Tag Archives: Fertilisers

Laughing gas rise leaves climate science anxious

Atmospheric levels of laughing gas are on the increase, thanks to agriculture. This is no joke for climate change.

LONDON, 14 October, 2020 − If humans are to meet the global heating limits set by international agreement in 2015, they will have to think very hard about the effect of the supper table menu on laughing gas, more formally known as nitrous oxide.

That is because food production depends heavily on nitrogen fertilisers. But greenhouse gas emissions driven by agriculture are increasing atmospheric levels of nitrous oxide (N2O).

This is a greenhouse gas − popularly known as “laughing gas” − that is 300 times more potent than carbon dioxide, and it tends to stay in the atmosphere, driving up the thermometer, for at least 100 years. And in the 200 years since the start of the Industrial Revolution, atmospheric levels of nitrous oxide have risen by 20%, and are still rising.

Nitrous oxide is one of the six greenhouse gases identified in the Kyoto Protocol, the pioneering global climate agreement, as a danger whose emissions should be reduced by all its signatories.

The ratio of N2O to other gases is tiny, a thousand times lower than carbon dioxide, for instance, but an increase can still make a significant difference. In 1750 the ratio stood at 270 parts per billion. In 2018 it had reached 331 ppb, with the fastest growth all in the last 50 years, thanks to humankind’s demand for food.

“There is a conflict between the way we are feeding people and stabilising the climate”

And this, say 57 scientists from 14 nations in a report in the journal Nature, now threatens to eliminate any hope of containing global heating to “well below” 2°C by the year 2100. This is the target set in the Paris Agreement in 2015 by 195 nations.

Right now, the world has already warmed by 1°C in the last century and on all the evidence so far it is heading by the end of the century to be at least 3°C hotter than the average for most of the last 10,000 years of human history.

“The dominant driver of the increase in atmospheric nitrous oxide comes from agriculture, and the growing demand for food and feed for animals will further increase global nitrous oxide emissions,” said Hanqin Tian, of Auburn University’s School of Forestry and Wildlife Sciences in Alabama in the US. “There is a conflict between the way we are feeding people and stabilising the climate.”

He and his colleagues call their research an inventory of the traffic in nitrous oxide from human and from natural sources. The most significant human source is the fertiliser added to croplands.

They found that the highest growth in nitrous oxide emissions came from emerging economies in East Asia, South Asia, Africa and South America, from synthetic fertilisers and from livestock manure. In the course of the next few decades global population will soar, and so will the demand for food.

Total rethink

Researchers have consistently argued for a new approach to agriculture,  with ever-greater emphasis on plant-based diets, as a way to help contain climate change on a scale that is likely to actually threaten global food security.

“Europe is the only region in the world that has successfully reduced nitrous oxide emissions over the past two decades,” said Robert Jackson,  of Stanford University in the US, who chairs the Global Carbon Project.

“Industrial and agricultural policies to reduce greenhouse gases and air pollution and to optimise fertiliser use efficiencies have proven to be effective. Still, further efforts are required, in Europe as well as globally.”

And another author, Josep Canadell of Australia’s Commonwealth Scientific and Industrial Research Organisation, said: “This new analysis calls for a full rethink in the ways we use and abuse nitrogen fertilisers globally and urges us to adopt more sustainable practices in the way we produce food,  including the reduction of food waste.” − Climate News Network

Atmospheric levels of laughing gas are on the increase, thanks to agriculture. This is no joke for climate change.

LONDON, 14 October, 2020 − If humans are to meet the global heating limits set by international agreement in 2015, they will have to think very hard about the effect of the supper table menu on laughing gas, more formally known as nitrous oxide.

That is because food production depends heavily on nitrogen fertilisers. But greenhouse gas emissions driven by agriculture are increasing atmospheric levels of nitrous oxide (N2O).

This is a greenhouse gas − popularly known as “laughing gas” − that is 300 times more potent than carbon dioxide, and it tends to stay in the atmosphere, driving up the thermometer, for at least 100 years. And in the 200 years since the start of the Industrial Revolution, atmospheric levels of nitrous oxide have risen by 20%, and are still rising.

Nitrous oxide is one of the six greenhouse gases identified in the Kyoto Protocol, the pioneering global climate agreement, as a danger whose emissions should be reduced by all its signatories.

The ratio of N2O to other gases is tiny, a thousand times lower than carbon dioxide, for instance, but an increase can still make a significant difference. In 1750 the ratio stood at 270 parts per billion. In 2018 it had reached 331 ppb, with the fastest growth all in the last 50 years, thanks to humankind’s demand for food.

“There is a conflict between the way we are feeding people and stabilising the climate”

And this, say 57 scientists from 14 nations in a report in the journal Nature, now threatens to eliminate any hope of containing global heating to “well below” 2°C by the year 2100. This is the target set in the Paris Agreement in 2015 by 195 nations.

Right now, the world has already warmed by 1°C in the last century and on all the evidence so far it is heading by the end of the century to be at least 3°C hotter than the average for most of the last 10,000 years of human history.

“The dominant driver of the increase in atmospheric nitrous oxide comes from agriculture, and the growing demand for food and feed for animals will further increase global nitrous oxide emissions,” said Hanqin Tian, of Auburn University’s School of Forestry and Wildlife Sciences in Alabama in the US. “There is a conflict between the way we are feeding people and stabilising the climate.”

He and his colleagues call their research an inventory of the traffic in nitrous oxide from human and from natural sources. The most significant human source is the fertiliser added to croplands.

They found that the highest growth in nitrous oxide emissions came from emerging economies in East Asia, South Asia, Africa and South America, from synthetic fertilisers and from livestock manure. In the course of the next few decades global population will soar, and so will the demand for food.

Total rethink

Researchers have consistently argued for a new approach to agriculture,  with ever-greater emphasis on plant-based diets, as a way to help contain climate change on a scale that is likely to actually threaten global food security.

“Europe is the only region in the world that has successfully reduced nitrous oxide emissions over the past two decades,” said Robert Jackson,  of Stanford University in the US, who chairs the Global Carbon Project.

“Industrial and agricultural policies to reduce greenhouse gases and air pollution and to optimise fertiliser use efficiencies have proven to be effective. Still, further efforts are required, in Europe as well as globally.”

And another author, Josep Canadell of Australia’s Commonwealth Scientific and Industrial Research Organisation, said: “This new analysis calls for a full rethink in the ways we use and abuse nitrogen fertilisers globally and urges us to adopt more sustainable practices in the way we produce food,  including the reduction of food waste.” − Climate News Network

Food waste offers unforeseen benefits

FOR IMMEDIATE RELEASE Disposing of food thrown away by those rich enough to be able to afford to do so is an expensive problem – but it can provide renewable energy and other benefits. LONDON,12 July – Societies all over the planet are running out of holes in the ground in which to dump their waste, so they’re under increasing pressure to find alternative solutions. In the European Union one of the problem wastes is food – rich people buy too much in the supermarket and throw a lot away. This is a disaster for local authorities that have to find a way of disposing of it, and a problem for the planet because rotting food produces large quantities of methane, a global warming gas 23 times more potent than carbon dioxide. Pressure to do something about the problem has been increased by ever-growing taxes on local authorities and companies who throw away waste in landfill, making it more expensive every year to rely on holes in the ground. A successful solution to the problem has been found in Oxfordshire in England, which not only solves the waste problem but also produces gas to provide electricity and fertiliser for local farmers. One of the local authorities involved is the Royal Borough of Windsor and Maidenhead, which collects the food waste from Windsor Castle, one of Queen Elizabeth’s favourite homes. Each household in the borough puts its food waste into containers provided by the borough, which then collects them, takes them to a processing plant and turns the contents into a thick soup. Other organic waste from food processors, large supermarkets, restaurants and green waste from forestry, which would also go to landfill, is added to the mixture. This is then fed into a sealed container, called an anaerobic digester, which is designed to allow bacteria – in the absence of any oxygen – to eat the waste, producing methane in the process. The methane is extracted, cleaned and used to generate electricity.

For rich and poor alike?

When the bacteria have done their job all that’s left of the food is a carbon-rich fertiliser prized by farmers. The entire process takes about 100 days, so a whole series of digesters is needed to keep up with the flow of waste and to provide a regular supply of gas to the electricity turbines. The plant, not far away at Wallingford in Oxfordshire, processes 45,000 tonnes of waste a year and cost £10 million to build. It produces 2.3 megawatts of electricity annually, enough to meet the needs of over 4,000 average British households. Each year it produces enough fertiliser for 2,500 acres of local farmland, replacing fertiliser made from fossil fuels, a further saving of greenhouse gases. The company that runs the plant, Agrivert Ltd, claims that it avoids the release of 22,000 tonnes of carbon dioxide annually. Agrivert runs a second plant nearby, which produces 2.1 MW. The big question is whether this system can be used globally, or just in rich societies. Agrivert points out that poor people don’t throw food away – and in any case it’s always cheaper to chuck waste in a hole in the ground or in the river, especially if the person throwing it away does not have to pay the clean-up cost. But it is not just waste food that can be treated in the digesters. Most organic waste from food processing and forestry and other green wastes can be put in them, converted to gas and used to make electricity and fertiliser. Alexander Madden, Agrivert’s chief executive, says palm, coffee, and banana plantations all produce waste that is ideal for digesters.

Worthwhile gains

Hylton Murray-Philipson, one of the company’s founder shareholders, says: “The technology can be applied anywhere, but you need the regulatory framework at both ends of the process, to make sure a steady supply of waste is collected for the digesters and that there is a market for the electricity at the end of it.” In Britain, he said, the company had 20-year contracts to provide the service and to sell the electricity. It had been so successful that it had made the Oxfordshire local authorities taking part in the scheme among the top ten best recycling authorities in Britain. At the moment Agrivert has its two plants up and running in Oxfordshire providing electricity for 8,000 homes, with another under construction in Surrey. Other companies are also building plants elsewhere in Britain and many other EU countries as a way of disposing of this difficult waste, but until now British government help has been lacking. This month, however, the Government’s new green investment bank said it was considering investing £50 million in new projects. This could create 35,000 jobs and help produce 10% of the country’s gas needs. Mr Madden says the growth potential of digesters will ultimately be limited by the amount of waste available, about four million tonnes a year in Britain, enough to feed 150 medium-sized plants. At the moment only 25 have been built. – Climate News Network

FOR IMMEDIATE RELEASE Disposing of food thrown away by those rich enough to be able to afford to do so is an expensive problem – but it can provide renewable energy and other benefits. LONDON,12 July – Societies all over the planet are running out of holes in the ground in which to dump their waste, so they’re under increasing pressure to find alternative solutions. In the European Union one of the problem wastes is food – rich people buy too much in the supermarket and throw a lot away. This is a disaster for local authorities that have to find a way of disposing of it, and a problem for the planet because rotting food produces large quantities of methane, a global warming gas 23 times more potent than carbon dioxide. Pressure to do something about the problem has been increased by ever-growing taxes on local authorities and companies who throw away waste in landfill, making it more expensive every year to rely on holes in the ground. A successful solution to the problem has been found in Oxfordshire in England, which not only solves the waste problem but also produces gas to provide electricity and fertiliser for local farmers. One of the local authorities involved is the Royal Borough of Windsor and Maidenhead, which collects the food waste from Windsor Castle, one of Queen Elizabeth’s favourite homes. Each household in the borough puts its food waste into containers provided by the borough, which then collects them, takes them to a processing plant and turns the contents into a thick soup. Other organic waste from food processors, large supermarkets, restaurants and green waste from forestry, which would also go to landfill, is added to the mixture. This is then fed into a sealed container, called an anaerobic digester, which is designed to allow bacteria – in the absence of any oxygen – to eat the waste, producing methane in the process. The methane is extracted, cleaned and used to generate electricity.

For rich and poor alike?

When the bacteria have done their job all that’s left of the food is a carbon-rich fertiliser prized by farmers. The entire process takes about 100 days, so a whole series of digesters is needed to keep up with the flow of waste and to provide a regular supply of gas to the electricity turbines. The plant, not far away at Wallingford in Oxfordshire, processes 45,000 tonnes of waste a year and cost £10 million to build. It produces 2.3 megawatts of electricity annually, enough to meet the needs of over 4,000 average British households. Each year it produces enough fertiliser for 2,500 acres of local farmland, replacing fertiliser made from fossil fuels, a further saving of greenhouse gases. The company that runs the plant, Agrivert Ltd, claims that it avoids the release of 22,000 tonnes of carbon dioxide annually. Agrivert runs a second plant nearby, which produces 2.1 MW. The big question is whether this system can be used globally, or just in rich societies. Agrivert points out that poor people don’t throw food away – and in any case it’s always cheaper to chuck waste in a hole in the ground or in the river, especially if the person throwing it away does not have to pay the clean-up cost. But it is not just waste food that can be treated in the digesters. Most organic waste from food processing and forestry and other green wastes can be put in them, converted to gas and used to make electricity and fertiliser. Alexander Madden, Agrivert’s chief executive, says palm, coffee, and banana plantations all produce waste that is ideal for digesters.

Worthwhile gains

Hylton Murray-Philipson, one of the company’s founder shareholders, says: “The technology can be applied anywhere, but you need the regulatory framework at both ends of the process, to make sure a steady supply of waste is collected for the digesters and that there is a market for the electricity at the end of it.” In Britain, he said, the company had 20-year contracts to provide the service and to sell the electricity. It had been so successful that it had made the Oxfordshire local authorities taking part in the scheme among the top ten best recycling authorities in Britain. At the moment Agrivert has its two plants up and running in Oxfordshire providing electricity for 8,000 homes, with another under construction in Surrey. Other companies are also building plants elsewhere in Britain and many other EU countries as a way of disposing of this difficult waste, but until now British government help has been lacking. This month, however, the Government’s new green investment bank said it was considering investing £50 million in new projects. This could create 35,000 jobs and help produce 10% of the country’s gas needs. Mr Madden says the growth potential of digesters will ultimately be limited by the amount of waste available, about four million tonnes a year in Britain, enough to feed 150 medium-sized plants. At the moment only 25 have been built. – Climate News Network