Think of Earth as an apple and the soil as the peel. Now, imagine that more than 70% of this apple’s surface is covered in water. That veneer of peel suddenly seems very small indeed.
Dig beneath the surface and you realise that the world’s soil resources aren’t as plentiful as you first thought. When you take into account all of the uninhabitable, non-arable land on our planet, including the snow-bound poles and deserts, you’re left with just 3% of total landmass to grow all the fruit and vegetables we eat.
After reminding her listeners of some stark facts at the Soil resources in the UK: overlooked and undervalued? webinar, Jane Rickson, Professor of Soil Erosion and Conservation at Cranfield University, reminded us that soil is a precious, finite resource. “We’re dealing with a very thin resource that has to deliver all of these goods and services.”
You just need to think of your breakfast, lunch, and dinner to realise just how important soil is. Of all the food we eat, 97% comes from terrestrial sources. However, in recent decades, the many benefits brought by soil have been taken lightly. Apart from providing food, animal fodder, and a surface for football, it plays a vital role in climate change mitigation.
‘Soil is excellent for climate change mitigation,’ said Professor Rickson, recipient of the prestigious Dr Sydney Andrew Medal for 2021. ‘We know that healthy soils can support vegetation and crops and plants in taking out atmospheric CO2.’
A cross section of soil layers. Unless you live on fish and seaweed, it’s likely that almost all of your food sources will come from terrestrial sources.
However, she and her colleagues at Cranfield University have unearthed some unsettling facts about the state of our soils. She mentioned that 12 million hectares of agricultural land worldwide is lost each year due to soil degradation. In the UK, soil erosion rates can be as high as 15 tonnes per hectare per year, with soil formation rates only compiling at a rate of 1 tonne per hectare per year; and, based on current rates of erosion, some soils could disappear completely by 2050.
So, what is being done to arrest this problem? The obvious mammoth in the room is climate change, with extreme weather events such as flash floods precipitating a huge amount of soil erosion. Obviously, climate change mitigation measures on a national scale would help, but adjustments to farming practices could also improve soil resilience on a more local level.
A lot of work is also being done to reduce the intensity of farming to improve soil health. The aim, according to Rickson, is to maintain a fertile seedbed while retaining maximum resistance to soil degradation. There are lots of different ways to do this.
One approach being taken is cover cropping, whereby a crop is grown for the protection and enrichment of the soil rather than for immediate sale. This enriches the soil and helps prevent soil erosion. Another approach is strip-tillage – a minimum tillage system that disturbs only the portion of the soil that contains the seed row, with the soil between rows left untilled. She also mentioned the benefits of soil improvement, with poultry manure and mushroom compost used to improve soil health by Benedict Unagwu among others.
Cover crops such as vetch and oats improve the structure and fertility of the soil.
It is difficult not to have sympathy for farmers at the moment. Climate change falls heavily upon their lands, and they must battle flooding and drought to keep their farms financially viable. Professor Rickson often speaks to the farming community about soil health, with the focus placed on realistic solutions. As one farmer told her: ‘It's hard to be green when you’re in the red.’
Perhaps soil doesn’t capture the imagination the same way as an oak forest or a field ablaze with wildflowers, but its mismanagement is costing us a fortune. She estimated that the combined annual economic cost of soil degradation in England, Scotland, and Wales is £1.5 billion.
According to Professor Rickson, the US is probably the home of soil conservation following the harsh ecological lessons learnt from the Dust Bowl disaster of the 1930s. However, she believes the UK has plenty of knowhow in the area.
‘The UK has an opportunity to be world-leading in this,’ she said. ‘I think we are as good as anyone. Our scientific community understands soil and is really pushing the boundaries in terms of soil science.’
To some, the almond is a villain. This admittedly tasty nut takes an extraordinary amount of water to grow (1.1 gallons per nut) and some in California say almond cultivation has contributed to drought.
And so it is no surprise to see the almond lined up in the rogue’s gallery of the thirstiest foods. In a study in the journal Nature Food, University of Michigan (U-M) and Tulane University researchers assessed how the food we eat affects water scarcity.
Meat consumption was found to be the biggest culprit in the US, with the hooves and feet of livestock accounting for 31% of the water scarcity footprint. Within the meat category, beef is the thirstiest, with almost six times more water consumption than chicken.
Almond crops in California have come under heavy criticism due to their heavy water consumption
However, the picture is a little more nuanced. Lead author Martin Heller, of U-M's School for Environment and Sustainability, explains: “Beef is the largest dietary contributor to the water scarcity footprint, as it is for the carbon footprint. But the dominance of animal-based food is diminished somewhat in the water scarcity footprint, in part because the production of feed grains for animals is distributed throughout less water-scarce regions, whereas the production of vegetables, fruits and nuts is concentrated in water-scarce regions of the United States, namely the West Coast states and the arid Southwest.”
Certain types of diets drain the water supply. People who eat large quantities of beef, nuts such as the infamous almond, walnut, and cashew, and a high proportion of water-intense fruits and vegetables including lemon, avocado, asparagus, broccoli, and cauliflower take a heavy toll on the water footprint.
The Brussels sprout is not just for Christmas… it is a less water intense option for your dinner table.
“The water-use impacts of food production should be a key consideration of sustainable diets,” adds study co-author Diego Rose of Tulane University. “There is a lot of variation in the way people eat, so having a picture with this sort of granularity – at the individual level – enables a more nuanced understanding of potential policies and educational campaigns to promote sustainable diets.”
So, what do you do the next time you feel a pang of water guilt? According to the researchers, you could swear off asparagus and that crushed avocado on your toast and replace them with less water intense foods such as fresh peas, Brussels sprouts, cabbage, and kale (but maybe not on your toast). Those beef steaks and hamburgers could make way for other protein sources, such as chicken, pork, and soybeans, and you could graze on peanuts and seeds instead of those honey roasted almonds you love so dearly. Just think of all those gallons of water you’ll save.
For more on this study, visit: https://www.nature.com/articles/s43016-021-00256-2
Bit by bit, the green hydrogen revolution is coming to our shores. The news that a planning application has been filed for the UK’s largest electrolyser in Glasgow could be a boon for hydrogen evangelists, the local communities, and the political class.
The 20MW electrolyser will form part of the green hydrogen facility on the outskirts of Glasgow near Whitelee, the UK’s largest wind farm. The proposed project would produce up to 8 tonnes of green hydrogen each day – the equivalent of 550 return bus trips from Glasgow to Edinburgh.
If approved, the scheme would be delivered by ScottishPower, BOC, and ITM Power as part of the Green Hydrogen for Scotland Partnership. BOC would operate the facility using solar and wind power produced by Scottish Power and ITM Power would provide the all-important 20 MW electrolyser. Renewable energy would power the electrolyser, which would split the water into hydrogen and oxygen gas. The hydrogen produced by this process could then be used in various applications including transport.
Fundamentally, the people who will benefit most are the people of Glasgow, with the project aiming to provide carbon-free transport and clean air for people across the city area, while satisfying some industrial hydrogen demand. And we can all rest easy now that we know politicians will be pleased about it too, for the project coincides nicely with the United Nations 26th Climate Change Conference, which will be held in Glasgow later this year.
The new facility will be based beside a plentiful renewable energy source, Whiteless wind farm in Eaglesham Moor. | Editorial credit: Maritxu / Shutterstock.com
If all goes swimmingly, the facility will supply hydrogen for the commercial market by 2023. “Whitelee keeps breaking barriers, first the UK’s largest onshore wind farm, and soon to be home to the UK’s largest electrolyser,” says Barry Carruthers, ScottishPower’s Hydrogen Director. “The site has played a vital role in helping the UK to decarbonise and we look forward to delivering another vital form of zero carbon energy generation at the site to help Glasgow and Scotland achieve their net zero goals.”
Tumbling renewable prices
This exciting news follows on the back of some bold green hydrogen claims made in a recent Bloomberg New Energy Foundation (NEF) report: the 1H 2021 Hydrogen Levelised Cost Update. According to Martin Tengler, BloombergNEF’s Lead Hydrogen Analyst, the report authors believe the cost of renewable hydrogen could fall 85% by 2050, 17% lower than they had previously predicted. This, he says, is due to falling renewables prices.
It is becoming cheaper all the time to produce solar and wind power, which is good news for those producing green hydrogen.
Tengler also says that renewable hydrogen should be cheaper than blue hydrogen (when natural gas is split into hydrogen and CO2 via processes such as steam methane reforming) in many countries by 2030. Furthermore, Bloomberg NEF predicts that green hydrogen will be cheaper to process than natural gas in many countries by 2050.
With the prices of solar and wind power constantly tumbling, it would be no surprise to see the authors of these reports revising their projections even further in the coming years. In the mean-time, we welcome the green shoots peeking through outside Glasgow.
When you live in a cold country, you think of hot days as a blessing. Air conditioning units are for those in far-away places – humid countries where the baked earth smell rises to meet you when you step off the plane.
But cooling comes at a cost. According to the UN Environment Programme, it accounts for 7% of global greenhouse gas emissions. Some of us are visual learners; so, the sheer cost of cooling really hit me when I stared up at an apartment building in Hong Kong with hundreds of air conditioning units perched above the windows like birds.
And it isn’t just the Hong Kongers feeling the heat. The cooling industry as a whole is under pressure to cut its greenhouse gas emissions. The International Energy Agency expects emissions from cooling to double by 2030 due to heat waves, population growth, urbanisation, and the growing middle class. By 2050, it forecasts that space cooling will consume as much electricity as China and India do today.
Air conditioning units cling to a building
All of this was captured by the Cooling Suppliers: Who's Winning the Race to Net Zero report released by the Race to Zero campaign, the Kigali Cooling Efficiency Program (K-CEP), Carbon Trust and other partners in the UN Environment Programme-hosted Cool Coalition.
This report's authors found that only five of the 54 cooling companies they assessed have committed to net-zero targets. The document outlines three areas that must be addressed on the Cooling Climate Pathway: super-efficient appliances, ultra-low global warming refrigerants, and the widespread adoption of passive cooling measures such as clever home design and urban planning.
So, while builders adjust window sizes, introduce trees for shading, and choose materials (such as terracotta cooling systems) thoughtfully to temper the sun’s gaze, others are availing of different methods.
For example, the COP26 (the 2021 UN Climate Change Conference) Champions Team has just released its Net Zero Cooling Action Plan that includes a Cool Calculator tool to help companies and governments run simple calculations to see where they could decarbonise their cooling systems. Similarly, the UK's Environmental Investigation Agency (EIA) has launched a net-zero cooling product guide that showcases energy-efficient products run on natural refrigerants.
Green walls are one of many passive cooling approaches used to reduce our reliance on mechanical systems.
However, it’s clear that the softly-softly approach won’t suffice. The EIA has called on governments to do more to encourage organisations to adopt sustainable cooling, to make concrete policy commitments, and speed-up the phase-out of climate-warming refrigerants such as hydrofluorocarbons.
“The development and expansion of net-zero cooling is a critical part of our Race to Zero emissions,” said Nigel Topping, UK High Level Champion for COP26. “In addition to technological breakthroughs and ambitious legislation, we also need sustainable consumer purchasing to help deliver wholesale systems change.”
We all love the technological panacea – innovations that will cure all the climate ills we have inflicted on the world. But the solution will also involve stodgy government regulations and changing consumer habits, and a reliance on the continued fall in renewable power generation.
For those in traditionally cooler climes, it’s no longer someone else’s problem. It was a balmy 22°C in London this week and we’re not even in April yet. So, it’s certainly time to turn up the heat on the cooling industry.
What do grape stalks, pineapple leaves, corn cobs, rice husks, sheep’s wool, and straw have in common? Apart from being natural materials, they have all been used to insulate homes. Increasingly, people are turning towards natural, sustainable materials as climate change and waste have become bigger problems.
Existing building insulation materials such as synthetic rock wool are excellent at keeping our homes warm in winter, but the conversation has moved beyond thermal performance. Energy use, re-usability, toxicity, and material disposal are all live considerations now, especially with regulations and emissions targets tightening. So, rock wool might perform better than straw bale insulation but straw is biodegradable, reusable, easy to disassemble, and doesn’t require large amounts of energy to process.
Sheep’s wool and hemp insulation have also become attractive to homeowners and housebuilders alike, but an even more encouraging prospect is the use of waste materials to create next generation insulation. In this spirit, researchers at Flinders University in Adelaide, Australia, have taken waste cooking oil, wool offcuts, and sulphur to process a novel housing insulation material.
Recycled paper is one of many waste materials that has found its way into domestic insulation.
To make this composite, they followed several stages. In the first stage of the synthesis, the researchers used inverse vulcanisation to create a polysulphide polymer from canola oil triglyceride and sulphur. They then mixed this powdered polymer with wool and coated the fibres through electrostatic attraction. This mixture was compressed through mild heating to provoke S−S metathesis in the polymer and bind the wool. The wool bolsters the tensile strength of the material, makes it less flammable, and provides excellent insulation. The result is a sustainable building material that fulfils its function without damaging the environment.
For Associate Professor Justin Chalker, the lead author of this study, this work provides an ideal jumping-off point. “The promising mechanical and insulation properties of this composite bodes well for further exploration in energy saving insulation in our built environment,” he said.
It is clear that ventures like the one in Adelaide will continue to sprout all over the world. After all, necessity dictates that we change the way we build our homes and treat materials.
A recent report from Emergen Research predicts that the global insulation materials market will be worth US $82.96 billion (£59.78 billion) by 2027. The same report was also at pains to mention that the increasing demand for reduced energy consumption in buildings will be a significant factor in influencing industry growth.
“Market revenue growth is high and expected to incline rapidly going ahead due to rising demand for insulation materials... to reduce energy consumption in buildings,” it said. One of the main reasons given for this increased green building demand was stricter environmental regulations.
And Emergen isn’t the only organisation feeling the ground moving. Online roofing merchant Roofing Megastore, which sells more than 30,000 roofing materials, has detected a shift towards environmentally friendly materials, with many homeowners sourcing these products themselves.
Rock wool insulation panels have come under greater scrutiny in recent times.
Having analysed two years of Google search data on sustainable building materials, the company found that synthetic roof tiles are generating the most interest from the public. Like the Flinders insulation, these roof tiles make use of waste materials, in this case recycled limestone and plastic. And you don’t need to look far down the list to find sustainable insulation materials, with sheep’s wool insulation in 9th place, wood fibre insulation in 10th, and hemp insulation in 12th.
Over time, the logic of the progression towards natural, less energy-intensive building materials will become harder to ignore. “Traditional materials such as synthetic glass mineral wool offer high levels of performance but require large amounts of energy to produce and must be handled with care while wearing PPE,” the company noted. “Natural materials such as hemp or sheep’s wool, however, require very little energy to create and can be installed easily without equipment.”
So, the next time you look down at your nutshells, spent cooking oil, or tattered woollen sweater, think of their potential. In a few years, these materials could be sandwiched between your walls, keeping you warm all winter.
Insulating composites made from sulphur, canola oil, and wool (2021): https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/cssc.202100187?af=R