The Climate in Emergency

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


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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.


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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.


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About Batteries

Now and then I hear battery-operated versions of various machines touted as “environmentally friendly” because they produce zero emissions. Of course, a moment’s thought shows that this is not true–or not necessarily true, anyway. A battery stores energy, and if the energy in question came from a coal-fired power-plant then the battery-powered machine is responsible for a a lot of emissions. Those emissions are simply somewhere else.

But is that the only caveat batteries carry? Between personal electronics and new “greener” technologies such as hybrid and plug-in electric cars, batteries are a huge part of the modern energy landscape–and yet, I realized, I didn’t really know much about how they work or what problems they might cause. I set out to learn the basics, and here I pass them on.

As I’ve been saying for years, rechargeable batteries only store energy, they don’t create it. Of course, nothing except whatever started the Big Bang creates energy, that’s part of the First Law of Thermodynamics, but a gallon of gas is an energy source in a way that a battery isn’t. Most people know this, but don’t seem to really think about it. For example, plug-in hybrid cars receive praise for their wonderful gas mileage even though that’s the wrong measure of efficiency for those cars. Such a hybrid could be an absolute energy guzzler, sucking down kilowatts, and still use very little gas. And if the electricity comes from a coal-fired power  plant, the carbon footprint of a plug-in could actually be higher than for a traditional car of the same weight and engine type.

But batteries do not store energy the same way a jug stores water. For one thing, electricity, by nature, moves. You can’t keep it in a box any more than you can shine a light into a closet, close the door, and expect the brightness to still be there when you get back. Instead, a battery converts chemical energy into electricity–and back again, if it’s rechargeable. That means that beyond asking where the energy comes from, we also have to ask what happens to it inside the battery and whether storing the energy is actually a good option.

I had a really hard time tracking down information, here, in part because I didn’t understand the right questions to ask. In turns out the answers are both very technical and very specific to each battery type–turns out “a battery” is something like “a sandwich” in that all the members of the category look recognizably similar and all accomplish roughly the same thing, yet the insides of two batteries might have no more to do with each other than do peanut butter and roast beef. I didn’t research all possible types of batteries, and I am very far from being an electrician, but I can give you the questions I’ve found–and a few examples of some answers.

  • How efficient is the battery?
  • Can old batteries be recycled into new batteries indefinitely?
  • What is the environmental impact of building and eventually disposing of the battery?
  • How does the battery compare with relevant energy alternatives?

 

How efficient is the battery–and its charger?

When you put energy into a battery, how much of it do you get back out again? The answer depends on the battery type, its age and condition, and how it is being charged, but it’s never 100%. First of all, every time energy changes form, some of it dissipates, as per the Second Law of Thermodynamics. Charging a battery converts electrical energy into chemical energy, so some is lost in that process. Some is lost again when the battery is used, converting chemical energy to electricity. And of course charging a battery requires a charger, which is also not 100% efficient for a similar reason. For example, depending on its initial state of discharge, an eight-hour charge cycle for a lead-acid battery could be anywhere from 36% to 64% efficient. That means that if you’re charging car batteries to do a job that you could just as easily accomplish with an extension cord, you could find yourself using almost three times as much electricity as you really need. The picture gets worse if you leave the charger attached too long; these batteries accept less and less charge the closer to full they get and the electricity they don’t except just makes the battery hot. It’s wasted.

Can old batteries be recycled into new batteries indefinitely?

Not all batteries are rechargeable. It is possible to make a crude battery out of half a grapefruit and those don’t need an initial charging–the energy is present in the relationship between the fruit juice and the electrodes. If commercially available batteries also don’t need an initial charge, then they are, essentially, a form of fuel and we need to ask the same questions about them as we would with any other fuel–like, are we going to run out?

I was unable to answer this question, because internet searches on charging non-rechargeable batteries yield websites all about how to recharge non-rechargeable batteries (which, by the way, is a bad idea. We tried by accident some years ago and very nearly killed out cat in the process). But it doesn’t really matter because the important question–are we going to run out–applies to all batteries regardless of when or if they are charged. To put it simply, any battery made of something that cannot be recycled back into the same type of battery indefinitely is unsustainable long-term.

As far as I can gather, at least the primary materials in many popular battery types, such as lead or lithium, are closed-loop recyclable in theory. These are metals, and metals are pretty simple to work with. But that doesn’t mean they are being recycled. The issue is whether the price of the material is actually high enough to pay for the processing. With the exception of lead, it generally isn’t. In some cases, even the carbon footprint of recycling could be larger than that for mining, though I have not seen an analysis of that. Sometimes batteries are recycled at a financial loss for environmental reasons, but this isn’t closed-loop recycling. Recycled lithium might be sold for use as a lubricant, for example. Even in the best case scenario, most batteries also have non-recyclable components, such as plastic, that recycling centers simply incinerate.

What is the environmental impact of building and eventually disposing of the battery?

Potential environmental impacts include the life-cycle carbon footprint of the battery (how much carbon dioxide-equivalent greenhouse gas it is responsible for, from mining through final disposal), physical disruption of the land associated with mining, and any toxicity related to disposal. Again, the answer depends on battery type, but we just don’t have all the answers. For example, cadmium in the ocean might have come from batteries, but then again it might not have. Life cycle energy analyses have not been done for all battery types, and some of those that have been done may be out of date. Generally, lead-acid batteries have the lowest energy footprint and are the most recyclable, but they are also quite toxic if not recycled.

How does the battery compare with relevant energy alternatives?

This question is the big one. In some circumstances, batteries are clearly the best option around. They make small-scale solar or wind power generation practical, for example. Without them, these systems would only deliver when the sun shone or the wind blew. In other circumstances, since as in the duel between a lead-acid battery and an extension cord imagined earlier, they are clearly wasteful. Still other times, they fall into a gray area of very nuanced decision-making.

Any time energy changes form, some of it is lost. Part of overall energy efficiency is therefore keeping the number of transformations as low as possible. For example, if you have several gallons of gasoline and want to boil water, your best bet is to use some kind of gasoline-burning stove. Using the gas to power a generator to make electricity to run an electric stone is wasteful because it involves so many more transformations. If everything else is equal,therefore, any kind of heating device, from stoves to baseboards to clothes dryers, are better run on gas than on electricity, if the electricity was generated by burning fossil fuel (as it often is). But everything is not always equal.

For example, how energy-efficient is gas delivery? If it has to come a long distance by truck (in which case it will probably be propane, not gasoline), the calculation might even out. The situation gets even more complex with motors since the relative weight of different designs and the circumstances of operation all come into play. For example, a battery-powered car does have emissions, it simply has them at the power station not at the tail-pipe. But if the car drives into an area that is very vulnerable to pollution, leaving the emissions behind at the plant might be important.

What does it all mean?

The bottom line is that batteries are not a panacea. In fact, they make thinking about environmental issues much more complicated. They’re handy tools for “green-washing,” as long as the public believes that battery power always means pollution-free. But they are also important tools for increasing overall energy efficiency and sustainability, especially if used in concert with electricity generation from renewable sources.

The important thing to remember is that we can’t create energy, nor do we get to decide how much energy a given task requires. If you want to accelerate a two-ton vehicle up to sixty miles an hour, that will take X amount of energy whether you use a gas engine or an electric motor to do it. The electric version might well be better in some respects, and if so then that is definitely the version we should pick. But mobilizing that energy always comes with some cost, somewhere, and if we can’t see what the cost is, we need to start asking questions..

The only way to truly go “zero emissions” is to use less energy in any form.

 


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Syria

The Syrian refugee crisis is starting to get scary. I mean, obviously the Syrian refugees themselves have been terrified for a long time, that’s why they have become refugees, but what I mean is that this is not a run-of-the-mill humanitarian disaster. This one has the potential to change the world, but not in a good way. The people are running from violence, primarily, and also poverty. For four years, now, people have been coming out–more than four million already. Mostly they go to neighboring countries, but many–more than three hundred and fifty thousand this year so far alone–make their way into Europe. Some are now being sent on to the United States.

To put this in perspective, Syria’s total population is now less than 24 million people, meaning that about one in every seven people in that country has recently left. Forced migrations on this scale leave scars that last for generations and radically change the cultures that take in the migrants–I’m thinking here of the Irish Potato Famine, which killed a million people and displaced a million, far fewer than in the Syrian crisis, but then Ireland was a much smaller country at the time. The whole world was much smaller. Almost two hundred years later, the Irish Diaspora continues to enrich the rest of the world–and the great-grand children of Irish refugees continue to take their history personally. I do, anyway.

The fact that I’m talking about Syria here suggests that climate change is involved somehow–and indeed it might be. The connection is that from 2006 to 2011, parts of Syria were in a very serious drought. Huge numbers of farmers were forced off their land and into the cities looking for work. The Syrian government severely mishandled the crisis, triggering the present civil war. The drought, of course, is just one more event made more likely by climate change. No less an entity that the US Defense Department warns that climate change is a destabilizing influence, capable of creating exactly the sort of mess currently exploding in the Middle East and into Europe.

The climate-deniers have, of course, cried foul, questioning the science of the drought attribution point by point. It is a mistake to argue science with those whose real objection is cultural or ideological, so I’m not going to offer a detailed rebuttal–but the point is not a direct causal chain, anyway. The point is that large areas of the Middle East and Africa are extremely poor, huge numbers of people living just above the poverty line–if anything goes wrong, they fall off into the abyss. Climate change simply makes it more likely for things to go wrong.

For rich countries, like the United States or most of Europe, a serious natural disaster (and we’re having two at present, the California drought and the related western fires) hurts us but does not destabilize us. We have enough of a safety margin that we can not only continue to take care of our own, we can simultaneously offer aid to other countries and take in refugees.

The reason the Syrian crisis is scary is that its scale hints at the possibility of a world where we will no longer be able to do that, where even if the United States remains comparatively rich, the number of things going wrong will rise so high that we will no longer be able to take our stability as a country for granted. Fourteen years ago today, many Americans made the unsettling discovery that we are not immune from attack. I did not–I never thought that our country was special in that way. It’s true we don’t get attacked very often, but that’s not because we live in a protective bubble. It’s not because we’re immune. But I gotta say, I’ve gotten kind of used to this national stability thing.

For weather to contribute to a civil war is nothing new. Weather and climate have always been one of the drivers of history–as James Burke elegantly demonstrated almost twenty years ago. Where crops fail and where they succeed, where floods and fires occur and where they do not, even something as simple as where the weather is pleasant, all these things have always been one of the several facets of historical events. The only thing that has changed is that weather, that thing that has always shaped events, is becoming ever more chaotic.

And the problem is that as long as we keep pumping greenhouse gasses into the sky, there will be no new normal to adapt to. Stability will not be available.


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Mini Ice Age? Not Likely

Could the Earth be heading for a new ice age?

In a word, no, the insistence of the Internet last week notwithstanding. In fact, any suggestion that scientists have announced otherwise is a bald-faced lie. What scientists—or, rather, scientist, singular—have announced is that in about fifteen years the sun could enter a period of dramatically reduced sunspot activity, a condition last seen during the coldest part of the so-called Little Ice Age.

Valentina Zharkova gave a presentation on solar variation to a group of astronomers last week in which she described her prediction regarding sunspots. Although her research is not new—it’s material she published last year—apparently someone just now realized its potential to cause climate confusion. The logic is that since a lack of sunspots also means a very slight reduction in solar energy output, the Maunder Minimum, as it is called, caused the Little Ice Age and a new minimum will repeat the process.

But I have yet to find any suggestion that these dots were connected by scientists. Dr. Zharkova herself made no claims concerning climate. She had no idea her research would be taken this way; she meant only to talk about sunspots. This is why I’m calling the “scientists say” claims a bald-faced lie.

(Curiously, Dr. Zharkova is a climate doubter, but I have not encountered any suggestion that she is working to foster doubt among other people. She appears to be innocent in this.)

There is a good reason why scientists aren’t running with the mini ice-age idea—it’s full of holes. Most obviously, the Maunder Minimum began about three hundred years after the Little Ice Age started. Perhaps the Minimum deepened the Ice Age, but it obviously did not trigger it. The trigger may have been a series of volcanic eruptions followed by changes in ocean currents.

More subtly, the reduction in solar energy we’re talking about is extremely small. If everything else were equal, it would cool the Earth, but everything else is not equal, and the effect of solar variation on the climate is now completely swamped by the greenhouse effect—at most, we’re looking at somewhat slower warming for a few decades. A new Maunder Minimum can’t save us.

In fact, our current enhanced greenhouse effect makes it harder for anything to trigger a new ice age, and the more greenhouse gas goes into the sky, the higher the ice age threshold will rise—making it less likely the next glaciation will happen at all.

I was not surprised to find that this mini ice age prediction is erroneous. It sounded fishy the first time I heard it because I already knew what sort of things trigger ice ages and I knew that none of them are likely to work in the near future.

I don’t mean to set myself up as something special. I’m sure a lot of people, maybe even most people who aren’t climate skeptics or deniers, had similar suspicions. My point is that if you have a basic understanding of a given scientific field, then you can make pretty good guesses about what’s right and what isn’t in that field. It’s never a sure thing—even scientists are sometimes surprised by their work (they really like surprises, actually). But it’s like knowing a person well; some years ago, a friend of mine was charged with a crime and I knew he had not done it, because I know him. Sometimes people do commit crimes that shock their friends, but that’s pretty rare. In fact, the charges against my friend were dropped for lack of evidence.

This is my working definition of science literacy; knowing enough about a given field to be able to make intelligent guesses about which stories are true and which spurious. I am literate in both ecology and climatology. I am probably close to literate in botany, zoology, medicine, astronomy, and physics. I am not remotely literate in chemistry. I know a little, of course, since there is overlap between it and the fields I know about, but you could very easily construct some chemical malarkey that I’d believe.

How does a person go about becoming science literate in this sense? I wish there were a simple, unambiguous way to do it, but I know of none. A master’s degree helps, but they’re expensive. There are plenty of books and websites out there, but in the beginning it can be difficult to tell the difference between real science and pseudoscience—especially since mainstream opinion is sometimes wrong. How do you tell the difference between a brilliant new theory and something somebody just made up?

I’ve touched on that before and I will again. For now, I’ll just say that in the beginning it is better to go with mainstream scientific ideas, since the scientific process is pretty good at weeding out malarkey whereas the popular press has no such protections at all. Writing a book about how your pet fantasy is “a ground-breaking truth mainstream scientists don’t want you to hear” is easy. Making it through the peer-review process to get published in a reputable journal is hard.

So what does trigger ice ages?

Short-term cold periods can be triggered by volcanism, changes in ocean and air currents, or possibly, yes, solar variation. Human history can also play a part; large-scale reforestation in the wake of the Black Death in Europe (which killed about a third of the population, leading to crop field abandonment) may have helped deepen the Little Ice Age, which was then only a few decades old.  It also may not be a coincidence that after a brief warming, the Little Ice Age returned and deepened dramatically after a series of pandemics dramatically reduced the population of the Americas (again causing large-scale crop field abandonment and reforestation) since changes in land-use patterns can alter the carbon cycle.

But the really big glacial advances are generally caused by changes in Earth’s orbit.

The Earth’s orbit varies in three ways: the shape of the orbit shifts from strongly elliptical to nearly circular and back again; the tilt of our axis varies; and which hemisphere has summer while the Earth is closest to the sun changes. All three cycles are very long, in the tens of thousands of years. All three influence the climate, but major glacial advances happen when the cold part of all three cycles coincide.

Or, more precisely, when all three cycles together make Northern summers relatively cool. The Northern Hemisphere has much more land in high latitudes than the Southern Hemisphere does, so when snow on those land masses doesn’t completely melt in the summer, the resulting glaciers get large enough to trigger feedback loops and drop the global temperature still further.

The process takes a long time; from an interglacial to the deepest part of a glacial advance takes tens of thousands of years. It would make a very boring disaster movie. Melting, which happens when the three orbital cycles move out of alignment again, is comparatively quick, but still takes thousands of years. The climate change we are causing now is freakishly fast (and still makes a boring disaster movie).

These orbital variations are not new, of course, but in the last few million years, changes in the shape and arrangement of continents (the creation of the Isthmus of Panama and the Himalayan Plateau)have shifted air and water currents in such a way as to balance the planet precisely between freezing and thawing. Slight shifts in solar energy caused by the orbital variations are enough to shift the balance one way or the other.

The thing is, the warmest part of our current interglacial happened five thousand years ago—we’d been gradually cooling since then, until human activity reversed the trend. Could the Little Ice Age have actually been the onset of a true ice age, interrupted by the Industrial Revolution? I have not been able to find out. But the thing is, anthropogenic climate change is already occurring against what should have been a cooling trend. I was suspicious of the mini ice age because I knew that we’ve already put enough greenhouse gas into the atmosphere to overpower and delay the onset of normal glacial advance.

Which is pretty horrific, if you think about it.


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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.


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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.