosphere when the plant rots or burns or is metabolized and exhaled. Eating food is the exact chemical equivalent of burning fuel. So, when a human eats a pound of plant matter, “burning” that “fuel” results in carbon emissions. But when we eat a pound of meat, that meat represents all the plants that animal ate to grow that meat–and all of that plant-fuel is “burned,” whether in the meat-animal’s body or in the human’s. More plant-fuel burned means more emissions released.

Cattle and sheep are both ruminants, meaning they don’t actually eat food directly. The food they swallow is eaten by bacteria in their guts, which in turn create food for the cattle. So you get another layer of energy transformation and thus another layer of energy dissipation–the bovine gets less energy out of the food and has to eat more, so more plants are “burned” as “fuel” for somebody. And the waste product of these bacteria is methane, which is a very powerful greenhouse gas.

So, meat has a larger carbon footprint than vegetables and ruminants (cattle and sheep) have a larger carbon footprint than other animals (pigs, chickens, turkeys, etc.).

Does grass-fed matter?

Most animals raised for the industrial food supply spend at least part of their lives–and sometimes all of them–in some version of a small cage being fed some kind of grain-based, heavily processed diet. There are all sorts of reasons why this is a terrible, horrible thing and why if you are going to eat meat, you should really choose only free-range animals (please note that “free-range” is a legally slippery term and that finding meat that lives up to the intent of the phrase takes some research). Is the climate another such reason?

The answer to that one depends who you ask.

An animal’s personal freedom has no particular bearing on carbon emissions. What makes the difference is whether it is grazing or browsing, as opposed to being fed corn (as would happen in a cage or cage-like feedlot). Logically, feed carries a larger carbon footprint because it must be transported and processed, whereas pasture is eaten where it grows. In fact, one of the best ways to keep open land from being converted into housing developments is to put cows on top of it. All of that argues for grass-fed meat having either a smaller carbon footprint, or possibly a slightly negative footprint, if pasture sequesters more carbon than cattle release.

On the other hand, cattle, at least, have to live longer to get to slaughter weight if they stay on pasture. More time living means more time farting, which could mean a larger carbon footprint. And while cattle are healthier eating grass, they get more energy from eating grain (which must be why they gain weight faster that way). So a day eating grass presumably means more farts than a day eating grain, too.

Which argument is actually true seems unclear at this time and might depend on the details of the cattle operation in question. And I have not found anything on how free-range living might influence the carbon footprint of other food animal species.

Wait–haven’t there always been cattle?

This question was posed by one of my Facebook friends and it’s a good question. How could cattle be a factor in increased climate change given that cattle themselves are hardly new?

This was my answer:

xkcd land mammals

From XKCD, https://xkcd.com/1338/, used in accordance with the cartoonist’s policy

 

This graphic shows that almost half of the land mammal compliment of the planet, by weight, is cattle. The vast majority is either humans or animals that humans eat. The reason it makes sense to do this comparison by weight rather than by head is that weight is a good proxy for how much animals eat and, thus, how much plant “fuel” they burn and how much CO2e is released. Consider that the energy in a pound of mouse meat is probably similar to the energy in a pound of hamburger–about the same number of calories. There are some potential complications here, but two thousand pounds of mice probably eat very roughly the same amount as two thousand pounds of cow. So, the fact that our planet has a huge number of tons of cattle right now means that a huge amount of plant-fuel is being “burned” by cattle these days.

Now, I am fairly confident that while there have been cattle for millennia, there have not been THIS MANY cattle until very recently.

I also suspect that this massive pile of mooing would not be possible without fossil fuel–and it certainly wouldn’t be economical. Feed could not be cheaply moved in to feed lots and beef (grass-fed or grain-finished) could not be distributed widely enough to meet enough consumers to justify the size of the herd. If this is the case, then excessive cattle farts are simply another symptom of fossil fuel use.

But, even if the huge herd of cattle is new, surely something else was eating all those plants before, and releasing a corresponding amount of waste and flatulence? Like, all the wild animals we’ve squeezed out of existence lately? Maybe and maybe not. Perhaps a lot of those plants used to just not get eaten and to enter into long-term storage on their way to becoming fossil fuel. Or maybe the wildlife released more carbon dioxide and less methane and so had a lower carbon footprint. There are possibilities. Or maybe the farts of cattle are actually irrelevant to climate change and the real carbon footprint of food is only the fossil fuel use and the ecological degradation associated with it?

That one I do not know.


2 Comments

California Methane Leak

As you may already be aware, California is leaking.

More specifically, a giant natural gas storage facility just north of Los Angeles is leaking, and the amount of methane coming out of this thing is huge. It’s been going on since October and is likely to go right on until March. My Facebook feed has been filling up with dire warnings about Armageddon, but the nightly news has been strangely quiet.

So, what’s the story with this leak, how bad is it really, and is it really being nationally ignored?

It’s easy to find a detailed description of the problem online, so another detailed exposition seems superfluous. Here is just a quick summary to get us all on the same page.

The storage tank in question is actually the space in the rock where a huge pool of petroleum used to be. Industry pumped the petroleum out and sold it and then decided to use the empty space for temporary storage of natural gas. Basically, the owner, the Southern California Gas Company (or SoCal Gas) wanted to be able to keep a lot of inventory on hand so as to be able to respond quickly to changes in price and demand. This is a storage tank bigger than anything humans could actually build and it is accessible only by a well sunk deep in the rock.

SoCal Gas has a lot of these things, but the Aliso Canyon facility is the second-largest in the Western US. 86 billion cubic feet of capacity–that’s a cave that, if actually cube-shaped, would be almost half a mile on a side. It’s almost a mile and a half underground.

I’m not sure whether anyone knows when the leak started, but SoCal Gas found it on October 23rd. Since then, the rate of leakage has varied, and apparently it’s only measured occasionally, so no one knows exactly how much has leaked, but it’s probably around 50,000 kilograms per hour, or about 7% of the nation’s total natural gas emissions. Big.

Natural gas, remember, is mostly methane, a powerful greenhouse gas. The term is used to specify methane from fossil sources, as opposed to biogas.

Methane is not toxic (though if you tried to breathe too much of the stuff you’d suffocate for lack of oxygen), so the main threat here is through the greenhouse effect. But the gas in the storage facility is mixed with mercaptan, the stuff used to give gas a recognizable odor. So the whole situation quite literally stinks, and while mercaptan is not considered dangerous, is it very mildly toxic and area residents (human and otherwise) are experiencing symptoms like headaches and nausea–and for some, more serious symptoms. Small amounts of other chemicals, present in the gas (including benzene, which is seriously dangerous) may also be contributing factors.

No one knows exactly why the well is leaking, but SoCal Gas might have been able to shut the thing off if they hadn’t decided to remove rather than replace a critical valve (and lie about it) back in 1979. For this and other reason, the company is now being sued within an inch of its life. Governor Brown has declared a state of emergency, but did so in such a way as to make sure that neither taxpayers nor ratepayers would pick up the costs. California is not playing around on this one.

SoCal has tried to pump mud down into the access well to plug the leak, but that has not worked. Now they are drilling a second well that is supposed to intersect the first–for reasons I do not understand, this is supposed to make the leak easier to plug. Drilling a well that deep will take a long time, which is why the leak might not be plugged until March.

The whole situation is bizarrely reminiscent of the Gulf oil spill, both in terms of its scale and in terms of of the technical detail of plugging the well. But there are some important differences, too–notably, methane is invisible and non-toxic, making this leak insidious. Once the well is plugged and the mercaptan disperses, it will be easy to pretend the whole thing is over. There will be no tar balls washing up on scenic beaches, no disturbing fish and dolphin kills from this one. But the methane will remain in the atmosphere, warming the planet further, for roughly a century.

So is this climate Armageddon?

Not really in any way it wasn’t before. This leak is huge, for a single leak, and it is enough to have a real impact on what strategies we use to bring our emissions down; to meet our goals, we’ll have to work even harder, now. But at the same time, the US alone is producing lots more methane–from other, smaller natural gas leaks, from landfills, and from the guts of our huge herds of cattle. And even adjusting for its greater power as a greenhouse gas, methane still only produces less than a 6th as much warming as carbon dioxide does because there is so much less of it. The real heavy-hitter is still carbon dioxide.

The bottom line is that this leak is not the end of the world all by itself, but plugging it up isn’t going to save the world by itself, either. It’s just another few straws on an already badly overloaded camel. And that could explain the relative lack of news coverage.

It’s true that the California leak rarely makes the major news outlets. I have not done an exhaustive study on the subject, but a search of online records and the memories of my social media contacts does suggest it’s not being treated like front-page news by anybody. If you don’t follow environmental news specifically, and are not connected by social media to anyone who does, you might well miss the story completely. But it’s not being blacked out, either–CNN and NPR have both covered the story on their websites, though I am not clear yet whether either did so on air, and there are plenty of articles in the online/print media, including some on mainstream sites.

Broadcast media simply cannot cover as many stories as print/online media can. There aren’t enough hours in the day. And this genuinely does not sound like the top-tier disaster that some people are making it out to be. I don’t think anybody’s trying to keep this quiet in any deliberate way. Instead, I think we’re witnessing the silence of a mainstream journalism that still doesn’t consider the environment generally, or climate change specifically, very important.

Maybe we need to call or write in again and ask them to cover this? Because while the California leak is bad, media undercoverage of a major issue is far worse.

The other thing that’s far worse is that this is not the only large methane storage facility there is–and while California at least is taking steps to improve safety, at the moment we don’t know when the next leak will come or how big it will be.


Leave a comment

Your Tuesday Update: More Pipelines?

So, they want to build a natural gas pipeline in New England that would likely involve taking some land through eminent domain and would certainly involve exposing more land and water to contamination from leaks. Remember that, even if the chance of a pipeline leaking in any given year is low, if the pipeline runs for enough years the cumulative chance of an accident rises. The bottom line is, pipelines leak–we don’t know where or when, but we know the leaks will happen.

Now, there are those who say this risks are worth it for the greater good in order to meet the energy needs of the region. I have not examined the situation in detail, so I am not in a position to judge one way or the other except that I am inclined to object to all fossil fuel infrastructure. I don’t like pipelines, to be honest.

But what I like or don’t like is not in itself important. I will look into the situation and make an informed decision as to whether to weight in, and so should you; Google “pipeline in New Hampshire” to start with and you’ll find plenty of information. But my point at the moment is to question how we as a society make these kinds of decisions. Are the things we stand to gain from pipelines like this really worth the things we have to lose?

Is building new fossil fuel infrastructure really a good idea, when our time, money, and ingenuity desperately needed elsewhere? In getting ourselves out of fossil fuel, rather than further into it?


Leave a comment

If We Stopped Tomorrow

What would happen* if we stopped causing climate change tomorrow?

It’s a fantasy, obviously, though an appealing one. It’s also food for a lot of interesting thought. What would life be like? What kind of climate would we be left with? Would climate change stop right away, or would there be residual change? Here, I’m going to explore the climate part of the question; if humans stopped producing greenhouse gas emissions right now, how would the climate respond?

For simplicity, our scenario is that all humans everywhere simply vanish and that all our machinery shuts itself down safely at once–I’ll ignore complications caused by unattended machinery blowing itself up and so forth. I want to be clear that I do not actually think my whole species should go extinct, I just don’t want to get pulled off topic by an overly complex scenario.

When do greenhouse gas emissions stop?

Emissions of different greenhouse gases stop at different times in our scenario. These gases are carbon dioxide, methane, nitrous oxide, and two groups of related gases, the chlorofluorocarbons and the hydrofluorocarbons (CFCs/HCFs), plus water vapor. I’m going to ignore water vapor here because the primary way its atmospheric concentration varies is not from emissions but from changes in the hydrologic cycle.

So, in our scenario, fossil fuel use and its carbon dioxide emissions stop immediately–but that’s only 57% of total greenhouse gas emissions worldwide by weight. Another 20% of the total is carbon dioxide from other sources, such as forest fires or aerobic decomposition. 14% is methane, 8% is nitrous oxide, and 1% is CFCs/HCFs. These gases come from different processes and some of these processes would continue a while.

Nitrous oxide comes largely from the production and use of nitrogen fertilizer. Its emissions should therefore drop off pretty quickly in our scenario. CFC/HCFC comes from industry and refrigeration and would therefore drop off much more slowly as abandoned refrigeration units slowly broke down and leaked. But the real issue would be methane and non-fossil-fuel-related carbon dioxide.

If the world were simple, then after our piles of wood and paper and other biomas finished burning or rotting (that might take a few years), atmospheric carbon oxide levels should stabilize. The only remaining emissions would be from natural wildfire or decay and that carbon would be taken up again as other plants grew. But the world is not simple. One of the things climate change is doing is shifting some places from forest to savanna. It’s unclear how much of that shift has happened yet, but it’s quite possible that some of our forests are essentially dead trees walking, so to speak. They won’t get the rain they need to survive and when they die they will be replaced by grass, shrubs, and the occasional tree, not forest. In that case, their carbon won’t be recovered, driving the atmospheric concentration up. One of the nightmare scenarios we’re looking at is if climate change caused by forest dieback becomes enough to cause further dieback–a runaway positive feedback cycle in which the planet starts warming itself.

If that nightmare feedback loop has not started yet, I doubt it would under our scenario, given the substantial emission cuts from the end of fossil fuel use. But elevated CO2 emissions will persist at least as long as it takes those forests doomed by climate change to die and rot or burn.

Methane levels might actually not drop in our scenario. Methane occurs as a fossil fuel and is also produced by anaerobic decomposition at the surface. Agriculture is a major source, mostly from rice cultivation and animal husbandry, and these emissions would probably taper off pretty quickly. Our vast herds of cattle are not going to survive us for very long. But landfills and leaky fossil fuel facilities will keep producing methane for a long time–only we won’t be here to capture and burn off those emissions (burning converts methane to carbon dioxide, which is actually a good thing because methane is a much more powerful greenhouse gas). So those emissions could actually increase without us. I do not have enough information to calculate what the net result would be. And the nightmare scenario is that melting permafrost liberates enough methane to warm the planet enough to melt more permafrost and release more methane….

So, what we’re looking at is that if humans vanished and neither nightmare cycle has begun yet, total greenhouse gas emissions would drop immediately by somewhere around 60% and then probably decrease further over a period of years. When the system would reach equilibrium seems unclear. The relative contributions of each gas would change dramatically as well, with methane becoming co-dominant with CO2 by weight. Since methane is both more powerful and less persistent in the atmosphere, this shift would be very important to anyone running climate models of our scenario.

How long will the climate keep warming after emissions stop?

Even if the atmospheric concentrations of all the greenhouse gases stabilized today (which under our scenario they would not), the global climate would continue to warm for a period of years. This lag between cause and effect is actually a very familiar principle; if physics didn’t work this way, cooks would not have to use timers because food would become fully cooked the instant it went on the stove or into the oven. Earth’s climate has a longer lag than it might otherwise because we have oceans and water can swallow a huge amount of energy before changing temperature, but basically things just take a while to warm. The experts aren’t sure, but Earth’s lag is probably around 40 years–which means we are now experiencing the consequences of the greenhouse gas emissions of the 1970’s.

In our scenario, then, the loss of humans does not start to show on our climate for another couple of decades. Only then will the planet start responding to the dramatic decreases in emissions.

How long will sea level keep rising after the warming stops?

Here is another familiar principle: ice takes time to melt.Glacial dynamics are a bit more complicated, since they receive new snow as well as lose meltwater and they move, but when scientists say a certain amount of melting is “locked in,” that basically means that a certain amount of ice already has the conditions necessary to melt. It’s like an ice cube set out on the table at room temperature; that ice cube is going to melt away to nothing even if the air in the room does not get any warmer. Because glaciers are very big, some of the melting now locked in might take thousands of years–or it might go faster. Scientists aren’t sure, and of course the rate of melt is likely to increase because the temperature will keep rising (for at least 40 years!), but however long the process takes, the melting we have already triggered will cause at least three feet of sea level rise, probably more.

How long will greenhouse gas levels stay elevated?

Under our scenario, and assuming those cycles of viciousness aren’t in operation yet, greenhouse gas levels would level off as soon as emissions stopped and then eventually start falling. How long would it take for the atmosphere to return to something close to what it was before? The answer depends on which gas you’re looking at.

CFCs/HCFs and their kin vary a lot. Some can stay in the atmosphere for thousands of years, some for less than a year. I do not know how many of each kind we have up there and in what proportions, but we’re looking at a process that begins immediately and lasts for a very long time. Nitrous oxide breaks down in the stratosphere and takes just over a century to do it. Methane is quick, lasting only about 12 years (my source does not say what any of these chemicals becomes afterwards–I am suspicious that methane may become carbon dioxide, a complicating factor!).

Carbon dioxide is the tricky part, since it can leave the atmosphere by several different means. Much of it is absorbed into the ocean pretty quickly, where it no longer causes the greenhouse effect but instead causes ocean acidification. Also, this mechanism only works if there is more CO2 in the air than what the water near the surface can absorb. The upper layers of the sea are getting “full” now, meaning that not much more CO2 will go into the water until ocean mixing brings new water up to the surface. Chemical weathering of rocks also absorbs CO2, as does, of course, photosynthesis. And that last is the complicated one.

If the distribution of plants across the globe is roughly stable, then carbon sequestration by photosynthesis will be roughly matched by carbon emissions from fire and decay. But reforestation–and the re-establishment of wetlands–could become a powerful force for carbon sequestration with humans out of the way. Unless environmental damage has in some way precluded regrowth, which is possible, and unless the nightmare cycle has begun.

Without factoring in regrowth, somewhere above 65% of our carbon dioxide will be absorbed by the oceans in the next 20 to 200 years and the rest will drop very gradually, finally reaching equilibrium after a few thousand years. If plant regrowth proves significant, the process could go faster, maybe much faster–there is evidence that reforestation following the conquest of the Americas caused the Little Ice Age. In our scenario, it would be the entire world regrowing.

So what’s the scenario?

Bringing all of this information together, we can fill out the details of this scenario.

Humans either vanish or somehow become ecologically negligible in November of 2015. Right away, that very month, greenhouse gas emissions drop by about 60% and then continue dropping gradually over a period of years. Atmospheric concentrations of these gases also start to drop right away, though more gradually. Within a few years, meaningful reforestation begins in some areas, possibly balancing out climate-related deforestation elsewhere.

But the global average temperature keeps climbing–and it’s climbing faster than ever because the oceans have absorbed enough energy that now they’re warming rapidly, too. Extreme weather gets more so. If there are any humans left, they are having a very rough time of it. Somewhere around 2055, the climate begins to stabilize, although what it looks like by that point is anybody’s guess.

But by that point the atmospheric concentration of methane has fallen and leveled off at whatever its new normal is. Carbon dioxide levels are starting to fall meaningfully. I don’t know whether there is the same lag on cooling as there is on warming, but by sometime around the turn of the century I’m guessing the planet has started cooling again–and the cooling gradually accelerates over the following century as nitrous oxide starts to break down and as more and more carbon dioxide is absorbed by the oceans and by growing plants.

All this time, the sea level is rising. Water creeps gradually across the hurricane-ravaged ruins of many of the world’s major cities and upstream into previously fresh areas of the world’s rivers. Oysters grow on the streets of Manhattan.

I’m guessing that the cooling will take much longer than the warming, because greenhouse gas levels will stay somewhat elevated for thousands of years. The  planet would also see a lot of delayed effects of the warming–along the lines of changing plant growth patterns or changing ocean salinity triggering various feedback loops. I don’t know what those loops would be or when they might occur. At some point the pace of change would slow enough that the biosphere will start to recover–but recovery from a mass extinction takes about ten million years.

Feeling depressed?

I don’t mean this as an exercise in pessimism. I mean it as an illustration of what optimism looks like at this point, what we can look forward to in the best possible scenario we can anticipate. If being limited to this as optimism bothers you, consider how the next generation will feel if we do not get our butts in gear right now.

 

  • Note: After writing this, I’ve thought of a bunch more complications that might change the details of the picture I’ve given. I stand by my factual statements, but my suppositions might be muddy. Creating a detailed, accurate climate projection is not my intention, though–that requires a supercomputer I don’t have. The point is to draw attention to the questions, to the issues of lag and lingering emissions–to provide food for thought.


4 Comments

Fire

Ok, now Canada is on fire. As of two days ago, at least, British Columbia had all of its firefighters working, and still needs more help. Alberta’s resources are likewise becoming strained and the province has invited in firefighters from Mexico to help–the teams from Jalisco have partnered with Alberta before and the two groups have coordinated their training programs.  Saskatchewan and Manitoba are also struggling with many major fires, and the smoke has triggered serious air quality warnings in parts of the United States. Virtually all of the US is now smoky to some degree; I saw a thin, grey-yellow haze in Maryland last week. This is not the first time I’ve seen continent-wide smoke, but it’s still a startling thing.

When disaster strikes, it’s reasonable these days to wonder how the problem relates to climate change.

I wrote a few weeks ago about the fires in Alaska. The international boundary between Alaska and Western Canada is essentially a figment of human imagination, so it’s not surprising that most of what I wrote about fire in Alaska also applies on the other side of the boarder. I have not been able to find much in the way of detail on the ways global warming might be causing these fires (or, more precisely, making them more likely); generally, the farther from the equator an area is, the more its climate is changing–and the changes involve not just increasing average temperature, but increased extremes. That includes more extreme droughts and heat-waves, which promotes more fires. So, while there are other factors in play, fires in Alaska and Canada are getting worse, and climate change is one of the reasons why. Fire is the new normal in Western Canada, that much is clear.

What is even clearer is that these fires also exacerbate climate change, not only by releasing huge quantities of carbon dioxide but also by accelerating the melting of permafrost–that will eventually release huge quantities of methane, a very powerful greenhouse gas. Then we could fall into a nightmare scenario, where more warming melts more permafrost, releasing more methane, which causes more warming….

The ironic thing here is that as sensitive as Canada is to climate change, the Canadian government has been very poor at doing anything about the problem. Canada has one of the highest per-capita greenhouse gas emission rates in the world, it pulled out of the Kyoto Treaty, is not on track to meet its Copenhagen obligations, and is allowing the exploitation of the tar sands at horrible environmental and human cost.

Not to pick on Canada; it’s not like it’s the only country in the world that needs to get it’s act together on climate.

What strikes me in all of this is that we live in extraordinary times and by and large fail to notice that fact. Much of a continent lies veiled in smoke, half of Canada is rapidly exhausting its firefighting capacity, and science can tell us to expect more of the same. And yet, many people go on with life as before, continuing to talk about whether global warming will happen at some future point!

Recently, I’ve been watching The Abolitionists, on The American Experience. I can’t help but think that the timing of this rebroadcast is not a coincidence but instead represents a partial response by PBS to the deaths of Freddie Grey and others like him and to the recent violence against a string of black churches, beginning with the shooting in South Carolina. It is startling to watch the courage, dedication, and, in some cases, short-comings of the abolitionists against the context of current events.

However, I am also struck by how familiar the impatience of people like Frederick Douglas, Harriet Beecher Stowe and John Brown seems to other contexts. While other people in their society either insisted slavery wasn’t that bad or seemed content to let the trajectory of history “bend towards justice” with glacial slowness (apparently many white abolitionists were primarily concerned with the souls of white slaveholders and saw the welfare of actual black people as a kind of foot-note to the movement), they became insistent that slavery end now. Every minute of delay, they knew, was another minute of suffering and pain for millions of people. They were conscious of an emergency, and, each in their own way, acted on that knowledge.

Yes, I’m comparing slavery to climate change.

Some readers may accuse me of appropriating somebody else’s fight, of attempting to use the imagery and energy of the resurgent civil rights movement for my own ends. That’s a reasonable charge and I respond to it, with respect, thus; first, climate change is a social justice issue, since it hurts the disenfranchised first and most deeply, and second, the intersectionality of various issues leads to common and interrelated problems, so why not recognize the solutions as related as well? The fact of the matter is that human beings should be braver and more intellectually honest than they are, whether in light of churches burning in the South or forests and tundra burning to the North. I find the abolitionists inspiring. They rose to the occasion of their lives, and so should we.

Every moment of delay before a real solution is a moment lost.


2 Comments

Alaska Burning

Alaska is on fire at the moment.

Well, not all of it, but the state’s wildfire Preparedness Level is at 4. The scale only goes up to 5, so PL 4 means the state is starting to have real trouble dealing with its fires and needs help from other states. For a state, or region to go to Level 4 is not all that unusual–the state and regional wildfire response systems are not designed to be self-sufficient–but the fires are not inconsequential, either. In recent weeks, both forests and tundra in Alaska have burned–and some of the fires have been quite large and dangerous.

Fires are not exactly a new thing in Alaska, but there are more of them now, for a variety of reasons including the current successional stage of previously logged forests, the effects of fire-suppression policies, and, yes, climate change. Alaska’s climate is changing much faster than that of more temperate areas, becoming both hotter and drier. And the fires, in turn, might be causing dramatic changes to both the climate and ecology of the region.

In forests

Recent research suggests that larger, more intense and frequent fires might dramatically alter forest compositions that have been stable (despite repeated natural climate changes) for six thousand years–although the forests themselves could then act to slow further changes.

In the interior of Alaska, there are essentially two main types of forest; most areas are dominated by black spruce, berry bushes, and moss, but there are forests of aspen and other deciduous trees as well. Both types of forest burn, perhaps every hundred years or so, but after the fire, the same type of forest eventually grows back. The result is a mosaic of different forest communities that has kept the same pattern since before the pyramids were built. Basically, each forest type produces its own distinctive type of forest floor. Because spruce forest floors are very thick and wet, they don’t burn down to bare soil, whereas the thin deciduous leaf-litter layer does. After a fire, the two different forest floor types guide ecological succession in different directions so that, in time, black spruce and aspen each return to the areas where they grew before.

As Alaska dries out, however, the black spruce forest burns more intensely and more often, destroying its distinctively thick duff. Once the soil is bare, the deciduous trees can move in–and there they stay.

The neat thing about ecology, though, is that nothing is simple–as the number of deciduous groves in interior Alaska increases, it seems likely that the situation will stabilize itself because the deciduous trees do not burn as easily and may act to slow down and break up large fires. These trees are paler in color, too, and they release more water back into the air and so may act to cool the region somewhat. Both effects may act to protect the remaining black spruce forests, at least for a while.

All by itself, changes in the composition of Alaska’s forests is not necessarily a disaster, although we don’t know for sure that it isn’t, either. Both the human cultures in the region and much of its wildlife have developed ways to use both types of forests in different ways, and it is not obvious what changing the proportion and distribution of the two types is going to do. Change is not automatically bad, but the fact that we are changing something this old should certainly give us pause.

Of more obvious, clear-cut concern is the fact that black spruce forests, with their thick, slowly-decaying duff, are a carbon-sink. That is, they take in more carbon than they release and thus are one of the reasons global warming is not worse than it already is. The loss of these duff layers, either because forests convert to deciduous communities or because spruce forests can no longer build up as much duff between more frequent, more intense fires, is already starting to convert Alaska’s forests into a net carbon source.

That’s a problem.

In the tundra

Much of Alaska is still treeless tundra, plant communities dominated by shrubs, mosses, grasses, and lichens. The tundra, too, is a net carbon sink, because huge amounts of organic matter build up in the soil and do not rot. The layers of ligroundving and dead organic matter also insulate the soil, helping to keep the permafrost from melting. The permafrost, in turn, keeps groundwater close to the surface and keeps buried methane trapped. As permafrost melts, some lakes are actually draining away, destroying important habitat for fish and for migratory birds. And, of course, that methane is bubbling up–methane is a much more powerful greenhouse gas than carbon dioxide is.

Alaska’s forests have permafrost as well, but it is discontinuous–rather like big, underground boulders of ice. Beneath the tundra, the permafrost is more like bedrock.

The thing is, when the tundra burns–as it may be doing more often now, in part because northern Alaska is getting more lightening strikes because of its warmer weather–it’s not just the thin living laying but also the soil that goes up in smoke. A tundra fire can release as much carbon dioxide as a forest fire can. Without as much insulation, and given the much darker color of the charred surface, the permafrost beneath can then melt all the faster.

Positively problematic

I have written before about how positive feedback loops are anything but positive in the colloquial sense of good or happy. A positive feedback loop is a self-intensifying cycle, such as where rising temperatures melt permafrost, releasing methane, which makes temperatures rise faster, melting more permafrost….

The really scary thing here is that initiating these loops–pushing systems to the point where they start releasing greenhouse gasses–means that even if we stopped burning fossil fuel tomorrow, climate change might continue to get worse. We are losing the option to save ourselves.

That isn’t an argument to give up, of course–no situation is so bad that it cannot be made worse, and that means no situation is so bad that we  cannot make things better by our restraint. But it does mean that the hour is later than we might think. The Earth is a live thing, and it has been protecting us from ourselves to some extent–but it won’t do so forever. To those of you who are doing the equivalent of calmly reading the paper while your house burns around you; it is time to get up, now.