Month: Apr 2019

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.

Win Win Win Win: The Magic Science of Plasma Waste Converters

/ Small Change / 10 Comments

First Published in the UCD College Tribune

Humans have an incredibly extensive waste problem. Right now, most of that waste is sent to landfills where it takes up space for thousands of years, leaching harmful chemicals and gases into the soil and atmosphere. Alternatively, we send our waste to incinerators which burn it for energy, but which release harmful greenhouse gases (GHGs) and toxic by-products in the process. A large proportion of our plastic waste ends up in the ocean, where it strangles and poisons fish, seabirds and marine mammals. What if I told you that there was a way to get rid of almost any type of waste in one machine, that the machine would release no harmful chemicals or GHGs, and that the process would produce useful by-products and excess energy that could be sold back to the grid? Such a machine exists right now; the plasma waste converter (PWC).

While incinerators are able to extract about 15% of the potential energy from rubbish, PWCs can extract an incredible 80% through a process called ‘gasification’. Plasma is ionised gas, meaning that it contains roughly equal numbers of positively charged ions and negatively charged electrons. It is often called the fourth state of matter since its characteristics are so different to those of liquids, solids and gases.

One way you can make plasma is by creating an arc of electricity between two rods, then passing a gas like argon through it. This set-up is known as a plasma torch and can heat gases to a higher temperature than the surface of the sun. Plasma torches were invented by NASA in the 60s to test how much heat the hulls of their spaceships could withstand. The crucial difference between using a plasma torch and using an incinerator is that in PWCs, combustion doesn’t take place. That means no smoke, no GHGs and no ash. The plasma breaks down the bonds between atoms, separating them into very simple forms. Despite the extremely high temperatures, it would be wrong to say that the waste is being ‘burned’; rather it is being decomposed at an accelerated rate.

One of the products of gasification is, you guessed it, gas. This energy-rich gas, known as syngas, is largely made up of hydrogen and carbon monoxide. Syngas mainly comes from the gasification of organic matter. As the gas expands, it spins a turbine, generating electricity. The high temperature of the gas can also be used to evaporate water, generating steam to turn another turbine. The syngas itself can then be burned for fuel or scrubbed with water and released safely. Remember, all of this energy production and revenue is coming from rubbish. We are talking about the plastics that are decimating marine life. Metals, fabrics, wood, even toxic or hazardous waste from industrial run-off or medical facilities. This is stuff that we desperately need to get rid of and by getting rid of it like this, we can also take some of the stress off an already strained energy production sector.

The solid by-product of gasification is called ‘slag’. Slag is produced mainly from inorganic materials like metals. It can be used in construction to bulk up concrete and tarmac, making it a very useful commodity. The molten slag also pools at the bottom of the chamber and helps to maintain the temperature, reducing the energy consumption of the PWC. The real magic happens when you pass compressed air through molten slag to create a material known as ‘rock wool’. Rock wool is currently made by drilling into rock, melting it down and spinning it in a centrifuge. Made in this way, rock wool is sold at one US dollar per pound. When it’s made of rubbish instead, it can be sold at just ten cent per pound.

Rock wool can be used in a number of ways. As an insulation material, it is twice as efficient as fibreglass and could significantly decrease heating and air conditioning bills, further reducing the carbon footprint of gasification. Surprisingly, you can also hydroponically grow plants from seed in rock wool. Perhaps its most amazing use is that it can clean up oil spills. Rock wool is lighter than water and extremely absorbent. This means that if you spread it out over the surface of an oil spill, it will float and absorb all the oil. The rock wool can then be collected with relative ease. Slag and rock wool are two more saleable products that can increase the economic viability of plasma waste conversion.

PWCs are currently being built all around the world. Some plants are already so efficient that they need to take rubbish out of landfills to use as feedstock. There is even a mobile plasma torch on the back of a truck in the US which can be jammed straight into landfills, which act as makeshift gasification chambers. The need to reduce GHG emissions and simultaneously fix our massive waste problem has generated huge interest in PWCs in recent years. Landfills have only one way to make money; they charge you a ‘tipping fee’ for getting rid of your waste. Since PWCs can generate revenue from both energy production and by-products, they can make their tipping fees much more competitive.

So why haven’t these things solved the problems of pollution and climate change already? The answer is largely that PWCs are still a relatively new technology. The cost of building and operating one is still much higher than that of some of its competitors including landfills and incinerators. There has not yet been standardisation of the design and thus the huge and complex machinery must be custom-built every time. The energy needed to power PWCs is also very high, especially compared to incineration, which requires only a match. It must be said, however, that although it takes a lot of energy to run a PWC, you will very quickly make all that energy back and more. PWCs are extremely efficient long-term; unfortunately, short-term profits dictate much of what happens in society.

One worry is that by making waste a profitable commodity, we encourage people and companies to keep polluting with impunity. The best way to solve pollution is not to pollute more and then clean it up better. It is to reduce the amount of pollution we are producing, whether that is by reducing our individual consumption, or by researching innovative ways to package our goods without making a mess. There is, on the other hand, already a lot of waste out there, languishing in landfills and contributing to the decimation of marine ecosystems. The best thing to do with all that waste is to get rid of it with the fewest possible emissions and the most possible benefits. PWCs may be just the technology for the job.

The price of fossil fuels is slowly being raised by various economic policies to reflect the cost to life on earth and we need to find as many alternative sources of energy as we can. With countless landfills already full and the world still producing around 2 billion tonnes of waste per year, rubbish will not be scarce for a very long time. This really is a win win win win win. One machine can get rid of harmful waste, cut GHG emissions, produce fuel, energy and construction materials and clean up oil spills all while making a profit. An investment in plasma waste converters is not only economically sound, it is also an investment in the future of our planet.