How renewable are renewables really?

Renewables are on the rise. The International Energy Agency (IEA) forecasts global capacity of wind, solar and hydropower will grow 43% in the next five years. Such technologies are called renewable since their source of energy (e.g. sun, wind or flowing water) naturally replenish themselves. This can be contrasted with fossil-fuel generation, whose fuels (e.g. coal or gas) can be depleted and take millions of years to regenerate.

The classification into renewable and non-renewable refers only to the process of electricity generation. Over their whole lifecycle, renewable technologies use resources that can both be depleted and lead to greenhouse gas emissions in their extraction process. Furthermore, they need a lot of them: per unit of electricity, wind turbines require 6-14 times more iron and 11-40 times more copper than fossil fuels. Meeting one quarter of global electricity demand from wind by 2050 would require an additional 1 million onshore and 100,000 offshore wind turbines, and the IEA estimates that decreasing energy related greenhouse gas emissions by 50% doubles the material requirements per unit of electricity. Obtaining the additional materials required may negatively impact the environment in their extraction and in their processing.

Furthermore, renewable energy production requires materials that may be scarce, toxic, or required for domestic electronic devices. An important example is the lithium and cobalt required for lithium ion batteries. The demand for these is expected to grow exponentially because of their use in portable electronics, electric cars and storing renewable electricity (see a previous article on this topic). Both metals are available only in a small number of countries, with cobalt a particular concern; more than half of world supply comes from DR Congo, a country infamous for its political instability and plagued by civil war. The combination of high demand and supply uncertainty has even lead to deep-sea mining pilots, worrying many environmentalists. Clearly, the environmental impacts of a massive renewable transition should be considered carefully — we must be careful that one source of environmental damage (greenhouse gases emissions) is not substituted for another.

Figure 1: Lifecycle greenhouse gas emissions per unit of electricity generated for different renewable and non-renewable energy sources. Source: IPCC, 2011 Special Report on Renewable Energy Sources and Climate Change Mitigation (Chapter 9).

In this backdrop, shrinking renewable technologies’ material requirements is a key priority. Many approaches fall under the age-old mantra Reduce, Reuse, Recycle. One strategy is to design new technologies that require fewer scarce resources. The lithium ion battery is itself an improvement on its lead acid predecessor, and the race to build a new battery, free of lithium and cobalt, is in full swing. Another is to increase the effective lifecycle of existing technologies. As everyone with an old mobile phone recognises, battery performance declines over time, and this is usually the first reason to discard an otherwise working model. The same applies to wind power: the harsh conditions experienced by turbine blades, including lightning strikes, storms and ice, decreases the efficiency of wind turbines 60% in their first 15 years of operation. Replacing blades periodically or making them more resilient lowers material requirements, but comes with considerable technical challenges.

A third option is to recycle materials. The first generation of large-scale renewable projects built in the 1990s are reaching the end of their lifetimes, meaning millions of tonnes of old wind farm and solar panel materials will be decommissioned. Estimates suggest that by 2030, there will be 300,000 tonnes of waste from old wind turbines annually in Europe alone, and most of these parts are made from costly unreformable plastic that cannot be melted down or given a second life. Reusing components both reduces demand for mining and prevents costly materials ending up in landfill sites. Examples include a planned recycling centre in Texas where old wind turbines are cut up and given a second life in composite panels and a French chemical firm building blades from reformable plastic. In the EU, research funding and targeted landfill bans have lead to pilot projects into the recycling of solar panels and batteries. Some of these batteries have even been given second lives in grid-scale storage. However, recent attempts have been slow to get off the ground, and for many of these technologies, mining new materials remains cheaper than recycling. Furthermore, recycled materials typically cannot be reused in renewable technologies again and must be sold to other sectors.

Many of the issues outlined above relate to the fact that these technologies are still in their infancy. Fossil fuel technologies have been the dominant energy source for more than a century, and trillions of dollars have been invested to maximise their efficiencies. If and when such sums start being spent on renewables, technologies are expected to improve significantly. These improvements have already sent the price of renewables plummeting, and they may make the renewable resource question disappear altogether in the future.

Furthermore, despite the hefty material requirements, a study by the Norwegian University of Science and Technology estimates that the planet has enough resources to support the large-scale transition to renewables, and it’s not the case that fossil fuels don’t use any materials for their infrastructure — imagine, for example, the amount of metal and energy required to build on oil rig. In terms of lifecycle greenhouse gas emissions, renewables are a clear improvement on non-renewables (see Figure 1). However, having enough resources for the foreseeable future does not mean this will be the case forever.

Becoming a truly renewable society requires not just the adoption of renewable technologies, but also their improvement. Otherwise, it may be that in solving one sustainability issue, we are creating another.

Adriaan Hilbers – PhD student researching Mathematics of Power Systems at Imperial College London

Mariana Clare – PhD student researching numerical fluid and sediment transport models at Imperial College London

What’s the Deal with Nuclear?

Some people think nuclear is the best solution for climate change, and others want it gone tomorrow. What’s the deal? Source: Burghard

As the world strives to reduce its carbon emissions, massive efforts are being undertaken to decarbonise electricity. In most developed countries, fossil fuels like coal are on the way out, being gradually (albeit slowly) replaced by renewables such as solar and wind. However, keeping the lights on while generating most power from weather-dependent renewables comes with significant challenges (see a previous article that discusses this in more detail). The key difficulty arises because electricity supply and demand must always match perfectly. Traditionally, this involved adjusting power plant output to meet demand, including rapid spikes or dips. In fact, grid operators tune in  to popular TV shows to ensure supply is increased exactly as thousands of people turn on their kettle at the end of an episode.

A famous graph showing total UK electricity demand during the 1990 World Cup Semi-Final against Germany, with spikes at times when watchers massively turned on their kettles. Source: National Grid

Weather-dependent renewables make this balancing act more difficult since generation levels are controlled by e.g. the wind or sun and cannot be adjusted as required. In fact, the supply-demand balance requirement means that, in countries without the possibility of hydropower (requiring mountainous and rainy terrain) or geothermal power, it is virtually impossible to go 100% renewable without drastically increasing electricity prices. This is sometimes referred to as the energy trilemma: in most regions, only two of supply security, affordable energy and environmental sustainability can be satisfied. Two of the most promising solutions, grid-scale storage (storing excess renewable production at times of high supply and using it when supply is low) and carbon capture-and-storage (storing carbon emissions before releasing them into the atmosphere), are unproven and not yet economically viable. For this reason, most countries still generate most of their electricity from fossil fuels — it’s too difficult or expensive to match supply and demand any other way.

In this backdrop, nuclear power seems perfect: fully controllable output levels without any greenhouse gas emissions. It’s also a proven technology, generating electricity from the United States to Pakistan. Nonetheless, the future of nuclear power is a contentious issue. From this author’s personal experience, the UK energy community seems to be in a perfect dichotomy between those who think nuclear power should be the strategy to mitigate climate change (at least in the short term) and those who think all reactors should close tomorrow. Why all the disagreement? This article hopes to give a balanced account of the advantages and disadvantages of nuclear power, and the controversy surrounding it.

Firstly, there are ethical arguments. Current nuclear technology produces poisonous nuclear waste that must be stored safely for thousands of years. Nuclear detractors question the morality of leaving behind toxic material for future generations to take care of, while nuclear supporters opine that the social costs of unmitigated carbon emissions are much higher.

Secondly, there are political factors. For a number of reasons, decisions regarding atomic energy are typically made at government level. The first is scale; nuclear power plants are so expensive that energy companies are unable or unwilling to take the risk building them. They are usually built either by governments themselves or involving some government financial support. And even when market players do build new plants, the extensive planning permissions mean that, in the end, it is usually the government who decides. For this reason, decisions regarding nuclear power are susceptible to the whims of political sentiment, and this explains many of the trends in the sector.

Politicians (especially in democracies) are concerned with public opinion, and the general perception of nuclear power is a complicated topic. It’s reputation has been tarnished by a number of high-profile disasters, most notably Chernobyl (former USSR, currently Ukraine) and Fukushima (Japan). Both contaminated the surroundings, left areas uninhabitable for decades and required hefty cleanup costs. The United States had its own accident at 3 Mile Island, of comparably smaller impact but nonetheless negatively affecting the perception of the safety of nuclear power.

Nuclear power: contentious around the world. Source: capotian

Nuclear proponents sometimes argue that the technology’s nature gives it an intrinsic disadvantage in public opinion. Disasters can be of almost biblical scale, and images of atomic explosions or radioactive ghost towns appeal to human emotion more than e.g. a gradual rise in temperature or the lives lost each year in coal mine accidents. Furthermore, public perception of nuclear energy is often based on emotive imagery as much as reasoned analysis. One US study indicates that support is higher among those either better informed about it or living in close proximity to a nuclear power plant, and that the majority of opposers can be convinced of its merit just by telling them that it is the “only electricity source that provides both clean air and 24-7 electricity”.

When nuclear power goes wrong, it really goes wrong, as the ghost town of Pripyat (near Chernobyl) shows. Source: Amort1939

The effect of public sentiment can be seen in Germany’s 2011 decision to phase out nuclear power, taken in the wake of the Fukushima disaster. While widely supported politically, energy scientists point out that it delayed Germany’s energy transition multiple years by requiring coal plants (with the highest carbon emission of all major generation technologies) to stay open. For this reason, despite a slightly higher renewable electricity production, Germany’s carbon emissions per unit electricity are around twice as high as the UK, where coal power has almost totally disappeared.

Despite all this, nuclear’s high cost is broadly considered the main driver behind its decreasing role in world energy supply. For the Hinkley Point project, aiming to build the first new UK plant in decades, the government has agreed to purchase electricity at around twice the current average price. This has been described as “ridiculously expensive”, especially in the face of plummeting renewables costs. Supporters argue that the ability to generate when needed (as opposed to only at sunny or windy times) justifies the higher price, but the fact remains that nuclear power cannot compete on a pure cost basis . Furthermore, its economics worsen in combination with renewables. Nuclear power plants are expensive to build, but cheap to run, so should be run as often as possible. Since renewable-heavy grids only need backup power at times of low renewable output, it becomes more difficult for nuclear plants to “earn back” their considerable construction expense with low generation costs.

Nuclear power — on the way out? Even while global electricity demand has grown, nuclear production has stalled since around 2000. Source: World Nuclear Association

A fantastic website, electricitymap.org, shows real-time greenhouse gas emissions from electricity generation in many parts of the world. The data displayed serves as a good indication of the present reality. There are essentially two ways to generate power without emitting greenhouse gases. The first is hydropower, which countries like Norway use for almost all their electricity needs. The second is nuclear. Indeed, the only country with a population over 10 million people consistently emitting less than 100g CO2 per KWh of electricity without major hydropower is France, which generates between 60% and 80% of its power from atomic fission. For many countries, going nuclear is the only way to decarbonise electricity.

The greener the country, the lower the carbon emissions per kWh of electricity. Only three countries in Europe are really green: Norway (majority hydropower), France (majority nuclear power) and Sweden (combination of  hydropower and nuclear power). Source: electricitymap.org

However, something currently being true does not mean it will be forever. Much of the difficulty in nuclear decisions relates to uncertainty about the future. With Hinkley Point, the UK government agreed to pay, for multiple decades, a price that may seem unjustifiably high. Nobody knows what will happen in those decades. If breakthroughs in grid-scale storage or carbon capture-and-storage allow rapid decarbonisation of electricity, then Hinkley Point will probably be viewed as a mistake. If not, its construction may prove essential to meet climate goals. Some of the uncertainty comes from uncertain future developments of nuclear technology itself. One example is the development of small modular reactors (SMRs), essentially mini-reactors, that are easier for private companies to finance and build. Another is to (finally) harness the power of nuclear fusion, which produces almost no nuclear waste but has been “ten years away” since the 50s. The commercialisation of either of these may yet provide a nuclear resurgence.

All in all, a Grantham Institute briefing on UK nuclear power perhaps summarises the future of the technology most aptly:

“Nuclear power will be essential for meeting the UK’s greenhouse gas emissions reduction target, unless we can adapt to depend largely on variable wind and solar, or there is a breakthrough in the commercialisation of carbon capture-and-storage. […] We may regret building nuclear power stations if the cost of renewables continues to fall and we find solutions to the problem of the variability of these generation sources. On the other hand, if progress in reducing the costs of energy storage is insufficient, we may not be able to achieve climate targets without new nuclear generation capacity.”

The somewhat unsatisfying answer is that decisions made about nuclear power now can’t be evaluated for years. One the one hand, massive investments now will look foolish if technological breakthroughs allow power systems to decarbonise by other means or if a major nuclear disaster occurs. On the other hand, not investing will be a mistake if it turns out carbon emissions can’t be reduced without it, and the effects of climate change really start to hurt. Simply waiting is not an option: nuclear power plants take more than 10 years to build, so decisions must be made now to ensure carbon emission reduction targets are not missed. For the future climate, electricity bills, and the challenge of keeping the lights on, the next few years will be telling.

What are air masses?

One of the most admirable (or most irritating) aspects of children can be their thirst for understanding. This often manifests itself through a seemingly never-ending chain of questions beginning with “why…”?

Trying to explain the weather on a particular day can feel a bit like this. Every answer leads to another question, which can turn the process into a fruitless task! However, inspired by the name of this blog, this is the quest that we would now like to set upon.

This post is meant to launch a series of blog entries, with the eventual goal of untangling the causes of weather on a particular day. For the moment, we’ll just focus on the weather over London.

However, in order to reach our goal, we need to first provide answers for several of the most common `why` questions. We’ll then be able to refer to these when trying to justify the weather each day!

The first concept in this series concerns air masses. This is possibly the most important aspect in determining what the weather is like.

What is an air mass? Simply, it is a large body of air – thousands of kilometres in extent. The crucial point for the weather in the United Kingdom is that there are different types of air mass that can move over the country.

Typically these air masses can be categorised by the direction from which they’ve come. Each of these types of air mass will have different characteristics, and are related to different types of weather.

The UK Met Office website lists six types of air mass that affect the UK. These are labelled by the direction from which they come and whether it was from land (continental) or sea (maritime).

Each of these air masses has characteristic temperatures and humidities – i.e the amount of moisture they contain (for instance maritime masses bring more water with them). They also tend to occur at different times of the year. 2018 has been a year of extreme weather in the UK: the cold and snowy February was associated with polar continental and arctic maritime air masses, while the very hot summer featured tropical continental air.

Air MassDirectionAssociated Weather
Arctic MaritimeComes from the north, from the Arctic.Cold, snowy weather in winter, particularly to Scotland.
Polar MaritimeComes from the north-west, from Greenland and the Arctic sea.Generally brings frequent showers. In winter these are often over the western and northern sides of the British Isles, but in summer the showers are heaviest of the east. This is the most common air mass to affect the British Isles.
Returning Polar MaritimeOriginates over Greenland and Arctic sea, but comes from the west via the Atlantic ocean.This air has travelled further over the Atlantic ocean than Polar Maritime. It is usually dry but can bring a lot of clouds.
Tropical MaritimeFrom the south-west, from over the Atlantic sea.Warm but moist air, bringing low cloud.
Tropical ContinentalFrom the south-east, with air originating over North Africa.Hot dry air. Most common in summer.
Polar ContinentalFrom the east or north-east, with air originating over central or north-eastern Europe.The air is very cold but dry. Can bring clear skies and severe frosts, or if it travelled over the North Sea brings rain or snow showers.

You can read more about these air masses on the Met Office website:

https://www.metoffice.gov.uk/learning/atmosphere/air-masses/types

Why Renewables Are Difficult

Renewable energy represents one of the most promising solutions to climate change since it emits no greenhouse gases. However, it poses some difficulties for power systems. Source: U. Leone

The issues of climate change and sustainability seem to be everywhere throughout politics, media and public sentiment, and represent a significant challenge for current and future generations. Making our lifestyles sustainable will require, among other things, drastic reductions in worldwide greenhouse gas emissions. One of the biggest sources of such emissions is the generation of electricity, and this proportion is expected to increase as electric cars, heating and the internet-of-things takes off. “Greening up” power supply is essential. The good news is that it is possible to generate electricity without any emissions whatsoever through renewables. Examples include wind turbines and solar panels, which are called renewable since their source of energy (wind and sun respectively) do not run out. This can be contrasted with fossil-fuel generation, which uses finite fuels such as coal, oil or gas, and emits greenhouse gases.

Renewable technologies have been around for years, and public awareness of the need to reduce greenhouse gas emissions since around the 80’s. However, most countries still generate the vast majority of their electricity from non-renewables that emit carbon or damage the environment in other ways (e.g. nuclear waste). Why, after decades of both the problem and a solution being known, haven’t renewables taken off yet? This article hopes to give the reader a sense of why renewables are “difficult”, and how the world can keep the lights on into the future in a cheap, secure, and sustainable way.

Until recently, the primary reason for the slow uptake of renewables was economical. It was impossible to build wind turbines and solar panels cheaply enough to compete with fossil fuel technologies, which had become highly cost effective after more than 100 years of use. While there was some effort, governments were not willing to spend billions on subsidising renewables when electricity could be generated cheaply in other ways. Mark Rutte, the Dutch prime minister, frequently claimed in debates between 2010 and 2014 that “windmills are only powered by subsidy” (link in Dutch). However, as time passed, improved manufacturing methods, economies of scale and increased competition has sent prices plummeting. The price of solar panels has decreased by a factor over 100 in the last 40 years, and generation through many renewables is now cheaper than fossil fuels.

So, is it just a matter of time before fossil fuel electricity disappears? Why are societies still so hesitant to go 100% renewable? To understand why, a quick introduction to power systems (meaning the industries, infrastructures and markets based around electricity) must be given.

At their core, power systems are simply supply & demand problems. Industries and consumers use electricity that is provided by generators. One key feature distinguishes power systems from other economic markets: there is virtually no means of storing it at large scale (with the notable exception of hydropower, discussed below). This implies that supply & demand must be continuously matched exactly, and makes managing the grid both complicated and essential. Usually, some independent party, called a system operator, is issued this task.

(As an aside, in the UK, there is a fantastic website, called Drax Electric Insights, in which the total UK electricity demand, and exactly from which sources it is being generated, can be browsed through in real time as well as historically. Looking through it for a few minutes will give a better feel for how power systems work than any blog post can).

A still from Drax Electric Insights, where electricity demand and generation levels can be browsed through, both in real time and historically. Source: Drax Electric Insights

Before renewables, most electricity was generated by fossil fuel plants. Fuel (e.g. coal or gas) could be burnt at different rates, and level of electricity supply was directly adjusted to meet demand. One caveat to this is that output levels in some types of plants cannot be adjusted arbitrarily quickly. To combat this, planners use baseload generation to generate most electricity, and peaking plants, whose output could be varied rapidly, to meet short-term fluctuations in demand. For example, the UK’s system operator had to deal with a massive demand spike just after the royal wedding, as millions turned on their kettles at the same time. Throughout the rest of the article, the term conventional generation will refer to generation through fossil fuels for which the output levels can be directly controlled.

A famous graph showing total UK electricity demand during the 1990 World Cup semi-final against Germany, with spikes at times that viewers turned on their kettles en masse. System operators had to rapidly adjust supply to ensure the lights stayed on. Source: National Grid

With renewables, the single biggest difficulty is that their production levels typically can’t be controlled. It’s not always windy or sunny, and times of high renewable output do not always align with times of high demand. How does one ensure the lights stay on on a cloudy day or when the wind tails off?

In most countries, this is not yet a problem since renewable capacity is small and their output never exceeds demand. Renewables produce whatever electricity they can, and the rest is picked up by conventional generation. Two complications warrant mentioning.

Firstly, the flexibility required from the grid increases. As well as just demand fluctuations, systems must also be able to deal with renewable output variability. To prevent blackouts, conventional generation (fossil-fuel power plants whose output can be controlled directly) must be able to ramp up quickly enough to meet a simultaneous demand spike and rapid drop in wind levels. In the Netherlands, in May 2018, the domestic grid was unable to respond quickly enough to an unexpected drop in wind-speeds and associated wind power, and required emergency imports from Belgium at high cost (link in Dutch).

Secondly, the advent of renewables changes the economics of power markets. Power plant owners tend to have a standard business model: build an expensive power plant and pay off the investment cost using the proceeds from the sale of electricity. For this to work, electricity prices need to be high for a large proportion of the time. When renewables are added to the grid, this changes: at times of high wind or sun, they produce electricity virtually free, pricing out conventional generation. This means that investing in a conventional power plant, or keeping an old one open, may no longer be economical. However, if this happens, when renewable output is low, there is no conventional generation left to provide power! To counteract this effect, many countries, including the UK, host capacity auctions, in which they subsidise producers to meet demand when necessary. In this way, while renewables displace conventional generation, they tend not to allow for the permanent closure of conventional plants. Note that this economic reality applies to renewables too: the more wind is added to the grid, the more it pushes electricity prices down at windy times, thus eating into its own profits.

(Two additional complications, which will not be discussed at length here, are the issues of transporting electricity from windy areas to demand centres, and frequency stability through inertia. In Germany and Ireland, these issues have already led to multiple occurrences of wind curtailment, in which wind farm owners are paid to turn off their turbines).

The issues of both flexibility and supply security will intensify as more renewables are added to the grid. Thankfully, there are a few ways that society can both use renewables and keep the lights on in the future. They fall broadly into two categories.

The first is electricity storage. With grid-scale storage, excess electricity production on windy or sunny days can be stored and used in times when renewable output is low. Besides adding to supply security, this would enhance the economic picture for renewables since storage owners buy up electricity when price is low and sell it when price is high, evening out price jumps. At present, the reason storage plays only a small role is economical. Battery prices still have to drop significantly before they can be used at large scale.

The second possible solution is by interconnecting different countries better and allowing them to share electricity. When it is wind-free in London, the chance is high it is in Scotland as well. However, it may be windy in Germany or Spain. Transporting electricity around could help alleviate supply insecurity. The UK currently has interconnections with France, the Netherlands, and Ireland, and more are in the pipeline. This may eventually become what has been termed the European Supergrid, where electricity can be transported across Europe to balance out regional renewable supply peaks and troughs.

There is one important exception to storage being uneconomical: hydropower. It has been around since the early 1900’s, and typically involves a high dam being built in a river, creating an artificial lake and an elevation difference on either side of the dam. Water is allowed to flow down the dam, powering a turbine to generate electricity in the the process. The generation levels can be controlled by adjusting the flow level, and there is a natural storage function: when demand is low, water is allowed to accumulate in the lake. In this way, the lake is “charged” by nature when it rains and water from the mountains flows into it.

Hydropower provides an economical option to store electricity, but requires mountainous terrain. Source: skeeze

Hydropower is a great form of electricity since its output can be controlled and has no associated greenhouse gas emissions. Norway, for example, generates virtually all its electricity from such dams and exports power to other countries when their demand is low. A difficulty is that hydropower requires mountainous and rainy terrain, which not all countries have.

(Since hydropower is so convenient, some developed countries are attempting to engineer their own forms of hydropower even without the above-mentioned terrain. In the UK, a notable example is tidal power, in which an artificial lagoon is constructed that water can enter and exit through turbines, generating power. At present, there are fierce discussions about the economics of such a project.)

The prospect of combining hydropower and interconnections between countries is tempting, since it means countries with lots of wind but little storage capacity, like Germany or Denmark, could “use Norway as a battery” by exporting their excess wind power to Norway in windy periods, who allow their dams to accumulate water. In calm spells, the hydropower generation levels could be increased and excess electricity exported back the other way. Making this work will require significant increases in Norwegian hydropower infrastructure, interconnection lines and international cooperation.

The batteries in electric cars can be used for grid management provided that owners agree to this. Source: Marilyn Murphy

Another creative solution to the storage problem is to use the big and expensive batteries in electric cars. Electric car uptake will lead to demand spikes when people return from work and plug them in to charge. An electric car owner could get the option of cheaper electricity if it means her car’s battery is not charged, or even emptied, during demand spikes and recharged when demand is lower. This presents interesting dilemmas: suppose you arrive home from work at 6pm and will leave again the next morning at 8am. Would you accept a cheaper charging price, if it meant your car might not be charged if you had to leave unexpectedly at 8pm?

Current power systems are not yet ready to use renewables for the majority of their electricity supply. However, the immediacy of the climate change danger means business-as-usual is not an option, and a total energy revolution is required, including in the electricity sector. Presently, the most realistic short- and medium-term solution is the use of renewables. This article hopes to give the reader a sense of the problem, why renewables are “difficult” and some the possible solutions. It is an exciting time to be in energy, and nobody knows how the power system of the future will look. But everyone agrees it will be very different.

FAQ: Why do HFCs and CFCs contribute more to warming?

This question came from a young relative of mine doing a school project on climate change and it’s a really interesting one, bringing in a lot of important concepts about the climate that aren’t explained as much as they should be. Here we go!

Ultimately, it’s the sun that warms the planet. Well, okay, there’s some heat coming from the core, but the crust’s rock layer does quite a good job insulating so we can pretty much neglect it. I think we can agree that the sun is the hot thing – much much hotter than the ground.

As the sun heats up Earth, Earth needs to be being cooled down in some other way, otherwise it’d just get indefinitely warmer. There’s enough heat coming in from the sun that if we didn’t lose any, the surface of the planet would get considerably hotter every day!

We lose it through “earth-shine” or outgoing long-wave radiation, in the proper lingo. In the same way that the sun gives off light and heat we can feel when we go outside, the earth is giving off its own electromagnetic waves, just at a wavelength we can’t see. Wavelength is like colour: red, blue and yellow light are all different colours, but so are x-rays and radiowaves and what wifi and cell phone signals are transmitted through.

https://marine.rutgers.edu/cool/education/class/josh/em_spec.html

But since the sun-shine and earth-shine are at different wavelengths, they’re blocked by different things. Glass isn’t see-through to all light and nor is the atmosphere. Let’s take a close look at the diagram below:

http://cybele.bu.edu/courses/gg312fall01/chap01/figures/

The wavelength is measured in micrometers, which are million times smaller than a meter. The middle of the sun’s shine (“black-body”) curve is in visible radiation, very little of which is absorbed by the atmosphere (see the same region on the lower plot). For the earth-shine, it’s not so lucky. About 80% of the outgoing earth-shine doesn’t make it out – it gets trapped and re-emitted by the molecules in the atmosphere.

Those molecules work to block radiation because of their specific shape and how well they resonate (match) with the light at each wavelength. Water is really really good at it absorbing radiation at loads of wavelengths, but CH4 (methane) and CO2 (carbon dioxide) do a reasonable job too. They all block the outgoing radiation and make the surface of the earth heat up, like the glass in a greenhouse lets sunlight in but keeps heat from going out. That’s why we call them greenhouse gases.

Water has a special place because there’s so much of it coming in and out of the atmosphere in clouds and rain. We think of it as a response rather than a cause because you can’t inject it into the atmosphere and have it stay. The same is absolutely not true for carbon dioxide, methane and HFCs (hydro-flouro-carbons) and CFCs (chloro-flouro-carbons). They get added to the atmosphere by some natural processes and, unfortunately, by humans who have use them for fire extinguishers and refrigerants, and once they’re there, they stick around, blocking the earth-shine and changing the natural balance.

The question of how bad a particular greenhouse gas is is a difficult one. The first is whether it’s doing a job nothing else can do. The atmosphere has a lot of carbon dioxide and water in it, so adding a little more doesn’t make as much difference as adding something which absorbs in the gaps. If you look at the diagram below, you can see that CFCs (and the same is true for HFCs) absorb in the ‘atmospheric window’.

https://www.sciencedirect.com/science/article/pii/S0007091217334049

This means that every molecule added absorbs some radiation that would otherwise have gone through. Methane is powerful like that too. For CO2, a molecule added doesn’t have so much power – there’s already a lot of them so that each additional molecule doesn’t go so far. This is measured in the radiative efficiency.

The other thing that makes a molecule strong is how long it sticks around for (the lifetime). Methane turns into CO2 after a little while (10 years) in the atmosphere thanks to the active chemistry (driven in part by the sunshine) that goes on up there. Some CFCs and HFCs stick around much longer – check out the IPCC table here.

Now, suppose you put different things in the atmosphere and wanted to know how bad they are. You’ve got to combine two things: one is how much of a difference they make themselves (that is, how good they are at blocking earth-shine and whether anything else would have been blocking it anyway) and the other is how long it sticks about. That’s why we think about global warming potential.

From the EPA glossary

Global warming potential (GWP): A measure of how much heat a substance can trap in the atmosphere. GWP can be used to compare the effects of different greenhouse gases. For example, methane has a GWP of 21, which means over a period of 100 years, 1 pound of methane will trap 21 times more heat than 1 pound of carbon dioxide (which has a GWP of 1).

It adds up how much damage each gas does times how much of it is around over the course of 100 years. Take those together and you get a table like the one here. CFCs and HFCs come out pretty badly, with a GWP in the thousands!

But there is good news: we don’t make as much of them as some of the less nasty things, especially since the Montreal Protocol which came in in 1989. That’s one big success for global political agreements to curb climate change!

 

A puzzle: 100 year timeline over which to calculate global warming potential doesn’t do such a good job of taking into account your great-grandchildren! Over the molecule’s lifetime, something long-lived (like CO2) might do a lot more harm than something short-lived (like methane). So what should we prioritise?  Comparing 100-year global warming potentials or calculating warming per molecule over the molecule’s entire lifetime?

 

Eco-espresso?

3LpAs of 2011, the top five biggest commodities in the world were (in descending order) crude oil, coffee, natural gas, gold and Brent oil. As a first note, the presence of three fossil fuels in this list means that there is still a long way to go in the transition to a low carbon economy. But, yes, what I was actually trying to point out is that coffee is the second biggest commodity in the world. An estimated 1.6 billion cups of coffee are consumed worldwide every single day, with an estimated 55 million in the UK.

As former president of the University of Manchester Coffee Connoisseurs Club (UoMCCC), I set out to try and establish what kind of impact drinking coffee has on the environment, whether it is an issue that so much of the stuff is consumed every day and to what extent it can be sustainably sourced.

Fair Trade coffee has become widely available in recent years, with many big brands displaying the Fair Trade logo on their packaging. In the UK, almost 25% of total coffee sales are Fair-trade – a proportion which is steadily growing. This is certainly a step in the right direction regarding the coffee industry’s treatment of humans. Regarding treatment of the environment, on the other hand, it is not so obvious that improvements are being made.

 

Can’t see the woods for the lack of trees

Coffee is naturally found and traditionally grown, in tropical and subtropical regions of the world, in forested and often mountainous areas. Under the canopy of trees, the coffee plant is sheltered from constant direct sunlight. The rich biodiversity means the soil in which it lives is healthy and, further, there are few pests which are able to damage the crop before being swooped up by a predator. A human seeking to harvest coffee beans from such a plant cannot expect to get the greatest yield for a unit area, but at least the crop was grown in keeping with nature and without any need for pesticides or herbicides.

Since the 1970’s, monoculture and sun-grown coffee have become the norm. It was recently reported that

“By the end of the 1990’s, sun or reduced-shade cultivation systems accounted for almost 70% of Colombia’s land area devoted to coffee and 40% of Costa Rica’s.”

By clearing away regions of forest, farmers were able to increase their yield. In Central America alone, 2.5 million acres of forest have been cleared for coffee farming. Clearly, this deforestation results in the utter destruction of ecosystems far older than our society and which are among the most delicate on Earth. In the world of coffee, there is a tragic trade-off between a higher yield and less ecological damage. Needless to say, the cutting down of trees implies a reduced capacity of the natural world to absorb climate warming CO2, especially when applied on an industrial scale.

By removing the other flora and fauna which originally lived in harmony with coffee crops, the soil quality degrades and pests have free reign, meaning fertilisers, herbicides and and pesticides are the commonly used, as in the majority of global agriculture. Clearly, less than perfect handling of these chemicals can lead to further ecological problems such as water pollution and contamination.

IntroToCoffeeBeans_Content2Of course, many of the ecological problems discussed above are not unique to coffee and apply to many other crops grown in hot conditions. One factor that is particularly relevant, however, is waste.

As can be seen in the diagram opposite, the marketable product which is the coffee bean is just one, inner part of the harvested fruit, known as the coffee cherry. As any coffee connoisseur will be aware, there are many different processes by which the pulp is separated from the bean such as honey processing, natural processing, semi-dry/wet-hulled processing, washed processing… The enormous variety of flavours of coffee available on the market may be attributed largely to these different methodologies, which have heritage in different parts of the world from Ethiopia, to Indonesia, to El Salvador. Despite differences in what is done after harvest, each of the methods eventually discards the pulp and many require additional water and labour.

For the coffee connoisseur, the diverse range of coffee processes, origins and formats (from espresso, to siphon, to frappe-latte-mochachino), is astounding. The sad truth is that in order to obtain this diversity, an even richer diversity is often sacrificed – that of age-old ecosystems.

 

In the hands of the consumer

Unlike some crops sold on the international market, which are flown, coffee is usually transported by freighter ship or train, meaning that the environmental aspects of its transportation are not so bad. However, once on the shores of the consumer, yet more problems abound.

Not least of these are the problems of the waste theme, such as disposable coffee cups. An estimated 25,000 tonnes of waste is generated by the coffee industry in the UK alone, with 2.5 billion single-use coffee cups thrown away each year.
Further, if you decide to save money and brew your beverage at home, there are climatic impacts due to the fact that the kettle is a profoundly energy intensive device. Assuming you do not have a renewable power source, a recent investigation at Imperial College London revealed that boiling 1 litre of water in the average electric kettle results in approximately 70g of CO2 being released into the atmosphere. England’s all-time highest TV-related electricity demand surge was during half-time of the 1990 World Cup semi-final with West Germany, when the whole country went and put their kettles on to make a brew.

1990-Semi-Final-Pickups
Electricity demand during 1990 semi-final. Source: national grid.

Now I am not going to propose that everyone should give up coffee and all hot beverages along with it, for the sake of the environment. But there are certainly ways in which changes in the consumer habit could lessen the impact of the coffee industry on the world we inhabit.

In direct terms, only boiling enough water as is needed and carrying a reusable cup are two commonly given, but far less often followed, pieces of advice which need no further explanation.

Sustainable coffee does exist. Recent attempts involve shade grown coffee, which mimics the way coffee grows naturally, in tune with nature. Whilst coffee grown in this way is sometimes more expensive, its environmental impacts are much less than the conventional farming methods, the social responsibility is significantly higher and the benefit for ecosystems is great. The Huffington Post recently reported the head of sustainable agriculture at Rainforest Alliance, Chris Wille, as saying that

“Our scientists say a certified coffee farm is the next best thing to rainforest,”

regarding shaded farms. In some cases, these products are even equivalently priced to sun grown coffees. Surely there is no good reason for an environmentally conscious coffee lover not to consider switching to shade grown coffee.

 

Resources

There are a number of shade grown coffees now on the market, which can be found on coffee-direct.co.uk, naturalcollection.com and birdandwild.co.uk.

Image sources: headergif, demand

Let’s make Earth great again

When in November 2016 Americans played their trump card, climate scientists faced a new challenge: how to persuade conservatives to start caring about our planet? Even though this task seems to be hopeless, research is being done – and I recently came across some very interesting results.

Researchers from Cologne discovered that conservatives are more likely to act against climate change when the problem is presented with reference to the past, as opposed to the future. We usually focus on future degradation of the environment, which doesn’t appeal to them. However, conservatives tend to be more concerned about the global warming, when we point out that the planet isn’t as “great” as it used to be.

German sociologists conducted a series of experiments on self-identified liberals and conservatives. As a part of the study participants were asked to donate money to one of two fictitious environmental charities: the one preventing future degradation or the one striving to restore the past state of the Earth. In all experiments conservatives were more likely to support the second organisation.

Does it solve our problem? Of course it doesn’t! Riley Dunlap, a sociologists from Oklahoma State University, commented on this study: “If you’re a good conservative, you need to be a climate change sceptic. Global warming has joined God, guns, gays, abortion and taxes. It’s part of that ideology.”

Even though sadly I must agree with Dunlap, I also believe that we should study ways of communicating climate change effectively to various social groups. One size doesn’t fit all – but we can find a good approach for many. If someone is blind in his or her scepticism, we probably can’t do much. However, I believe that with new communication methods we can persuade many people, who are ready to at least listen.

To make Earth great again.

Source: https://paularowinska.wordpress.com/2017/04/12/lets-make-earth-great-again/

 

Money blowing in the wind

I bet you’re not looking forward to receiving your monthly electricity bills. Can you predict how much you’ll be charged this time? Short answer: assume that more than you’d be willing to pay. Long answer: spend a couple of years studying how electricity prices evolve in time. Yes, that’s exactly what my PhD is about.

Power markets are surprisingly complicated. Trading energy is a relatively new idea, increasingly important because of the gradual liberalisation of the EU electricity industry. Not only do market rules in various countries differ significantly, but relevant laws change frequently. Therefore if you’re interested in any details, please don’t rely solely on my article, but refer to the website of the appropriate market (eg. European Power Exchange).

From the mathematical point of view, modelling any financial processes is an extremely difficult task. Stock values change in unpredictable ways, they also strongly depend on political events and human behaviour. Because of that, financial mathematics attracts increasing numbers of mathematicians with different backgrounds. Actually, not only mathematicians. For example, a building block for many financial models is a so-called Brownian motion, first used by physicists to describe chaotic movement of particles. The tools we can use are limited only by our imagination!

Energy markets are problematic, as they behave differently than traditional stock exchanges, so we have to come up with completely new ideas to model them. The main difference is that the supply and demand for electricity must always match. Storing electricity is almost impossible, in the best case very expensive, so we cannot produce (or buy) more and leave it for later. On the other hand, the supply is inelastic, because industry and citizens require a specific amount of power for their regular activities. You don’t like blackouts, do you? And they happen exactly as a result of a significant imbalance in the energy market.

Thankfully many people work very hard (this is how I like to think about myself) to make sure that you don’t have to dig out these candles too often. Mathematical models help producers decide how much energy to generate and traders to buy and sell its appropriate amounts. Most of trading takes place in electricity markets.

Two main types of contracts are traded. First, spot contracts (traded at noon) oblige producers to deliver a specified amount of energy for 24 hours, from midnight of the following day. Second, one can also trade futures contracts for a specified delivery period: a week, a month or a year. For example, if a producer signs a “2 months ahead” contract today (June 2017), she or he would have to deliver the electricity between 01/08/2017 and 31/08/2017.

However, predicting the prices so far in the future is a difficult task. We don’t know the general state of economy or if Donald T. decides to build a *huge* bridge from New York to the Moon (which would require a lot of power, I guess). And, what interests me most, what the weather will be.

Weather conditions significantly influence electricity prices, both the demand and supply. In countries like the UK or Germany, in general the demand is higher in cold months, when we need to heat our houses and offices, as well as use more light due to shorter days. In warmer places, also in the summer a lot of energy is needed for air-conditioning. On the other hand, renewable energy production strongly relies on the weather. We can’t generate wind energy without wind!

This is why in my models I have to take into account weather forecasts. As you know, they’re pretty useless a few weeks in advance, not to mention a few years. Therefore the models need to account for uncertainty related to these forecasts.

You might wonder if these factors really matter. They actually do! Now many markets even allow the prices to be negative, which means that we get paid for the electricity usage. It happens rather rarely, so you won’t even notice. However, it’s interesting to note that almost all negative prices are observed in early morning hours after a windy night. This means that a high level of wind energy generation, combined with a low demand (most factories are closed at night, we also tend to sleep), can significantly decrease electricity prices.

In other words, the chance for a lower electricity bill is literally blowing in the wind.

Source: https://paularowinska.wordpress.com/2017/06/11/money-blowing-in-the-wind/

A tale of a statistician without an umbrella

You should have seen our office today – our cycle to work resembled swimming rather than biking, so wet clothes were hanging everywhere. Well, I can blame only myself, since a normal human being would assume that 98% probability of rain means “it WILL rain, take a bus”. However, being an incurable optimist, I counted on these 2%. In the end, improbable things happen a lot, as Jordan Ellenberg (a mathematician, of course) says. But how improbable was a bit of sunshine in London today? And why on Earth do I try to squeeze some maths even in the weather prediction?!

If you live in the UK, chances are that you begin your day checking your favourite weather app. Based on the information you gained, you know what to wear – unless you’re a proper Briton, then you wear shorts, no matter what, don’t you? Regardless of the website you use, the forecast is probably provided either by Met Office or ECMWF, who constantly compete to produce the most reliable weather prediction in the world. Despite, or maybe because of this rivalry, their forecasts are more and more accurate. So again, why can’t they just get it right, why do they give us percentages?

Weather is chaotic. You might associate chaos with the butterfly effect, a term coined by Edward Lorenz. If you think that it means that a butterfly in Asia can create a tornado in America, then please, please forget this concept; or, even better, read an excellent book by Ian Stewart, Does God Play Dice?, or request an article about it in the comments. The bottom line is that weather forecasting centres will never be able to predict the weather with the accuracy of 100%, no matter how hard they try. Never. Ever.

lorenz
A chaotic system: a slight change in the intial conditions can lead us to a different “wing” (by Computed in Fractint by Wikimol [Public domain], via Wikimedia Commons)
Instead, they calculate their confidence in a particular weather forecast. For example, 98% PoP (probability of precipitation) between 8 am and 11 am in London means that there is 98 in 100 chance that in this period we’ll get at least 0.1 mm of some precipitation. Basically, if you kept going back in time and went for a walk in London today between 8 and 11 one hundred times, twice you would be lucky and came home completely dry.

What?! It doesn’t make any sense! We can’t go back in time! But computers can. Even better, they can look into the future. Because weather is chaotic, small changes in the initial conditions (so the temperature, pressure, clouds etc. in the moment when we start simulations) can lead to big changes in the outcome. This is why Met Office and ECMWF use so-called ensemble forecasting. They run many simulations starting from slightly different conditions and look at their outcomes; it’s a bit like in Groundhog Day, but less creepy. And this means that today I believed in these 2 measly forecasts out of 100 – and that’s why my neighbours asked me if I cycled into the Thames on my way home (not funny).

Learn your probabilities and figure out your chances for a dry day. Or take an umbrella, just in case.

Source: https://paularowinska.wordpress.com/2017/08/09/a-tale-of-a-statistician-without-an-umbrella/

 

One Planet Living

If everyone in the world lived as the average UK resident, three planets’ worth of natural resources would be required to support humanity. By no means is this a responsible example of sustainability. But any such negative statement is useless unless accompanied with a proposed better alternative. Are there countries on Earth which pose as a model society, whereby extrapolation of their consumption rates would give true sustainability?

 

HOW LONG WILL RESOURCES LAST?

Last month, a fellow MPE CDT student and I volunteered on a project with the Nuffield Foundation, which saw six maths students spend 2 weeks at Imperial College London during the summer between their A-level years. Together, we brainstormed some ideas about important aspects of mathematics (such as geometry, calculus and numerical methods) and important elements of Planet Earth (such as the atmosphere, oceans, flora and fauna).

Following their brainstorming, the students ranked by importance and urgency some related problems, such as predicting temperature rise due to climate change, analysing the way in which glacier melt leads to sea level rise and trying to estimate how many years’ worth of natural resources remain for humanity’s usage. In the end, the students decided they were most interested in the latter problem and set to work trying to figure out how they could use their mathematical abilities to tackle this problem and what the implications of their findings might mean.

The students decided to consider two developed countries (Japan and South Africa) and two developing countries (Cuba and Uganda), in order to see the range of impacts being made across the world. Assuming the birth rate and death rate of these countries to be constant, the students considered two simple models of population growth: the Malthus model and the Logistic model

The former model prescribes an exponential growth or exponential decline of population, with the rate of increase or decline determined by the birth rate and death rate.  For the logistic model, a so-called carrying capacity must be specified, beyond which a population could not be sustained by the planet whatsoever. Demographers estimate this value to be around 10 billion, which we are not so far away from at the present time. From these simple models, the students could make basic predictions of the future populations of the countries considered, and indeed, the world population if everyone gave birth and died at a constant rate.

As well as birth and death rate data, the students collected information regarding the biomass, coal, gas and oil stocks and consumption rates of their chosen countries. Using the previously estimated population curves, the students were able to approximate the associated usage of the four fuels. The latter three models are fairly simple, since a constant rate of consumption per citizen is assumed, and there is effectively no return rate of the fuel stocks. In the case of biomass, however, the students had to consider the fact that trees grow back over a few years, and so the resulting equations are a little more difficult to solve.

Having forecasted the diminishing of the fuel reserves, the students were able to go on to say how much CO2 would be released into the atmosphere by each country, estimate the consequent concentration in the atmosphere and provide a first approximation to the associated temperature increase to the planet. Here they made a major assumption that CO2 is not re-absorbed, which is of course not true in reality. However the project centred on making a first approximation to what is going on, so many simplifications must be made.

eff892564d7c8014da2261b2d04229e015c1c05e

Rather than copying their results, I have considered similar calculations for four other countries which pose as markedly different examples in their approaches to environmental protection and resource consumption. Consider India, China, UK and USA. As can be seen in the map above, the One Planet Living initiative claims these countries fall into the categories of using less than 1, 1-2, 2-4 and more than 4 planets when their trends are projected onto the worldwide populace, respectively. That is, if the entire world were to behave in the same way as these countries in terms of population change and resource usage, the number of planets’ worth of resources needed would be as indicated. Python code is available for how I calculated these projections on GitHub.*

world_Oil_Malthus

In the following plots, only the contributions of domestic coal, natural gas and oil are considered. As has been mentioned, the Nuffield project students also considered biomass, but they discovered that it is rather difficult to get data on the consumption thereof and the mass to CO2 conversion varies depending on the particular biomass fuel used. Of course, there are plenty of other resources (such as food, clean water and rare earth materials) and plenty of other sources of pollution (such as emissions from livestock, waste and aviation) which could be considered, but here we focus on the three main fossil fuels since they make contributions in both categories.

For an example of the predictions relating to one resource, if the whole world acted as the USA, the graph above indicates that oil reserves would drop dramatically, completely drying up after 70 years. Similar plots can be made for the other fuels, through which we can get a picture of the total resources used, and hence the total carbon emissions. Subject to a number of assumptions both stated here and neglected, the associated additional mean warming to the atmosphere would look as displayed in the plot below. From this plot, if the whole world acted as the UK or India in terms of its population change and fuel usage, we should expect an extra warming contribution of around 2°C after one century has passed. In the case of China, this would be more like 4°C and in the case of the USA 10°C.

temp_change_Malthus_g=OFF_trees=OFFThese are very rough estimates, as has already been mentioned, but there seems to be significant evidence to suggest that we shouldn’t only be concerned with using the resources of one planet, but also which resources we choose to use, and at what rate. This is especially true when taking into consideration that the international agreement made at COP21 aims to keep warming below 2°C above pre-industrial levels. UK Met Office research indicates the world has already warmed 1°C since then.

Calculations above were performed in the Malthusian case. In the case of the Logistic model, predictions are more conservative, due to the world population being unable to breach 10 billion. The resulting plot is indicated below. There the range of additional temperature increases is approximately 0.3-3°C. Even under this more conservative approach, it doesn’t look likely that we could meet the cumulative 2°C target in any case.

temp_change_Logistic_g=OFF_trees=OFFNot only are there some countries which use ‘more than one planet’ and some which use ‘less than one planet’, the average taken across all of humanity is currently actually about 1.6 planets. The interpretation of this claim is not that we are generating resources out of nothing or collecting them from space, but that we are consuming resources faster than they can regenerate naturally. Resources are being used at such an alarming rate, and the natural environment is being damaged so badly, that the regenerative ability of the planet has been significantly reduced.

 

CAN YOU BEAT THE AVERAGE?

This summer’s Nuffield Project was not the first time I considered mathematical problems related to One Planet Living. On Open Data Day in March this year, I attended a hackathon at the European Centre for Medium-range Weather Forecasts (ECMWF) in Reading. There, a team of us attempted to create an app which enables the user to calculate their carbon footprint and thereby to find out whether or not their contribution is greater or smaller than the average for their country of origin. Whilst in the Nuffield Project we only had time to consider fuel usage, in this project only road, rail, bus and aviation transportation was taken into consideration.

Sadly, the app we worked on in the hackathon never came to a particularly user friendly stage, due to tight time constraints and a lack of app developing experience. However, the Bioregional initiative provides a calculator for finding out how many planets would be required to sustain a planet of Yous, covering far more aspects than we could ever have hoped to consider. Even if you produce zero waste, cycle everywhere and never fly or drive, it is fiendishly difficult to become a One Planet Citizen. My output is shown below, and I clearly have some progress to make.

Screen Shot 2017-09-23 at 09.23.36.png

The different coloured sections on the bottom bar correspond to energy generation, transport, food, goods, government, capital assets and services, respectively. I’m not going to start making excuses for why the calculator tells me I use more than one planet, but I will just make a few comments on its output:

  • Notice that at least 28% of my footprint is purely due to the government, dispelling the myth that individuals can tackle climate change, resource conservation and ecology deprivation completely on their own. Authorities have to make an effort, too.
  • Goods, food and services have extra footprint included because there is a large implicit contribution in supply chains. This factor points out that businesses have an environmental responsibility, as well as governments. Personal impact in this case can be reduced by shopping at second hand shops, charity shops and local markets.
  • Finally, it is difficult to improve on the energy contribution if you live in rented accommodation, since it is up to your landlord to install things like loft insulation, condensing boilers, cavity wall insulation and solar panels. However, if you get on with them you could maybe consider suggesting these.

 

UNTO THE FUTURE

Last month I attended a symposium of talks at Imperial College entitled ‘Balancing sustainability and development: cities in the 21st century’ on the need to adapt future cities to the omnicrisis of issues faced by present and future citizens, such as overpopulation, rising temperatures, inequality, resource scarcity and overstressed infrastructures. The symposium was opened by a talk by David Thorpe, author of ‘The One Planet Life: a Blueprint for Low Impact Living’. He claims the world’s ‘biocapacity’ was breached in the early 1970’s and since then we have been running on ‘borrowed time’. The World Wildlife Foundation (WWF) lists nine ‘planetary boundaries’, four of which have already been passed: climate change, biosphere integrity, soil quality and nitrate pollution.

slide.5planetintroThorpe claims, with the present population, the only way to ‘get back on track’ is for the entire world to have a ecological footprint as in Central Africa. This does not, imply the reduction in living standards one might expect for more privileged citizens, as in the West. For instance, whilst research by the One Planet Living initiative indicates that residents of the USA use ‘two more planets’ worth of resources than the average European (see diagram opposite), there are many metrics by which one might claim Europeans are better off than Americans.** Does all that extra resource and carbon impact really make for a happier, more fulfilled life? Who says the UK couldn’t reduce its impact and maintain the same quality of life or, indeed, improve it?

Thorpe works on a One Planet Living initiative in Wales, where the word ‘sustainability’ has been made equivalent to the ‘well-being of future generations’. His motto,

“if it gets measured, it gets saved”

motivates the reduction of ecological footprint in line with closer control on consumption levels and methods. Thorpe’s thinking recently influenced a public advice spreadsheet available on the Welsh government website. In principle, the creation of a One Planet society is not an enormous undertaking. All that is required is some careful planning of how waste is to be dealt with, how electricity is to be generated and which materials are to be used for construction and packaging (if any). What is difficult, on the other hand, is converting a currently damaging society to a One Planet one.

Model cities do exist. Thorpe points to Freiburg, Germany, which has been heralded by many as a leading example, through its restrictions on polluting traffic, energy saving schemes and use of efficient technology. Perhaps unexpectedly, China also provides an example in terms of its recent efforts to develop vertical farming, which requires less space, water and effort and can bring impressively increased yields of staple foods.

One conclusion of the symposium was that there are very real limits to growth, to quote the Club of Rome (1972). This is something discussed by John Burnside in his once-three-weekly Nature column in New Statesman this January. There he pointed out the inherent contradictions between the growth modern countries are fixated on and the very clear bounds enforced by the forces of nature. That we can continue as we have in the past decades indefinitely and with little to no consequence for the residents (human and otherwise) of this planet is an utter lie.

Can you take up the One Planet challenge? In a way it is the least you can do.

 

[Also posted on my personal blog Cut Waste, Not Trees Down]

 

NOTES:

*: References for resource consumption data used:

**: In a New York Review of Books article, Europe vs. America, Tony Judt points to the following statistics:

  • “[T]he EU has 87 prisoners per 100,000 people; America has 685.”
  • “[A]ccording to the OECD a typical employed American put in 1,877 hours in 2000, compared to 1,562 for his or her French counterpart.”
  • “Whereas Swedes get more than thirty paid days off work per year and even the Brits get an average of twenty-three, Americans can hope for something between four and ten, depending on where they live.”
  • “45 million Americans have no health insurance at all.”

[Image sources: headermap, plots (and Python code), calculatorplanets]