Changing global diets is vital to reducing climate change

AlphaGalileo via University of Cambridge: Healthier diets and reducing food waste are part of a combination of solutions needed to ensure food security and avoid dangerous climate change, say the team behind a new study. A new study, published today in Nature Climate Change, suggests that – if current trends continue – food production alone will reach, if not exceed, the global targets for total greenhouse gas (GHG) emissions in 2050.

The study’s authors say we should all think carefully about the food we choose and its environmental impact. A shift to healthier diets across the world is just one of a number of actions that need to be taken to avoid dangerous climate change and ensure there is enough food for all.

As populations rise and global tastes shift towards meat-heavy Western diets, increasing agricultural yields will not meet projected food demands of what is expected to be 9.6 billion people - making it necessary to bring more land into cultivation.

This will come at a high price, warn the authors, as the deforestation will increase carbon emissions as well as biodiversity loss, and increased livestock production will raise methane levels. They argue that current food demand trends must change through reducing waste and encouraging balanced diets.

If we maintain ‘business as usual’, say the authors, then by 2050 cropland will have expanded by 42% and fertiliser use increased sharply by 45% over
2009 levels. A further tenth of the world’s pristine tropical forests would disappear over the next 35 years.

The study shows that increased deforestation, fertilizer use and livestock methane emissions are likely to cause GHG from food production to increase by almost 80%. This will put emissions from food production alone roughly equal to the target greenhouse gas emissions in 2050 for the entire global economy.

The study’s authors write that halving the amount of food waste and managing demand for particularly environmentally-damaging food products by changing global diets should be key aims that, if achieved, might mitigate some of the greenhouse gases causing climate change....

"Belshazzar's Feast," from 1860

Giving up beef will reduce carbon footprint more than cars

Damian Carrington in the Guardian (UK): Beef’s environmental impact dwarfs that of other meat including chicken and pork, new research reveals, with one expert saying that eating less red meat would be a better way for people to cut carbon emissions than giving up their cars.

The heavy impact on the environment of meat production was known but the research shows a new scale and scope of damage, particularly for beef. The popular red meat requires 28 times more land to produce than pork or chicken, 11 times more water and results in five times more climate-warming emissions. When compared to staples like potatoes, wheat, and rice, the impact of beef per calorie is even more extreme, requiring 160 times more land and producing 11 times more greenhouse gases.

Agriculture is a significant driver of global warming and causes 15% of all emissions, half of which are from livestock. Furthermore, the huge amounts of grain and water needed to raise cattle is a concern to experts worried about feeding an extra 2 billion people by 2050. But previous calls for people to eat less meat in order to help the environment, or preserve grain stocks, have been highly controversial.

“The big story is just how dramatically impactful beef is compared to all the others,” said Prof Gidon Eshel, at Bard College in New York state and who led the research on beef’s impact. He said cutting subsidies for meat production would be the least controversial way to reduce its consumption....

Cattle branding in Queensland, around 1897

Dietary shifts driving up phosphorus use

Seed Daily via SPX: Dietary changes since the early 1960s have fueled a sharp increase in the amount of mined phosphorus used to produce the food consumed by the average person over the course of a year, according to a new study led by researchers at McGill University. Between 1961 and 2007, rising meat consumption and total calorie intake underpinned a 38% increase in the world's per capita "phosphorus footprint," the researchers conclude in a paper published online in Environmental Research Letters.

The findings underscore a significant challenge to efforts to sustainably manage the supply of mined phosphorus, a non-renewable resource widely used as fertilizer.

When phosphorus is lost through agricultural runoff or sewage systems, it can pollute waterways downstream. In addition, because deposits are heavily concentrated in a few countries, global supplies and prices for the resource are vulnerable to geopolitical tensions.

In recent years, many researchers have explored how human activity has altered the phosphorus cycle in the environment and how management of phosphorus could be altered to ensure long-term sustainability. This new study sheds more light, in particular, on how diet choices have affected the intensity of phosphorus use around the world.

"Our results demonstrate that changes in diet can be a significant part of the strategy for enhancing sustainability of phosphorus management," says lead author Genevieve Metson, a doctoral student in McGill's Department of Natural Resource Sciences. "In particular, reduced consumption of meat, and especially beef, in countries with large phosphorus footprints could put a big dent in demand for mined phosphorus - since it takes many kilograms of feed, which is fertilized, to produce a kilogram of meat."....

Illustration from Brockhaus and Efron Encyclopedic Dictionary (1890—1907)

Eat less meat and improve farming efficiency to tackle climate change

University of Exeter: We need to eat less meat and recycle our waste to rebalance the global carbon cycle and reduce our risk of dangerous levels of climate change. New research from the University of Exeter shows that if today’s meat-eating habits continue, the predicted rise in the global population could spell ecological disaster. But changes in our lifestyle and our farming could make space for growing crops for bioenergy and carbon storage.

Though less efficient as an energy source than fossil fuels, plants capture and store carbon that would otherwise stay in the atmosphere and contribute to global warming. Burning our waste from organic materials, such as food and manure, and any bioenergy crops we can grow, while capturing the carbon contained within them, could be a powerful way to reduce atmospheric carbon dioxide.

Published today (20 June 2012) in the journal Energy and Environmental Science, the research suggests that in order to feed a population of 9.3 billion by 2050 we need to dramatically increase the efficiency of our farming by eating less beef, recycling waste and wasting less food. These changes could reduce the amount of land needed for farming, despite the increase in population, leaving sufficient land for some bio-energy. To make a really significant difference, however, we will need to bring down the average global meat consumption from 16.6 per cent to 15 per cent of average daily calorie intake – about half that of the average western diet.

The researchers argue that if we change the way we use our land, recycle waste, and dedicate enough space to growing bioenergy crops we could bring down atmospheric carbon dioxide to safe levels. Not doing this means we would lose our natural ecosystems and face increasingly dangerous levels of atmospheric carbon dioxide....

Vegetarian symbol created by Erik Wannee, Wikimedia Commons, under the Creative Commons CC0 1.0 Universal Public Domain Dedication

Cut meat consumption in half to curb emissions

Newswise via Woods Hole Research Center: Meat consumption in the developed world needs to be cut by 50 percent per person by 2050, and emissions in all sectors – industrial and agricultural – need to be reduced by 50 percent if we are to meet the most aggressive strategy, set out by the Intergovernmental Panel on Climate Change (IPCC), to reduce the most potent of greenhouse gases, nitrous oxide (N2O).

The findings are results of a study by Dr. Eric Davidson and are published today in IOP Publishing’s Environmental Research Letters. Dr. Davidson, who is President and a Senior Scientist at the Woods Hold Research Center in Massachusetts, demonstrates the magnitude of changes needed to stabilize N2O concentrations in the atmosphere.

N2O is the third highest contributor to climate change behind carbon dioxide (CO2) and methane (CH4); however, it poses a greater challenge for mitigation since nitrogen is an essential element for food production. It is also the most potent of these three greenhouse gases, as it is a much better absorber of infrared radiation. But total anthropogenic emissions are about 6 million metric tons of nitrogen as N2O, compared to 10 billion metric tons of carbon as CO2.

The main sources of N2O in the atmosphere are due to the spreading of synthetic nitrogen fertilizers onto agricultural soils and the use and storage of livestock manure. The nitrogen contained in fertilizers and manure is broken down by microbes that live in the soil and released into the atmosphere as N2O. In order to reduce emissions, it will be necessary to apply certain changes to the food production process.

Dr. Davidson believes that this can be achieved through improved management of fertilizer and manure sources, as well as through reduction of the developed world’s per capita meat consumption that will relieve pressure on fertilizer demand and reduce growth in the amount of manure being produced. “We have the technical know-how and the tools to greatly improve efficiencies of fertilizer use in agriculture,” states Davidson, “although several economic and political impediments often stand in the way of their adoption.”....

Shot by Ericd, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

A new meat eater’s guide spotlights beef’s outsize carbon footprint

Environmental Working Group: The Environmental Working Group today released its groundbreaking Meat Eater’s Guide to Climate Change and Health, a powerful, multi-featured tool that allows both consumers and experts to understand easily how food choices affect both their environmental footprint and their health.

Taking into account every stage of food production, processing, consumption and waste disposal, the guide documents in unprecedented detail how consumers who eat less meat and cheese can significantly reduce the greenhouse gas emissions, pollution and health risks linked to their dietary choices. Previous studies have focused mostly on emissions from the food production phase only.

The calculations reveal that if everyone in the U.S. ate no meat or cheese just one day a week, over a year, the effect on emissions would be the equivalent of taking 7.6 million cars off the road.

The research also highlights the surprisingly large environmental impact of meat that goes into the trash, which accounts for more than 20 percent of all meat-associated emissions.

“By eating and wasting less meat, consumers can help limit the environmental damage caused by the huge amounts of fertilizer, fuel, water, and pesticides, not to mention the toxic manure and wastewater, that goes along with producing meat,” said Kari Hamerschlag, EWG senior analyst and author of the report. “Choosing healthier, pasture-raised meats can also help improve people’s health and reduce the environmental damage associated with meat consumption.”…

The stockyards in Omaha, with the Omaha Livestock Exchange in the background, shot by Jerry Mathiason (Library of Congress photo)

Beef drives 80% of Amazon deforestation

Mongabay: Nearly 80 percent of land deforested in the Amazon from 1996-2006 is now used for cattle pasture, according to a report released today by Greenpeace at the World Social Forum in Belem, Brazil. The report, Amazon Cattle Footprint: Mato Grosso: State of Destruction [PDF], confirms that cattle ranching is the primary driver of deforestation in Earth's largest rainforest: the Brazilian Amazon.

Over the past decade more than 10 million hectares – an area about the size of Iceland - was cleared for cattle ranching as Brazil rose to become the world's largest exporter of beef. Now the government aims to double the country's share of the beef export market to 60% by 2018 through low interest loans, infrastructure expansion, and other incentives for producers. Most of this expansion is expected to occur in the Amazon were land is cheap and available — 70 percent of the country's herd expansion between 2002 and 2006 occurred in the region.

The number of cattle bred in the Legal Amazon is growing fast: between 1990 and 2003, the bovine herd more than doubled, from 26.6 million to 64 million head of cattle – 60% of the herd are in the states of Mato Grosso and Pará.

Recent reports suggest that much of this expansion has been illegal. Laws for maintaining a "legal forest reserve" on Amazon land are widely flouted and many landowners acquire land without proper title. Corruption is rampant in frontier areas making law enforcement ineffective and sometimes complicit in illicit activities — including illegal logging and abuse of workers — that often accompany land clearing….

Amazon deforestation seen from space, NASA