organic waste

Rising methane emissions

October 22, 2024 By EarthWise Leave a Comment

Methane is a colorless and odorless gas that occurs abundantly in nature and is also a product of certain human activities. It’s a short-lived but highly potent greenhouse gas and, as a result, is a major driver of climate change. In fact, methane heats the atmosphere nearly 90 times faster than carbon dioxide over a 20-year period.

Despite a global pledge from more than 150 nations to reduce methane emissions by 30% this decade, methane emissions continue to rise. In fact, according to a new paper led by researchers from Stanford University, total annual methane emissions have increased 20% over the past two decades.

The paper, which was recently published in the journal Environmental Research Letters, found that atmospheric concentrations of methane today are more than 2.6 times higher than in pre-industrial times. In fact, atmospheric methane concentrations are currently the highest they’ve been in at least 800,000 years.

Methane emissions from coal mining, oil and gas production and use, cattle and sheep ranching, and decomposing organic waste in landfills are responsible for driving the growth. In 2020, the most recent year for which data was available, nearly 400 million tons – or about two-thirds – of global methane emissions came directly from human activities.

Methane concentrations in Earth’s atmosphere have increased at record speed over the past five years. According to the research team, only the European Union and possibly Australia seem to have decreased methane emissions from human activities over the past two decades. This trend “cannot continue if we are to maintain a habitable climate.”

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Methane emissions are rising faster than ever

Photo, posted December 4, 2010, courtesy of Dani Mettler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon-Negative Concrete | Earth Wise

June 6, 2023 By EarthWise Leave a Comment

Concrete is a mainstay of modern civilization. The world produces more than 4 billion tons of it each year and the process requires high temperatures, mostly obtained by burning fossil fuels. The chemical reactions that produce concrete also produce large amounts of carbon dioxide. In all, cement production is responsible for about 8% of total global carbon emissions by human activities.

This situation is the impetus for a wide range of research activities aimed at reducing the environmental impact of concrete production. Researchers at Washington State University have recently developed a way of making carbon-negative concrete: a recipe for concrete that absorbs large amounts of carbon dioxide.

There have been attempts in the past to add biochar to concrete. Biochar is a type of charcoal made from organic waste that sucks up carbon dioxide from the air. In earlier attempts, even adding 3% of biochar would dramatically reduce the strength of the concrete.

The WSU researchers found that treating biochar with concrete washout wastewater makes it possible to add much more biochar to concrete without reducing its strength. Mixing it with biochar adds calcium, which induces the formation of the mineral calcite, which in turn strengthens the concrete.

The researchers were able to add up to 30% biochar to their cement mixture. Within a month, the resultant concrete was comparable in strength to ordinary concrete. But at the same time, the biochar was able to absorb up to 23% of its weight in carbon dioxide from the air. The new concrete is potentially the most environmentally friendly concrete ever developed.

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Researchers develop carbon-negative concrete

Photo, posted January 31, 2012, courtesy of Michael J. Nevins / U.S. Army Corps of Engineers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Food Waste And The Environment | Earth Wise

November 25, 2022 By EarthWise Leave a Comment

It is tragic that 31% of the world’s food production goes uneaten. About 14% isn’t distributed after it is harvested. Another 17% ends up wasted in retail or by consumers. Worldwide, the amount of food that is wasted is enough to feed more than a billion people while at least 828 million people continue to be affected by hunger. To make matters worse, food waste accounts for 8 to 10% of global greenhouse gas emissions, which is at least double that of aviation. Food waste, rotting away in landfills, produces methane gas, a major source of global warming.

Around the world, there are efforts being launched to try to improve the situation. California now has a law that requires grocery stores to donate edible food that would otherwise be disposed of or they face fines. The state’s cities and counties are required to reduce the amount of organic waste going into landfills by 75% by 2025 and compost it instead.

In London, grocers no longer put date labels on fruits and vegetables because the labels were leading people to trash perfectly good food. France now requires supermarkets and large caterers to donate food that is still safe to eat.

South Korea has little space for landfills. So, the country has been campaigning against throwing away food for 20 years. Nearly all organic waste in the country is turned into animal feed, compost, or biogas. Koreans even have to pay for throwing out food waste. There are now trash bins equipped with electronic sensors that weigh food waste.

All of these things can help. There is no single magic bullet for reducing food waste, but it is essential to do for so many reasons.

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Inside the Global Effort to Keep Perfectly Good Food Out of the Dump

Photo, posted November 30, 2020, courtesy of Marco Verch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Food Waste Into Wearables | Earth Wise

November 20, 2020 By EarthWise Leave a Comment

A new startup company spun out of the University of Toronto wants to make clothing from food waste. If they are successful, you may someday buy a shirt or a pair of gym shorts made from banana peels, rotten tomatoes, coffee grounds, or moldy bread.

A problem faced by the clothing industry is that most textiles are blended with synthetic and non-renewable fiber polyester, which makes them unrecyclable. An alternative that has come on the scene in recent years is polylactic acid (or PLA), which is a decomposable bioplastic that is currently used for food packaging, medical implants, and 3D printing. It is likely that a sustainable future for the fashion industry will depend on the ability to make use of biodegradable and carbon-neutral materials.

PLA is typically made from cornstalk, but the startup – called ALT TEX – does not want to rely on a crop already used for feedstock, human consumption, and alternative fuel. Furthermore, there is no need to plant more corn when there is an abundant supply of unused post-industrial food waste from growers, producers, and retailers that contains the same biological building blocks for producing PLA.

ALT TEX has been conducting experiments using discarded apples to create a PLA-based fabric that is strong, durable, decomposable, and cost effective. They are working with farmers and food suppliers to access their waste. If their efforts are successful, it would be possible to divert significant amounts of organic waste that currently emits the powerful greenhouse gas methane and instead enable the fashion industry to be more sustainable.

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Earth-friendly fashion: U of T startup turns food waste into wearables

Photo, posted August 30, 2019, courtesy of Ruth Hartnup via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewable Natural Gas

September 30, 2019 By EarthWise Leave a Comment

Small-scale biogas systems have collected methane from landfills, sewage plants, and farms for decades. Here in the US, biogas is finally catching up with modern techniques with the advent of third-party operators introducing more sophisticated technology to capture methane and pump it directly into pipelines.

Renewable methane or natural gas represents a significant mostly unexploited source of energy. Examples include the vast amounts methane generated by manure from some of the 2,300 hog farms in eastern North Carolina, biodigesters that can turn clusters of large California dairy farms into energy hubs, as well as diverting food waste from landfills and transforming it into vehicle and heating fuels.

According to a 2014 EPA study, the U.S. could support at least 13,000 biogas facilities, fed by manure, landfill gas, and biosolids from sewage treatment plants. Those facilities could produce over 650 billion cubic feet of biogas per year – enough renewable energy to power 3 million homes.

A study by the World Resources Institute estimated that the 50 million tons of organic waste sent to landfills or incinerated every year in the U.S. has the energy content of 6 billion gallons of diesel fuel, amounting to 15% of all diesel consumed by heavy-duty trucks and buses.

Utilizing all that biogas could help lower greenhouse gas emissions from some of the most difficult sectors to decarbonize – transportation, industry, and heating buildings. In addition, ramped up renewable gas could keep organic waste out of landfills and prevent manure runoff into rivers and water supplies.

Renewable natural gas could be the next big thing in green energy.

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Could Renewable Natural Gas Be the Next Big Thing in Green Energy?

Photo, posted June 19, 2013, courtesy of Alan Levine via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.