Efficiency

Carbon Neutral Lent: Week 1 – Food

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Welcome to the first week of Carbon Neutral Lent! The pancakes are gone, which means the time has come for spreadsheets. This week we will be looking at the messy and complicated topic of the carbon footprint of food. Don’t forget to head over to the CNL landing page to download the tracker spreadsheet which will allow you to estimate your carbon ‘foodprint’ at the end of each week by asking you one simple question! Also, come on down to our event in the Landmark pub in Dublin on the 3rd of March, where CNL founder Darragh Wynne will be joined by a variety of guests to talk about the carbon footprint of food. Come for the information, stay for the music!

Ireland’s carbon footprint is an unusual one. At 34% of the total national emissions, agriculture has a greater impact on our emissions profile than any other European country. For comparison, waste (which includes the footprint of all our plastic) is responsible for just 1.5% of our emissions. Even so, it seems like businesses and well-meaning citizens are far more concerned with ditching plastic straws than they are with reducing the footprint of the foods that we eat.

Our unusually high agricultural footprint is not, however, necessarily a result of our eating habits. It is because we make our money producing extremely high-carbon foods and then exporting them to other countries. To be precise, it is because we produce a whole lot of beef and dairy. Dairy cow numbers increased in Ireland by 27% between 2013 and 2018, in large part due to the removal of the milk quota in 2015.

This goes to show that the types of food we grow and eat can have a massive effect on our emissions. A kilogram of locally grown, in season carrots comes in at 0.25 kgs of CO2e (carbon dioxide equivalent). The same weight of beef is a whopping 17kg CO2e. In other words, pound for pound, beef produces 68 times more carbon than locally grown carrots.

Of course, the comparison is not so simple as this. A kilogram of beef contains about 5 times more calories and about 25 times more protein than a kilogram of carrots. Still, 5 times the calories for 68 times the carbon is a monster trade-off. Getting 1 calorie from beef produces around 14 times more carbon than one calorie from a carrot. Plus, carrots contain far more fiber and carbohydrates and far less fat than beef.

As for protein, how much you need depends on how much you weigh and how active you are. The rule for a sedentary person is that you need 0.8 grams of protein per kilogram of body weight per day. As a 70 kilo man, I would need 56 grams of protein per day. Conveniently, that is exactly the average recommended intake for a sedentary man. That’s about 3.2 Tesco beef burgers of 84 grams each.

Alternatively, you could get that protein from non-animal sources for a fraction of the carbon price. Quorn burgers, for example, contain 18g of protein per hundred grams. In other words, I’d need 3.7 Quorn burgers of 84 grams each to get my daily dose of protein. What’s more, the carbon footprint would be reduced by 90%!

Quorn is far from being the only low-carbon source of protein. We get protein from almost everything we eat. 100 grams of chickpeas, for example will give you 20 grams of protein. Soybeans are also a great source, with 100 grams containing 16.6 grams of protein.  It is easy to see how, over the course of a day, we can take in as much protein as we need without the help of meat.

It is important to note, however, that the recommended protein intake for someone who partakes in a strenuous physical activity like weight lifting or endurance running is considerably higher. Nearly twice as high, in fact, with strength and endurance athletes recommended to take in 1.2 to 1.7 grams of protein per kilogram of body weight per day. If I were to spend all day in the gym, then, I would need 119 grams of protein per day. For active people such as this, protein shakes can provide the rest of the daily protein that you are not getting from food. Plus, there are vegan options available!

That brings us nicely to the question of how much better veganism is for the environment than vegetarianism. One study found that you can cut 1.82 kilograms of CO2e per day by switching from a medium-meat diet to a vegetarian one. The same study found that switching from a vegetarian to a vegan diet would save nearly a kilogram more carbon per day. In other words, going vegan is a fair bit better for emissions.

Cheese is the third highest-emissions food after beef and lamb. That’s right, a kilo of cheese produces more emissions than a kilo of pork or chicken, although it must be said that cheese is usually eaten in much smaller quantities. Vegan food also uses less land and water to produce than eggs and dairy, further reducing a vegan’s impact on the environment. Whether or not food comes from animals is perhaps the best indicator of how high-carbon it will be. If you hadn’t guessed, animal products are almost always worse. But why is meat so bad for the environment?

The simple answer is that growing crops and eating them is a far more efficient process than raising animals for food. That is because you have to grow a lot of crops to feed to the animals while they grow big enough for slaughter. It uses much less land and water and produces far fewer emissions to cut out the middleman and go straight to the source of the nutrition; the plants.

Plants build their bodies using carbon they take from the air, water they take from the ground and energy they take from the sun. They don’t need to move, digest food, pump blood around their bodies or keep themselves warm and that saves them a lot of energy.

Animals, on the other hand, burn up most of the energy they take in from plants by walking around, breathing and keeping warm. If you feed a cow 100 calories in the form of grain, only 3% of those calories will be returned in the meat. That means that you have to feed them a whole lot more over their lifetime than you will get back in the end.

In the case of ‘ruminant’ animals like cattle and sheep, there is the added problem of methane. Ruminants are hoofed mammals that have a 4-chambered stomach, one of which is called the rumen. Microbes break down the ruminant’s food in a process known as ‘enteric fermentation’, which produces a lot of methane. To be precise, it produces 30% of all anthropogenic methane emissions.

Water use is another major consideration, with a 2003 study finding that “Producing 1 kg of animal protein requires about 100 times more water than producing 1 kg of grain protein”. I worked out for a previous article that eating a pound of beef wastes about as much water as leaving your shower on for about 15 hours.

Eating plants is not just low-carbon. It is also gives a much higher yield per hectare than producing meat. In a much-cited study from 2013, Emily Cassidy et al. found that “given the current mix of crop uses, growing food exclusively for direct human consumption could, in principle, increase available food calories by as much as 70%, which could feed an additional 4 billion people”.

In other words, if it were not for the fact that we waste plant nutrition by feeding it to livestock, the population could grow to 10 billion by 2050 (as projected) and we could still feed every person on earth with ease. According to the same study, “36% of the calories produced by the world’s crops are being used for animal feed, and only 12% of those feed calories ultimately contribute to the human diet”. That is a huge amount of waste considering how many people do not have enough to eat.

That brings us very neatly to the incredibly important topic of food waste. In Ireland, over a million tonnes of food are wasted each year. The excellent Climate Queens podcast figured out that that’s enough to fill Croke Park with food waste twice each year. Globally, one third of all food produced goes to waste. That is more than enough to feed the roughly 11% of people in the world who are chronically malnourished.

If food waste were a country, it would have the third highest emissions of any country on earth after the US and China. That is because approximately 10% of all carbon emissions globally come from food waste, costing the world about €550 billion per year.

Food waste is a win-win area in which we can both seriously cut emissions and increase the total food available for consumption. Try keeping a journal of which foods you are throwing out. If you find that you are regularly throwing out half a tub of coleslaw, for example, you can start buying a smaller tub. It really is that simple!

There is so much more we could say about the carbon footprint of food. I haven’t even touched on the emissions from fertilizers, how different types of feed affect the emissions profile of livestock or the very important topic of animal cruelty in agriculture.

If you take two things away from this piece, however, let them be that
a) you should cut down on meat and dairy as much as possible and
b) you should eat the food that you buy.

If we all made these two simple rules a priority when it comes to which food we choose to buy, we could massively cut emissions of CO2, methane and nitrous oxide. In the process, we would also increase the land available for crop production, forests, wetlands and renewable energy projects. Plus, we would save a whole lot of money and water.

What are you waiting for?

Short Change: The Vampire in your Living Room

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TVs, Printers, microwaves, chargers, DVD players, desktop computers and many other devices all drain energy when turned off or not in use. This drain is known as ‘vampire’ or ‘standby’ power and is responsible for a huge amount of energy loss each year. Since that energy is largely generated by burning fossil fuels, vampire power accelerates the rate of global warming as well as raising your electricity bill.

According to UC Berkeley, Americans lose 200-400 terawatt hours per year to vampire power; that’s enough electricity to power all of Italy! That is quite something, given that the US population is only about 5 times larger than that of Italy. Some investigations into vampire power have found that many appliances actually use more energy during the time when they are idle than they do when they are in use. One survey of office buildings in Thailand found that 90% of the electricity used by printers, copiers and fax machines was vampire power. In other words, it would cost 10 times less money and emissions to run these devices if they were simply unplugged when not in use. Another study found that 80% of electricity used by video recorders in Australia was used in standby mode.

So how can you identify an energy vampire? Unfortunately it is not as simple as throwing holy water at your devices. There are, however, some good rules of thumb. Anything that can be turned on with a remote control is likely an energy vampire, since the sensor which picks up the signal must remain on 24/7. Another likely culprit is any device, like microwaves or radios, which constantly displays the time on a screen. There are, however, many other devices which consume power when not in use but show no external signs of doing so.

This issue negatively affects both the bank accounts of the average consumer and the global effort to combat climate change. Compared to dismantling the fossil fuel industry or convincing everyone to stop eating meat, this is a relatively easy fix. One way to slay vampire power is on the side of the consumer. If you buy a couple of extension cords with on/off switches, you can easily cut power to things like TVs and printers when they are not in use. Try keeping your remote control beside the extension cord so that you can flip the switch when you go to pick it up. There is, however, only so much we can do.

The more promising solution to vampire power is technical and is the responsibility of electronics manufacturers. For example, energy-saving devices can be built which automatically cut power when not in use for a certain amount of time. Another example would be phone or laptop chargers which cut the power when the device is fully charged or unplugged. It is estimated that changes to the power circuits of devices could reduce vampire power by as much as 90%, so manufacturers have the power to largely fix this issue all by themselves. One problem with this is that consumers are more likely to buy, for example, a TV which can be turned on remotely, so manufacturers have an incentive to keep producing goods which drain power when not in use.

Cutting vampire power would allow us to supply many more people with electricity without a corresponding increase in CO2 emissions. Improvements in efficiency such as this will be necessary to fight climate change, but must occur in tandem with a number of other tactics, including a conscious effort to reduce energy consumption across the board. It is the responsibility of manufacturers and consumers alike (but mainly manufacturers) to be careful about how much power is being used, and to identify and eliminate any power drain which is not absolutely necessary.

Gas in the Tank: How Methane could be the Future of Fuel

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Almost all the talk of climate change in the media focuses on CO2, as it is the most abundant greenhouse gas (GHG) on earth. It is not, however, the most potent. Not by a long shot. Over a 20-year period, methane is around 86 times more effective at trapping heat than CO2. This is worrying since humans have caused, in just 300 years, an increase in global methane from 715 parts per billion to 1774 parts per billion, the highest level in 650,000 years. That works out to about a fifth of all global warming, making methane the second most significant GHG on earth. Roughly 60% of all atmospheric methane is the result of human practices like large-scale animal agriculture and poorly-managed landfills.

Before I get going, I would like to acknowledge the paper “Biotechnological conversion of methane to methanol: evaluation of progress and potential” as it proved to be an extremely useful research source on this topic.

New research has shown that it may be possible for us to convert methane into fuel cheaply, quickly and on a large scale. The key to this energy revolution will be exploiting a type of bacteria known as methanotrophs. Methanotrophs are incredibly abundant in nature. They account for 8% of all heterotrophs on earth (organisms like us that have to ‘eat’ rather than photosynthesising their food). Methanotrophs were first identified way back in 1906 but in the 1970s, 100 types were isolated, characterised and compared in a landmark study. These incredible bacteria are capable of converting methane into methanol very easily, a process that has been referred to as the holy grail of modern chemistry. If we could perform this conversion as easily as methanotrophs, we could seriously cut down our GHG emissions.

In May of 2019, researchers at Northwestern University identified the cofactor involved in catalysing the conversion of methane to methanol, providing a huge step forward in our understanding of how methanotrophs carry out this incredible process. Methanotrophs are known to carry out the conversion using an enzyme called methane monooxygenase (MMO), but the researchers have now identified the copper ion which accelerates this process and the site at which that copper ion is bound.

Methanol is an energy-rich fuel that can be used for everything from automobiles to electricity generation. In fact, methanol can be put straight into a standard internal combustion engine, meaning that we would not need to design new types of engines in order to make the switch. Burning methanol in an engine produces 20-25% less GHGs than burning petrol, but even these emissions are cancelled out by the fact that methane is removed from the atmosphere to produce the fuel. In other words, it’s already better than burning petrol, and the fact that it removes methane makes it better still. Remember, methane is far more potent than CO2 as a GHG. By converting methane to methanol then using the methanol as fuel, you are essentially converting methane to CO2, which causes much less global warming. The conversion happens at a ratio of 1:1, meaning that simply converting methane to CO2 would result in a serious decline in GHGs in the short term. In addition, the energy you get from burning the methanol means that you don’t have to burn as many fossil fuels, further lowering the carbon footprint of the process.

Right now, we are able to convert methane to methanol. In fact, we have been doing this on a relatively large scale for quite some time now. In 2015, the global demand for methanol was 70 megatons. The difference between current methods of converting methane to methanol and using methanotrophs instead is the temperature and pressure under which the reaction can be carried out. Current methods require temperatures of 900 degrees Celsius and pressures of 3 megapascals. In other words, that is roughly the same temperature as lava and roughly the same pressure that is exerted on a submarine 1,000 feet below the sea. Methanotrophs can perform the same conversion at room temperature and atmospheric pressure (the normal pressure at sea-level). This is known as ‘ambient conditions’ and describes the temperature and pressure wherever you are reading this article (provided you are not reading this in a volcano or a submarine).

The problem with needing extremely high temperature and pressure to perform the reaction is that it requires a lot of energy, cancelling out many of the gains made with respect to GHG emissions. That energy needs to come from somewhere and 9 times out of 10 that somewhere is fossil fuels. In addition to this, the process is currently too expensive to be economically viable, a factor that hugely influences whether or not a technology enters the mainstream. If we can harness methanotrophs’ ability to convert methane to methanol at ambient temperature and pressure, the process will become far cheaper, far quicker and far more environmentally friendly.

There is an important distinction to be made between low affinity and high affinity methanotrophs. Low affinity methanotrophs are found only where there are high concentrations of methane (more than 40 parts per million). So far, every strain of methanotroph we have isolated has been low affinity. High affinity methanotrophs, on the other hand, can perform the conversion at ambient levels of methane (less than 2 parts per million). Isolating and exploiting high affinity methanotrophs is the real holy grail, since this would allow us to convert the methane in the air all around us into fuel rather than just being able to perform the conversion in places where concentrations of methane are high.

Another way this process might reduce GHGs is by creating an incentive for oil companies to stop ‘flaring’ natural gas when exploring for oil. As you bring the oil to the surface, natural gas comes with it. To prevent pressure building up in the pipes, the gas is burned (which is why you sometimes see oil wells with flames shooting out the top). 4% of all natural gas which is extracted worldwide is flared. Using 2017 figures, that works out to 139 billion cubic meters of gas wasted every year (nearly 1 and a half trillion Kwh). That is slightly more energy than is used each year in India, a country with nearly one and a half billion people. Since natural gas is around 85% methane, development of cheap methane-methanol conversion techniques would provide an incentive to capture and store the gas rather than burning it unnecessarily and releasing huge amounts of GHGs into the atmosphere in the process. This is an example of how we can use our current knowledge of low-affinity methanotrophs to begin cutting down on emissions.

Transporting methane is currently very difficult, since it is a gas under ambient conditions. Liquids take up far less space than gases and are also far more energy-dense. By converting methane to methanol, we seriously boost how much potential energy can be carried by a single truck. By cutting down on how many trips are required to transport the same amount of energy, we also cut down on the fuel required for transportation. Efficiency gains such as this will be vital in our transition to a sustainable society if we wish to retain our current levels of comfort.

Burning methanol is also far cleaner than burning petrol, releasing half the carbon monoxide and just 1 eighth of the nitrous oxide. Over a 100-year period, nitrous oxide has a global warming potential 265-298 times greater than CO2. The reason you don’t hear as much about it in the media is that we release far less nitrous oxide into the atmosphere than we do CO2 or methane. The problem of climate change is so huge and so urgent, however, that we need to look at ways to reduce every GHG all at once by whatever means possible. An eightfold reduction in nitrous oxide from transport would go a long way.

One possible issue with this technology is that methane is only more potent than CO2 in the short term (a century or two). It could be argued that since CO2 stays in the atmosphere for thousands of years, we are simply pushing the problem back without solving it. To this I would reply that we are dangerously close right now to setting off feedback loops which would take climate change out of our hands and make the problem unsolvable. By procrastinating on this massive issue, we give ourselves time to develop technologies that can capture CO2 on a large scale as well as technologies that can provide us with clean energy. In other words, we are in desperate need of a band-aid.

Another objection might be that the process provides a financial incentive to keep fracking for natural gas when really we need to be leaving it in the ground. This objection, I think, holds more water. While burning methanol is more environmentally friendly than simply burning the natural gas, it is less environmentally friendly than not burning it at all. One way to respond to this is by arguing that it is naïve to think that we will stop extracting natural gas and oil any time soon. Global energy demand is huge and rising and these needs must be met somehow. It is better to meet them using efficient new technologies than to continue the practices that got us into this mess in the first place. In addition, if we can develop this technology to the point where we can remove atmospheric methane rather than just converting natural gas to liquid, it could actually result in negative emissions, meaning that we would be simultaneously meeting our energy needs and reducing our impact on the environment. The potential for this technology is massive.

Conversion of methane to methanol under ambient conditions and on a large scale would be a huge step forward in developing the green energy infrastructure that is required if we are to transition to a low-carbon world. I’ve said it so many times before, but it bears repeating that if we don’t make this transition very soon, the consequences will be extremely severe for humans and other animals around the globe. We are talking about a worldwide shortage of food and water, an increase in the frequency and severity of natural disasters, rising sea-levels and much more.

Climate change is happening right now all around us, from the wildfires of California to the hurricanes of Puerto Rico. How we respond in the coming years determines whether this will be a difficult century on one hand, or a complete transformation of the Earth that could last for hundreds of thousands of years on the other. So long as we can limit warming to below the levels required to trigger feedback loops, I have faith that humans can ride out the storm relatively unscathed. It is worth remembering, however, that this is the greatest challenge our species has ever undertaken. This is why the development of technologies like methane to methanol conversion is so critical and so time-sensitive. This tech will not solve the problem all by itself, but it will give us some time and breathing room to overcome the larger issue.