Biodiversity and national security

 I recently read the government report ‘Global biodiversity loss, ecosystem collapse and national security’ [1]. This was published in January so I am a bit behind in getting to it. It makes for grim reading. The national security issues of concern include migration, conflict and competition for resources.

People’s Emergency Briefing

Last night (Saturday 18th April) I went to a showing of the film ‘People’s Emergency Briefing’ [1] at Pembroke College. I was a bit concerned this might turn out to be horribly alarmist but actually it was not overly negative - the facts are quite frightening enough - and the briefings included sensible actions we can take to reduce the impacts [1]. Do go and see it with your friends and family and consider supporting the campaign to get this shown on TV and get more MPs to see it (screening map here https://www.nebriefing.org/screening-map). The format of the film is friendly and non-technical. It is a bit like Gogglebox with clips of experts explaining the issues interspersed with reactions from a small panel sitting on a sofa.

I can’t say there was a great deal that was new to me but it did reinforce some important facts.

Life without electricity

I recently went to one of a series of talks (https://cambridge.resilienceweb.org.uk/) on the theme of resilience (a critical issue due to climate change increasing the frequency of severe weather) and yesterday I came across this report from the Royal Academy of Engineering [1] which gives a vivid picture of how Lancaster coped with a major power cut due to flooding in December 2015. This post gives a flavour of some of the problems described in the report. However, it was written a decade ago. Technology has changed a bit since then; below I have suggested some alternative solutions now available.

What makes a deposit return scheme successful?

A large proportion of our waste is comprised of single-use drinks containers and far too many of them end up littering our high streets, beaches and countryside. Plastic drinks containers ultimately break up into tiny pieces (microplastics) which go on to cause harm in the natural environment. (Glass containers cause different problems when they break and litter the streets with bits of glass that can cut animal’s feet and cause infections).

To reduce the problem of this unsightly and damaging litter, the UK is to introduce a deposit return scheme (DRS) [1], starting in October 2027. This means you will pay slightly more for your drink but get some back when you return the container to a collection point.

If the scheme is successful this will increase the recycling rate for plastic and other bottles, reducing the need for more virgin material and the GHG emissions from the fossil fuel plastic is made from. You will still be able to leave your plastics for collection by your local waste collection services as now but you will not get the deposit back that way. The DRS route is better for recycling because the bottles will be sorted rather than mixed in with other rubbish as now. The scheme will be managed by a not-for-profit Deposit Management Organisation (DMO) .

There are already successful schemes in Germany [2] and Sweden that we can learn from. These schemes achieved returns rate of 98% [2] and 87.6% [3] respectively in 2024.

The key factors for high collection rate are:

• Significant deposit value to incentivise consumers
• In Germany, the deposits for multi-use containers range from 0.08 - 0.25 euro (7p-22p). For single-use containers the deposit is 0.25 euro (set by the government) [2]
• In some places the deposit varies with the size of the container. For example in Sweden you get 1 or 2 SEK (8p or 16p) for aluminium cans depending on the size, or 2-3 SEK (16p – 25p) for PET bottles [3]
•  Many nearby collection points
•  Reducing the effort required to take containers back
• To increase the density of collection points, retailers may be obliged to take collections, or take part in a shared collection service such as Re-turn
• In California there is no obligation on retailers to take back containers and the recycling rate is much lower – only 60%
• Most Items included in the scheme
• Typically glass and aluminium containers are included and often recyclable plastic such as PET. 
• PET plastic is usually shredded and reformed into pellets to make new bottles
•  The UK scheme will not include glass because of safety issues with broken glass. However glass is included in the Extended Producer Responsibility scheme [1].
• To reduce costs for the retailer
• Shared services
• Revino supports wine producers in Oregon in re-using wine bottles. They provide sorting and washing services
• Collections can be automated, for example by reversed vending machines [4]

In summary: deposit return schemes can be very successful in raising recycling rates for containers and hence reducing GHG emissions. However they can be onerous to use for both consumers and retailers. To achieve high levels of participation it needs to be convenient for consumers to take the containers to collection points and/or fines for con-compliance by the retailer. Shared services and/or automation can reduce costs.

[1] Introducing the deposit return scheme for drinks containers Jan 2025 (blog.gov, Jan 2025) 

 

[2] A look at Germany’s bottle deposit scheme (dw.com, Nov 2021) 

[3] New data says Swedish DRS recycled 2.8 billion beverage containers in 2024 (Packaging Europe) March 2025

[4] Reverse vending machines: The benefits of automation for retailers in deposit return schemes

 

Disgruntlement with EV charging services

I could not resist this blog post I was so charmed by the concept of user disgruntlement as a quantitative measure of service quality. Disgruntlement is measured as the difference between scores for the expectation of a service provision and the actual delivery scores. For example, do users of EV charging points expect the ability to buy refreshments while they are waiting for their car to charge? If refreshments are important to them and lacking, then it would probably be worthwhile to provide such things. However if this service is not important or costly to provide then probably not. The underlying scores for importance and delivery are given on a likert scale (1-5). If delivery score exceeds expectation then users are well satisfied and the disgruntlement is negative whereas if expectation exceeds delivery score then disgruntlement is positive (i.e. users are disgruntled)).

Should I use an electric bike?

Electric bikes can be very clean in terms of GHG emissions. They use electricity which can be zero carbon; making the batteries are the main source of emissions in most cases. In comparison, using cars, tyre wear is a major source of microplastic pollution - the tyres wear out as do the lines of paint on the road which flake off but bicycles are much lighter so there is less wear both on tyres and paint. In particular an electric bike can enable carbon savings compared to alternative transport options. A small group from Transition Cambridge were talking about this yesterday.

One of our number was recently recovered from knee problems which prevented them from using a conventional push bike for long or hilly journeys. Using an electric bike allowed them to make longer journeys (e.g. 20 miles) without 'range anxiety' due to the dodgy knees. Assuming the journey was necessary, alternative transport modes (such as car or bus) would have had higher GHG emissions due to use of fossil fuels as well as additional microplastic pollution from tyre/road wear [1]  Using the electric bike reduces your climate change impact.

You could save even more emissions by not using the battery power to assist your movement. However, that would mean more food consumption and more range anxiety.

The European Cycling Federation has reported a comprehensive life cycle analysis calculation comparing different transport modes: pushbike, ebike and walking in terms of emissions per km travelled [2]. The ebike comes out best by some margin. The differences are dominated by emissions from food. Walking requires the most food, then the pushbike, then the ebike. The food emissions can be reduced if the human consumes a carbohydrate rich diet - or it can be hugely increased if the dietary energy is mainly meat. The chart below shows the GHG emissions they calculate. They have used 383 g CO2e per/Wh for electricity and 1.4 gCO2e/Wh for food: typical for Europe. The emissions for UK electricity are less 177 g CO2e/Wh [3]: Overall the DESNZ/DEFRA emissions factors for EVs [3] are typically about 40 g/CO2e/km so between cycling and walking estimates.

Data from [2]

[1] Bike-to-Work Day: Keep the Car in Park to Reduce Microplastic Pollution (oceandiagnostics.com) 

[2] How green is cycling? Riding, walking, ebikes and driving ranked (bikeradar)

[3] UK Government GHG Conversion Factors for Company Reporting 

Review: Shared Prosperity in a Fractured World: Dani Rodrik

Yesterday I went to a seminar about economic policy relating to climate change which was basically a book launch for Shared Prosperity in a Fractured World. I was sufficiently impressed to buy the book. Here are some key takeaways from the seminar and the first few chapters of the book which I have read today.There are 3 primary challenges to address and they are to some extent linked with tradeoffs.

1. Climate change - failure to address this has severe consequences for global health as well as the global economy and we are already experiencing more frequent and worse extreme weather. The main way to address climate change is to promote green industry based on renewable energy.
2. Reducing global poverty - this is always a good thing. The usual way out of poverty is economic growth but that is quite strongly linked to increasing energy use and GHG emissions which is bad for (1). Also people living in poverty do not buy much so markets shrink which makes it more difficult to address (3)
3. Rebuilding the middle class - When the middle class feels insecure they tend to react with a retreat to populism and fear of immigrants or automation 'taking their jobs'. The main way to rebuild the middle class is to ensure they can have good jobs. So we need growth in job friendly sectors such as retail and health care. In this context good jobs means security and satisfaction and/or good remuneration.

(There seems to be something magic about '3'. I am reminded of the 3 requirements for energy provision that it is cheap, clean and reliable. However these three are more obviously in tension. It is easy to satisfy any two simultaneously but all three is hard.)