SteamyTea

To within 2 SDs

Because it is in a warm, high humidity/damp environment. The problem is where it is, not the sealant.

Or just leave it as a GRP roof.

Not sure to be honest. The styrene will evaporate off for a few years, and the fumes can still cause problems. So really depends on the amount of ventilation between the two. Just look at a polyurethane system, they have the secondary advantage that they can be used when the substrate is damp. Would need to use a powder bound chopped stand matt, rather than an emulsion bound one, and that has the advantage that it does not itch anything like as much.

The physics will be the same, just the climate reg9ime a bit different. The air is not thin enough to make any real difference, the biggest problem will probably be lo0cal wind speeds. Much is said about solar housing in Denver, Colorado. High altitude, very cold winters, and hot summers. But then they are at a latitude of 39.5°, 9° further south than Paris and about on par with Toldeo, Spain.

What type of build is it, and where in the country. Something sounds very wrong.

Most GRP roofs will be made with polyester resins. The problem with polyester, as opposed to epoxy and polythene resins, is that the crosslinking of the polymers is not so great (why they are cheaper and weaker than epoxy). This means that there is free MEKP (the hardener) and styrene monomer (used as a thinning agent and what smells), both of these are oxidants, so can cause steel to rust. So while you can do it, and it will probably last a decade or so, it really does depend on the roof steel coating. If it was me, I would look at using a polyurethane resin with glass reinforcement. I would also make up a test sample and 'rapidly age' it.

"How do these figures look" Your PV production is very good for your location. I don't know about 'up there', but our weather has been dreary down here all year.

If it is noisy, then it is undersized.

Is the climate change food crisis even worse than we imagined? Extreme weather and a growing population are driving a food security crisis. What can we do to break the vicious cycle of carbon emissions, climate change and soaring food costs – or is it already too late? By Michael Le Page 11 November 2024 Роман Заворотный/Adobe Stock You have probably already noticed that the price of many of the foods in your grocery basket has risen – a lot. In the UK, the cost of white potatoes is up 20 per cent in the past year, with carrots up 38 per cent and olive oil up 40 per cent. And while that means the expense of putting together a roast dinner is soaring, specialty items are suffering even bigger hikes – you will now pay nearly double for some bars of chocolate. What is driving prices up is complex, but one of the biggest factors is climate change. In the short term, extreme weather caused by a warming climate has had devastating consequences for growers. In northern Europe, for instance, torrential rains in spring 2024 left fields too sodden to harvest vegetables or plant new crops. Meanwhile, a drought in Morocco, which typically exports a lot of vegetables to Europe, meant there wasn’t enough water for irrigation. The result was soaring prices for potatoes and carrots. As the average global temperature zooms past 1.5°C above pre-industrial levels in the coming years, heatwaves, droughts and extreme storms are going to become even more common and severe, causing greater disruption to food production. But current efforts to compensate for the impact of poor harvests – such as clearing forests to grow more crops – make many other problems worse, from biodiversity loss to increasing carbon dioxide levels. With such big impacts on so many foods already happening, have we underestimated how bad the effect will be? And what can we do about it if we have? Every crop needs particular conditions to thrive – too hot or too cold, too wet or too dry, and yields will be lower. To understand how global warming will affect yields, climate scientists use computer models to work out how conditions might change in growing regions. Early versions of these models suggested yields could fall in areas near the equator, where crops are already near their heat tolerance limits, but rise in areas further north or south. In fact, a 2007 report by the Intergovernmental Panel on Climate Change (IPCC) concluded that, thanks in part to the fertilising effects of higher atmospheric CO2 on plants, food production would rise overall until the increase in global temperature exceeded 3°C, after which it would begin to fall. Farming in crisis The forecast now, based on improved modelling, is less optimistic. The latest IPCC report, issued in 2022, warned that food security will be increasingly affected by global warming and the climate events associated with it, creating the “possibility for surprises”. Not only are newer climate models projecting much stronger effects, both positive and negative, but the latest crop models also suggest the impact on yields will be much greater too, says Jonas Jägermeyr, a climate scientist at NASA’s Goddard Institute for Space Studies in New York. A recent modelling study by his team projected that wheat yields could rise by up to 18 per cent by 2100 in a high emissions scenario, while maize yields could fall by 24 per cent. These figures aren’t forecasts, but rather give us an idea of what would happen if farmers keep doing what they are doing now. How we broke the water cycle and can no longer rely on rain to fall We thought Earth's water cycle was resilient to human meddling, but new analysis shows our supplies of water in plants and soil that are critical to generating rainfall are dangerously low. Here is what we must do to repair the damage But current models also have some serious limitations. “Realistic projections probably would be a little bit less optimistic,” says Jägermeyr, noting that climate models aren’t good at projecting extreme events and that crop models tend to underestimate impact. Another major limitation is that these models don’t consider the risk of pests and diseases. As the planet warms and becomes more humid, some pathogens will spread to areas where they haven’t been able to survive before. “Where the crops are doing better, their pests and diseases will tend to do better as well,” says Dan Bebber at the University of Exeter in the UK. “We need to be prepared for invasions of new pests and pathogens that we haven’t seen before.” For example, one factor behind soaring olive oil prices is a devastating bacterium called Xylella fastidiosa, which, after being found in Puglia, Italy, in 2013, went on to kill more than a third of the region’s olive trees within a decade. Warmer temperatures are helping it spread in Europe. Another issue with the model studies, according to David Lobell at Stanford University in California, is that they often focus on staples such as wheat and maize, rather than also considering specialised crops like cocoa and coffee. Because these grow in fewer places, their supply has proven more vulnerable to extreme weather. Most of the world’s cocoa comes from just four countries in West Africa, where recent harvests have been devastated by drought, heavy rainfall and a disease called swollen shoot virus. Prices of chocolate have risen precipitously in the past few years in response. “We didn’t really have a good sense of what was going to happen there,” says Lobell of specialty crops. The real cost of food production So far, it is also proving harder for farmers to adapt to the changing climate than we thought – which is deeply worrying, given that the changes now are small compared with those expected in the next few decades. “Earlier studies did show the potential for negative impacts, but they were quite optimistic on how easy it would be to avoid those impacts by just making shifts in the types of varieties that are being grown,” says Lobell. “It’s not going to get any easier if the changes are bigger.” And yet, overall food production has been rising. Lobell’s studies suggest that wheat and maize yields would have been a few per cent higher by now in a world without climate change, but we have kept ahead of the climate curve in part by increasing adoption of fertilisers and mechanisation by farmers. However, that means we are having to use more energy to grow the same amount of food, says Bebber. “Once you control for our agricultural technology, the impact of climate change is already with us.” Drought and wildfires are both on the rise, with negative impacts on crop yields Claudius Thiriet/Biosphoto/Alamy The other reason for rising food production is that the global area used for growing crops is expanding rapidly. This often involves turning forests into farmland, which is catastrophic for biodiversity. Clearing trees also puts a lot more CO2 into the atmosphere, adding to farming’s already large carbon footprint – about a third of our greenhouse emissions come from agriculture. A climate change tipping point Alarmingly, we seem to be at the start of a vicious cycle: global warming is making it harder to grow food, so farming is becoming more emissions-intensive to keep up, leading to yet more warming. The rising temperature will also amplify other threats to world food production, including ocean acidification, groundwater depletion and soil loss, intensifying that cycle further – for instance, hotter temperatures mean farmers need to use more groundwater for irrigation. “The risk that we face is not a risk just to the food system. The risk we face is to the entire climate system, to the entire ecosystems of the world,” says Lobell. “Problems with food quickly spread to land-use change, biodiversity loss, climate emissions. That’s the scenario that we definitely want to avoid. But in some ways, we’re in that scenario right now.” Energy expert Vaclav Smil on how to feed the world without trashing it The systems we use to produce food have many problems, from horrifying waste to their dependence on fossil fuels. Vaclav Smil explains how to fix them The biggest short-term concern isn’t that those on a high income will go hungry, but that we will continue to damage the planet trying to keep supermarkets stocked. To be clear, as the 2022 IPCC reports warns, simultaneous extreme weather events in several parts of the world could lead to major food shocks, but we do have buffers in the form of food reserves and the repurposing of crops currently used for biofuel and meat production for human consumption. For those on low incomes, things are very different. Estimates say more than 700 million people – 9 per cent of the global population – faced hunger in 2023, 150 million more than in 2019. That number is expected to increase with global warming. “It’s not just about producing more food,” says Jägermeyr, it is about producing food where it is needed, at a price people can afford. How counting the true cost of cheap food could make a better world What we pay for food and other goods doesn’t reflect the environmental and social damage they cause. But a radical new approach to economics could change that However, if we pass some potential climate tipping points, maintaining the global food supply for everyone will become even harder – and we may be approaching one fast. Vast areas of the Brazilian rainforest are being burned down to become cattle ranches. Close to 18 per cent of the Amazon has been deforested, says Carlos Nobre at the University of São Paulo in Brazil, making the region hotter and drier and increasing the risk that the Amazon will die. “Studies indicate that if we reach 20 to 25 per cent deforestation, and global warming exceeds 2°C, we are going to reach the [Amazon rainforest] tipping point,” says Nobre, making it more difficult to grow food. That will have significant negative consequences for all of us – Brazil produces around 10 per cent of the world’s food by weight, including half of global soya bean exports and a third of beef exports. How can we preserve food security? So what do we need to do to keep producing enough to eat, without causing even more problems? “The short answer is everything,” says Lobell. No single solution is a magic bullet – averting the coming food crisis will take a myriad of innovative and scalable responses. One big answer is eating less meat. A huge proportion of the food we grow, especially maize and soya, is fed to animals rather than eaten directly by us. “If we use land more efficiently and feed humans rather than livestock, then all the problems go away,” says Bebber. Unfortunately, the opposite is happening. Although global beef consumption is down from around 11 kilograms per person per year in the 1970s to just over 9 kg today, population growth has meant that overall beef production has nearly doubled over this time. The global production of dairy and all meats has been rising steadily for decades, with no sign of any change in that trend – as incomes rise around the world, people eat more meat on average. One way to tackle this is to introduce taxes on meat that reflect the environmental damage its production causes. But few voters want that and, so far, no country has tried it. We can also do more with the food we have. According to a 2024 United Nations report, a fifth of the food that reached shops, restaurants and consumers in 2022 went to waste. Producing that wasted food generated 8 per cent of global greenhouse gas emissions, while gases produced by food rotting in landfills also has a warming effect. Only a few countries are making progress on this: the UK, Europe’s largest waster of food but also a signatory to the UN 2015 voluntary food waste reduction goal, is among them. Between 2007 and 2021, the country saw an 18 per cent reduction in food waste, and new legislation requiring businesses to separate food waste from other streams will come into effect from March 2025, showing that change is possible. How genetically modified crops could feed us and help safeguard nature There has been plenty of controversy over GM crops, but if deployed well they could have a positive environmental impact, says Graham Lawton Modifying our behaviours can undoubtedly mitigate the damage (see How you can help solve the food crisis, below), but there are other tools, too. Work to make crops more heat, drought and pest resistant is already under way. Scientists are also trying to design crops capable of making their own nitrogen fertiliser. Legume plants such as peas and beans host bacteria in their roots that convert nitrogen in the air into chemicals that plants can use, but researchers have so far been unable to induce this process in other crops. However, if achieved this would dramatically reduce greenhouse gas emissions caused by the manufacture and use of fertiliser, plus make food cheaper. Other researchers are working on photosynthesis, the process by which plants harness sunlight to create the energy they need to grow. Photosynthesis is surprisingly inefficient – only about 0.3 per cent of the energy in the light hitting a field of wheat ends up in the harvested grain. In 2022, a team led by Stephen Long at the University of Illinois Urbana-Champaign reported yields up to a third higher in soya beans modified to make them photosynthesise more efficiently. This claim has been disputed, but further trials are ongoing. If it works, the impact would be huge: selective breeding has improved the yields of soya beans and maize by only about 1 to 2 per cent each year, and these are among the highest gains for any crop. But by combining multiple ways of boosting photosynthesis, Long says it might be possible to increase yields by more than 50 per cent. Technology can also improve farming practices: precision agriculture and robotics can, for example, apply nitrogen fertilisers more efficiently, reducing greenhouse gas emissions and the pollution from agrochemicals washed off land into rivers and streams. Then there is taking the field out of farming. Growing plants in controlled conditions, such as in greenhouses, can protect them from extreme weather and make yields more reliable, but the energy cost to keep conditions controlled can be high. Another not entirely new approach is to grow food in vats – the meat substitute Quorn, for example, is produced this way from a soil fungus. However, the challenges of growing fungal, plant or animal cells in vats means the products can be prohibitively expensive. Those cells also still have to be fed, and because the nutrients used presently come from crops grown in fields, the environmental footprint of the final product isn’t necessarily that much better than the products they replace. Governments should pour money into securing food production, but they are doing the opposite But what if we could make nutrients directly using energy and plentiful raw materials, rather than relying on photosynthesis to do the job? Earlier this year, a Finnish company called Solar Foods became the first to produce food commercially this way, using electricity to split water into oxygen and hydrogen, then feeding the latter to bacteria that use it as their main food source. The final product is a yellow protein-rich powder called Solein that can be used as an ingredient in a variety of fare. Snack bars containing Solein are already on sale in Singapore. Compared with producing the same amount of plant proteins, the company claims producing Solein results in a fifth less CO2 emitted, while requiring a 20th of the land and a 100th of the water. Questions remain whether this can be scaled up and whether people will buy it, but this kind of approach could have a big impact even if it is used only for animal feed. We do have what it takes to make our food system more productive and resilient and less damaging to the environment. However, at a time when governments should be pouring more money into such efforts, they are actually spending less, says Lobell. “The combination of less innovation and more climate change is a very scary one,” he says. “I think we can do a lot on both of those. But it’s not going to happen overnight.” How you can help solve the food crisis Composting food waste is one way to help reduce emissions Jim West/Alamy EAT MORE ADVENTUROUSLY Growing a wider range of crops would make our food system more resilient to weather extremes, pests and diseases. But it is difficult for farmers to switch to crops for which there is little demand. So try some foods you may not have sampled before, such as breadfruit, and if you like them, keep on buying them. THINK TWICE BEFORE YOU BUY ORGANIC Organic food is marketed as environmentally friendly, but on average yields are lower. This means we would need a lot more farmland if everyone ate organic, accelerating deforestation and the loss of biodiversity as well as increasing greenhouse emissions related to land clearance. EMBRACE GM FOOD To save the rainforests, we need to produce more food on less land. Genetic modification is one of the best tools for achieving this. Take bananas, which have one of the lowest carbon footprints of any food, even when you factor in shipping. The popular Cavendish variety is being hard hit by the spread of a fungal disease, but a resistant variety has been created by gene editing. Its adoption, however, is being slowed by the opposition to genetically modified crops. FAVOUR LOW-EMISSION FOODS Producing a kilogram of mutton or cheese results in less than half the greenhouse gas emissions of 1 kg of beef, while 1 kg of pork and chicken results in a 10th of those emissions. So simply picking one kind of animal-derived product over another can make a big difference. Fruits and vegetables usually have much smaller carbon footprints than any animal product, so eating more of them is better and healthier, too. DON’T WORRY TOO MUCH ABOUT FOOD MILES Buying local is a long way from being the most important thing when it comes to the sustainability of what you eat. Locally raised beef can have a carbon footprint around 100 times as large as bananas shipped thousands of miles. Focus on what you eat rather than where your food comes from. WASTE NOT, WANT NOT An estimated 60 per cent of food waste happens in households, so we all have a part to play in reducing this – which would be a win-win for us and the planet. There are lots of ways to reduce waste, but the biggest, of course, is to avoid buying food you are unlikely to eat before it spoils.

Spraying rice with sunscreen particles during heatwaves boosts growth Zinc nanoparticles, a common sunscreen ingredient, can make plants more resilient to climate change – in a surprising way By James Dinneen 4 November 2024 Spraying rice with sunscreen particles during heatwaves boosts growth Zinc nanoparticles, a common sunscreen ingredient, can make plants more resilient to climate change – in a surprising way By James Dinneen 4 November 2024 Sunrise over rice terraces in Bali, Indonesia Aliaksandr Mazurkevich / Alamy A common sunscreen ingredient, zinc nanoparticles, may help protect rice from heat-related stress, an increasingly common problem under climate change. Zinc is known to play an important role in plant metabolism. A salt form of the mineral is often added to soil or sprayed on leaves as a fertiliser, but this isn’t very efficient. Another approach is to deliver the zinc as particles smaller than 100 nanometres, which can fit through microscopic pores in leaves and accumulate in a plant. Researchers have explored such nanoparticles as a way to deliver more nutrients to plants, helping maintain crop yields while reducing environmental damage from using too much fertiliser. Now Xiangang Hu at Nankai University in China and his colleagues have tested how zinc oxide nanoparticles affect crop performance under heatwave conditions. They grew flowering rice plants in a greenhouse under normal conditions and under a simulated heatwave where temperatures broke 37°C (98.6°F) for six days in a row. Some plants were sprayed with nanoparticles and others weren’t treated at all. When harvested, the average grain yield of the plants treated with zinc nanoparticles was 22.1 per cent greater than the plants that hadn’t been sprayed, and this rice also had higher levels of nutrients. The zinc was also beneficial without heatwave conditions – in fact, in these cases, the difference in yield between treated and untreated plants was even greater. Based on detailed measurements of nutrients in the leaves, the researchers concluded that zinc boosted yields by enhancing enzymes involved in photosynthesis, as well as antioxidants that protect the plants against harmful molecules known as reactive oxygen species. “Nanoscale micronutrients have tremendous potential to increase the climate resilience of crops by a number of unique mechanisms related to reactive oxygen species,” says Jason White at the Connecticut Agricultural Experiment Station. The researchers also found that rice treated with zinc nanoparticles maintained more diversity among the microbes living on the leaves – called the phyllosphere – which may have contributed to the improved growth. Tests of zinc oxide nanoparticles on plants like pumpkin and alfalfa have also shown yield increases. But Hu says more research is needed to verify this could benefit other crops, such as wheat. Journal reference Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.2414822121 Any delay in reaching net zero will influence climate for centuries Reaching net-zero emissions is essential for halting climate change - but even after we achieve this goal, parts of the planet will continue to warm. Delaying net zero will worsen these effects By Madeleine Cuff 11 November 2024 Ice collapsing into the water at Perito Moreno Glacier in Los Glaciares National Park, Argentina R.M. Nunes/Alamy Even a few years’ delay in reaching net-zero emissions will have repercussions for hundreds or even thousands of years, leading to warmer oceans, more extensive ice loss in Antarctica and higher temperatures around the world. Nations around the world have collectively promised to prevent more than 2°C of global warming, a goal that can only be achieved by reaching net-zero emissions – effectively ending almost all human-caused greenhouse gas emissions – before the end of the century. But once that hugely challenging goal is achieved, the planet will keep warming. “Even if we do reach net-zero emissions – and that has to be a goal – we still have lots of aspects of the climate that are going to evolve for a very long time,” says Andrew King at the University of Melbourne. Climate modellers are using a new generation of models that capture the way carbon is absorbed and released by land and the ocean to simulate how Earth’s systems might respond to a stable net-zero emissions world. Most of these experiments simulate a net-zero world for around 100 years, but King and his colleagues have gone further, simulating 1000 years of net-zero emissions. The team modelled scenarios in which emissions continue to rise rapidly before reaching net zero at five-year intervals from 2030 to 2060. This resulted in seven simulations of net zero under different levels of warming. They found that although warming over land stabilises once net zero is achieved, the deep ocean continues to warm for centuries to come, as heat from surface waters descends, pushing up global mean temperatures. “The unfortunate thing is that we have changed the climate, and in some aspects it is going to keep going further and further away from its pre-industrial state for quite a long time, even under net zero,” says King. Certain parts of the world will experience more ongoing change than others. In the northern hemisphere, most land regions reach peak warming within a few centuries of net-zero emissions being reached. By contrast, the Southern Ocean continues to warm for 800 to 900 years. This leads to a long-term decline in Antarctic sea ice over the centuries, and more warming in Australia than elsewhere. The later we achieve net zero, the larger these changes will be, suggest the simulations. Delaying net zero by just five years results in a warmer ocean, lower levels of sea ice and higher average temperatures around the world. For example, if net-zero emissions are reached in 2060, under a high-emissions scenario, the city of Melbourne will warm by a further 1°C after that point. “If we equivocate or delay in reaching net zero, it will take a long time for that delay to be washed out,” says King. “The faster we get to net zero, the better.” While some aspects of the climate system will keep changing after net zero, others appear to return to a pre-industrial “normal” in the simulations. In some areas, such as the Mediterranean, rainfall patterns return quickly to 19th-century levels. The El Niño and La Niña weather patterns, which have seen their heating and cooling effects strengthened by climate change, will also damp down again once we reach net zero. Much more research is needed into these kinds of regional change under net zero, says King, who cautions that the results are based on just one Earth system model. Plus, the findings may not factor in every relevant climate “tipping point” that could trigger sudden, irreversible changes to regional climate systems at a certain level of warming. Nevertheless, Paulo Ceppi at Imperial College London says the results may enhance our understanding of how net-zero emissions will change regional climates. “I am sure there are some aspects here that would be robust across models,” he says. An important thing to keep in mind is that the simulations aren’t direct predictions of a net-zero emissions future. For one, the model simulated emissions being cut from high levels down to zero overnight, rather than a more realistic tapering down over decades. “It’s completely unrealistic to go to net zero overnight,” says Ceppi. Meanwhile, the simulations assume the world stays at net-zero emissions. Climate campaigners hope that once humanity achieves net zero, there will be an effort to remove even more carbon dioxide from the atmosphere to start reversing some climate impacts. Journal reference Earth System Dynamics DOI: 10.5194/esd-15-1353-2024 2024 is set to be the first year that breaches the 1.5°C warming limit This year’s average global temperature is almost certain to exceed 1.5°C above pre-industrial times – a milestone that should spur urgent action, say climate scientists By Madeleine Cuff 6 November 2024 Firefighters work to control a blaze in California in July ABACA/Shutterstock 2024 is now almost certain to become the first year on record when average temperatures exceed 1.5°C above pre-industrial levels, breaching the threshold set by the Paris Agreement. “At this point, barring an asteroid impact or a massive volcanic eruption… I think it’s safe to say this will be the first year above 1.5 degrees,” says Zeke Hausfather at US non-profit Berkeley Earth. Last year, the average surface temperature across the globe was 1.45°C above the 1850-1900 average, which is used as the pre-industrial baseline, with a margin of error of 0.12°C, according to the World Meteorological Organization. It uses an average of five major datasets to arrive at this figure. For the first eight months of 2024, the average temperature surpassed that for the same month in 2023, says the US National Oceanic and Atmospheric Administration. The average for this period was 1.54°C above pre-industrial levels, according to data from the Met Office, the UK’s weather service. Although the average for September was cooler than at the same time last year, there is little doubt that 2024 as a whole will exceed the global target for the first time. “It would take quite a notable and unusual cooling event to bring the annual average below 1.5°C,” says Colin Morice at the Met Office. Temperature datasets collected by various agencies and institutions around the world vary slightly, mainly due to differences in how ocean temperatures have been collected and analysed over the decades. But the five main datasets are set to indicate 2024 temperatures settled around 1.5°C above pre-industrial times, with several just above this mark, says Hausfather. “While not all of the datasets are going to be above 1.5°C this year, it is going to be the first year where the average… is above 1.5°C,” he says. The primary driver of rising global temperatures is human-caused climate change, says Carlo Buontempo at Copernicus, the European Union body that monitors climate. “This is not coming out of the blue,” he says. “The main driver for this warming is increasing greenhouse gas in the atmosphere.” A recent, strong El Niño pattern – the Pacific Ocean phenomenon that generally brings higher global temperatures – is another significant factor. But the scale and persistence of the heat has shocked many experts, who expected temperatures to subside once El Niño ended in May 2024. Instead, the record-breaking heat continued well into the second half of the year, puzzling scientists. Competing explanations abound. The sun reached a so-called solar maximum in 2024, slightly increasing the solar radiation hitting Earth. Meanwhile, changes to shipping pollution rules in 2020 have reduced air pollution over the world’s oceans, potentially magnifying heat absorption from the sun as certain pollutants are known to have a cooling effect. But research into the impacts of these factors is still inconclusive, says Piers Forster at the University of Leeds, UK. “We do not completely understand why this extra spike in surface temperatures has continued,” he says. He warns it may be that the rate of climate change has accelerated. “If you just look at historical temperature changes, they do not increase in a monotonic way – they seem to go in fits and starts,” he says. The world has already experienced a 12-month period above 1.5°C of warming, with temperatures between July 2023 and June 2024 1.64°C above pre-industrial levels, according to Copernicus. Nevertheless, the passing of the 1.5°C threshold in one calendar year is a totemic moment for the climate community. The limit has become a guiding light for it, after being included as a “stretch goal” in the 2015 Paris Agreement. Yet years of failure to cut global emissions have made a breach almost inevitable, despite research since 2015 showing warming beyond 1.5°C would be far more dangerous than first thought. However, a single year above 1.5°C of warming will not count as a breach of the Paris Agreement – which is judged on a 30-year average. On that basis, most climate models expect the 1.5°C threshold to be exceeded at some point in the early 2030s, unless the world makes immediate, dramatic cuts to emissions. Nevertheless, Hausfather hopes 2024 will underscore how fast the world is changing due to human activities. “Hopefully it will serve as a wake-up call for policymakers, and then history will look back on it as the year when the world changed and started finally taking this problem as seriously as it deserves,” he says. Forster echoes this sentiment, arguing it should spur leaders into taking action to cut real world emissions and adapting societies to prepare for future climate change. “I want to try as much as possible to connect this passing of 1.5°C with what we have to do to protect our society from the impacts of climate change,” he says.

A while back someone asked about the amount of energy it takes to batteries( @JamesPa). At the time I did some quick research, and as Hannah Richie has found out, it is not that easy to get to the bottom of this, and she has a lot more resources than I do. She produced this report, from this study. Well worth reading (I would have copied and pasted, but it does not do a good job. There is also this report about recycling existing RE technology. Low-carbon tech needs much fewer materials than it used to; this matters for resource extraction in the future Improvements in material efficiency + recycling = super-circularity. Hannah Ritchie Nov 12, 2024 The concept of a “circular economy” has always sounded nice and aspirational: running an economy on refurbished and recycled materials so that the amount of new materials you need to extract is close to zero. I have to be honest and say that I was always a bit skeptical of this vision: wonderful in theory, but just not how the world will ever work. Of course, a fossil-fueled economy is as far from circular as you can get. Fossil fuels are dug up, burned once, and the process repeats. It requires continuous extraction, with no hopes of recycling. Low-carbon technology gives us some opportunity to get closer to a circular model. Many materials can be recycled, even if they’re not being recycled right now (see my previous post on battery recycling stats). Yes, we will need a large ramp-up period of mineral extraction as the world shifts to renewables, batteries, and electric cars, but the hope is that we then reach a better equilibrium where materials for new solar panels and turbines are coming from old ones that have reached the end of their life. Total circularity seems unlikely, but maybe we could get close. But I think this circularity discussion actually underestimates how much of a difference low-carbon technology could make in the model of the resource economy. That’s because we underestimate, forget, or are not aware of the massive improvements in material efficiency of these technologies. A solar panel built today uses far fewer materials than one a decade ago, and the same goes for batteries. My vision of circularity has always been a 1-to-1 conversion or loop: the best we could achieve would be turning one old solar panel into one new solar panel, or using my old phone battery as the battery in my new phone. Sure, the recovery rate of materials might be 80% or 90% rather than 100%, so one old panel provides a little less than a full new one. But the overall aim is to get as close to “one in, one out” as possible. But, if we’re able to achieve very high recovery rates for valuable materials, then a solar panel built 20 years ago can now supply the materials for far more than one today. It’s not just “circular” — it’s what we might call “super-circular” or, to use environmental language, “regenerative.” That’s because it now takes far less silicon, lithium, silver, cobalt, glass, or other materials to produce a solar panel, turbine, or battery than it did in the past. Material intensity has improved massively (and this has been one reason why prices have plummeted). It’s surprisingly hard to find material intensity data for these technologies. If anyone has access to good public data on this, please let me know—I’d love to build a dataset that people can use and explore. But I did find data on polysilicon and silver for solar panels, which I’ll use as an example. In 2004, one watt of solar PV needed around 16 grams of poly-silicon. By 2023, this had dropped to 2 grams. One-eighth of the amount. Source: Fraunhofer Institute for Solar Energy Systems (2024). A solar panel installed in 2004 will be reaching the end of its life sometime this decade. Now, if we could recover most of that silicon (which isn’t common today, but scientists are making progress on methods to recycle it back into silicon suitable for new panels), then theoretically it could be enough to make eight new panels.1 Realistically, recovery rates wouldn’t reach 100%, so let’s assume it’s only 80%—that would still be enough for six new panels. With the 16 grams of polysilicon, you could have made one watt of solar power in 2004, 2 to 3 watts in 2014, and 6 to 8 watts today. ⚠️ Note that for simplicity — and to make the key message more soluble — I’m going to assume the wattage of a solar panel hasn’t changed over time. In other words, the change in silicon needed per “panel” is the same as the change per watt. This is so I can help people visualise the transformation. Or take the example of silver. The amount of silver needed per watt of solar fell by 20% for every doubling of global cumulative capacity.2 That’s very similar to the “learning curve” of solar costs: every doubling in cumulative capacity led to a 20% drop in costs. In 2010, solar used around 55 milligrams (mg) per watt. By 2020, this was around 20mg. And recent figures from Jenny Chase (legendary solar analyst at BNEF) have it at around 10 to 13 mg in 2023.3 So, the silver used in one solar panel built in 2010 would be enough for around five panels today (or four if recovery rates are just 80%). By the time a 2010 panel reaches the end of its life — in 2035 or 2040 — silver consumption might be as low as 5mg. In this case, it’d be enough for 10 panels (or “only” 8 if the recovery rate is 80%). High recycling and recovery rates will be key This is very different from the standard vision of “circularity,” where, at best, one product at the end of its life is reincarnated into one new product. Instead, it could look something like the model below—at least for some minerals.4 For other materials, efficiency improvements might be much lower, so the amount of steel used decades ago would still only be enough for one panel today. We might be able to achieve some degree of circularity even while demand for products such as solar panels and batteries continues to grow. Even if this super-circular model is too optimistic, improvements in material efficiency could, at the very least, offset the amount of material that’s lost in recycling processes that are below 100%. If recycling rates recover just 80% of the material, as long as the material efficiency has improved by 20%, there will be enough material in one panel, turbine, or battery to make another one. No extra minerals needed. I’ve heard Michael Liebreich make this point several times before on his Cleaning Up podcast. Of course, this model depends on achieving high recycling rates, especially recycling materials to a “good enough” grade that they can be reused in low-carbon technologies. I admit, this is a significant contingency. But if we can overcome it, there’s enormous potential to reduce pressure on new mineral extraction for decades to come. Material consumption data is hard to come by, and academics are constantly lagging behind You’ll notice that I focused on polysilicon and silver here. That’s because they were the two minerals that I could find public reports and discussions on. There is a dire lack of publicly available data on the material intensity of different technologies. How much cobalt and lithium do lithium-ion batteries use compared to a decade ago? I couldn’t find any good numbers. If you know of datasets that document the changes in material use of low-carbon technologies over time, let me know! I’d love to build a small dataset that others could use. This lack of transparency is probably one of the reasons why so few people are aware of how dramatic the improvements in material efficiency have been. Even academics and analysts writing key papers on the state of the energy transition and material requirements can’t keep up. I was only aware of the amazing silver story because of this exchange between Seaver Wang and Jenny Chase. The fact that researchers can’t keep up with developments in low-carbon energy is, in many ways, a good thing. It means things are moving quickly. But it also means that a lot of the literature is too pessimistic, using outdated assumptions on costs, and the amount of materials we’ll need in the future. 1 Hoseinpur, A., Tang, K., Ulyashin, A., Palitzsch, W., & Safarian, J. (2023). Toward the recovery of solar silicon from end-of-life PVs by vacuum refining. Solar Energy Materials and Solar Cells, 251, 112181. Preet, S., & Smith, S. T. (2024). A comprehensive review on the recycling technology of silicon based photovoltaic solar panels: Challenges and future outlook. Journal of Cleaner Production. 2 I'm being a bit conservative here because recovery rates closer to 90% are more likely": Li, L., Zhang, X., Li, M., Chen, R., Wu, F., Amine, K., & Lu, J. (2018). The recycling of spent lithium-ion batteries: a review of current processes and technologies. Electrochemical Energy Reviews, 1, 461-482. 3 Hallam et al. (2022). The silver learning curve for photovoltaics and projected silver demand for net-zero emissions by 2050. 4 This is from her fantastic (and fun) book, Solar Power Finance Without The Jargon (Second Edition).

Is that when it 'sees' a speed restriction sign on the back of a lorry?

Does that mean you won't be coming on here any more?

That is a big statement, what are the reasons?