Dealing with uncertainty in climate change risks

The inspiration for this post comes from a couple of reports from the Institute and Faculty of Actuaries.  [1] and also [2] about how climate change policy has often failed to evaluate climate risks adequately. 

 

Hemp for building insulation

It is illegal to grow hemp without a license as it is the plant source of cannabis, a class B drug. However the strains used for construction material do not contain significant amounts of THC. Historically hemp fibre has been used to make rope, sailcloth, parachute webbing and heavy duty clothing but recently it has been used as a natural insulation material and as a reinforcing fibre for concrete and plastic. It is even used in making body parts for cars (famously introduced by Henry Ford [1])

Other fibre crops can also be used such as flax and bamboo. However hemp is stronger than either [2].

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)).