Monthly Archives: July 2013

Bicycles

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The DOT says that bicycling is awesome, and has a happy dude in a suit to prove it. see site.

Make sure you make it all the way to the bottom for the funny comic!

What's the big deal about bicycles? Everything! You get exercise and you get around. MrMoneyMustache has a great post on bicycles that you should check out if you have time.

So what's this doing on a climate change website? This one is easy. Unless you eat only beef all the time, a bike produces less CO2 per mile than a car.

Maths!

Good news! The maths this time are super easy! Also, great news! You can eat bacon and then bicycle and it is better for the environment than driving a car!

Burning a gallon of gas gets you about 20 miles and produces 8kg of CO2. Let's assume you weigh 175 lbs and bicycle 20 miles. Most calculators show you burning about 1000 calories to do this. Let's further assume you eat potatoes to get that energy. Potatoes are about .2kg CO2 per kg potato, and a kilogram of potato has about 500 calories that we can use (it has many more, but we can't consume them all perfectly). So you need to eat 2kg of potatoes in order to gain 1000 calories and then bicycle a mile. This equates to .4kg of CO2, or literally only 5% the emissions of a car.

Let's go to worst-case scenario. You eat only beef (note that you will likely die young) which makes way more CO2 in its production than potato (just picture how much cows fart, and that they produce a very strong greenhouse gas). Luckily cow is very energy dense, and you only need to eat .6kg to get 1000 calories. Unfortunately, a cow makes 29kg of CO2 equivalent per kg of meat, and 1000 calories produces 20kg of CO2 equivalent. So you are pumping the equivalent 20kg of cow farts into the air to get those 20 miles (more seriously, it is probably like .5kg of cow farts, plus some CO2, cause them cow farts really are strong greenhouse gases).

So good, but not worth it for the environment

Okay, so I have good news! before you go all vegan on me, Pigs are much more efficient! You only need to eat .3kg of these bad boys to get 1000 calories, and they only produce 8kg of CO2 per pound (pigs don't fart as much methane, I guess? Actually they require less feed and less water to make meat). So you produce about 3kg of CO2 if you eat bacon and bike 20 miles, which is still better than a car. Moral of the story: eat bacon and buy a bicycle. Or you could eat potatoes and veggies and be really good for the environment, but let's be realistic, Americans aren't gonna eat much less meat, so at least they can substitute pig in there.

Eating bacon and bicycling: the only way to eat bacon and get sexy.

Eating bacon and then bicycling is still better for the environment than driving.

Other important stuffs (like getting fit and sexy)

I bike in Boston and Cambridge. I bike to work every single day. I never have to worry about finding parking. Better yet, I get to go straight from my door to the door of work. I go shopping with my bike, and that's even better. Nearly all stores have a place to park my bike right at the door, and I can usually fit all the foot I need into a large backpack.

I bike to bars at night, I bike home from the same bars. When I go to a friend's party, I always bike. I pretty much never drive anywhere, and usually don't take the subway. It turns out that biking takes less time than nearly any form of transportation. One great example: my friend Erik and I were walking home from a party (I was walking my bike). He hailed a cab, I jumped on my bike as soon as he was in the cab. Erik lives next door to me. Going at my usual after-party biking pace I beat him home. And then I waited for the cab to arrive, arrogantly leaning my bike against his apartment complex like it wasn't an effort. I had just saved a $10 cab ride and a few minutes.

This is not rare. If traffic is heavy, I beat friends in a cross-town trip by about 20 minutes. I live a mere mile from work, but I can get there faster than any other form of transportation. It's faster than driving cause I don't need to go pick up my motorcycle from the garage and then find parking at work.

Biking is faster than the subway in nearly all cases, and more convenient in Boston cause my bike doesn't shut down at midnight (nor has it been stolen). Also, every time I take my bike instead of the subway, I save at least $4 round trip. Usually it is more like $20, cause I don't have to take an expensive Boston cab back home after a night out. So let's say I go out twice per week and save an average of $10 every time. That is $20 per week, for 50 weeks, or $1000 per year. Just paid for several of my bikes, yo. Or like 3 beers a week.

What's the best part about bicycling everywhere? Being fit. Your clothes will fit better, you will have more energy, and people find you sexier. Including your spouse or significant other. Yes, yes, they do say that they love you as you are. They are lying. Get on a bike.

So wait. I just said you could do something that saves time, saves money, saves the environment, makes you more attractive, and will get you the ladies/men and/or make your relationship spicier? Why isn't everyone biking right now?!?

More seriously, people might have three reasons: you work too far away (this is a bad idea to start with, both environmentally and from a money perspective), up front cost, and safety concerns.

The first: future post. Too big to include in this one. Suffice it to say, if you don't live close enough to work to bicycle there, you live too far from work. If your job is in an area where you don't want to raise your family, you are probably either in a rough place financially or maybe you are financially well-off financially and are still making poor life decisions (more on this later, too).

The second: A bike costs a lot less than a car. Buy a cheaper car and then buy a bike. More legitimate: you have enough money to afford monthly subway fare, but not a bike. And/or you live in an area where your bike gets stolen. I got nothin' for you here. Try to take public transportation or walk, cause driving is still bad for the environment. If you can afford a car, you can afford a bike and a lock.

The third: Safety! Wear a helmet. Everyone on a bike should wear a helmet. I know helmets make you sweat and mess up your hair. You know what is worse than having bad hair from a helmet? Becoming a vegetable from getting smeared on the road.

Back to accidents. Bicycles do have a slightly higher accident rate per mile. But if you live near work and bicycle, you drive few miles. If you then consider that you cover 6x as many miles on your average car commute as your average bike commute, your death rate per minute is actually equal to that of a car. Mr Money Mustache does a great job of describing this, so I won't go farther. Moreover, If you factor in the health benefits of bicycling, you gain health and actually increases your chances of living longer (same link describes this).

Okay, this is getting long. Time to Summarize!

Bicycling will save the environment, save you time, prolong your life, make you sexier, and save you money. It's a damn miracle drug, and if you aren't on it, you are doing something wrong with your life.

Bicycling

 

-Jason Munster

Electric Cars

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Electric Cars

Electric Cars. Are they really all they are hyped up to be? The short answer: hell yeah. These things are sweet. I want to get my hands on one right now.

Energy flows in the US.

Energy flows in the US. Transportation accounts for 28% of all energy use, primarily from burning petroleum. 

35% of US energy consumption is in transportation. Transportation requires that the energy source be within the vehicle (unless you are in South Korea, where the energy source is induction and is beneath the road. Pretty badass, if you ask me). Batteries currently weigh a lot, don't have nearly as much energy per pound as gasoline, and require a long time to charge. But if we could replace a huge percent of this with more efficient electric cars, it would go a long ways towards arresting GHG emissions.  

120 million Americans commute to work by car. The average person lives fewer than 20 miles from work. Substantially all of them commute alone. The Nissan Leaf gets 75 miles before it needs to be recharged. The Tesla model S goes about 275 miles. No matter what the source of energy for an electric car, it produces less CO2 than a normal car.

How does an electric car produce less CO2 than a gas one? No matter the source of the electricity, even if it is an old inefficient coal plant, the conversion efficiency of an electric car will result in lower CO2 emissions per mile than a gas powered car. The EPA estimates that the Nissan Leaf gets an estimated 125mpg using CO2 equivalent of gasoline. The recent fleet average for the US is about 30mpg for passenger cars. So electric cars emit only 25% the CO2 of your average normal car. Lets be generous and say they emit 40% the CO2 of your best gasoline powered cars.

Commuters would make a very significant difference in emissions if they changed over to electric cars.

Power

Most Americans base the acceleration needs of their car on the idea that they someday need to accelerate down on onramp to get to 65mph on the highway. The amount of power a car has is typically listed as horsepower (hp). This is a terrible measure. The real measure of power of a vehicle is Peak Torque.

Allow me to explain this concept. Roughly speaking, torque is the force going into a rotation of an object. It makes sense to use torque to describe cars, cause they have rotation parts. Think of it as the amount of energy going into the car from the tires rotating on the road.

(yes, that is a cross product) where r is the radius, or distance from the center of rotation, and F is the force. For the most part, the torque of a vehicle is entirely determined by its engine. It directly translates to how fast you can accelerate. More torque yields less time from zero to 60.

My motorcycle. Pretty, eh?

Let's compare some examples. First,  my favorite. My bike, a Kawasaki VN750, vs. a Hayabusa (fastest production bike in the world) and an electric bike from Zero Motorcycles, the Zero DS. The electric motorcycle gets up to the equivalent of 400mpg. Compare to a normal bike of around 40-50mpg.

VN750 Hayabusa DS-electric
Style Cruiser Sport Sort of cruiser
Weight 500 lbs 563 lbs 400 lbs
Torque (ft-lbs) 47 99.6 
69

Before comparing, let's talk about peak torque. Peak torque is the maximum torque an engine can put out. For a gasoline engine, it is pretty much right before it redlines. So the numbers of 47 and 99.6 you see for the first two bikes means that it is the best they can do. You can think of an electric motor as pretty much always putting out peak torque. In other words, the hayabusa has to jump up to 6500rpm before it can be at full power, then it shifts up a gear, and drops back down out of its full power range. The electric bike doesn't shift gears, either.

Let's look at the Hayabusa power band to illustrate this difference.

Hayabusa power band in yellow. It is not a flat line.

As you can see, the torque output of a gas engine changes with RPM. You will notice the Kawasaki ZX-14 has more max torque, but less torque at the lower end. This is one of the main reasons the 'Busa is considered faster. It comes off the line far faster than other bikes, cause it has higher starting torque. Compare this to an electric engine, which has max torque from 0 RPMs up. You probably see my point about how sweet electric engines are.

So now we can compare electric vs gas based on torque. The electric motorcycle trounces my motorcycle all the time. In the first few moments, it will likely nearly match the Hayabusa. In fact, until the 'Busa hits 3000 RPM, the electric bike won't look too shabby. Why? First, cause it has the same torque as the 'Busa up til the Busa hits 3000rpm. Second, cause it weighs 150 lbs. less. In short, a smaller electric bike kicks butt. (note that the electric bike doesn't have super wide tires to accommodate all its power, so it might slide around a bit when you hammer down).

Where does the electric bike fall short? Range. This bad boy will only go 75 miles on the highway between charges. Funny enough, it'll go 125 in the city. This is all owed to wind resistance.  Back to the point, you can't refill this guy as easily. You need to plug it in. It takes a while to recharge. You can just fill up a motorcycle and go on your way. This bike is pretty much for commuting or visiting friends in nearby cities.

(*2017 update! New electric motorcycles are capable of going 200 miles. Then they have to recharge for a long time. But 200 miles is a long trip).

Also, let's admit it, both my bike and the 'Busa are sexier.

The cars.

Audi A5 Nissan Leaf Tesla S
Cost $38k $21.3k 62,000
MPG 22 102 90
Peak Torque 258 210 443
Weight (lbs) 3549 3354 4650
Range (miles) unlimited 75 275

As you can see, if you are commuting the Nissan leaf makes a lot more sense in every possible way. It costs less to buy than most cars, it has the acceleration potential of a high-end Audi A-5, and the range you need to get to work and back. This beast will accelerate onto the highway just fine. Also, there is the whole power band thing. These electric cars have peak torque all the time.

Overview

Electric vehicles. These puppies accelerate as fast or faster than most vehicles in their class. The shorter range ones are less expensive to buy than most cars, and the cost of making them move is lower. Oh, and they save the environment relative to normal cars.

Whats the drawback? Range anxiety: the other event people think of when they don't want an electric car. Visiting Grandma. People want to buy one vehicle that can do everything they want. There is also the concern of "what if I am in an emergency and really need a car that can drive far right away?!?" How many times has that happened to you in your life? For me, the answer is 0. Any family emergency I had, I took a plane or a bus to.

Most families still own two cars. At least one should be electric. Here's an idea: get one gasoline car to visit grandma when you need, and then get an electric for your commute. Here's another idea: get an electric car or two, and rent a car when you need to go visit Grandma. You will save money either way.

The ridiculousness that is trucks and SUVs? Get a subaru with a roof rack, and rent the trucks and SUVs otherwise. Why the heck are you in a vehicle getting 12 miles to the gallon when gas is expensive, and when burning that gas helps wreck the environment? You, person who commutes to work in a pickup, are a selfish person.

Grid Stabilization

In the Solar and Wind articles, we read that these technologies produce intermittent power. In other words, they can't provide power on demand or at night. Imagine, if you will, that those 120,000,000 commuters all had electric cars. And that they all had excess batter capacity. They could charge up while the wind was blowing and the sun was shining, and discharge while the sun was sleeping and while the wind was lazy. Suddenly part of the problem with wind and solar has some help. This is a huge topic, though, and I won't go farther into it.

Shortest version:

Get an electric car for your commute.

Hokay, that is all for now. I will edit this as I get comments. Thanks for reading!

Jason Munster

Geoengineering

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So. Science can fix anything, right? Only if we have lots of time and money. And grad students that function as indentured servants in a pyramid scheme to get tenure.

Back to the point. The truth is that science can't fix everything on short time scales. Climate is one of them. Geoengineering can help to a degree, but it will only get us part of the way there to avoid the worst consequences of climate change. Let's discuss some.

White roofs, white roads, white buildings.

Two articles back, we discussed albedo, or reflecting sunlight. Ice reflects 90%, water reflects 90%. Whatever is reflected tends to go to space and not stay in the Earth system and warm it up. In fact, whatever is absorbed then gets in the greenhouse trapping loop, warming up the Earth a good bit. Dark surfaces (our roofs, our roads, most of our buildings) reflect little and absorb a lot. So, paint them all white, and more light is reflected. Excellent!

"But Jason," you say, "Cities are only a small percentage of land area. How could this possibly help? I mean, the rest of the Earth will still absorb just as much heat. Right?"

And to you I say, "Excellent, sir! That is true. Making all our stuff white won't do much for the overall heat budget of the Earth. I am so proud of you for reading most of my website so you quickly figure stuff like that out."

So what does it do?

 

The heat island effect is based on the fact that cities are covered in dark buildings and pavement, and have a very low albedo, so they absorb heat

Cities are fucking warm. They suffer from this thing called the "heat island effect." That is a fancy way of saying that they are so dark, they absorb the sunlight and are easily 10 degrees F (around 5 degrees C) warmer than they should be. Turn everything white, and you can cool the city. This will actually have a very large effect on how hard our AC units have to work in the summer. Imagine if your city was suddenly 10 degrees F cooler. How sweet would that be? I posit that it would be pretty rad.

This one seems to help a bit, but we will still be using tons of energy and producing CO2 in all other ways. Moreover, it won't solve the problem of the agriculture, ice caps, and acidifying ocean.

Putting CO2 in the ground

There are two ideas of sequestering CO2 in the ground. The first is capturing it at the source. Like power plants. This sounds like an easy idea, but the first problem is the energy it takes to capture it. Thermal power plants take in atmospheric air. Which is 78% nitrogen, and 21% O2. Even if all the O2 were converted to CO2, what comes out of the power plant stack is still 78% nitrogen. Separating the two to store the CO2 takes more energy. In fact, the power plant is roughly 30% less efficient. So it needs to burn a lot more coal or natural gas to produce the same amount of power, and will cost a lot more to build. And any fancy idea you have to get around this 30% efficiency hit won't work. No matter what, you either have to pre-concentrate O2 to get a pure stream of CO2 on the other side, or separate the CO2 on the emission side.

The next problem is where to store it once you get it. Gases like to leak out of things. Some companies are trying to store the CO2 underground, much like petroleum is stored underground in a lot of places. This is why you need to separate it from the nitrogen in the air. There just isn't enough space to store both the CO2 and the nitrogen, and also it is expensive to pump stuff underground. Another issue is that it is unclear how long storing CO2 will last in the ground, since it more or less needs to be done indefininately.

Finally, since 35% of our energy use is from cars driving down the road, and it is impossible to capture that CO2. So Carbon Capture and Storage (CCS) from the source still won't do everything we need.

Direct Capture
The next idea is to capture CO2 directly from the air. We have increased CO2 in the atmosphere from 280 parts per million (.028%) 400ppm. The idea of direct capture is to do the opposite. Draw down the CO2 and then store it somewhere. Some might suggest we store it in trees, but that is an awful lot of trees, and unless we bury them trees somewhere underground, they are just gonna get consumed by bacteria and become CO2 again. Other options are to mechanically and chemically separate CO2 from the air, and them store it underground as above. This is very expensive. It might work in the future, but for now it won't.

The bonus of this, if it ever works, is that it is the best way to reverse our issues from an engineering standpoint. We can turn back the clock.

Stratospheric Injection

Injecting small sulfur or other particles into the atmosphere cools the entire globe by reflecting some small portion of sunlight before it hits the rest of the Earth. We know this cause when mountains like Pinatubo and St. Helens explode, they launch particles into the stratosphere and we get a cold year.

SO2 increase in the stratosphere by exploding volcano

Some people have suggested that we could do this. Just inject stuff into the stratosphere to reflect sunlight. The problem? It turns out that everything small enough to cause the proper scattering just happens to be the right size to promote adsorption of water particles. Which then allows for rapid recycling of CFCs in the stratosphere.

"But Jason," you say, "I thought recycling was good!"

Recycling plastics is good. Stratospheric recycling of CFCs is bad. Cause what happens is a CFC reacts with ozone, breaking it apart, wrecking the ozone layer, and then usually is all like, "Man, I am exhausted from catalyzing that reaction, I am gonna take a break." But that water that adsorbed onto our reflective particle provides an excellent place for it to re-radicalize. Which means it is ready to take out another Ozone particle. That's right, our CFC goes to chill out on some water droplets, effectively taking a restful timeout at a pool, and gets ready for work again destroying the ozone layer.

Let's pull this all back together. We try to put stuff in the upper stratosphere, if could make CFCs more effective at destroying the ozone layer, and then we are all screwed in a much much larger way than climate change. Cause the ozone layer is what protects us from getting fried by a lot of UV rays.

Here's where things get fun. Imagine you are a small country of 1 million people living on an island. And that island is going to get inundated with water in 20 years unless climate change is reversed. You don't give a damn about a chance of destroying the ozone layer. You only care about saving your people and your country. Stratospheric injection isn't exactly nuclear science. We aren't going to have rogue nations stumbling through how to do this, and failing all the time.

I'll leave you to ponder what all that means, cause it is more fun that way, and we are already at 1200 words.

The upshot of this is that it also fails to solve the acidifying of the ocean, we don't know how well it will work, and we don't know what will go wrong.

Solar Reflector

Another idea is to put huge mirrors in space and reflect a chunk of the sunlight coming in. This could work. Wasn't this a plot in some Bond movie, though? Also, it would be mad expensive. Probably much more expensive than some other options. And much like the option directly above, we still acidify the ocean.

Review

Hokay, so. Most of the technologies for fixing our problem don't exist, don't work, are too expensive, or could kill us all. And if they do work in the future, they won't solve all the problems we are creating. Even the one that does solve all the problems, direct capture from the atmosphere, won't do crap for our plight if we rely on that alone. As a species, we can easily outstrip any CO2 removal measures just by burning more things. Even if after rigorous testing proved all these work, we would need to some combination together to get anywhere. And even with that, we need to reduce the continued growth of emissions worldwide, otherwise no science or engineering solution will stop climate change.

Depressing, eh?

Thanks for reading,

- Jason Munster