When I came across The Barista Paradox, I started to imagine a queue of puzzled people standing outside my favourite café. Would it’s door open or not?

The Barista Paradox is as follows: in a small town there is one barista, where the rule is that they make coffee for those people, and only those people, who don’t make it for themselves. But, who makes coffee for the barista? There are two situations:

1. If she makes it for herself, then because she only makes it for those that do not make it for themselves, she can not make herself a coffee.

2. If she does not make it herself, then because she makes it for all those that don’t make their own coffee, she makes herself a coffee.

Therefore, the barista only makes herself a coffee, if and only if she does not make herself a coffee. A paradox! At this point, most philosophers would say that the only answer to this paradox is that the barista doesn’t exist. No door opening soon at the café!

The first thing to notice about the paradox is the sprinkling of the terms ‘all’, ‘only’ and “if and only if” which signals that this is a problem in logic rather than a real life problem ( all the baristas that I know make their own coffee ). They add up to saying that for all coffee drinkers who do not make their own coffee they can only get it from the barista, and nobody else. Not a realistic situation, especially if the café is going to have a secure financial future.

The barista paradox shows what happens when a description of buying coffee is squeezed into a problem in logic. Logic has many applications; electronics, computer science and mathematics, but not buying a coffee. At this point, Wittgenstein would point out that the words from logic have been used in a situation where they have lost their meaning, and we have been sucked into the vortex called philosophy. Rather than spending lots of time puzzling over the meaning of the paradox we should grasp it for what it is: nonsense, and have another coffee.

Philosophers spend most of their careers thinking about our lives. Questions about what we know and the world that we live in, including how we should live with people. What they find is wrapped up in books that most of us don’t open. However, they can influence decision makers who are always grasping for a banner to wave as a gathering point, such as monetarism, classical liberalism, securonomics etc. Maybe we should have a closer look at what they are waving, just in case it is riddled with paradoxes which lead us nowhere.

Next time you are in your favourite café and the barista is crafting a delicious coffee, why don’t you buy them a coffee to make sure that they don’t fall into the The Barista’s Paradox.

Increasing swings in extreme weather are happening globally: it is clear that climate change is underway. If I was a gambling person, what odds would be favourable enough to place a bet that we would reach the global target of net-zero greenhouse gases by the end of the century?

Taking up a pen and paper I started carry out a back-of-the-envelope calculation to estimate the odds of reaching net-zero greenhouse gases by the end of the century. As Sir David Attenborough constantly reminds us, greenhouse gases are driving climate change which is a product of human activity. To get a handle on calculating our impact, I broke it into the following factors: population growth, technology development, climate policy, energy transition, and geopolitical stability.

The current global population is around 8 billion people. The best estimates give a spread of between 7 billion and 10 billion by the end the century. Therefore, I would give it a probability of about 50%, that the population will stabilise at around the current size and therefore its contribution to green house gases stabilise. Next is technology development which covers AI, biotechnology, green technology, and probably technology that we haven’t dreamed of yet. However, based on the speed of adopting new technology, which is always slower than we think because of high initial costs and the lack of skills to implement it, then it could take tens of years to stabile greenhouse gases, therefore I put it at a probability of 30%. Now for the one that is in the headlines most climate policy. The Paris Agreement set the global climate goals: limiting global warming to well below 2°C above industrial levels, preferably limiting the increase to 1.5°C and achieve net-zero global greenhouse gases in the second half of the 21st century. As of 2024, 140 countries have set net zero targets including: EU, UK, USA, Japan, and South Korea by 2050, China by 2060 and India by 2070. The current status is that the global greenhouse gases are still not declining fast enough to stay below 1.5°C, and it is currently estimated at 1.2°C, therefore it would be fair to conclude that climate policies are not working effectively, and therefore the probability of success is around 30%. Next is the energy transitions from oil based to clean sources such as electric sources of energy. Currently, only ~15% of global primary energy, that is, total energy used across all sectors, including heat and transport, comes from clean sources. Most applications such as transport, heating, and industry still rely heavily on fossil fuels. Although many businesses are giving out optimistic messages about the transition, I am not as hopeful that it will be fast enough to stabilise greenhouse gases, so I put the probability at 50%. Finally, geopolitical stability which is difficult to assess. If people are busy fighting for their survival then greenhouse gases and climate change isn’t a priority. There is more conflict in the world than reported in the media. For example, in 2023 about 14% of the world’s population lived within 5 km of a violent conflict. Therefore, I gave the probability of 30% that geopolitics will distract from work on reducing greenhouse gases and therefore it will not stabilise by the end of the century. Pulling all of the factors together to calculate the overall probability of reaching net-zero by the end of the century gives: \(0.5 \times 0.3 \times 0.3 \times 0.5 \times 0.3 = 0.00675\) or approximately 1 in 150 ^*chance that we will reach net zero by the end of the century - not good odds!.

Of course the above are all guesstimates supported by a lot of hand waving. But the key point is that there are many complex factors involved in reducing the greenhouse gases to net-zero. For example even if we were very optimistic about the success of each factor and recalculated e.g. \(0.9 \times 0.9 \times 0.9 \times 0.9 \times 0.9 = 0.59\) or which is only an evens change of reaching net zero. Global leadership needs to be made more accountable at reaching net-zero, honest about the success of reducing greenhouse gases to net zero, and put more effort into mitigating the effects of green house gases that are already built in to climate change. What bookmaker would give us favourable odds for achieving that?

^* To convert from a probability to odds, divide the probability by one minus that probability. So if the probability is 0.00675, then the odds are 0.00675/(1-0.00675) or approximately ‘1 to 150’

Most of the campaigns that I have supported have fallen at their early stages. Many have turned out to be sound-bite issues: a lot of coverage in the socials and then they go silent. What is going wrong?

At the end of 2023, I signed up to the campaign Get Fair About Farming. Its aim was to ensure supermarkets buy the UK fruit and vegetables that they were committed to, payed on time, confirmed long-term agreements, defined fair specifications, and honoured agreed prices. It was an important issue because around 49% of UK fruit and vegetable growers feared collapse within the year. A petition with 113,000+ signatures was collected and it was supported by public figures such as Dragon’s Den star Deborah Meaden, chef Rick Stein and wildlife TV presenter Chris Packham. The target of the campaign was to strengthen the Groceries Code Adjudicator who is responsible for regulating the relationships between the UK’s largest grocery retailers and their direct suppliers.

I followed the debate held in Parliament during the early part of 2024. Then it went silent. I contacted a few MPs and the originator of the campaign to find out what was happening but the silence continued. I eventually found out, through web searches, that Minister Mark Spencer, the then Minister of State at the Department for Environment, Food and Rural Affairs acknowledged the debate but indicated no intention to change the Grocery Supply Code of Practice. Instead, he stated the government’s plans to introduce statutory supply chain codes under the Agriculture Act, but without clear timelines.

It is important to put the Get Fair About Farming campaign in context. The UK imports approximately 54% of the fresh vegetables that it consumes, and around 84% of fruit comes from overseas. Tariffs on imported fruit and vegetables vary by product, typically 6–16%, but many are zero under trade deals. The ability to import fruit and vegetables with minimal import tariffs puts the supermarkets in a powerful buying position with little or no economic incentive to buy UK products.

The fundamental problem for farmers is selling enough produce at a price that sustains their business into the future and at the same time improving the environment. With over 100,000 signatures gathered by the the Get Fair About Farming campaign, the organisers should have used the support to apply pressure on the government after the Parliamentary debate and the Minister’s decision. With about 30% of the UK population meeting the recommended 5+ portions daily they could have joined in the wider movement to get more fruit and vegetables on people’s plates and combined forces with campaigns such as Peas Please, Eat Then To Defeat Them or supported the NHS’s trialFruit & vegetable on Prescription. The campaign could have shone a light on the problems that they were experiencing with the supermarkets which are undermining the aims of the wider health initiatives, and campaigned for the government to ‘level up the playing field’ with imported fruit & vegetable through adjusting import tariffs.

I have signed up to a range of campaigns over the years, whether improving the health of rivers to reducing poverty. So far, they have all ground to a near standstill. Campaigns need to identify the key issue that they are addressing and be prepared to maintain its momentum with ongoing public engagement. Next time you are asked to sign up, or contribute either time or money, to a campaign ask your self if they are targeting the underlying issues or is it another sound-bite campaign.

I came across the word ‘riparian’ when trying to answer a question about river ownership. I thought I had stumbled across a word used in the film Jurasic Park. But the word describes an important role in managing the health of a river.

As an angler, I have often been made aware of who owns a river through the many signs saying ‘no fishing allowed’. Also, shouts from annoyed landowners when I have transgressed onto their river bank. Even worse is when they run across fields to shout warnings about crossing an imaginary boundary in the middle of a river. However, the matter is clear. The water in the river is not owned, it is a public resource. Parts of a river such as the riverbed and banks are owned, and the owners can have rights to use the water such as abstraction. These rights are regulated by public agencies e.g. the Environment Agency in England. The word riparian describes the land along a river bank and can cover surrounding wetlands and lakes. The term ‘riparian ownership’ identifies the owner of the land.

The riparian owner has various rights such as the use of water for reasonable domestic purposes, and responsibilities such as keeping the bank clear and avoiding pollution. There are several pieces of legislation in place that reinforce this responsibility. They range from Water Resources Act 1991 which governs water quality, pollution control and abstraction, to the Wildlife and Countryside Act 1981 which protects species like otters, water voles and certain fish. However, the prosecutions under the network of legislation have resulted in either punitive fines of hundreds of pounds or suspended prison sentences. The Environment Act 2021 strengthens the duties on water companies and regulators to reduce river pollution and introduced a biodiversity net gain requirement that can apply to river habitats in development projects. There has yet to be any specific prosecutions under its provisions. In all of the legislation, riparian ownership is never explicitly defined but is implied through loose descriptions. However, riparian ownership falls under common law and covers issues such as rights to natural flow of water, reasonable use and protection against pollution from other riparian owners.

Walking along many river banks it is clear from their condition that many riparian owners take their responsibility as an inconvenience. But they have an important part to play in the recovery of the health of our rivers. The approach to making riparian ownership more responsible must be based on a combination of support and clearly defined responsibilities. The support can come in two forms: financial through funding such as ELMs to improve riverbank management, water quality and flood management, and best practice from organisations who work with riparian landowners such as the Wye and Usk Foundation and the River Mease Partnership. Responsibility should be strengthened through legislation by clearly defining the responsibilities of the riparian owner and backed up with severe fines for any infringements.

Next time a politician knocks on your door asking for your vote why don’t you ask them how they are going to improve the health of the local rivers, and in particular how the riparian owners are going to be both supported and made accountable for the quality of the river that passes through their land? Why wait until the next general election? - email them today!

There is nothing more disheartening than walking along a river that is dying. It is muddy, littered with rubbish and barely moving. In the UK we have have developed many ways to strangle the life out of rivers.

Fish are the best indicator of the health of a river. In good health it supports sustainable populations by providing: a good supply of food, air to breath ( yes - fish need oxygen ), areas to breed and hide from predators. Of all of the fish species that a river can support the wild brown trout is the gold standard. In the UK their population is in a steep decline. Data from the Office for National Statistics indicates that the number of rod-caught trout in the UK has steadily declined by 51% between 1994 and 2019.

The health of a river depends on a number of factors. Currently, pollution is the headline grabber in the shape of sewage discharges. It introduces pathogens and excess nutrients into a river. Pathogens can cause fin rot, ulcers, gill disease, and systemic infections that weaken immunity and reproductive failures. Still under the heading of pollution is agricultural runoff from fertilizers, pesticides and animal waste that cause eutrophication and algal blooms. Eutrophication is a process where a body of water becomes excessively enriched with nutrients which can lead to plant die-offs, harming species like water crowfoot and pondweeds as well as affecting invertebrates. If that was not enough then there is industrial pollution with chemicals and heavy metals. Finally litter such as plastic bags and sacks, old tyres, paint cans, wood, fridges, bicycles, bottles and the infamous supermarket trolley.

The next factors is land use and recreation. Urbanisation increases more concrete which means less natural absorption, increasing surface runoff and pollution. Deforestation and poor land management reduces natural filtration and increase sediment in rivers. Drainage and canalisation changes to natural river courses alter flow patterns and habitats. Then there is us. Anglers gear, if not properly cleaned, can introduce spores and larvae and other invasive species. Swimming can introduce contamination from sunscreen and insect repellents, and disturb sediment and habitats. It’s a similar situation with dogs, pathogens can be introduced from their pooing and peeing when they swim in a river. Also, the use of flea deterrents can be harmful to insects living in the river.

If the above factors are not enough then there is water abstraction. Excessive water is removed for agriculture, industry, or public supply which lowers river levels and harms aquatic life. The list continues with invasive species of non-native species like American signal crayfish or Himalayan balsam which disrupt local ecosystems and outcompete native species.

Finally, the factor that affects us all is climate change. Increased global temperatures affect oxygen levels in a river which impacts on the ability of fish to breath. The increasing frequency of droughts reduce river flow, concentrate pollutants, and shrink habitats. More intense storms cause flooding and spread pollution.

Reducing the impact of one of these factors is an important step but they all have to be addressed at the same time if a river is going to return to full health. For example, if pollution from sewage discharges was totally eradicated and the rest of the factors stayed the same then there is no guarantee that a river will recover full health. Next time you are asked to support an organisation that is going to tackle one of these factors, ask them how the other factors will be affected. It won’t be until their elimination is coordinated that the wild brown trout will return to all of our rivers.