Monthly Archives: December 2013

Eating Beef and Mutton Causes 15% of Climate Change Emissions

Posted on by
1

Meat!

In what may be the worst article I ever read (not in terms of scientific quality, but in terms of making me a sad clown), eating certain types of meat causes 15% of climate change. Unfortunately, you, reader, do not have access to the full article, so I will pull some of the quotes from it.

"Worldwide, the livestock sector is responsible for approximately 14.5% of all anthropogenic greenhouse gas emissions3 (7.1 of 49 Gt CO2e yr−1)." 5.7Gt of this is from ruminants, animals that have more than one stomach and chew their cud (about 4.6Gt from cows, .6Gt from buffalo, and .5Gt from sheep and goats). 1.4Gt are from monogastric, ie single stomached, animals: pigs, chicken.

Why do ruminants produce so much? Cause they belch methane. On a 20 year timescale Methane is 75 times more powerful a greenhouse gas than CO2. And why is this? We've discussed this before, but it is worth revisiting.

The Science of Heat-Trapping Gases (skip this part if you don't like science)

(Any atmospheric chemists reading this: I apologizes for bastardizing the science a little bit, but this is meant for a general audience, so I will gloss over details and simplify some concepts)

Electromagnetic Spectrum! (source)

First, let's revisit the idea of radiance. Everything gives off light. It's not light like we normally consider it, as in what we can see. Instead it is all sorts of light we can't see, either. Like infrared, UV, and even x-rays. You've heard of the electromagnetic spectrum. It's the picture above. Visible light is only a tiny fraction of it.

So. Again, everything gives off light. The wavelengths of light an object gives off is based on its surface temperature. Humans give off a characteristic light at around 35C, cause that is roughly our body temperature. This is just a small part of the infrared. The Earth absorbs the light that the sun gives off, warms up, and then emits its own light based on surface temperature. And this light it emits? It is heat. It is the planet/sun/person losing its heat energy.

And that light it gives off is in the range shown in the picture below.

Image from UCAR. Look at CO2, and then look at the region around 8.

The image above tells the whole story. Consider the drop in the line to be absorption %. In other words, a sharp dip in the line indicates that compound is re-absorbing the light that Earth gives off, trapping it in the atmosphere. If you look at the CO2 band between 4 and 5, and then the higher CO2 band, you see that it pretty much is absorbs all the light. If you look around 8, where methane absorbs, you see that it is pretty much wide open. So every bit of increase in methane is fully effective at trapping more heat emitted from Earth.

"But Jason," you say, "If CO2 absorbs pretty much all the light in it's region, how does more CO2 increase how much heat it traps?" Well, my friend, you ask an excellent question. You know the Doppler effect? The one where an ambulance siren sounds differently coming towards you than it does when it goes away? That is because the vehicle is traveling an appreciable % of the speed of sound, so it slightly compresses the sound waves when it comes towards you (the ambulance sort of is trying to keep up with sound waves, so it emits subsequent waves closer to each other) and spreads those waves out when it is moving away from you (the ambulance is kind of trying to move ahead of each sound wave it emits, so a little extra space is between wave peaks). Your ear interprets the pitch of sound based the distance between these wave peaks.

How the heck does this relate to CO2? Well, this doppler effect occurs in light absorption as well, mostly related to effects based on the distribution of temperatures in a set of molecules. There are many different types of effects with light absorption that can act similarly, and they are together referred to as Broadening Effects. They are called this because they smear out the absorption region. So, more CO2 in the atmosphere, more broadening of the light absorption. In other words, CO2 absorption expands out sideways in that picture of light absorption, which is less efficient than expanding directly down, like CH4 does.

Back to the Meat!

CO2 equivalent emissions from various types of meat. From Ripple, W, et al (2014). Ruminants, climate change and climate policy. Nature Climate Change.

CO2 equivalent emissions from various types of meat.
From Ripple, W, et al (2014). Ruminants, climate change and climate policy. Nature Climate Change.

Briefly, ruminants produce a lot of CO2 per kg of meat. The above chart compares them all. Stick with poultry and pork.

Cow alone contribute nearly 10% of anthropogenic greenhouse gas emissions. There are 1.4 billions cows in the world. About 20 million get added per year. That's pretty much a cow for every first-world citizen. Now, I'm a die-hard carnivore, but that sounds like a lot.

Now that I've spent a ton of space on describing methane, let's talk about some other causes of emissions from cows. With 20 million more cows needing places to eat and live per year, there is massive deforestation. Cows also tend to destroy environments, making it difficult to grow stuff there later. In some cases, it rapidly converts land to desert. But watch this video where a guy talks about how managed livestock movements can actually reverse desertification.

Okay, back on point. We apparently eat too much cow. Well, we eat too much in general. I am sure that the people eating too much in general are also eating too much cow.

Scary point: I recently read that the amount of extra food that went into making our world's obese could feed 300 million people for life. In other words. nearly half of world starvation could be completely fixed if a bunch of us weren't overeating. And we'd be a good chunk closer to stopping climate change.

Shorter version: next time some vegan tells you that eating meat causes 15% of climate change, first, agree with them. Then let them know that it is mostly from people over-eating cow, and that since you eat mostly chicken and pork, they should bring their complaints somewhere else.

On a more serious note, I do not like admitting the reality of cow being bad for the environment. I love eating cow. I make smoked meat. But we need to trust the numbers and be impartial towards these things. So I make mostly smoked pulled pork and pork ribs. And I eat a ton of chicken.

thanks for reading!

- Jason Munster

Apartment Rentals and Energy Waste

Posted on by
Reply

Landlords usually suck. And they probably cause some notable percent of emissions by being lazy (I would guess like 1+%) and not modernizing their apartments (modernizing by 1980s standards).

Drafty rental unit?

Background

A few months ago, I wrote my most-trafficked article about why living in the suburbs is bad for your wallet, and bad for the environment.

A lot of people had some ridiculous responses.

The ultimate point of the article was that living in a city is better for the environment than living in the suburb. Many responses mostly ignored the environmentally friendliness part. These butthurt folk only cared about the size of their house (which, as we showed in the previous article, means they probably suck in terms of energy efficiency). If they did, they would have pointed out the giant gaping hole in my argument: most landlords don't give a care about energy efficiency of your apartment. They aren't paying for utilities, they only care about your rent.

Some Sources of Energy Waste in Houses

In my last article, I pointed out that all houses need some amount of venting. So bigger houses will likely need a lot more energy to heat and cool than smaller houses. The driver of this was how many times per day the house cycled all of its air. It will surprise most people to find that the amount of ventilation that is still considered safe will dump all of your heated / cooled air 15 times per day.

Drafty windows, much? (same disclaimer as below, burrowed image from a commercial website)

In most cases, your landlord doesn't care about how drafty your place is. On other words, the old place I lived in in Somerville probably exchanged all of its heat to the atmosphere about 100 times per day (we could perceptively feel drafts through every window and door). So the place took about 4-8x as much energy to heat as a well-sealed house of the same size.

What incentive does the landlord have to fix this? Absolutely none. He doesn't pay any utilities. He gets rent no matter what. Given that a majority of people won't ask what the air-exchange rate of an apartment is, he won't have to fix it.

What about appliances? Stoves are pretty easy. Electric stoves produce heat by using electricity to heat an element. They are pretty efficient at converting electricity to heat, but newer ones can definitely be more efficient and save you money. Gas stoves, as long as they don't leak, do pretty well despite age.

Remember these fridges? (note: I just burrowed this from a random site since I couldn't find a .gov site with an old fridge)

Fridges, dish washers, clothing washers, and dryers, or really any other appliance (including hot water heaters, etc.) are a very different story.

Just go here and play around with how much you'd save in electricity annually to figure out how much you'd save by buying a new fridge.

And then remember that 1 kwh of electricity requires 1 lbs. of coal. And then let's consider that replacing an early 1990s era fridge with a new energy efficient one in MA will not only save about $200 per year, but will save nearly 1300 kwh. Or 1,300 pounds of coal, if you get all your power from coal (or about 700 lbs. of methane (recall that methane produces a lot less CO2 for the same energy production)). I am going to repeat that again. Replacing a 20 year old fridge will prevent the equivalent of burning 1300 lbs. of coal in environmental change per year.

That's right. Your landlord being lazy and cheap is making us burn 1,300 lbs. of coal per year. And the energy savings from replacing other old appliances is similar.

What about replacing windows, doors, etc., for ones that don't leak? For ones that have a lower amount of heat transfer directly through the window (double paned, triple glazed, etc.)? It's huge. You can even get tax credits to replace old windows, making the payback time less than 5 years. But many landlords don't care about this, because they don't face the costs of heating a home. They would just be paying money for replacement appliances and windows, and they would never see a return on this investment.

I don't think I need to belabor this point. Old appliances and leaky housing are things your landlord doesn't care about, but they are things that matter in terms of energy use.

So how to fix it? That's for policy people to figure out. I'm not one of them. But I would suggest a few things:

1. Require that landlords report yearly costs of heating to 65F in winter, and cooling to 75F in summer, as well as electricity bills, every time they show an apartment to a potential tenant. This way tenants can add this price in to their monthly rent, and it will force landlords to make a correction for the market.

-or-

2. Require landlords to not have appliances that are more than 15 years old, and windows and doors that are not more than 25 years old

Obviously #1 is much better with market mechanisms, paperwork, etc. I would go with that, since there is pretty much no overhead involved.

Anyone else have any ideas to address this? Leave it in the comments!

Also, if you liked this, please subscribe & share. Thanks for reading!

- Jason Munster

*Recall from an earlier article that the energy use of heat from electricity depends entirely on the "energy mix" of the grid. If enough of that electricity comes from renewables (let's conservatively say 3/4), then the amount of CO2 produced from using electric heat will be better than gas heat (even if the last 1/4 is dirty coal, hence using the 3/4 conservative #).

Why Giant Houses Always Use More Energy

Posted on by
Reply

Big houses use more energy to heat and cool, for reasons you might not suspect. Houses lose heat to the outside. Nearly all houses are drafty in some form or another, and they need to be somewhat drafty, as we will soon find out.

When energy prices skyrocketed in the 70s due to price gouging and market manipulation of oil (thanks, OPEC), there was a big movement to make it so houses didn't leak air (and leak their heat energy in the process). The idea is that for every bit of air you heat and then let out into the environment, you have just wasted energy. So the process of sealing houses began.

OPEC oil embargoes of '73 and '79. The prices of energy spiked worldwide.

Some groups bragged that they could build houses that only exchanged 1% of their air per hour with the outside. In other words, it would take 4 full days to lose all the heat or AC energy of a house to the outdoors. Excellent, right?

It was excellent in terms of energy savings. But anyone with a flatulent spouse/significant other can tell you that being stuck in a place that is producing unhealthy fumes is dangerous if you don't vent it. It turns out that a lot of basic human activity, like cooking and heating, produce things that are bad for humans and need to be vented.

Much more importantly for advanced cultures*, cooking (it boils water, yo) and breathing and sweating make the air inside a house humid. Humidity in a house causes mold that can make you ill or, in extreme cases, kill you. One of the most effective ways to remove all this humidity is to let the air exchange with the outside.

So here we have a problem. We need to seal our houses well in order to save energy on heating and cooling, yet we also need to allow loss of all this heated and cooled air so we don't sweat ourselves out and cause bad mold to grow.

And we arrive to the crux of the matter. A good exchange rate is .6, or that 60% of a houses air is exchanges per hour. Sounds like a lot? It kind of is. But it's what is healthy for normal technology (we aren't all going to install CO and CO2 scrubbers and dehumidifiers in our houses). So in 24 hours, we have

hours exchanges per day. Of your entire house volume.

So. You have to exchange air in your house. About 15 times per day. Otherwise you might start falling ill. If you have a gigantic house that is 2x larger than you need, then you will use 2x as much energy to keep the place heated and cooled as you need to. So, in short, living in a giant house is a bad thing for energy conservation (take notice, Al Gore**)

Next week we will suspend our assumption that all houses have decent exchange rates, and discuss why this is a huuuuge policy gap.

You don't really need to live in a place like this, do you?

Thanks for reading!

- Jason Munster

*Developing countries still use coal. By 2020 there will be up to an estimated 400,000 deaths per year in China from indoor air pollution associated with burning coal for heat and cooking in poor rural homes (160,000 median estimate). Obviously this is more pressing than mold.

**I was going to rip Al Gore a new one for having had a huge electricity bill just after making An Inconvenient Truth, but it turns out that in 2007, before it was cheaper or easier, he elected to power his home, in TN, with solar and wind power almost exclusively, jacking up the price to a level higher than most Americans pay. So yeah, he did have a much higher electricity bill than the average American, but he only used about 4x the electricity, apparently. Which is still a lot. Except that he and Tipper both also work out of their houses. And now they have solar panels all over it. So it's not that bad. Though it is still huge.