12 Feb 2020

The risks we face

Back in November 2019, I blogged about plate tectonics and, in particular, how we live - and die -with the earthquakes, tsunamis and volcanoes that result from us living on an unstable planetary surface. It set me thinking more about the more general risks we face and how we can categorise them.

Plate tectonics covers the below-ground risk. But what about things dropping on our heads from outer space? These could be solid, like meteorites or asteroids, but they could also be unwelcome rays from the Sun or elsewhere. We don't see much evidence of these risks but they do happen and very occasionally they can be very deadly. A single huge collision with another heavenly body 65 billion years ago is believed to have been  responsible for the extinction of the dinosaurs.

The third field of risk is atmospheric. The Earth's surface is surrounded by a relatively thin layer of gases which we depend on for life. As the Earth both rotates and tilts on its access, the resulting winds and weather patterns cause all manner of mayhem at the surface. Think Droughts. Storms and Hurricanes. Monsoons. Flooding. Extreme temperatures. Fog. Snow. Ice. Fires (albeit at one stage removed but remember that oxygen is an essential component of fire).

The atmosphere also dictates which life forms, if any, will occupy the surface. No rain = dessert. Frozen rain = snow = Arctic like conditions and glaciers. Lots of heat and rain = jungles. Lots of rain and coolish temperatures = Manchester.

We interact with our atmosphere in ways we don't with the ground beneath or space above. For instance, we can turn fog into smog by adding burnt carbon to the atmosphere. And we can alter the characteristics of the atmosphere itself by tinkering with its component gases. In particular, with carbon dioxide which, despite being only a trace gas making up just 0.04% of the Earth's atmosphere, is known to act as a thermostat for global temperatures.

A more nuanced example of this was our production of CFCs, a 20th century phenomenon, which then drifted into the upper atmosphere and reacted with ozone. This resulted in large holes in the ozone layer which acted as a dampening layer for incoming solar radiation. This made sunshine a far more dangerous factor for those outdoors and led to increases in skin cancer. The Montreal Protocol, in 1987, was a fine example of nations working together to ban the use of CFCs and to bring about a gradual repair of the ozone layer.

An even more nuanced example would be the current fear about the spread of the cornonavirus from China. The atmosphere carries with it not just the threat of challenging external weather conditions, but also as a carrier of communicable diseases.

So there you have it. We live on a Planet with an unstable surface, subject to bombardment by things from outer space and dependent on a thin zone of gases which behave in a somewhat chaotic manner, and which we have started to use as a waste dump.

Having said that, it's a beautiful morning here in Cambridge and it's good to sometimes feel that Earth is not such a bad place to be posited on for a while.

1 Feb 2020

Carbon-free electricity

The race is on to produce zero carbon electricity, which is the most straightforward way of slowing/stopping climate change. But how realistic is this goal, and how long will it take? Here's a summary of the situation in the UK.

When we say 'zero carbon electricity' we are referring to how electricity is made, not what's in it. Using fossil fuels to make electricity (the traditional method, if you like) burns lots of carbon which releases loads of carbon dioxide (CO2) into the atmosphere. Renewable technologies, hydro power and nuclear power produce electricity without burning any carbon and are therefore said to be zero carbon. The electricity we now use is from a mix of sources and therefore can be said to have a carbon intensity factor, depending on how much is derived from fossil fuels (carbon) and how much from zero carbon sources. The higher the proportion from fossil fuels, the greater the carbon intensity is said to be.

The standard measurement (or metric) used to express the carbon intensity of electricity is grams of CO2 equivalent per kWh (kilowatt hour) of power, written XXXgCO2ee/kWh. The word "equivalent" is in here because other climate changing gases (notably methane) are also released during the production processes and these have to be taken into account when considering the global warming effect of the different gases. It's a complex field and the maths is not quite as straighforward as we might hope for. Methane has a large global warming footprint, but only stays in the atmosphere for a few years, unlike CO2 which hangs around for centuries before slowly being absorbed by the oceans.

When we first started making electricity on a commercial scale, the preferred method of production was to use coal-fired power stations to drive huge turbines. Coal-fired electricity has a very high carbon intensity factor, as it releases masses of CO2: anywhere from 750 to 1,000g/kWh, depending on the type of coal and the efficiency of the plant. Coal also happens to be a dirty, toxic fuel which poisons a lot of people, but that is not what concerns us here. Using gas to make electricity is a much better option than coal (and it's cleaner) but it still produces a lot of CO2 —  it scores between 380 and 480g CO2ee/kWh/kWh.

In contrast, with the notable exception of biomass, all the non-fossil fuel production methods are zero-carbon. That doesn't mean there aren't other issues surrounding their use: nuclear power maybe zero-carbon but it is not zero-problem (Chernobyl, Fukashima etc). But from a carbon intensity point of view, they all score zero. Or 0g CO2ee/kWh. To be pedantic, there are carbon costs with renewables but they are solely to do with the construction or manufacture of the equipment — known as embodied carbon.

The carbon intensity of fuel table can be summarised thus (all in g CO2ee/kWh):
Lignite: 850 - 1100
Coal: 750 - 1000
Oil: 550 - 700
Natural gas: 380 - 480
Biomass: 50 upwards
Nuclear: 0
Wind, solar: 0
Hydroelectric: 0

More details via Google or Wikipedia but a good source is here.

The history of UK electricity production shows the carbon intensity was high, at around 700g CO2ee/kWh in the 1970s when it was almost all produced by coal-fired power stations. As the switch to gas took place over the following decades, the intensity falls to around 450g CO2ee/kWh. Here is a useful summary of the situation up till 2015.  However, since 2015, the rate of change has accelerated dramatically, as you can follow here. The principle reason for this is the switch to offshore wind farms, which have had a massive effect. Maybe because it is happening out at sea, we are only barely aware of this major infrastructural change. Other factors include decreasing demand for electricity overall (which makes it easier to drop coal from the energy sources), an uptake in solar PV and a switch from coal to biomass as the huge Drax power station in Yorkshire which alone accounts for around 8% of the UK electricity demand. Currently UK electricity averages around 230g CO2ee/kWh

What it means is that electricity has gone from being a much higher carbon intensity than gas to becoming much the lowest carbon intensity power source, all in the past five years. And it is due to head lower still over the next 15 years, as we move to decarbonise the grid. Electricity is, however, over three times the price of natural gas, so a switch to electric heating is still unlikely any time soon, especially as the cost of heat pumps, the obvious technology to employ here is way more than a standard gas boiler.

I for one hadn't realised quite how quickly this change would take place and as a result fitted a gas condensing boiler in our new home - a decision made in 2017 - on the basis that we had done everything possible to minimise the heat load and that, as electricity released rather more CO than gas, it made sense to go with the cheaper power source.

The government has recently published the Future Homes Standard which is a mixed bag of proposals outlining measures to decarbonise our housing over the coming decade. It's received a very lukewarm review from almost every commentator, but the headline move contained in the proposals is that ‘new homes should not be connected to the gas grid from 2025’. 

Given the huge change in the mix of energy sources we are using to make electricity, this single proposal will rank as the most significant decarbonising measure we have ever taken.

25 Nov 2019

On the Tragedy of the Commons

The theory known as the Tragedy of the Commons was first postulated by British economist William Forster Lloyd in 1833, but it was popularised by the American philosopher Garrett Hardin in 1968 in an article in Science Magazine. It is now widely used in the field of environmental studies.

So what is it?

Imagine an area of common grazing land. By common, I mean it is owned by everyone, rather than by an individual. Such common areas have been a feature of European culture since mediaeval days. Now, the population at large enjoy grazing rights and are free to let their cattle graze on the grass growing on the common. Furthermore, it’s a good use of the grass because otherwise it would have to be cut by machines and taken off-site for hay storage. 

Over the years, more and more people take advantage of their grazing rights on our imaginary common and the number of cattle put out to graze there grows steadily. Then one summer, there are just too many cattle grazing and all the grass is eaten long before the winter comes. The common land turns to mud and the cattle starve. The land has been overgrazed. What a tragedy we have cooked up here – we've been undone by our own greed! 

Well, technically speaking, this is not a tragedy at all, it’s a balls up, but let’s not get too Shakesperian about this. It’s known as the Tragedy of the Commons and the name has stuck.

So what to do about it? The basic question is to first work out what the sustainable level of cattle grazing is for our common. Say, for argument's sake, it is 25. 25 cattle on the common in the summer and everything stays hunky dory. But put 26 on it and, pretty soon, the grass can't keep up with all those hungry cattle. So a logical approach here would be to limit the grazing rights to 25 cattle. This is where it gets tricky.

Who decides which 25 cattle get to graze the common?  You could do it by drawing lots, but what then would the unlucky losers do with their cattle? Sell them on? Or hold out for a better draw next year? 

Alternatively, you could sell grazing rights to the highest bidders – but then it has stopped being common land. Or maybe you could subdivide the common into 25 plots and sell the land. Then it’s called enclosure and you have really moved way away from the common ground idea. 

By and large, when it comes to land ownership, we have as a planet moved away from common grazing rights towards private ownership as a solution to this conundrum. You could sort of see the history of agriculture as being mostly about enclosing common land. The fence is the enemy of the common. But there are lots of assets (the oceans? the atmosphere?) which can’t be divided up like this and where we have to work out a common destiny in order not to queer the asset. 

It’s not hard to see how this question plays out in a world of many billions of people. It is just possible that our planet can cope very comfortably with, say, 3 billion people living a Western lifestyle enjoying full bellies, good housing, social security, pensions and foreign holidays, but that at 10 billion the grass will stop growing and we will all fall out of bed with a bump. Yes of course it's possible. It is quite likely even. But how would we know where the sustainable boundary is? It is not as though we will find out in the course of one summer's grazing.

We move here into the subject of planetary boundaries which explores just where our limits may lie. The most sophisticated model for this hails from Sweden. Planetary Boundaries: the Stockholm Resilience Centre.  

They suggest there are 9 boundaries of which climate change is but one. But, as with the cattle on the common, it is one thing to identify just how much developmental pressure our planet can take, quite another to decide how to implement best practice. It is horribly compromised by us having divided the world up into a series of nations who jealously guard their own boundaries. Some countries (Russia, Canada) are well equipped to deal with planetary changes and resource depletion. Rather more countries are poor, have high populations and are very vulnerable to shifting climates.

Environmentalists like the metaphor of the Tragedy of the Commons because it sticks it to the neoliberals. It's a great example of market failure and it cannot be sorted out without some form of political intervention. The planetary boundaries are real enough and the technical solutions are understood. But what actually happens is all down to politics. And international co-operation-type politics, something we are very poor at.

19 Nov 2019

On Plate Tectonics

The theory of plate tectonics is much more recent than our understanding of climate change. It was first postulated by Alfred Wegener in 1912, and what he talked about came to be known as continental drift. I can still remember learning about this phenomenon at school in the 1960s. Around that time other researchers took Wegener's hypothesis and ran with it so that soon theories started appearing about just how vast Continents could actually move around on top of the Earth’s crust.

Plate Tectonics postulates that there are nine major plates and many little ones and that they are essentially floating around, bumping into each other, and over many millions of years, they are shifting quite long distances around the planet's surface. For instance, the largest plate, made up pretty much of the Pacific Ocean, is currently moving northwards at a rate of 7cm/annum. It seems incredible, but it has quickly become accepted as a scientific fact. In comparison, the basics of climate change theory was established in the 19th century and is in many ways far more readily understandable as it's all down to demonstrable physics.

Why are there no plate tectonic deniers? Good question, but the answer is very easy to spot. We have no part in its processes — other than suffering the consequences when the colliding plates periodically erupt. 

And what consequences do we suffer. This century has already witnessed two terrifying tsunamis: the 2004 Indonesia event killed 230,000 and the 2011 Japan tsunami killed 20,000, not to mention devastating Fukishima nuclear reactor. Besides these, we have also suffered 13 earthquakes with death tolls above 1,000– the worst ones being Haiti 2010 (300,000), China 2008 (87,000) and Pakistan 2005 (87,000). All since the year 2000: about a million deaths, all through people happening to be in the wrong place at the wrong time.

In contrast, the most severe storms rarely result in huge death tolls. Typically a really awful hurricane or typhoon may cause deaths in the low thousands, but nothing compared to the devastation caused by earthquakes. Unlike earthquakes and tsunamis, people know about storms before they arrive and take defensive action. Similarly with wildfires. They may look horrific, but most people are able to evade the flames. When there are death tolls, they are measured in the tens, not the tens of thousands.

Even if the number of typhoons and hurricanes and wildfires were to double in frequency and intensity over the coming decades, which most climate scientists predict, the resulting death tolls are unlikely to come close to the damage caused by our tectonic plates shifting. Other effects of climate change are more subtle and long lasting, mostly to do with weather patterns changing and people being forced to move to different regions because of droughts and desertification, but events like this rarely get into the headlines.

It is also worth bearing in mind that the death tolls from extreme events, whether climate-related or not, are as much a feature of the ability and wealth of the local population. The reason 300,000 people died in Haiti in 2010 was not because their earthquake was so much worse than others (it was a 7.0 event on the Richter scale, high but by no means exceptional), but because Haiti is so poor that the population weren't able to protect themselves either from the quake or the devastation left behind afterwards. 

That poor countries get knocked sideways by events which wealthy countries take in their stride is a truism that keeps cropping up. It is frequently used as an argument for re-distribution of wealth from rich countries to poor ones. This may be equitable and even desirable, but the way the political winds are blowing, it seems unlikely to happen any time soon.

This is the main reason that the climate change "debate" is so terribly charged. Whereas what plate tectonics throws at us is not in our control, climate change has our fingerprints all over it and so we have to take responsibility for the consequences. Let's rephrase that. We ought to take responsibility for it. To date, all we've really done it talk about it a lot and make a few tentative steps towards reducing our CO2 footprint.

Arguably, the two phenomena are not really quite so different. Whereas we cannot be held responsible for earthquakes and tsunamis, these events can be mitigated against through pre-planning and good building codes. And these are things you get right when there is wealth and good politics.

As an endnote, it is worth considering that globally over 1million people die each year in road accidents, and most of them are young and physically fit. If things carry on this way, that will be over 100 million deaths this century, a figure which far outweighs the likely death toll from plate tectonics. In all probability is also likely to be far higher than deaths arising from the effects of climate change. Road accident deaths are very much in our control. We could restrict car speeds to 20mph which would reduce road deaths by 90%, but we choose not to because we value speed so highly. Is there a parallel here with CO2 emissions? 

30 Jun 2019

Is the Eden Project a vision of our future?

In early June, I went to visit the Eden Project in Cornwall. It's been open since 2001, so you might wonder just why its taken me so long to get there, as I have been in Cornwall many times over these years. But it seems to me the Eden Project was built as a rainy-day visitor attraction and maybe I had been lucky with the weather up till now. But a wet June day finally saw me cross the threshold, buying tickets for our party of four at an eye watering price, and following the many other rain dodgers down into the gigantic tropical biodome which is its centre piece.

It's bloody hot and humid in there and after about an hour wandering around I was feeling quite exhausted. But also amazed by the sheer scale of the structure. I've been in hot humid glasshouses before — we have several in the Botanical Gardens in Cambridge — but the Eden Project biodome is the size of a large airport terminal. Our party was pleased to get out of it into the relative coolth of the adjacent Mediterranean dome, and even more pleased to get out into the open air half an hour later.

On the way home I started musing about whether the Eden Project has anything to teach us about the impending climate crisis. If we fail to keep the average temperature rise down to manageable levels, we will render much of the Earth's surface uninhabitable. Well much of it already is, let's be frank. But parts which are now readily inhabitable will become too unpleasant to forge a life in. But spaces like the Eden Project, provided they can get good supplies of energy, will continue to function even at very much higher temperatures, because we can create an indoor climate which will be very comfortable for human beings, and indeed, animals and plants.

In a sense these changes are already happening. We are tending to move into cities which are certainly non-natural environments. We already have homes which are already heated and cooled spaces, insulated form the outside environment, and we mostly travel in cars, buses and trains which have controlled environments. Cross what we already are doing with Eden Project type biodomes and you have a viable future landscape. It's a bit like what would happen if we were to colonise another planet where the air wasn't capable of supporting us. There we would have to build an artificial atmosphere around us, as indeed many science fiction writers have postulated. It's as if we were bringing our plans for the colonisation of Mars back down to Earth to tide us through this climate emergency.

The downside to this is that it is unlikely to support the 7 to 10 billion people reckoned to be living on earth by mid-century,  not to mention their feedstock animals and plants. These biomes would probably be constructed in places which would be relatively immune to the tempestuous weather we may experience, and on high ground to avoid rising sea levels. Probably away from earthquake and hurricane zones as well, so as to maximise their chances of long term stability.

The wild, untamed outside areas would probably consist of 99% of the Earth's land cover and we would be free to explore these areas, weather and climate permitting. But live there? Not really possible anymore. There might be vast areas used to collect solar and wind energy needed to keep us humans comfortable in our biodomes, or maybe we would have all gone nuclear by then, because no one will be too worried if there is a radiation spill as there will be no one living within 100 miles.

How many people would this sort of future support? I guess that depends on how many of these biodomes we managed to build. But say each biodome was around 10km2, a 3.5km diameter circle. A luxurious one might support as many as 100,000 people (having 10m2 each). That's just about feasible to comprehend. It would be like putting a roof over an entire town.

Of course you would immediately be cast into a world where there would be upmarket biodomes (maybe 25m2 each) and low rent ones (less than 10m2 each). And then there would be those who couldn't afford to live in a biodome and maybe they'd be left to fend for themselves in the wild parts of the planet. Or maybe not....

It would be very expensive to build biodomes of this scale, but what exactly would be the alternative?  The most obvious answer is to mitigate - to reduce our dependence on fossil fuels, and keep the whole planet's atmosphere in defined limits so that it is one big functioning biodome. But despite so many people's best wishes, at the moment this seems unlikely, as the political will required to do this is sorely lacking. Another option is to start tinkering with the planet's atmosphere and try and keep it within comfortable bounds. But at the moment, this also seems an unlikely prospect.

Life on Earth will continue, whatever we do to the climate. But just how much life, and under what conditions, is still a very open question.

18 Jun 2019

Housebuilders Bible 13

The text and images are ready to go on the next edition of my Housebuilder's Bible. Final proofing stage has been reached and the book is set to be printed in July for an August launch. This will be the 13th edition. The first edition one came out in December 1994, so the "project" (for that is what it is) is now in its 25th year. The book has sold just over 175,000 copies in that time which works out at a sale every 75 minutes.

I know it's been helpful to many because I've had a lot of feedback over the years, but it's position has changed because selfbuild, as an activity, has become far better known and there is so much more knowledge out there now. Not to mention the coming of the internet, which barely existed in 1994.

Still, the internet can be a lonely place, and there are many questions that it doesn't answer terribly well. Sales patter....it's full of it. Opinions....everywhere. But a simple question, like how best to build a house, really isn't addressed at all. I hope Edition 13 can shed some light on this. Whereas in 1994, my aim was simply to be a conduit for lots of useful information, today it's become a little more nuanced. Now it's more about trying to make sense of an overload of information out there.