GEOGRAPHY

How and Why do Species Losses Occur? 🐾

You have probably heard the term ‘biodiversity crisis’ at some point, but discussions of climate change often ignore the risk of extinction that species of plants, animals, and microbes are facing. Scientists have been debating for the past few decades about whether we are experiencing a sixth mass extinction event. Jarred Diamond (1984) outlined 4 key factors that led to species’ deaths: habitat loss, overexploitation, introduced species, and chains of extinction. This so-called “Evil Quartet” can be joined with the new problems of pollution and climate change. So, what does the science say about species losses?

💡 Things to consider

• Species loss has been a common phenomenon throughout human history: Ever since humans started farming, habitats have been destroyed, along with their inhabitants who can no longer tolerate the conditions that have been created. As humans have become more mobile with railways, airplanes, and cars, our ability to transport species from one place to another has grown too. And we’ve also come to desire things we didn’t even know existed before. For example, in January 2024, a massive bluefin tuna sold for almost $800,000 in Tokyo. Why was it so expensive? One reason is due to bluefin’s scarcity, caused by overfishing for the high-end sushi market, meaning that the tunas cannot reproduce quickly enough to replace their stocks. If bluefin tunas become extinct, other species will be affected, since they are top predators. Squid, herring, seabirds, mackerel, sharks and whales could all be at risk if bluefin die out.

  

  Bluefin Tuna

• But risks to species intersect too: The fertilisers used in agriculture are posing problems for marine species too. When deposits of phosphorous and nitrogen run into the oceans, they can cause eutrophication, and coastal dead zones. The chemicals lead to rapid growth of seaweed and algae on the surface of the water. These prevent sunlight from reaching flora deep in the oceans and nothing can photosynthesise, triggering mass die-off of organisms due to hypoxia (lack of oxygen). The dead algae, seaweed, and phytoplankton decompose on the seabed and consume more oxygen through microbial respiration. Nothing can survive. Invasive species and overfishing have interacted with this process to result in dead zones in the Baltic and Black Seas.

  

• What about land mammals?: The larger the mammal, the more vulnerable it is to extinction. This is because traits that make them more vulnerable, such as being slow to reproduce, tend to scale with body size, and these intrinsic factors combine with environmental factors to trigger extinction. The size of the species’ population, shifting species distributions due to climate change, and other factors such as hunting, logging, mining, fires (slash and burn agricultural techniques, wildfires), and the effectiveness of protected areas also influence land mammals. Simply put: there’s no one factor that leads to species extinction, and it can take anywhere from decades to millennia to occur. Extinction is hard to study for this reason, and it's difficult to use a large-enough geographical scale to understand the problem. Species could go extinct before we’ve even discovered them.

🔎 Find out more

• More about Bluefin Tuna

• More about dead zones and marine ecosystems:

  • Spreading Dead Zones and Consequences for Marine Ecosystems 

  • Microbial Respiration

  • National Geographic Resources 

MFL

Eugène-René Poubelle: the OG Parisian bin man… 🗑️

If you’re studying French, you’ve almost certainly come across the word poubelle, which translates to ‘bin’ (or ‘trash can’) in English. But you might not know that this word entered the French language in the late 19th century thanks to politician Eugène-René Poubelle…

A staunch republican and trained lawyer, Poubelle became Préfet of the Seine on 13th October 1883. This was a very important position: at this point, the Paris commune had no mayor, so the prefect of the Seine operated in the same way as mayoral positions in other cities. During his time as prefect, Poubelle’s main contribution was two government decrees on 24th November 1883 and 7th March 1884 obliging property owners to provide their residents with covered iron containers for their household waste. He mandated the use of three separate containers: one for compostable items, one for paper and cloth, and one for glass and shells. This was revolutionary. Paris had become infamous for its smell and sludge as early as the Middle Ages, and previous attempts to resolve the issue had been unsuccessful. When Poubelle’s waste receptacles were introduced, Parisians quickly coined the term la boîte poubelle, and the later shortened version la poubelle entered Le Larousse dictionary in 1890.

💡 Things to consider

• Stick to the status quo: Much of the Parisian population were unhappy with this new rule. Property owners disliked being expected to front the cost of the scheme, and chiffonniers (rag and bone men) felt that the new poubelles were threatening their livelihood. Was it therefore a form of revenge to name these hated rubbish bins after the man who introduced them?

  

  … said the homeowners having to foot the bill.

• Health…and wealth: Poubelle also successfully campaigned for direct drainage throughout Paris, after a resurgence of cholera in 1892. He declared that all buildings were to be connected directly to the sewers, at the expense of the building’s owner. Once again, Poubelle was asking individuals to pay for his public schemes. Is this right? Should Poubelle have used public money instead?

• Poubelle’s legacy: Even though it wasn’t until after the Second World War that dustbins and regular refuse collection became commonplace in France, Poubelle’s mandates formed the system of recycling that we still use today. What’s more, his work catalysed the development of household waste removal vehicles. This made rubbish collection a common worldwide phenomenon by the start of the 20th century. So why is it that so few people know who Eugène Poubelle is?

🔎 Find out more

• 6 Key Dates in Poubelle’s Life

🍒 The cherry on top

• 🦠 Tuberculosis: Tuberculosis (TB) might sound like a relic of the past, but this treatable disease remains a global killer. This thought-provoking YouTube lecture explores the history of TB and how, despite a known cure, it continues to claim over 1.5 million lives annually. A great watch if you’re into Medicine or History!

• 🏴󠁧󠁢󠁳󠁣󠁴󠁿 Scotland’s Freethinkers: From promoting open debate to connecting free speech with moral virtue, Scotland’s freethinkers chipped away at the absolute power of religion in the 19th century. Check out this article if you’re interested in History, Religion, or Politics!

• 👗 Balenciaga and Art: This article explores the fascinating influence of abstract art on the visionary fashion house Balenciaga. Recommended for those that are interested in Art and Fashion!

👀 Keep your eyes peeled for…

• 29th April:

  • Sheffield Law Taster Session

• 30th April:

  • Trinity Hall Cambridge English Webinar

  • UEA Webinar: Why do People go to University?

  • UEA History Webinar

  • York Open Literature Lecture: The Englishman Abroad: The Medieval Origins of an Identity

  • Sheffield Linguistics Taster Session

  • Sheffield Urban Studies and Planning Taster Session

• 1st May:

  • Sheffield Philosophy Taster Session

  • Sheffield Chemical and Biological Engineering Taster Session

  • Sheffield Human Communication Sciences Taster Session

  • Sheffield Architecture Taster Session

• 2nd May:

  • Disabled Students’ Allowance Webinar

  • Sheffield Bioengineering Taster Session

  • Sheffield Chemistry Taster Session

  • Sheffield Applied Social Sciences Taster Session

🗳️ Poll