ScholarTribe Climate Briefing VIII
Thursday 28th July
Good afternoon, and welcome to the eighth edition of the ScholarTribe Climate Briefing! It’s been a crazy few weeks since the last edition - especially in the UK, with a Conservative leadership election, England reaching the final of the 2022 Euros, and the hottest ever temperature of 40.3 degrees being recorded in Lincolnshire. But of course, the most seismic news event of them all is the launch of our new marketplace! This has taken a huge amount of effort from everyone here at ScholarTribe, and we are delighted with how it has turned out. If you haven’t already, please give it a look here.
Now on to the newsletter; you may be thinking that the topic of the UK heatwave would be ripe for discussion this week. And you’d be absolutely right - there are lots of aspects to that heatwave which are absolutely exceptional, not least the fact that it was so well forecast. But this can wait for the next edition, once the dust has settled a bit. Instead, this week we will be hearing from an exclusive, super-special guest author, the esteemed Mr Finn Whiteley, who will be taking you through some of the research that has interested him this week. Finn has being doing a short placement with us this week, and has been instrumental in helping get our marketplace out into the world. So thanks Finn, and without further ado - over to you!
🌲 Global trends in forest resilience
💡 Outside-the-box thinking on climate change solutions
🌡 and why humid heat feels worse than dry heat!
Finding a root forward
A recent paper, published in Nature, has found that climate change is having an increasingly detrimental effect on the resilience (the capacity of forests to recover after disturbance) of tropical, arid and temperate forests worldwide. It shows that roughly ‘23% of intact undisturbed forests’ have already reached ‘critical’ threshold. This decrease in resilience is a net effect from many different impacts of climate change. While an increase in CO2 fertilisation and greening tend to contribute towards an increase in forest resilience, in these cases the negative effects from water limitation and more frequent extreme weather events outweigh the positives.
The thought of losing these forests is worrying, as they are crucial in operating as a carbon store, acting as a sequester for 3.32 Gigatonnes of carbon. Forest resilience will be increasingly important moving forward with forest growth and management being some of the largest nature-based solutions to climate change. Possible side effects of the future deterioration of forests are also highlighted by Forzieri et al. – for example, decreased biodiversity caused by loss of habitat and the subsequent breakdown of ecosystems.
On a cheerier note, the paper also notes that the impacts of climate change favour boreal forests, and that these biomes are seeing increased resilience. Sadly we can’t get our hopes up, as the impact of boreal forests as a carbon store is far less than that of tropical, arid and temperate forests.
Forests are key to the success of the future climate, so we need to make preserving them a priority.
Innovators gonna innovate
Fully pedestrianised cities are purely a concept for the imagination as things stand. This model would hugely reduce global carbon output if it could be carried out on a large scale, as transport is one of the biggest CO2 pollutants and 56% of the world’s population lives in cities. The United Nations’ Climate Change arm is trying to make this a reality - it has launched the Climate Innovation Hub project to use novel ideas to combat climate change. The Hub does not focus on typical product innovation, such as the development of EV batteries, to reduce emissions. Instead, it is asking more radical questions about whether cars are necessary at all, and suggesting that, for example, completely pedestrianised cities, or those with solely low carbon emitting public transport are credible solutions. This could help to ease the current demand for EV batteries, and reduce our reliance on them for reaching net zero.
If you want to read more, here is a report with an overview.
The Net-Zero Compatible Innovations Initiative are looking at a similar idea - they are also focused on human needs and process innovation. They have gone back to square one to look at elementary human needs (e.g. shelter, nutrition and social development), supporting those needs (e.g. with transport and data), and sustainably providing this support (through transforming emitters and material use). For example, one of their most recent projects was a portable cooling box using eutectic thermal panels for cooling. These cooling boxes satisfy the basic human need for food and drink, and the thermal panels constitute a means of achieving this sustainably without external power.
Projects are therefore designed in a fashion to maximise utility and minimise emissions, through innovative processes and products.
Their website can be found here, and it is well worth a look!
Thermodynamics corner: Dry heat vs wet heat
Hello everyone - it’s Dan again (boo! hiss! we want Finn back!). Just a quick one from me, as I thought we should at least have some heat-related content in this edition. I would like to quickly explain the difference between dry heat and wet heat, and why going too far in the wet direction* feels very unpleasant indeed.
To explain this, the first thing we need to cover is evaporative cooling. This occurs when liquid water on a surface undergoes a phase transition to water vapour. This phase transition (evaporation) requires a certain amount of thermal energy, known as the latent heat of vaporisation, and this energy is taken from a combination of the surface which the water is on, and the air. In the case of humans in a hot environment, the heat required to evaporate our sweat is provided by our bodies, which therefore cools us down.
So why does the humidity of the air matter? Well, this dictates how easy it is for our sweat to evaporate. If the air around us has a specific humidity of 100%, then the air cannot hold any more water vapour, and it is impossible for any sweat to evaporate. This leaves us without our biggest tool to cool down, and can be incredibly dangerous at high temperatures. On the other end of the humidity spectrum, however, the air is nice and dry and can accept lots of water vapour, meaning that evaporative cooling is highly effective.
A way of comparing days with different temperatures and humidities comes in the form of dry-bulb and wet-bulb temperatures. The dry-bulb temperature is what we are used to - it is just the temperature of the ambient air, no strings attached. The wet-bulb temperature, however, can be thought of as the temperature a thermometer would read if it was covered in a water-soaked cloth. It is always lower than the dry-bulb temperature, and it represents the lowest temperature it is possible to achieve given optimal evaporative cooling (as we mentioned before, though, if the relative humidity is 100%, then evaporative cooling is not possible and the dry- and wet-bulb temperatures are the same).
The aim of sweating is therefore to get the body as close as possible to this wet-bulb temperature. But even under perfect circumstances, with unlimited water and an electric fan, it can go no lower, which is why a wet-bulb temperature of anything above 30 degrees is very dangerous indeed.
*Wet Direction is also the rather unfortunate title of a new joint outfit between Wet Leg and One Direction
Thanks for reading! Maybe see you next time?