Greenhouse Effect

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?

3 Things You Should Really Know about Climate Change

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In recent years, study after study have confirmed our worst fears about climate change and the window for effective action is rapidly closing. Many people now find themselves scrambling to come to terms with the complexities of climate change. Here are 3 things you should know:

The Snowball Effect

One of the scariest things about climate change is that as it gets worse, new mechanisms are triggered which contribute to and accelerate the problem. Such mechanisms are called ‘positive feedback loops’. The most obvious and dangerous example of a feedback loop is the melting of the polar ice caps. Both land and the ocean are darker in colour than white ice. Since darker shades absorb more heat from the sun, the loss of reflective white ice causes the land, ocean and atmosphere to warm at an accelerated rate. As more ice melts, the earth gets hotter. As the earth gets hotter, more ice melts and a vicious circle is born.

Perhaps scarier is that the permafrost (soil or rock that has been frozen for more than 2 years) currently contains twice as much carbon as there is in the atmosphere. Permafrost is what is known as a ‘carbon sink‘ since it traps huge amounts of greenhouse gases (GHGs) that would otherwise be warming the planet. While there is plenty of CO2 in the permafrost, there is also an abundance of methane, a GHG that is 20 to 30 times more efficient than CO2 at reflecting heat back towards the earth over a 100 year period. Another positive feedback loop is that of forest fires. Each tree that burns releases all the carbon it has taken in over its lifetime and darkens the area where it stood, allowing for more heat absorption. Less trees means higher temperatures which means more fires and more fires means less trees.

Along with ice and trees, soil is another major carbon sink. Recent studies suggest that as the earth heats, microbial activity in soil causes the carbon that has been accumulating over millennia to be released into the atmosphere. Each year, the burning of fossil fuels releases about 10 billion tons of CO2 into the atmosphere. 3,500 billion tons are trapped in the soil. If the earth gets hot enough that significant amounts of this carbon are released into the atmosphere, the consequences will be dire for all life on earth.

Yet another example of a carbon sink that may turn into a carbon source is the ocean. The ocean is currently the largest carbon sink on the planet, having already absorbed half of all the carbon we have released since the industrial revolution. However, the warmer the water is, the less CO2 it is able to hold. In addition to this, water vapour is a greenhouse gas and climate change is sure to bring a huge increase in ocean evaporation. However, this particular issue is not as dire as it seems.

The problem of ocean evaporation has something that is rare when talking about climate; a silver lining. More water vapour in the atmosphere means more clouds which block incoming solar radiation. This is a negative feedback loop which could help to regulate the temperature of the earth. The more water that evaporates from the ocean, the more clouds there are to block the sun’s rays and hopefully help to cool the planet. Research has shown that the reflective properties of the extra cloud cover should actually cool the earth, despite water vapour being a GHG.

Feedback loops illustrate how fragile our climate really is. Given their existence, releasing greenhouse gases into the atmosphere is like poking a tiger in the eye. Because of feedback loops, relatively low emissions can have far greater consequences than they otherwise would. It is imperative that we cut our own emissions as dramatically and quickly as possible if we are to avoid setting off these chain reactions that would surely alter the conditions of our planet for millennia to come.

Going Veggie Makes a Difference

Animal agriculture is the second largest source of greenhouse gases after energy production. There is much talk of reducing greenhouse gases by taking the bus or by refusing to fly, but animal agriculture produces more greenhouse gases than all modes of transport combined. Not too long ago on an evolutionary scale, humans accounted for 1% of the earth’s mammals, with the other 99% being wild animals. Now, humans and our livestock make up a staggering 96% of all mammal biomass on earth.

It takes a huge amount of water to raise animals for food, cattle being the worst offenders. Between the water given to the animal directly and the water required to grow food for it, it takes roughly 7,000 litres of water to raise one pound of beef. That means that by eating a portion of beef about the same weight as 3 tomatoes you waste as much water as you would by leaving your shower on for about 15 hours. If you were to eat the 3 tomatoes instead, you would use about 100 litres of water instead of 7,000. Think about that the next time you decide that taking a bath is too wasteful.

Some people say that the effect of animal agriculture on climate change is exaggerated. I say it cannot be exaggerated enough. While animal agriculture accounts for only 11% of emissions directly (methane from animals burping), its effects on the planet go much further than that. One third of all ice-free land on earth is used to raise livestock, and one third of all grain on earth is used to feed them. This greatly reduces the space and resources available to wild animals.

Animal agriculture is a leading cause of deforestation, depriving many wild animals of their homes and access to food. In addition to this disastrous impact on biodiversity, trees are one of the most important carbon sinks on the planet. One acre of forest can accumulate 100 metric tonnes of CO2 over time and we cut down roughly 18 million acres of forests a year. That means that the trees we cut down each year contain between them approximately 1.8 billion metric tons of CO2. To give you perspective, the average emissions per person globally is 5 metric tons per year. In the world’s largest forest, the Amazon, 90% of deforestation is carried out in the name of animal agriculture. In many cases, the forest is cut down and the wood is simply burned just to make room for livestock, releasing all the carbon trapped during the tree’s lifetime back into the atmosphere all at once. By expanding our land use to feed our booming populations, we are depriving the planet of one of its natural defense mechanisms against rising CO2 levels.

It takes about 65 square feet of land to make a quarter-pounder. The average american eats about 62 pounds of beef per year. That works out to almost half an acre of land use per person for beef alone. If you expand that number to include all Americans, over 121,000,000 acres of land are needed for the production of beef each year. That is roughly the size of Spain. In reality, America produces more beef than it consumes. Right now, 654,000,000 acres of america are used for grazing (not just cattle). That is almost the same size as India, a country with 4 times the population. There are only 327 million Americans, but global populations are set reach 10 billion by 2050. If this is not unsustainable then I don’t know what is.

The crux of this problem is that there are only so many resources available to the animals that live here on earth. By redirecting the majority of those resources (like land, water and food) to just a few species (like cattle, chickens and pigs), we completely derail the balance that has existed in the global ecosystem for hundreds of thousands of years. People fail to make the connection between the food we eat and the massive loss of biodiversity which is currently taking place. The truth is that they could not be more linked.

Climate Change is not Binary

When people talk about climate change, the sentiment is often that we need to do something before it is ‘too late’ to ‘stop’ climate change. Unfortunately, that time has already passed. The carbon we have already released will take a long time to have an effect on the climate, and emissions are still rising. There is no way this is going to end perfectly. We have already sealed the fate of countless people by releasing as much CO2 as we have. This, however, is no reason to give up the fight. Many people have become fatalists about climate change, saying that its effects will be terrible now regardless of what we do. So why bother trying? The answer is that climate change is not a ‘yes or no’ question. If anything, it is multiple choice. Our actions now and in the coming years will dictate not ‘whether’ climate change will happen, but rather how badly the effects will be felt by future generations. It is never ‘too late’ to act, because things can always get worse.

I will be taking many of the stats in this section from a terrifying but brilliant book by David Wallace Wells called ‘The Uninhabitable Earth‘. According to Wells, it is estimated that at 2 degrees of warming, “the ice sheets will begin their collapse, 400 million more people will suffer from water scarcity”…”there would be 32 times as many extreme heatwaves in India, and each would last 5 times as long“. This is the fate we have all but guaranteed for the next few generations of people and animals. Things are going to get very, very bad and there is nothing we can do about it. However, the effects of 2 degrees of warming pale in comparison to those of 3 degrees.

According to Wells, at 3 degrees, droughts in Africa are predicted to last 5 years longer than they do now. In the U.S, wildfires would destroy at least 6 times as much land as they do now. The number of people without access to drinking water or food will continue to increase at breakneck speeds. Recent research suggests that if we immediately meet the goals set out in the Paris climate accord, we will still warm the planet by around 3.2 degrees. Currently, no industrial nation is on track to meet those goals. When it will happen is hard to say, but in the next couple of centuries, humans will be faced with the devastating situation I have just described. But even if we have locked in 3 degrees already, things could still get much worse.

Each degree brings with it new levels of unimaginable suffering for both humans and the rest of the animal kingdom. Our job now is to mitigate as best we can how badly climate change will be felt by generations to come. 2 degrees is better than 3 degrees, true. But 3 is better than 4. 4 is better than 5. 5 is better than 6 and so on. The UN predicts that we are due for about 4.5 degrees by the end of the century. Their worst-case scenario (if we carry on doing what we’re doing) is 8 degrees by the end of the century. With that amount of warming, one third of the planet would be uninhabitable due to direct heat alone and two thirds of our major cities would be underwater. Things will get bad, yes, but they don’t have to get that bad.