Paris Climate Accord

Shock Wave: Electricity From The Ocean

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First published in UCD College Tribune

Even in this futuristic world of ours, all our electricity is generated by simply spinning a turbine. The fossil fuels which are bringing us ever closer to a complete climate catastrophe are not just used to power our cars, but also to create steam which generates the electricity needed for everything from phones to lightbulbs. This is exactly the same principle employed by nuclear power plants. In both cases, fuel is used to create heat, which is used to generate electricity. There are ways, however, to generate electricity which do not require heat at all. Some renewable technologies harness the vast mechanical power available from a planet that is in constant motion. Wave power generators (WPGs) are a possible energy source of the future, but how do they compare with their rivals?

It is worth quickly comparing ocean energy and wind energy since the two are similar in a number of ways. This is why underwater turbines closely resemble those of wind farms. A major difference between the two is the potential energy contained within. Water is nearly 800 times denser than air, meaning that the same volume, travelling at the same speed, contains much more power. What this means on the practical side is that much smaller devices can produce the same yield of energy.

A major difference between WPGs and tidal power is the source of energy. Tides result from the gravitational pull of the moon dragging water up and down our shores as it passes by above us. WPGs, alternatively, find their energy source in the sun. Solar radiation does not heat the earth evenly. The air in places which receive more heat rises upwards, allowing colder air to rush in to take its place. That rushing of air is what we call wind. Since wind is the driving force behind waves, any energy that we harvest from waves comes indirectly from the heat of the sun. It is for this reason that WPGs are considered a renewable technology.

Tidal power is perhaps the most reliable source of energy on earth. Twice a day like clockwork, unimaginably vast quantities of water rush in and out of our coasts. Globally, there is as much power available from tides alone as there would be from nearly 5 and a half billion coal-burning plants. One of the problems, however, is that only a very small fraction of this energy could actually be harvested. There are only 40 or so places in the world where the difference between low and high tide is great enough to produce a worthwhile amount of power. One way that the power of the tides can be harnessed in such places is by building tidal ‘barrages’. These consist of huge dams which trap water from the rising tide, then release it slowly when the tide is low. As the water passes through the dam back into the sea, it spins a series of turbines to generate electricity.

WPGs come in a variety of forms. One very cool design that was deployed in the ocean as far back as 2004 resembles a giant sea-snake. Each segment of the snake is attached to the next by hinge joints which are connected to hydraulic rams. As the sections of the snake move back and forth over the waves, the hydraulic rams drive a series of electrical generators.

Another simple yet ingenious way of harnessing the power of waves is by using a device known as an oscillating water column (OWC). These machines consist of a hollow cylinder containing a turbine which is attached to a buoy. As the waves pass by underneath, air is forced up through the cylinder, spinning a turbine. What makes these devices truly remarkable is the special kind of turbine contained within. The so-called ‘Well’s Turbine’ is shaped in such a way that it can generate electricity regardless of which way the air is flowing. This means that power can be harnessed when the device is rising to the crest of a wave and also when it is falling to a trough, doubling the overall efficiency.

The final method for generating electricity from the ocean is called ocean thermal energy conversion (OTEC). This is another way we can indirectly generate solar energy using the ocean as a middle man. The way OTEC works is that a liquid with a low boiling point (like ammonia) is evaporated by the warm surface water of the ocean and expands, spinning a turbine. The ammonia vapour is then condensed using cold seawater and returned to the evaporation chamber to start the process over again.  The technology required for this method is simple and rapidly improving, meaning that OTEC is very much one to watch out for in the coming years.

So, which is better, WPGs or tidal barrages? WPGs hold greater promise in my view, largely because tidal barrages can be devastating to already strained marine ecosystems. Think about it; much of the ocean’s life is concentrated close to the shore. As the tide rises, both water and marine life can pass freely through the dam. Once that waterway is shut, however, the only way back to the sea is through a series of rotating blades. Many barrages are built on estuaries where rivers meet the sea. By preventing free movement through these estuaries, barrages can also seriously disrupt the spawning patterns of fish like salmon. WPGs, floating on the surface in open water, are much easier to build in a way that’s hospitable to marine life.

This is of vital importance; through plastic pollution, overfishing and ghost fishing, we have already utterly decimated almost all marine life. With plastic pollution and ocean acidification set to get much worse, we simply cannot afford to do any more harm to the beautiful animals that reside beneath the waves. If a plan is to be truly environmentally friendly, it must consider not only the CO2 it will emit, but also the effects it will have on our fellow animals. It is this major issue, coupled with the location problem mentioned earlier, which means that WPGs hold more promise than tidal barrages. In any case, it is clear that as both the financial and environmental costs of fossil fuels rise in the coming decades, blue power will assume an increasingly important position in the global energy industry.

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.

Getting High on Grass – Can Plants Really Fuel a Plane?

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Updated 11/09/2019

In the wake of recent studies showing how dangerously close to the brink we are when it comes to climate change, it is more important now than ever to seriously consider every possible alternative to environmentally damaging fossil fuels. One such alternative comes in the form of biofuels. Humans have been using biofuels for as long as we’ve been using wood to fuel our fires. In the last hundred or so years, however, we’ve begun to understand how plant matter can be converted into liquid fuels that could soon power a plane. In this piece, I’ll be looking at where biofuels are now and where they need to be if they are to significantly reduce CO2 emissions. I’ll be concentrating my efforts on recent attempts by the scientific community to make grass a viable fuel for transportation.

Grass is the most abundant plant on the planet. In my home country of Ireland, more than two thirds of all land is covered in naturally growing grass. If we could refine and perfect the process of turning grasses into fuel (grassoline), this could be a real contribution towards slowing the march of climate change. The problem right now is that it is expensive and inefficient. Many scientists in the field, however, think that given time and money, we could tap into this huge source of unharnessed power and perhaps help to save the planet in the process.

The reason grass in particular is being considered as a biofuel is not because it is necessarily the most efficient plant to use, but rather because of its abundance and willingness to grow in fields that are inhospitable to food crops, known as marginal lands. Another reason that grass is attractive as a biofuel is that it is not really needed for anything else. Other candidates for biofuels (like wood, sugarcane and soybeans) have the disadvantage of being useful for things like furniture, rum and tofu.

But why aviation fuel? One reason is that while cars are slowly turning electric, it is unlikely that planes will follow suit any time soon. This means that in the near future, cars could be powered by renewable sources whereas planes will continue to require liquid fuel. The other more pressing reason is that travelling by plane is far worse for the environment than any other mode of transport. This is down to two factors; first, planes are less efficient than other modes of transport in terms of emissions per passenger mile. Second, planes allow us to travel a far greater number of miles than we would otherwise be able to travel. The carbon footprint of flying from London to Hong Kong and back again is about a quarter of the average UK person’s annual carbon footprint.

The idea that we could use grass, algae and other plants to produce aviation fuel is not nearly as crazy as it sounds. The fossil fuels which we currently use are themselves made of organic matter that has, over a very long time, undergone a natural process called pyrolysis. Human beings have been using the process of pyrolysis for our own gain for thousands of years in the form of charcoal burning. Pyrolysis involves separating materials into their constituent molecules in the absence of oxygen. This means, very roughly, heating up the material to a specified temperature, covering it, and allowing it to separate into liquid, solid and gas. These products can then be refined into fuels. Recently, it has been found that microwave heating produces a higher pyrolysis yield than traditional methods since it can be done entirely in the absence of oxygen and at a very precise temperature. Another benefit is that the characteristic ‘hot spots’ of microwave heating aid in pyrolysis.

You might be thinking that grass is an important source of food for livestock. The beauty of using grass as a biofuel is that this resource would not be lost. The solid by-product of grass pyrolysis can still be fed to livestock. What’s more, by removing the liquid constituents, the feed can be preserved much longer than fresh grass cuttings. In the UK, biofuels already account for nearly 3% of all road and non-road mobile machinery fuel, but with the predicted change in efficiency given a few years, they could eventually account for a lot more than that.

Right now, scientists can only produce a few drops of biofuel from grass in the laboratory. Tests carried out at Ghent University in Belgium show, however, that there is a potentially very efficient energy source in grass if we can learn to harness it correctly. In April 2017, the researchers at Ghent found that a certain type of bacteria (clostridium) can be used to metabolize certain grasses into decane, a key ingredient in both petrol and aviation fuel. While this breakthrough cannot yet be used effectively, it is key knowledge that will inform future research into better biofuel technologies.

Hang on, you might say, if refining plant matter gives us the same fuel as we are already using, then why is it better for the environment? Surely biofuels release the same amount of CO2 as fossil fuels? This is indeed true. The difference is that the CO2 in living plants has only recently been absorbed from the air by the plant and is simply being released again. As the grass grows, it sequesters CO2 from the air. When it burns, that recently absorbed CO2 returns to the atmosphere to be trapped by the next batch of grassoline. Because of this, biofuels are said to be ‘carbon neutral’. With fossil fuels, the CO2 has been absent from the environment for a very long time, trapped underground. By burning it, we are releasing extra CO2 rather than what was already there.

A major obstacle to biofuel efficiency growth is that governments and companies are not willing to invest heavily in something that may not yield solid results for years to come. This is simply short-sightedness. The science will continue to improve. Lack of investment only slows down the process. The people who invest heavily now will surely see a huge return in a matter of years. Another well-known obstacle in the way of all renewable energies is the huge sums of money tied up in the fossil fuel industry. The industry is worth about 7 trillion USD globally. No wonder, then, that lobby groups are able so easily to sway policy-makers.

Biofuels are controversial among environmentalists, since they come with a number of downsides. Perhaps the most worrying is that every square foot of land which is used to produce the fuel is land that could instead be used to nurture biodiversity. Species are currently being lost so quickly as to constitute the sixth mass extinction in earth’s history. For me, using food crops like corn as feedstock is entirely off the table, since it opens the door to a future in which rich elites use corn-fed biofuel to fly away on their holidays while depriving poor people of food which is vital to their survival.

Another drawback is that biofuels are not very efficient when it comes to land use. According to Mike Berners-Lee, using solar panels instead to generate the power for flying would require 270 times less land than growing wheat for biofuel. The problem, however, is building a good enough battery. Right now, 1 kilo of jet fuel carries about the same energy as 20 kilos of premium lithion-ion batteries. One ray of hope came in March of 2015; ‘Solar Impulse 2’ began its attempt to become the first entirely solar powered plane to fly around the world. The journey was arduous and long for the two pilots. One of the pilots was named Bertrand Picard, a Swiss medical doctor who who was already the first person to fly around the world non-stop in a hot air balloon. Captain Picard of the USS Solar Impulse finally landed the plane in Abu Dhabi on July 26th 2016, from the spot where it had departed 505 days earlier.

Regardless of what figures like the US president may say, climate change is a very real and very serious danger. Biofuels are just one example of the many ways in which we can combat this danger, but they are one which will continue to grow in importance for years to come. The question is whether our money would be better spent developing renewable energies like solar and wind which require far less land and are thus better for wildlife conservation. When it comes to planes, however, grassoline may help to ease the transition to a low-carbon world. Every little helps in the fight against the huge and menacing entity that is climate change.

Some Further Reading and Research Sources