Reversing land clearing for meat production
Current animal farming practices are environmentally unsustainable and unethical (see this documentary showing the appalling way farm animals are treated), and always will be under pressure to remain so, in order to keep the cost of food low.
Also the WWF estimate 60-70% of the new diseases that have emerged in humans since 1990 (including Covid-19) came from wildlife, with beef, palm oil and soy being commodities frequently linked to the deforestation that increases these global health risks.
Despite a tripling of crop yields since the 1960s, half the world's habitable land is devoted to agriculture (whilst only 1% is used as built-up urban areas), with 77% of this being used for livestock that provides just 18% of global calorie supply (see side chart from here), so the "80/20 rule" applies, with only a little more than 20% of agricultural land producing plant-based food that provides about 80% of calories and still almost two-thirds of protein consumption.
Cattle grazing alone occupies 25% of the world’s ice-free land, which – coming on top of other human uses of land & oceans – threatens many species with extinction (despite some progress in the protection of biodiverse areas), whilst also contributing hugely to greenhouse gas emissions.
I estimate animal agriculture causes roughly 30%+/-10% of global greenhouse-gas emissions (similar to estimates reported here for all food), based on a low UN/IPCC estimate of about 20% that only includes emissions from new land clearing, whilst higher estimates include further "uncounted" emissions such as the lost opportunity to absorb CO2 by allowing forest regrowth on existing pasture land (a high estimate of about 50% produced by the WorldWatch Institute also includes over 10% for animal respiration which I don't think is valid, thus giving my revised upper estimate of about 40%).
Another paper claims animal agriculture is responsible for 87% of greenhouse gas emissions, on the assumption that 55% of further CO2 emissions will continue to be absorbed by plants & the ocean, whilst additional methane emissions from livestock will have a stronger effect over the next decade than assumed by the IPCC, which adopts a hundred year timeframe to account for methane gradually reacting with oxygen to form less harmful CO2. Whilst I can’t validate their approach, regardless, animal agriculture is clearly a major issue that must be addressed.
So besides benefiting animal welfare/species survival and human health, reducing meat consumption is probably an essential strategy for reducing greenhouse emissions and ensuring the world can feed a growing population (conversely, if the whole world adopted the current typical meat-rich New Zealand diet, we’d need almost twice as much habitable land as the earth actually has available). However, the benefits of avoiding animal farming may vary strongly with the specific situation, e.g. UK farmers claim their "emissions from beef are less than half the global average". The US EPA estimate that only 4% of US emissions are attributable to animal agriculture – despite the USA being the world's biggest beef producer – although this probably excludes any forest regrowth opportunity-costs and also reflects the USA having above-average energy use & related emissions (even though they've remained around the same level per capita since the 1970s). In Australia, land clearing is on a par with that of the Amazon in Brazil (where it surged in 2019 & has been worsened by fires used for clearing), with 73% of clearing in Queensland being for beef production (& over 90% in Great Barrier Reef catchments), although significant progress is being made to reduce or offset the emissions from cattle farming.
Reversing land clearing by investing in reforestation and coastal ecosystems - especially in the US, Canada, Australia, Russia, Brazil and China - could restore the habitats of endangered wildlife whilst also offseting other greenhouse emissions over a couple of decades until the forests reach maturity, thus buying us some time to allow for a more orderly & less disruptive phase-out of existing fossil-fuel systems (but note this is not an excuse to delay major action to reduce emissions). At the same time, sustainably grown, high-tech timber used for better, natural buildings with faster construction and possibly even better fire resistance than steel-reinforced concrete (or alternatively, hemp-crete/bricks/blocks/insulation, or bamboo, which absorbs 5 times more CO2 & releases 35% more oxygen than hardwood trees, as well as saving pandas) offers the potential — along with low-carbon concrete such as cement-free bendable concrete with captured CO2, cement from electrolysis or other strategies — to reduce the 8% of CO2 emissions created by cement production.
Meat production also requires huge amounts of water – e.g. 15,000 litres per kg of beef (vs 1000 litres/kg grain) – which means water use for food could be reduced 33-55% by switching to a vegetarian & fish diet (from typical levels of about 3,000 litres per person/day, though commonly 50% higher for the French as they need 7x more water per kg of wine than the 111 litres required for a kg of beer), thus benefiting natural eco-systems suffering from water diversion, and/or allowing for more water supply to drought-affected rural communities.
[Similarly, cotton growing requires 2-3 times more land & water than hemp (& infinitely more agricultural chemicals & pesticides) and is responsible for about 35% of all the water extracted from the Murray Darling Basin for irrigation (with all irrigation accounting for about 70% of all surface water extracted in the Basin). Prerequisites for better managing water are to stop wasting billions of dollars on irrigation subsidies and to start actually measuring water use so all parties to water laws can be held accountable and incentivised to be more efficient.
Cotton is also a significant input to the extraordinarily wasteful fashion industry, which exploits the poor and on current trends will be responsible for a quarter of all carbon emissions by 2050.]
China is responsible for over a quarter of global meat consumption, but consumes half as much meat per capita as the US & Australia. For health reasons (but with major environmental bonus) the Chinese government wants to further halve this. In the UK, a third of Brits have already stopped or reduced their meat consumption, for health, ethical & environmental reasons (but they do miss their bacon sarnies & pork scratchings!). However, far greater reductions in global meat consumption are needed to avoid severe global warming & environmental disaster, with Western countries needing to reduce beef consumption by about 90% through widespread adoption of "flexitarian" diets (with reduced but not zero meat, which may be healthier & more realistic than vegan and even better for the environment than a vegetarian diet that increases the negative impacts of dairy farming).
less intensive free-range livestock, along with:
cattle food such as seaweed additives that prevent methane burps – which is commencing commercialisation, although whilst seaweed has much potential for both cattle & human food (like healthy fake bacon!), as well as other uses, it's not yet clear whether such livestock foods will be realistic & effective at large scale (see also here),
and shifting consumption to chicken or pork rather than lamb & beef (see side graphic from here showing lamb causes about 4 times the greenhouse emissions per kg of meat, with beef another factor of 2 higher than lamb),
a more diverse range of foods than rice, wheat & maize, which currently make up nearly 60% of all plant-based calories humans consume (but not necessarily "organic" farming, which could nearly halve yields per hectare and result in a net increase in greenhouse emissions), and,
non-meat substitutes – the most cost-effective way to reduce greenhouse emissions – that could feed everyone with much less land & environmental impact, such as:
Beyond Meat's veggie-burger, the McVegan, KFC's "Imposter Burger", Hungry Jack's 'Rebel Whopper' (which I liked), and the Impossible Burger (said to be the most meat-realistic, which is now sold in Burger King and requires 99% less water, 93% less land, 90% less greenhouse emissions and 50% less energy than regular beefburgers),
an increasing range of "plant-based meat" & other substitutes for animal-based food available in supermarkets (especially those made from beans or jackfruit), which are now going "mainstream" with products from food-giant Nestlé along with others such as Sunfed's "chicken-free chicken" and Plant Asia's "vegan roast duck" (which are both nice), plus fake bacon, "meat" pies, fish (including vegan plant-based "tuna" & "salmon"), calamari & shrimp or prawns, deli meats and even better-than-real 'pork ribs' with high-protein edible 'bones'!
alternatives to cow-milk made from soy, oat or peas (although not all alternatives are environmentally better), or from genetically-modified fungi, plus award-winning vegan cheese & ice-cream and realistic casein-protein based cheeses under development, which can be produced with 500 times less water than dairy cheeses,
even real lab-grown meat, which should be in our supermarkets very soon and help us avoid all animal slaughter within 30 years. This includes chicken, beef & duck by Memphis Meats (backed by Bill Gates & Richard Branson), which is made from animal cells in brewery-like vats over a couple of weeks (starting production as "Upside Foods" in California in 2022), or fish (like salmon) and other seafoods (starting with "shrimp") and Eat Just's chicken, which, after sales in Singapore, has also been cleared for safe sale in the US. Without the inherent costs of animal farms, costs are dramatically reducing (heading towards $20/kg for lab-grown chicken in 2022), enabling Israel - which is leading the rapidly-growing, high-tech "alternative-protein" industry - to cost-effectively mass-produce chicken, beef, lamb & pork "20 times faster than traditional animal agriculture, with an expected 80% less greenhouse emissions, 99% less land and 96% less freshwater than traditional meat production",
other "farm-free" lab foods made by "precision fermentation" (such as "Quorn", which has been produced in the UK for decades, or "Fy", going into US production in 2021/2), which can drastically reduce the cost and environmental impact of all kinds of foods produced, even by literally making protein-rich food (or oil) from just water and carbon dioxide in the air (see also here & here).
In the meantime, be wary of any "backlash to plant-based meat" pushed by vested interests in the meat industry, and note also it would help if we reduced the 25-30% of food that is currently wasted (see also here), or maybe more, perhaps by reducing global inequality, since the nearly 1 billion of hungry, undernourished people in the world tend not to waste food like the 2 billion overweight or obese adults and wealthy Americans (consumers in Europe & North America waste about 10 x more food than those in sub-Saharan Africa & South Asia, although the majority of food waste occurs during production & retailing, and at fairly consistent rates in all countries, although for different reasons). Or more locally you could reduce waste by getting a bargain meal through here.
And for continuing animal farming, all farms could be mandated to have comprehensive CCTV that the public can view (e.g. by scanning a QR code on food packages), so customers know whether their purchases are contributing to animal cruelty (but instead, Australian law is currently being used to hide cruelty).