Why CO2 Should Worry You (Yes, Sceptics Too!)

By Levien van Zon

This article is also available in Dutch, and as PDF or ebook (EPUB and Kindle) for offline reading. The footnotes provide additional background information, and can safely be skipped or read separately.

I had originally planned to write my first article on a different subject, the ecological footprint. But World Climate Action Day and the UN Climate Summit last month persuaded me to write about CO₂ instead. I must admit, I think that maybe too much emphasis has been put on climate change over the last few years. It is but one aspect of an underlying problem, that of energy sources and energy use. Moreover, it distracts from other important problems, such as land use, biodiversity decrease and ethical issues. Sometimes one gets the impression that sustainability is equal to reducing CO₂-emissions, which is obviously not the case. Many people are tired of the discussion surrounding climate change. The arguments of climate sceptics and “climate deniers” have been quite effective in generating doubt among the general public. More than half of people worldwide do not believe climate change to be a serious problem.¹ Yet, despite all this, it is still important to talk about CO₂. Even if you doubt that climate change occurs, there are still good reasons to seriously reduce CO₂ emissions as soon as possible.

Six degrees and four kilos

So what’s up with carbon dioxide? Relatively speaking, there’s only a tiny amount of CO₂ in the air, less than one part in a thousand. In the natural situation² this is around 0.03% by volume, or ±300 ppm (parts per million). The rest of the air consists mostly of nitrogen gas (78%), oxygen (21%) and the noble gas argon (0.9%). So there’s really not a lot of carbon dioxide in our atmosphere, but still this little bit is actually rather important. For plants and algae, this smidgeon of CO₂ is the source of nearly all carbon, the main building block of organic molecules. And together with water vapour and a couple of other gases, CO₂ is responsible for what we call the greenhouse effect.³ And this is a good thing. Without this effect, things would be rather chilly on Earth, on average around -18°C. Thankfully this is not the case, average temperatures are a comfortable 14°C. The natural greenhouse effect therefore contributes roughly 33°C to our climate, which is important to keep it habitable.

There is, however, one problem: The magnitude of the greenhouse effect depends on how much of the various “greenhouse gases* we have in our atmosphere. And these amounts are not exactly constant. Before the industrial revolution, the air probably contained around 280 ppm CO₂ (on average). But since then, this concentration has been rapidly increasing. Currently it’s over 400 ppm, with an annual increase of 2 ppm (and rising). CO₂ contributes roughly 6°C to the (natural) greenhouse effect, but this contribution is increasing…

Of course our atmosphere is not merely a reservoir that is slowly filled by various gases. Living organisms and other natural processes constantly exchange substances with the atmosphere. Plants and algae need carbon to grow, and as already mentioned, they get this from the air in the form of CO₂. However, breaking this CO₂ down into carbon and oxygen requires energy, and plants get this energy from sunlight. Animals do the opposite: they eat plants, and use a small fraction of the carbon from plant molecules as building material. What happens to the rest of the carbon, you may wonder? It is used as an energy source, to stay alive! The carbon reacts with oxygen from the air, which results in CO₂. This releases energy, in fact the same energy that plants needed to break the CO₂ apart in the first place. The reaction of (in this case) carbon-based molecules with oxygen is also known as oxidation, or more commonly, combustion or burning. An average human combusts quite a lot of food every day, and from it produces around 1 kg of CO₂. This means that on an average day, the carbon dioxide you exhale roughly has the weight of a pack of sugar!

To put it differently, together we humans exhale around 7 billion kilos of CO₂. That may sound like a lot (and it is), but it’s only around 1% of the roughly 575 billion kg CO₂ that all living beings pump into the atmosphere on a given day. And us living beings have been doing this for quite a while, yet the CO₂-concentration in the air remains remarkably constant. The reason for this is that plants, algae and oceans also remove roughly 589 billion kg CO₂ from the atmosphere per day. Natural emission and absorption of atmospheric CO₂ are therefore almost in balance.⁴ However, a significant source of extra CO₂ was added quite recently. Below ground are all sorts of fossil remains of plants and animals, buried in the course of millions of years. In some spots, these remains have formed a reservoir of concentrated carbon compounds. We know this as oil, natural gas or coal. From the 18^th century onward, people have begun digging up these remains. Not that we particularly enjoy digging up dead things, but burning these carbon compounds does yield a lot of energy. And we need this energy to power our modern society: Over 80% of the energy produced by humans, is produced from such fossil fuels. In most western countries this percentage is higher, in my home country of The Netherlands for instance it is 92%.⁵

Obviously, burning all this dug up carbon does not just yield energy, it also yields CO₂. This relatively recent source emits around 23 billion kg extra CO₂ into the atmosphere on a daily basis. This comes down to an average of 3.3 kg per person per day, three times what we breathe out ourselves. And there is no extra sink for this extra source. Worse, the Earth’s capacity to remove CO₂ from the air has decreased in recent centuries, in part due to the large scale removal of forests. The result is that the concentration of CO₂ in the atmosphere has increased, with almost 50% in two centuries. Moreover, this increase is accelerating.

So far, this is all not very controversial. The recent increase in CO₂ can be measured, and its causes are quite well known. Less clear however, is what effect this extra CO₂ will have. One of the consequences is an enhanced greenhouse effect. This is simply because the extra CO₂ will cause extra heat to be trapped by the atmosphere. The problem is, we’re not sure how much extra heat, precisely, and we also don’t know how this effect will develop in the coming century. There is no doubt that the average temperature is currently rising.⁶ We can also say with a high certainty that this is, at least in part, due to an enhanced greenhouse effect. But the climate is a complex system with many feedbacks, so what will happen in the long term? Many predictions and projections have been made, but fact is that no-one really knows what will happen.⁷ Basically, two centuries ago we started the largest experiment in human history. And this experiment is virtually uncontrollable, the outcome is unknown and there is no panic button, should things go wrong.⁸ Maybe, this should worry us.

Acid is the new base

Of course, it might just turn out fine. Maybe the extra CO₂ will hardly have an effect, and all will be tickety-boo. On the other hand, maybe it will lead to runaway climate warming, rendering large parts of the planet unsuitable for agriculture. We don’t know. Personally, I think that’s a pretty big risk to take.⁹ But even if you really don’t believe that CO₂ contributes to climate change, or if you believe that this will not really be a problem, there are other reasons why an increase in atmospheric CO₂ should worry you.

Part of the extra CO₂ that ends up in the atmosphere, will eventually dissolve in surface water. For the global temperature this is a good thing, as it reduces the warming effect. But if carbon dioxide dissolves in water, it becomes an acid, known as carbonic acid. Dissolved CO₂ is what provides the “sparkle” in carbonated water (and in most soft drinks), and carbonic acid is what gives it a slightly sour taste. Carbonated water has a pH value between 3 and 4. Luckily, surface water contains rather less carbon dioxide than carbonated water does. Most of the surface water consists of oceans, and sea water tends to have an average pH just above 8. Those of you that have paid attention in chemistry class may know that this is not acidic. Rather, it’s the opposite: slightly basic.¹⁰ As far as we know, the average pH of sea water has remained fairly constant over the last 24 million years or so, between 8.1 and 8.3.¹¹ However, over the last decades, the average pH of the ocean water has been declining rapidly, from around 8.2 to just under 8.1. The oceans are becoming less basic, or to put it another way, they are becoming more acidic. A 0.1 unit decrease in pH may seem minuscule. In fact, in a glass of tap water it would be. But the oceans are not a glass of tap water, we’re talking about a well-buffered system with a LOT of water. In this situation, structural decrease in pH isn’t just a tiny natural variation. And for life in the oceans, a small decrease can be a big problem, especially given how fast it’s happening. Many of the smaller sea animals have an external skeleton that consists of calcium carbonate. Think sea shells, but also coral, and even some types of plankton. If water becomes more acidic, calcium dissolves more easily, and it becomes harder to build and maintain an exoskeleton. The current, rapid acidification of ocean water can lead (and probably already does lead) to large-scale extinction of corals, plankton and molluscs. And as these creatures are at the base of the ocean food chain, this could endanger the stability of the entire oceanic ecosystem.

As with the climate, no-one really knows what’s going to happen to the oceans. Even scientists cannot see the future, they can only extrapolate from current knowledge and trends. It could be that the effects of increased CO₂ levels are not so bad as we expected, and we’ll wonder what all the fuss was about. In fifty years we’ll probably know. On the other hand, the effects could also turn out as bad as we expected, or worse. In that case, we’ll probably wonder why the hell we didn’t act earlier. In any case, if we just sit around and do nothing, we’re taking a pretty big risk. It would be like playing Russian roulette with the stability of both the climate and the ocean ecosystem. And that’s, probably, not a good idea.

War, crises and resources

Risk management isn’t the only reason to curb the human emissions of CO₂. The underlying cause of these emissions, burning fossil carbon for energy, is actually a problem in itself. The largest reserves of fossil fuels are controlled by a relatively small number of regimes. And let’s just say that not all of these regimes are particularly known for their reliability and good will. Attempts to control and mine fossil fuel reserves have directly or indirectly led to many violent conflicts over the last century, and have caused much human suffering. Control over large fuel reserves gives some countries a lot more influence than might be desirable, and funnels a lot of money into corrupt regimes in Africa and Latin America.¹²

Apart from geopolitical considerations, if you value economic stability and poverty reduction, it is unwise to make the world’s energy supply dependent on a small number of centralised energy sources.¹³ If the supply is (temporarily) reduced, or is in danger of being reduced, the price of energy tends to sky-rocket worldwide. And with increased energy prices, the price of almost every product and service goes up fast. This is what happened for instance during the oil crises of 1973 and 1979, and to a lesser extent during the food crisis of 2007-2008.

Finally, apart from practical considerations, there are also ethical considerations. We could argue that every generation should leave the world as they found it, or preferably in a better state. Currently, this is not what is happening. Granted, socio-economic factors like wealth, technology and health do tend to improve considerably across generations. But playing roulette with the climate system and the oceans, and draining fossil fuels and other natural resources, clearly isn’t part of “leaving the world in a better state”. We still have sufficient fossil fuel reserves to last us at least a few decades. But fossil carbon shouldn’t just be considered a fuel, it’s a valuable non-renewable resource. One could argue that this resource is too valuable to simply be converted into heat by burning, within a timespan of less than three centuries…

A LOT of energy

There is no shortage of arguments for why we should reduce CO₂ emissions. Unfortunately this is easier said than done! If we add all direct and indirect emissions through consumption and services, then the average Dutchman or -women emits between 38 and 46 kg CO₂-equivalent per day. This is over forty times as much as we exhale ourselves! For other western countries the figures are similar: in the UK it’s around 42 kg, in Germany 41 kg, in France 36 kg, and in the US it’s a bit higher, around 78 kg. Of these emissions, around 88% is CO₂, the rest is mostly methane and N₂O.¹⁴ And the difficulty is, almost everything we do causes CO₂ emission, because everything we do requires energy. Switching to alternative energy sources is basically the only way to significantly reduce emissions. But this is not so simple, because we currently use a lot of energy! An inhabitant of The Netherlands directly and indirectly uses something between 100 and 250 kWh per day, on average.¹⁵ Again, for other westerns countries these figures are similar. In many countries, the electricity use is only a small part of the total energy use. Most of the energy is used to heat houses and offices, to drive vehicles and to produce all the stuff we buy. And that energy is almost entirely derived from fossil fuels.

Actually our energy use can already be reduced by a fair amount, simply by using the energy we have in a more efficient manner. I will write about this in more detail, in a separate article. But most energy is currently being wasted in transport and in heating. Internal combustion engines use only around a quarter of the energy from their fuel for actually moving a vehicle. The other three quarters are discarded into the air as heat, a “waste” product. An electromagnetic engine is much more efficient, with up to around 90% of input power getting converted into movement. Even if you would generate the electricity using coal (which also isn’t very efficient), the indirect emissions of an electrical car would still be slightly less than the direct emissions from a conventional one. So switching to electrical transport is already a good idea, even though storage of electricity is still a problem. While batteries these days are much more advanced than those two decades ago, they are still impractical and inefficient. Batteries cost a lot of energy, material and money to produce, they’re heavy, charging them is slow, their capacity is rather limited and they generally last only a few years.¹⁷ Therefore, we badly need more investment in developing alternative energy storage!

In cold and moderate climates, houses and offices are probably the biggest causes of wasted energy. In many countries, buildings are heated by burning gas. The conversion of natural gas into heat is actually extremely efficient.¹⁶ Unfortunately though, most of this heat tends to escape from buildings pretty rapidly. It is radiated by walls and windows, and it is carried away by moving air, that escapes through cracks, holes and ventilation systems. A lot of energy can be saved by simply keeping the heat inside the building a little longer! Think double glazing, insulating walls and ceilings, closing cracks, using heat exchangers, and in general better design of new houses and offices. Technology may help, but significant energy savings can already be obtained with merely low-tech solutions like insulation. Moreover, we don’t really need to obtain all our heat from burning gas, or coal, or wood. Nearly everything we do produces heat as by-product. Heat is our main “waste-product”, heat everywhere in our environment, and heat is relatively easy to store and move around. By better use of heat pumps and storage buffers, we can heat our buildings with a lot less fossil fuels. Currently there is a lot of interest in placing (photovoltaic) solar panels on houses. But if you live in a moderate to cold climate and want to cut down on fossil fuel use, it makes a lot more sense to start with placing a solar heater on your roof, installing a heat buffer below your house and modifying your heating system!

Alternatives wanted

By saving energy and increasing efficiency, we can certainly decrease CO₂ emissions by a sizeable fraction. But it will not be sufficient. To drastically reduce emissions we will need to solve the underlying issue of energy sources. This will however require some technological development. Many people believe that solar and wind power can provide all the energy we need, but currently this is not the case. Perhaps they could, one day, but the windmills and solar panels that are currently on the market produce relatively little energy, do cost a lot of energy and resources to produce, take up a lot of space and are relatively expensive. Moreover, our current energy infrastructure is not suited to such intermittent energy sources. We simply have no efficient way of storing lots of energy for later use. Better alternatives for batteries will no doubt appear at some point. Better solar cell technology is being developed, for instance at institutes like AMOLF in Amsterdam. But it will still take ten to twenty years for such technologies to reach the market. And the problem is, we can’t really afford to stand around for twenty years and wait for the technology to get better. If we want to reduce our use of fossil fuels any time soon, we’d better start placing as many conventional solar panels and windmills as is practical. They might not yet contribute much to the total energy picture, but they will contribute to an energy transition. The recent increase in demand for solar panels is already driving all kinds of developments in technology and infrastructure. Yet while technological development can be fast, infrastructure will take decades to adapt. We therefore need to invest more in modifying our energy infrastructure, and looking for ways to efficiently store surplus electricity. Especially the latter, energy storage, will be one of the great technological challenges for this generation.

Apart from renewable energy sources, other technologies are being developed that may contribute to significantly reducing CO₂-emissions. A thorium molten salt reactor may be able to produce nuclear energy without many of the dangers and drawbacks associated with traditional nuclear reactors. However, this technology will still require a few decades of research and development, before it is ready for large-scale application. This applies even more strongly to nuclear fusion, which will probably require another half a century or so of research and development. Until good, large-scale alternatives are available, CO₂ capture and storage could allow us to continue using fossil energy for a few more decades, without many of the associated greenhouse gas emissions. However, capture and storage of CO₂ isn’t free. It requires 20-40% of the energy that is produced, and currently it is not financially viable.

Whatever ways we will use to produce energy in the future, it’s important that we start acting now, and it’s important that don’t put all our eggs in one basket. If we want to decrease CO₂-emissions within a reasonable time frame, then we should start investing now in research and development of new energy technologies, rather than stalling and protecting existing interests. In this respect, most politicians and policy makers seem to show little vision and daring. Let’s hope that this will change the coming years.

And what can normal people do?

Important transitions in societies are seldom to never driven by politicians and policy makers. Important transitions happen because sufficient people want them to happen, because they can happen, or because we don’t have a choice. As a citizen and as a voter you influence politics, and you influence others around you. And as consumer, employee, researcher, entrepreneur, policy maker, teacher or whatever role you may fulfil, you don’t have to wait for politics, science or business sectors to start making large-scale changes. In your work and in your private life you can make choices, and in this way influence society. Granted, probably only a small part of society, but a part nonetheless. So make choices. Try to reduce your energy use, and thereby your emissions. Set an example.

I will end with a rather superficial list of things you can do to reduce your CO₂-emissions. In one of my next articles I will break down our greenhouse gas emissions from consumption in more detail, to see where the largest gains can be made. But for now, it will suffice to state that by far the largest fraction of our CO₂-footprint is formed by our buying consumption goods, by road and air traffic and by energy use at home. This footprint can be significantly reduced with a few relatively simple measures:

• Don’t buy things you don’t need. This may sound obvious, but take some time to check with yourself how many of the things you buy are actually required. Collectively we buy enormous amounts of food we don’t eat, clothes we hardly wear, trinkets and gadgets that sit unused in a cupboard, cheap devices that are outdated or break within a few months or years, and all kinds of other stuff that we think we need, but in the end doesn’t really contribute to our happiness. But all this stuff does cost a lot of energy and other resources to produce.

• If you do really need something, first see if you borrow, rent or lease it, or try to buy it second-hand.

• If you stop using stuff, don’t simply throw it in the garbage. Municipal waste tends to be either burned or sent to landfill. Either way, it ends up as CO₂, methane and/or as other forms of pollution. This is a shame, because many of the products and materials that are thrown away can easily be reused or recycled in some way. If things are still remotely usable, try selling them, giving them away or bring them to a second-hand store. Outdated or broken electronics equipment should be handed in at a recycling point, as it contains precious (and often toxic) materials that can easily be reused. It will cost you a little extra effort and time, but indirectly it can save a lot of energy and other resources.

• Make sure that the walls and attic (or roof, or ceiling) of your house, apartment or room are well insulated. Close cracks and holes through which warm air can escape. Consider adapting your warm water installation by fitting a heat pump, a solar heater and heat storage. Also consider installing photovoltaic solar panels, especially if you have a heat pump. If you rent your house, check with the house owner for possibilities regarding insulation and sustainable energy.

• If you don’t live in a particularly hilly area and road safety allows it, consider using a bicycle for short-distance travels. You can also consider getting an electric bicycle for longer distances, or for hilly roads. When cycling is not an option but public transport is present and bearable, travelling by train or bus is preferable to car or aeroplane. If you know your way around the train systems (especially discount tickets) and book a few weeks in advance, international travel by train can be cheaper than flying, or can be just as cheap. This is the case in many European countries, e.g. between cities such as Amsterdam, Berlin, London, Brussels and Paris. Over such distances, the amount of time you can save by flying is quite limited anyway, due to the overhead of getting to and from the airport and standing in line.
  Moreover, one or two long holidays are preferable to a lot of short trips, especially for intercontinental travel. And if you do travel by car, try to take as many people as you can. Using car-sharing networks such as Blablacar may allow you to reduce both cost and fossil fuel use. And who knows, you may even meet some interesting people along the way…

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