New Research: Copenhagen Metro ‘Surprisingly’ Polluted

Measures should be taken to control the levels of fine particulate matter (PM2.5) in the Copenhagen Metro with an increased supply of clean air and source control, according to the scientists behind the study.

The M3 line of the Metro system in Copenhagen, Denmark, has a “surprisingly” high level of fine particle (PM2.5) pollution, considering the system’s recent construction, according to the scientists behind a new study. The M3 line opened in 2019, but the issue with particulate pollution in metro systems was well known long before that.

The measured PM2.5 levels in the Metro are roughly 10 times higher than samples taken at street level in Copenhagen.

The researchers conclude that the closed-loop and fully underground design of the M3, and the usage of tunnel air for ventilation of the train carriages, are the likely culprits for the high pollution levels. They also opine that measures should be taken to control the levels of PM2.5 by using air filtration in the carriages and source control – meaning outside air for the ventilation, rather than tunnel air.

The authors suggest that the ventilation could be improved by using fans installed in draught relief shafts to actively exchange tunnel air with outdoor air, rather than relying on passive ventilation measures, such as the piston effect of the trains pushing air ahead of them. These fans are already installed, but currently only operating during emergencies. A choice that might be down to the cost of running them continuously, which can be considerable with the current energy prices.

Another improvement suggested by the authors, is fitting the trains themselves with air filtration systems, preventing the pollution from the tunnels from being passed into the carriages. This could be an “effective, and immediate measure against particulate matter in metro systems, particularly when exchanging with outdoor air is not optimal, for instance during winter.”

Study methods

The study sampled PM2.5 and CO2 levels in the entire Metro system, above and below ground. It was carried out by researchers from Denmark and Canada, and published in the peer reviewed Environment International journal.

The researchers found an average concentration of fine particles (PM2.5) of 168 μg m−3 in the M3 stations. In the M1, M2 and M4 lines, which are only partially underground, the researchers found a PM2.5 average of 109 μg m−3 in the below ground stations. The difference might be partly down to the aforementioned piston effect of the trains “pushing” fresh air through the tunnels from the outside.

The measurements were all taken outside rush hour, meaning that “it is therefore likely that commuters are exposed to even higher PM2.5 concentrations than those reported here, as several studies have found more frequent trains to cause higher levels of pollution,” the authors note.

The particulate samples have been analysed with particle-induced X-ray emission, which showed them to have an iron content of 88.6%. This is a composition that is quite different from samples taken above ground, and consistent with particle production mainly by train wheels, rails and brakes.

The researchers conclude that the sliding doors installed in stations are insufficient to keep the air clean in the carriages and stations in Copenhagen, and thus not helpful for improving air quality in the overall Metro environment. In fact, the sliding doors, while reducing the platform pollution some, increases the pollution in the train carriages, which in the study were shown to have an even higher average PM2.5 concentration of 219 μg m−3.

Effects of air pollution

Fine particulate pollution has been well documented over the years to be detrimental to human health. PM2.5 are small enough that the particles can penetrate far into the respiratory system and be deposited in the lungs, causing a variety of diseases, including cancer and cardiopulmonary disease.

In 2021, this accumulated knowledge led the World Health Organization (WHO) to update its air quality guidelines, with the new annual mean exposure threshold being set to 5 μg m−3 and a 24h average exposure should not exceed 15 μg m−3 for a maximum of three times per year.


Bad CO2 or Good CO2?

We all know that carbon dioxide (aka CO2) is bad, yes? That has been drilled into us for well over 20 years. CO2 is a greenhouse gas, and therefore CO2 emissions should be avoided at all costs, at least if we want life to continue without increasingly frequent droughts, floods, storms or [insert favourite natural disaster here].

This is probably why people tend to look at me funnily when I argue that CO2 can actually help save the planet from the disaster we are hurtling towards.

Enter CO2 as a refrigerant!

Say again? A what? Most people have never stopped to consider exactly how their beer (or favourite snack) stays cold in the fridge, or how limited-life-span veggies stay fresh on their trip halfway around the world. But, in order for these things to happen, we need refrigerants.

What is a refrigerant?

A refrigerant is a substance that evaporates when absorbing heat – and in the process cools down whatever it absorbs the heat from, like the food in a refrigerator. This evaporated gas can then be condensed back into its original form using a compressor and some electricity. And, voila, it is ready to absorb more heat. This cycle, called a vapour-compression cycle, is what drives most refrigeration and air-conditioning equipment.

All refrigerants used in such equipment have an impact on the climate. Therefore they have been given a so-called Global Warming Potential (GWP) value. The GWP indicates the magnitude of a refrigerant’s greenhouse gas effect, making it easier comparing the climate-effects of different types. CO2 — which is also called R744 when used as a refrigerant — has a GWP value of 1.

Why is CO2 not just bad?

Now we are arriving at the crux of the matter, because synthetic refrigerants (f-gases) have GWP values that, in many cases, are thousands of times higher. Two of the most popular f-gas refrigerants over the last 20 years around the world are called R410A and R32. R410A has a GWP of 2,100 and R32 has a GWP of 771. In other words, R410A’s effect on the climate is more than two thousand times bigger than CO2’s. So, just to hammer home the message… 1kg of R410A released into the atmosphere is 2,100 times as bad for the climate as 1kg of CO2!

So, in conclusion: CO2 refrigerant has a small effect on the atmosphere, and is contributing to climate change if it escapes the refrigeration equipment. BUT, when it comes to refrigerants the alternatives are thousands of times worse.

We need CO2 for cooling

Why is this important? Could we not just stop using cooling? No, I don’t think so. I’m pretty sure the world at large is not willing to give up its cold comforts, especially not with the climate getting hotter all the time. We also need to cool medicines like COVID-19 vaccines.

So, if we can’t live without cooling, we need to choose refrigerants (like CO2) with the smallest possible climate effect to avoid making the situation even worse.

In 2016, the Kigali Amendment to the Montreal Protocol was adopted. The Kigali Amendment is an international agreement that calls upon countries to phase down the use of f-gases called HFCs. The UN has calculated that if the amendment is fully implemented, we can save up to 0.4°C of global warming in the 21st century.

That may not sound like much. However, when we consider that we are currently on track for more than a 3°C increase in temperature, and we are trying to reduce that to 1.5°C, then suddenly a 0.4°C reduction is a big deal.

In other words, replacing the hugely impactful f-gas refrigerants with CO2 can actually help save us from the climate crisis, not make it worse.

So, as usual, life is not purely black and white. When it comes to the climate it is a nice muddy brown. CO2 is not just the bad guy mucking everything up. It could be a useful tool when used to phase out even worse gases while continuing to enjoy a cold beer or running the AC on a hot day.

NOTE on CO2 emissions!

This doesn’t mean that CO2 emissions from burning fossil fuels are suddenly unproblematic, most certainly not. It’s a matter of choosing the least bad option, and in the case of refrigeration, that means choosing CO2.


The patentability of AI-based inventions

Former US President Abraham Lincoln once called the patent system one of the three greatest advances in human history and for more than 200 years patents have promoted innovation, protected human creativity and driven economic progress.

However, the current version of the US Patents Act was adopted in 1952. This was a time before the term Artificial Intelligence (AI) had been coined, and where the idea that machines would one day be able to create independently was unimaginable, except maybe to a few science fiction novelists.

The vast increase in computing power in the decades since, and the amount of data we produce, has enabled the development of many different applications using AI. Indeed the development has progressed to a stage where AI applications have now become creators themselves by learning from the data they are given, and coming up with novel solutions to problems facing humanity.

Naturally the humans behind these AI applications still want to profit from their work, and more than 340.000 patent applications mentioning AI has been made since 1952.

The US legislation, and that of most other countries1,doesn’t recognise inventions made by a computer, stating instead that the inventor has to be an individual. This has created legal tension in the field, and a 2014 US Supreme Court ruling against the patentability of abstract ideas has affected the AI industry, as software or “computer-implemented inventions” often gets characterised as such.

Patent legislation is meant to promote creativity and progress, but in the case of AI it is now doing the exact opposite and stiffling it instead, according to researchers like Ryan Abbott, a professor of law and health sciences at the University of Surrey. Abbott suggests that we need to change the law and allow creative computers to be considered inventors.

That leaves one big question: Are we as humans ready to assign intellectual property rights to a machine, share our currently exclusive “right” to creative thinking, and thus make AI-based inventions truly patentable? Or, are Sci-Fi doomsday scenarios of sentient machines taking over the world still too deeply entrenched in our consciousness?

(1) The Chinese legislation is the major exception, calling for a strengthened protection of intellectual property in the field of AI, as well as improving “patent protection and standardization of interactive support mechanism to promote the innovation of AI intellectual property rights.”


Seek the truth and report it!

In 2019, after 25 years of internet for us mere mortals, we have more or less unlimited access to a world of online information and news. Ironically, this seems to have made it harder than ever before to discern what is true and what isn’t.

Four years ago in the pre-Trump era, not many people gave a toss about so-called fake news. Personally, I only became absorbed in the ethics of traditional media after watching a UK tabloid literally hunt down and destroy a friend of mine.

But boy, things have certainly changed since then. The concept of fake news is now on everybody’s lips. Unfortunately this change hasn’t made people any better at distinguishing between fact and opinion. They say that the first step in solving any problem is recognising there is one, so why does it feel like we’ve taken two steps backwards instead?

No quality (control)

For more than a hundred years we have had journalists and editors to do quality control of stories that enter the public sphere. They have checked facts and figures and presented us with their findings. Whenever they failed to fact check their stories properly, someone else usually found out and loudly lambasted them for their mistakes. This has created an unconscious belief that anything published in papers, radio or TV must be true.

Now these ingrained beliefs have been shaken to the core. In a world that’s being taken over by social media, this element of journalistic quality control has suddenly been removed. Anybody can publish a story and once it’s out there being posted and re-posted around the world; suddenly nobody knows where it originated. If you repeat something enough times, people are bound to believe it. In other words – If it has gone viral, it must be true right?

We have indeed entered a post-truth era, so much so that if a polititician doesn’t like the facts he or she is presented with, they cry fake news and paint themselves as a victim of nefarious forces trying to stop their message, and voila – problem solved!

Traditional media is struggling. Not many want to pay for something the can get for free online. So they end up with two choices. One, they can follow the tabloids and online media into sensationalism and misleading headlines. Two, they can stay true to the code and “seek the truth and report it”. The latter option is a lot more troublesome, it requires research, hard work and time; and the benefits might not be immediate or financial. That is why so many, even those branding themselves as serious media, is treading a slippery slope and focusing on content that can bring in immediate advertising revenue.

Hat’s off

In other words, it is getting increasingly harder, even for well-educated and well-read people to figure out what is up and down, and knowing where to go for reliable information. When we are constantly bombarded with new information, there’s no time to critically assess and contemplate what we see and hear. More than ever we need media that we can trust to tell us the truth; not to spin it in a way which only serves to make money.

However, I’m determined to see light at the end of the tunnel, and I do think there’s hope yet. In my current job within financial services, I’ve met many passionate and hardworking money journalists, dedicated to helping people and enable them to make informed decisions by seeking the truth and reporting it. I tip my hat to you and wish you luck in your battle with trolls and click-bait purveyors.


Are second referendums really “undemocratic”?

As Brexit draws ever nearer, and Theresa May desperately tries to convince parliament to vote for her EU deal, the rhetoric grows ever sharper. On 14 January, in a speech given in Stoke on Trent, May said that if the MPs failed to implement the plan, then people’s faith in the democratic process and their politicians would suffer “catastrophic” harm. She further stated that the alternative scenario of no Brexit would be a “subversion of the democratic process.”

In other words, May believes that it would be undemocratic to hold a second referendum to gauge if people still feel the same way about leaving the EU, now that they’ve seen what the consequences could be. So one referendum is good, but a second referendum is undemocratic and unworthy of the United Kingdom’s proud democratic traditions, according to May.

However, by stating that a second referendum is undemocratic, May also implies that countries like Ireland and Denmark are undemocratic. In 1993, Denmark held a second referendum on the 1992 Maastricht Treaty. Ireland has done it twice, with the Nice and Lisbon Treaties.

I’ll leave you to contemplate the fact that May are happy to accuse Ireland of being less democratic than the UK for a minute.. I’ll just add that both Denmark and Ireland ranks higher than the UK in the EIU Democracy Index. Denmark is ranked 5th most democratic country in the world and Ireland a joint 6th. For comparison, the UK is ranked outside the Top 10 as no. 14.

So with regards to the claim that a failure to implement her Brexit deal would cause “catastrophic” harm to people’s faith in their politicians, I would argue that the damage has already been done.


Is single-use plastic really the root of all evil?

In 2017, the BBC programme Blue Planet ll opened a lot of eyes to the effects of plastic in marine environments. As a consequence, single use plastic has become a symbol of unsustainable behaviour. But, is single-use plastic really the root of all evil, or are there other, bigger problems that it can help us solve?

The movement against single-use plastic has many different parts. One of them aims to reduce food packaging. A number of organisations advocate for consumers to buy unwrapped fruits and vegetables, to buy in bulk instead of smaller packages, and to buy fresh produce instead of frozen or tinned products. All in the hope of reducing plastic packaging, and to create less waste that might end up in the ocean.

There are even those who have encouraged people to remove packaging from their groceries before leaving the shop as a form of civil protest – demonstrating to the stores and manufacturers that we want less packaging, not more.

Reduced packaging increases food waste
The problem with this is that a lot of the advice aiming to reduce food packaging ends up increasing food waste instead. We buy a large bag of salad instead of two smaller ones to save on packaging, and then we don’t manage to finish it before it goes off. We buy unwrapped fruit and vegetables that have been shuffled around by supermarket staff (and prodded and poked by other customers in the shop), and therefore goes off sooner than we expected; so again we don’t manage to eat it all before we have to throw it away.

Food waste occurs throughout the production chain, but a large part of it occurs after the product is bought by the consumer. A comparative study found that in both the UK and the US we throw away about 25 percent of the food we buy.

How do we then square that circle? Do we waste food, or create waste by protecting our fresh food better? And of the two issues, which is most pressing when we look at the bigger picture?

The bigger picture
The Food and Agricultural Organisation of the United Nations (FAO) published a report in 2011, estimating that each year, one third of all food produced for human consumption is wasted. That amounts to about 1.3 billion tonnes per year. Other estimates are even higher; some say up to 50 percent. This means that we are no longer able to produce enough food to feed all seven billion people on our planet. Consequently, around 1 billion regularly starve. We also continue to burn forests and drain wetlands to create enough arable land for this inefficient food production, thereby creating a whole different set of biodiversity issues.

Can we make plastic more of a non-issue?
Is it therefore possible to create a scenario where plastic bottles and other forms of packaging is used to prevent and reduce food waste, but doesn’t end up as an environmental catastrophe? The answer is yes, there are other options than to dump it in a river, or even a landfill, where it will take hundreds of years to decompose.

Altering consumer behaviour
One of the most common items seen in both rivers and oceans are plastic bottles and drinks cans. Efficient deposit schemes can ensure that containers are recycled (or even re-used) instead of ending up in the sea, and other places where they don’t belong. Several countries in Europe have deposit schemes already. In Germany such a system has existed for many years, and the recycling percentage is 97%. The equivalent number in the UK is at present 43%, according to The Guardian.

Turning waste into energy
It is also possible to burn plastic (and other) waste in in specialised power plants, where waste-to-energy incinerators create electricity and heating. It does create a certain amount of CO2, but burning one tonne of waste creates only a quarter of the CO2 burning a tonne of oil would. The plants are equipped with filters so toxins and potential pollutants don’t get discharged into the atmosphere. Denmark has such a system, and it works. Around 96% of all plastic waste in Denmark is either recycled or burned to create energy. In the UK, only 31% of plastic is currently recycled and no nationwide system exists to burn household rubbish.

In my opinion, we should be careful not to get caught up in focusing solely on reducing single-use plastic at all costs, we need to look at the bigger picture. With proper recycling systems that make it easy for customers to sort their waste, deposit schemes and ways of turning waste into energy – single-use plastic need not coninue being the same huge problem it is today. I am not saying we shouldn’t try and reduce the use of plastic, or get manufacturers to take greater responsibility for their products. I just believe it will be counterproductive if we focus too narrowly, and in the process potentially increase other problems like hunger and biodiversity loss.