Worms, Glorious Worms

My faults are legion, but inability to compost isn’t one of them.

Like any Londoner with a square foot of outside space I own a compost bin. It houses remains of several years’ worth of leaves and hedge trimmings and not a single scrap of kitchen waste. Because: I also own a wormery – a lidded bucket which is home to several thousand tiger worms (eisenia foetida)[1].

Vermicomposting involves joint action of worms and microorganisms to break down organic waste. Since the process doesn’t rely on heat, it can be done on a small scale and entirely indoors.

I was inspired to give it a try by this guy’s article (and the update), except I didn’t construct my own wormery. I’m not good at making things.

The journey so far

I have been vermicomposting for three years. It hasn’t always been smooth sailing.

My first attempt ended in mass worm death. I took their bucket outside and chanced to placed it under a broken gutter. It rained heavily for several days. The wormery should have been able to cope with rain, but I guess a constant drip from a broken gutter was a stretch too far. It filled with water, the worms drowned. I felt bad about it.

In last summer’s heatwave we came close to another accident. It was 30 degrees in the shade, I hadn’t checked up on the worms for a couple of weeks, the wormery needed emptying of compost, I procrastinated. When I finally lifted the lid there was a layer of semi-dead barely moving worms on the surface. Decisive action saved the colony. They wouldn’t have lasted much longer.

The eco angle

Is having both indoor and outdoor composting facilities an overkill? Not for me.

In winter I rarely go out in the garden. If I didn’t have a wormery, in the cold months most of my kitchen waste would end up in the rubbish bin, thus adding to my landfill footprint. Because: my faults are legion and laziness is definitely one of them.

Luckily my worms don’t share my vices. These amazing little organic factories work tirelessly day and night transforming tea bags, pizza crusts and apple cores into a thick lavender hedge and several healthy rose bushes.

It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organised creatures.

– Charles Darwin

Even my long-suffering house plant perked up once I started feeding it worm fertiliser, else it would’ve been dead and composted a long time ago 😉

The composting angle

My garden is too small to keep the outdoor compost bin constantly supplied with carbon for the right C:N ratio (about 30:1). Some of my friends’ bins are fly-infested receptacles of smelly gelatinous mess because of that reason, especially in spring when there are no fallen leaves to balance out nitrogen-rich kitchen scraps[2]. With a tiny garden like mine, wedged in among terraced blocks of flats, this could provoke unwanted scrutiny from delicate neighbours, the council, and other assorted vermin.

It may be counterintuitive, but a small compost bin is more difficult to look after than a large compost heap. It’s more sensitive to outside temperature variations – there’s little to be done about it without turning composting into a full-time job – and there’s less leeway for mistakes.

A wormery can take a larger proportion of nitrogen than the outdoor bin. Worms eat the waste, so it doesn’t have time to rot or ferment; good drainage and ventilation keep anaerobic bacteria in check. This is further helped by worms burrowing in the compost and me occasionally digging in it as per instructions, and because I want to see the worms 🙂

Free fertiliser

Manufacture of synthetic fertilisers produces large amounts of greenhouse gas. On top of this, soil microbes convert excess nitrogen unabsorbed by plants into nitrous oxide, so a large chunk of the liquid synthetic plat food that people pour on their flower beds goes up in the air.

Worm compost is better for the environment than synthetic fertilisers: the nutrients are released slower, plants have more time to absorb them and less of the good stuff ends up in the atmosphere. It is also full of microorganisms that enrich the soil and help keep the plants healthy[3]. And best of all, it’s all free 😀

Worms make great pets

My worms live in the cellar in winter and out on the patio in a shaded corner in summer.  There’s no smell. If I stick my nose into the bucket and sniff hard, the most I get is a damp earthy smell, like a tomato plant.

Worms are quiet, don’t annoy, don’t whine, don’t chew up furniture, nor shoes, and there are no vet bills. They are ideal pets for the commitment-challenged. My wormery can go without food for weeks while I’m away – all I need to do before I leave on holidays is drain the bucket of any liquid (this can go straight in the garden, plants love it) and add a handful of kitchen scraps mixed in with plenty of paper or cardboard. Then place it back in the cellar, and I’m good to go.


If you’d like to give it a go, I recommend reading Eifion’s articles on The Ecologist blog. They are both informative and a good read 🙂 And then there’s always Youtube.


  1. Garden earthworms are not suitable. Apparently they have a thirst for freedom and need to burrow in soil – both undesirable tendencies for creatures you’re planning to keep in a bucket with damp shredded paper. On the other hand, tiger worms, also called red worms or manure worms, often found in fallen leaves on the forest floor or in manure piles, are surface dwellers and like living in colonies.
  2. I could use paper or cardboard, but honestly, I don’t see myself doing this for  my outdoor compost bin, checking it twice a week for temperature measuring the pH ratio, adjusting the mix of scraps I put there based on conditions. I find it easier to keep up the motivation when there’s some living thing I’m trying to not kill.
  3. I’m not an organic gardener (if I can be called a gardener at all) by any stretch of imagination, but I don’t like putting chemicals in the environment if I can help it.

What Carbon Bubble?

These woods were first the seat of sylvan pow’rs, Of Nymphs and Fauns, and salvage men, who took Their birth from trunks of trees and stubborn oak.

A couple of months ago, a post by Rhiannon Sowerbutts on Bank Underground revisited the question of a carbon bubble. This topic holds some interest to me. As someone who invests in tracker funds and entertains hopes to retire early, live long and prosper, I want to know what effect climate change could have on my plans for financial independence and early retirement.

The carbon bubble refers to the idea that decarbonisation of the developed world’s energy systems is likely to hit the valuations of fossil fuel companies and thus cause havoc in financial markets. This idea is not new: it’s been written about in papers, discussed by central bankers, think tanks, pension administrators, investment managers and oil consultants. The reasoning goes as follows:

  • The world’s governments have committed to limiting the global warming between now and 2050 to 2⁰C. In order to achieve this, atmospheric CO2 concentrations cannot exceed 450ppm.
  • Currently we’re at 395ppm1; this means we can only emit around 570 GtCObefore we reach the 2⁰C limit.
  • The carbon held in the world’s known fossil fuel reserves is equivalent to about 2,800 GtCO2, of which 745 GtCO2 is owned by publicly listed energy firms.
  • In order to stay within the 450ppm limit the majority of these reserves cannot be burned and are therefore impaired.

The problem is actually wide than this. The so-called “permissible” warming by up to 2⁰C is bound to cause a noticeable change in climate patterns. Some further sea level rise is already inevitable. Hence the term “carbon bubble” should also encompass the medium-term risk of stranded assets (e.g. loss of agricultural land, flooding of coastal property due to rising sea levels, the impact of prolonged droughts on water infrastructure) that is likely to occur even if the Paris climate agreement is implemented fully.

I’ll refrain from talking about the danger that global warming poses to 7 billion humans. The planet itself said it best, albeit its assessment is somewhat on the gloomy side. I’m sure at least some of us would survive – a bunch of tough monkeys we are. But other than recycling, composting, walking and cycling wherever practicable, limiting my flying, using energy efficient appliances and not wasting water and food (amongst other things), there’s not much I can do about the end outcome. So for now let’s focus on the investment aspect of what many, myself included, think of as the worst disaster in human history.

Consider two future scenarios:

  1. The humankind pulls its shit together and limits the global warming to 2⁰C above pre-industrial levels.
  2. It does not.

In the first scenario, any displacement in the financial markets would come from a rapid transition to a low carbon economy. Most of the impacts would be felt in the next 20 to 30 years, and they would be concentrated in energy, utilities and mining sectors. Let’s call it “the 2⁰C scenario”. The effects of second “business as usual” scenario would take longer to filter through to investment performance, but they would be both more severe and less predictable.

The 2ºC scenario

It is a truth universally acknowledged, that financial markets are not pricing carbon assets in line with the 2⁰C target. However, Mercer’s excellent 2015 study found that a transition to low carbon did not have to result in negative returns for long-term diversified global portfolios. At the portfolio level, poor returns of fossil fuel assets were balanced out by superior performance of other investments, such as renewables.

Quite interestingly, according to Mercer’s models, developed market sovereign bonds were virtually immune to climate change. Renewables had good outcomes under all scenarios.

When it comes to energy supply and demand, low carbon does not necessarily mean low on energy consumption. A reduction in carbon emissions will require a change in the energy mix, but 2⁰C is a significant enough increase in temperature, and a hot planet might turn out to be hungrier for energy than a cold one. The human population is projected to grow, albeit at a decreasing rate, for the rest of my natural life. These people will have to eat. Agriculture requires more energy in adverse conditions (both in terms of soil and climate), and if water becomes a problem, desalination and purification of marginal reserves is not going to be either low on energy use or cheap. Human beings must maintain a skin temperature below 35⁰C in order to effectively cool down and avoid heat stroke. Increasing weather extremes might mean that both more heating and more cooling is required.

The business-as-usual scenario

While past performance may not be an indicator of future performance in financial markets, when it comes to people, the best predictor of future behaviour is past behaviour. Politicians are people, and to date the politics of climate change have been abysmal.

In 2006 Stern published Economics of Climate Change, where he estimated that dangerous climate change could cause a drag on GDP of 5% to 20% per year.

What’s interesting though is that the relationship between the measured GDP and human utility is not linear. For global warming, the distribution of outcomes is bound to be uneven. In certain aspects climate change could very well end up being one of several examples of bad things that are good for business2. Much like crime, pollution and cancer, it could actually increase the profitability of some sectors, at least in the short to medium term.

Now take this empty glass. Here it is: peaceful, serene, boring. But if it is destroyed … Look at all these little things! So busy now! Notice how each one is useful. A lovely ballet ensues, so full of form and color. Now, think about all those people that created them. Technicians, engineers, hundreds of people, who will be able to feed their children tonight, so those children can grow up big and strong and have little teeny children of their own, and so on and so forth. Thus, adding to the great chain of life. You see, father, by causing a little destruction, I am in fact encouraging life. In reality, you and I are in the same business. [Jean-Baptiste Emanuel Zorg]
By the way, am I the only one who thinks that garbage robots in The Fifth Element were a bit rubbish?

Here’s one example. More than 17% of all infectious diseases are vector-borne. Most of these vectors are bloodsucking insects fond of heat and humidity. If, say, malaria moves far enough north, rich European countries will have to dish out on vaccinations. That’s good news for the pharmaceuticals sector.

Overall though, under the business-as-usual scenario, climate change would increase the divergence in returns on capital and labour, which in turn would further economic inequality – both within any given country and between countries.

According to the Mercer’s study, if we aren’t able to stay below the 2⁰C target and end up heading towards 4⁰C, the result is likely to be more market volatility, higher inflation, and, in the long term, lower overall returns due to higher production costs. Poorer countries would be impacted earlier and more severely, hence Emerging Markets equities would underperform as an asset class.

The full effects – financial and otherwise – of this scenario would begin to manifest in 50+ years, by which time I’d be in my late 80s. That’s not an ideal point to run out of money in retirement. Going back to work wouldn’t be much of an option then.

So what’s it all mean?

None of the reports I’ve read suggested that in the face of the global warming active portfolio management was set to outperform indexing. The only claim that active fund managers (Schroders and Caz. So, basically, Schroders) made for themselves was that investors who wished to take action on climate change by allocating capital away from carbon intensive industries had to rely on active portfolio management to effect divestment of carbon assets. I think, at least at present, this is true. While we have several S&P Fossil Fuel Free indexes and a few clean energy indices, there’s a lack of low carbon index tracker funds. Given McNabb’s recently publicised views on divestment campaigns, it’s quite unlikely that Vanguard et al will enter this market in foreseeable future.

For us lazy indexers, Mercer’s study gives some comfort that investments like VWRL can withstand the effects of carbon emissions reduction over the next 20 to 30 years if as the world’s governments work towards the 2⁰C target. If, however, it begins to look like we’re set to overshoot the two degrees, a slug of US Treasuries in the portfolio should be a good bet. And, since a larger increase in global temperatures appears to be associated with higher market volatility, the 4% SVR might come under pressure. I personally think something closer to 3% could be more appropriate, whatever the climate outcome.

It appears that, despite our best efforts, we’re going to live in interesting times.


    1. Based on 2013 data.
    2. The Bento Rodrigues dam disaster created an extensive clean-up operation and a huge amount of work for lawyers; cancer generates inexhaustible demand for pharmaceuticals; and crime not only provides employment to thousands of law enforcement, detention and judiciary personnel, but also fuels demand for home and industrial security systems, insurance services, and replacement goods.