The environmental impact of different foods

 From Visual Capitalist

Click on graphic to see it more clearly

Food and agriculture have a significant impact on our planet, particularly in terms of carbon emissions, water withdrawals, and land use.

To visualize how different food items contribute to this environmental impact, the above graphic ranks foods based on their greenhouse gas (GHG) emissions and water withdrawals, using data from Poore and Nemecek and Our World in Data.

Based on carbon dioxide equivalent (CO₂e) measurements, beef comes in first place as the food with the largest carbon footprint, emitting an astounding 99 kilograms of CO₂e per kilogram of the final meat product.

CO₂e emissions are a standardized measure that express the warming impact of various greenhouse gases—such as methane and nitrous oxide—in terms of the amount of CO₂ that would have the same warming effect.

The production of beef is extremely resource-intensive, demanding substantial land, water, and energy resources. Cows also produce methane during their digestive processes, a gas that has a warming potential 27–30 times higher than that of CO₂ over a 100-year time period [and 82 times higher over a 10-year period].  (See data table in the article)

Following beef on the list is dark chocolate, albeit not very closely.

Most of dark chocolate’s emissions come from land use changes—such as deforestation— which alters the balance of GHG emissions and reduces the Earth’s capacity to absorb CO₂.

All in all, however, the data shows us that animal products are generally more emission-intensive than plant-based foods.

The Food and Agriculture Organization (FAO) states that more than two-thirds of the world’s freshwater withdrawals are used for food production.

Interestingly, the trend that we saw when considering the carbon footprints of foods also applies when it comes to water use. Among the top 10 most water-intensive foods in the world, 70% are of animal origin, highlighting that animal products aren’t only more carbon-intensive but also more water-intensive than plant products.Peanuts, rice, and nuts (which include hard-shelled fruits such as hazelnuts, chestnuts, and walnuts) make up the plant-based outliers in the list.  (See data table in the article from Visual Capitalist)

Eating locally sourced foods is often posed as a solution for lowering our ecological impact, leading to the growing popularity of concepts such as “The 100 Mile Diet.”

An analysis done by Our World in Data, however, shows us that what we eat makes more of a difference in lowering our environmental footprints than where our food comes from.

More specifically, the data highlights that transportation accounts for just 5% of global food emissions. Land use change and farming activities, on the other hand, account for a much more significant portion.

As such, redirecting our attention from the distance food travels to the emissions associated with its production can yield better outcomes in our efforts to make more sustainable food choices.

26% of global emissions come from food, skewed heavily towards beef, dairy and mutton.  By comparison, ~30% come from burning fossil fuels to generate electricity, and ~20% from land transport.   The biggest single step you can take to reduce your emissions is to stop eating beef and mutton, and to minimise your consumption of cheese and milk.  Become vegetarian---it's better for your health, and for the planet's too!     If you can, buy your electricity from a green electricity provider (and not one that uses dodgy "offsets" to "reduce" its emissions) and, if you can't afford an EV, buy a hybrid.  They only cost a couple of thousand dollars more than the petrol-only version, but will reduce your emissions from driving by ~40%.

Making vegan cheese tastier

It's all about fermentation.

From Ars Technica

There is no questioning our ongoing love affair with cheese. From pizza and pasta to that decadent slice of cheesecake, we can’t get enough. But the dairy industry that produces cheese has had a negative impact on our climate that is not exactly appetizing.

While plant-based alternatives to cheese are easier on the environment—not to mention ideal for those who are lactose intolerant (raises hand) or vegan—many of them are still not cheesy enough. Now, a team of scientists from the University of Copenhagen in Denmark has created nondairy cheese with a taste and texture that’s much closer to the real thing. Instead of developing some sort of futuristic technology, they harnessed the transformative power of a process that has been used to make traditional cheese for thousands of years—fermentation.

Why are plant-based cheeses so notoriously difficult to make? Not all proteins are created equal. Because plant proteins behave so differently from milk proteins, manufacturers rely on coconut oil, starch, or gums as hardening agents and then add colors and flavors that give the finished product some semblance of cheese.

“Semblance” is the operative word here. The chemistry that makes cheese as delicious as it is goes down to a molecular level. Cheese starts as a colloid, or liquid medium with small particles equally dispersed within it. It gets its gel-like structure when this liquid thickens enough to behave like a solid.

The most difficult thing to replicate in plant-based cheese is the distribution of fat globules, which are dispersed when molecules of casein, the main protein in milk, unfold and break down when exposed to heat treatment. Bacteria are then added and start fermentation by turning lactose into lactic acid. This causes the pH to drop, which makes the flavor profile more acidic. Proteins join together because of this acidity and form blobs of curd that start to take on a firm texture and will eventually become cheese.

Could these bacteria do the same thing to plant protein, even in the absence of casein, and if so, would it have the texture and taste so many of us crave?

Led by researcher Carmen Masiá, the Copenhagen team found that when the same bacteria used in cheese production are introduced to yellow pea protein, they break down the structure of that plant protein to produce lactic acid and reduce pH, just like they do with milk proteins. They also formed the same kind of curd that retains water and oil without needing anything else to harden it or further improve the texture.

Masiá and her team experimented with 24 different blends of bacteria to see which combination would yield a cheese with the most realistic taste and texture. Most consumers are wary of plant-based cheese because of a “beany” or earthy aftertaste.

The characteristics the team specifically looked for were acidity, gel firmness, and how well the bacteria were able to cover up the vegetal flavors of the pea protein with buttery and creamy overtones reminiscent of dairy cheese. It turned out that fermentation reduced the undesirable flavors in all the samples, though combinations of bacteria tended to do better than individual species.

There were two compounds produced by the bacteria S. thermophilus that especially contributed to taste: diacetyl and acetoin. These are found in several dairy products, including cheese, and gave the finished product the fatty, sweet, and waxy flavors of real cheese. Another compound, dimethyl disulfide, which is especially high in cheddar cheese, was present in all the fermented cheese samples. As for texture, the best firmness was achieved by the combination of bacteria L. helveticus, Pediococcus and L. plantarum. Other compounds are also important in producing cheesy flavor and texture, but exactly how they do that is not well understood yet.

“Future work on different ripening conditions will follow to further investigate the effect of different bacterial blends on texture and flavor development over time,” the researchers said.

This cheese will not be hitting supermarket shelves anytime soon; much like actual cheese, the science needs some time to ripen. Maybe plant-based cheese will someday become so indistinguishable from dairy that we might not even notice the change.

Future Foods, 2023. DOI: 10.1016/j.fufo.2023.100250

Vegan blue cheese from the Vegan Grocery Store in Melbourne

Vegan diet massively cuts environmental damage

Researchers said people in rich nations needed to radically reduce their meat and dairy consumption for global food production to be sustainable. Photograph: Nathaniel Noir/Alamy

From The Guardian

Eating a vegan diet massively reduces the damage to the environment caused by food production, the most comprehensive analysis to date has concluded.

The research showed that vegan diets resulted in 75% less climate-heating emissions, water pollution and land use than diets in which more than 100g of meat a day was eaten. Vegan diets also cut the destruction of wildlife by 66% and water use by 54%, the study found.

The heavy impact of meat and dairy on the planet is well known, and people in rich nations will have to slash their meat consumption in order to end the climate crisis. But previous studies have used model diets and average values for the impact of each food type.

In contrast, the new study analysed the real diets of 55,000 people in the UK. It also used data from 38,000 farms in 119 countries to account for differences in the impact of particular foods that are produced in different ways and places. This significantly strengthens confidence in the conclusions.

However, it turned out that what was eaten was far more important in terms of environmental impacts than where and how it was produced. Previous research has shown that even the lowest-impact meat – organic pork – is responsible for eight times more climate damage than the highest-impact plant, oilseed.

The researchers said the UK should introduce policies to help people reduce the amount of meat they eat in order to meet the nation’s climate targets. Ministers have repeatedly said they will not tell people what to consume, despite the precedent of, for example, taxes on high-sugar drinks.

Prof Peter Scarborough at Oxford University, who led the research, published in the journal Nature Food, said: “Our dietary choices have a big impact on the planet. Cutting down the amount of meat and dairy in your diet can make a big difference to your dietary footprint.”

The global food system has a huge impact on the planet, emitting a third of the total greenhouse gas emissions driving global heating. It also uses 70% of the world’s freshwater and causes 80% of river and lake pollution. About 75% of the Earth’s land is used by humans, largely for farming, and the destruction of forests is the major cause of the huge losses in biodiversity.

Prof Neil Ward at the University of East Anglia said: “This is a significant set of findings. It scientifically reinforces the point made by the Climate Change Committee and the National Food Strategy over recent years that dietary shifts away from animal-based foods can make a major contribution to reducing the UK’s environmental footprint.”

The study also showed that low-meat diets – less than 50g a day – had half the impact of high-meat diets on greenhouse gas emissions, water pollution and land use. However, the differences between low-meat, pescetarian and vegetarian diets were relatively small.

Prof Richard Tiffin at the University of Reading said: “This study represents the most comprehensive attempt to link food consumption data to the data on the environmental impacts of food production.

“Encouraging high-meat-eaters to reduce meat consumption and encouraging vegetarians to become vegans should result in lower emissions,” he said. “However, it’s hard to justify changes to the diets of moderate omnivores on the basis of these results, other than to switch to a completely vegan diet.”

The researchers who conducted the new study said diets enabling global food production to be sustainable would mean people in rich nations “radically” reducing meat and dairy consumption.

They said other ways of reducing the environmental impact of the food system, such as new technology and cutting food waste, would not be enough.

The biggest difference seen in the study was for emissions of methane, a potent greenhouse gas produced by cattle and sheep, which were 93% lower for vegan diets compared with high-meat diets.

There is so much we as individuals can't do about cutting emissions.  Governments are owned by fossil fuel companies and billionaires.  Governments continue to subsidise fossil fuel production.  Changing things means persuading others to vote for parties which will actually enact policies which cut emissions.  We can't all afford an electric car.  And even though electric grids are greening, we still produce emissions every time we turn a light on (unless you can join a utility which produces 100% carb-free electricity) 

But there is at least one thing we can do:  turn vegan.   That will cut your personal emissions by 1/3rd, on average.   Even becoming vegetarian will cut your personal emissions by 15%, according to this study.   We need to cut emissions by 50% over the next 10 years to prevent catastrophic climate change.  If rich countries go vegan, we'll be more than halfway there.  And if we succeed in replacing petrol (gasoline)/diesel cars and light trucks, we'll have achieved the 50% cut we need.