Animal Agriculture

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

/ Small Change / Leave a comment

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.

3 Things You Should Really Know about Climate Change

/ Small Change / 6 Comments

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.