The meat-free way to a healthier planet

Professor James Lovelock, the controversial creator of the Gaia hypothesis (basically the idea that our planet is a living, self-regulating system and quite capable of looking after itself, thank you), has a very simple message for mankind if we are not to disappear in the fog of our own CO2 emissions.

To paraphrase Lovelock: ignore the overhyped contributions of wind power, biofuel, solar power, aircraft emissions and the like; they are comparatively marginal, he says, compared with two issues at the heart of the way we live. His challenge? Stop producing so many humans and stop consuming meat. Both, he says, contribute massively to the causes of man-made emissions. It is to the meat diet that I want to pay a little more attention. According to a recent study published by the combined brainpower of the UK Met Office and universities across the world, 100 peer-reviewed scientific studies categorically confirm that "warming in the 20th century was so intense and widespread that the likelihood of it being explained by natural variations is less than five per cent". So, to put it another way, there is a 95 per cent chance that climate change is the fault of mankind and our activities.

For those who feel a sense of powerlessness or are even apathetic about the fate of the planet, a much more personal fix is being presented. It seems that what you eat could provide a more compelling solution to our environmental problems than ditching your SUV or exchanging it for a Prius, carbon-offsetting your air miles or investing in solar panels. According to a 2006 report by the Livestock, Environment and Development Initiative in the US, the livestock industry is one of the largest contributors to environmental degradation worldwide, and modern practices of raising animals for food contribute to air and water pollution, land degradation, climate change and the loss of biodiversity.

In 2006 it was estimated that the worldwide meat industry contributed 18 per cent of all greenhouse gas emissions. This figure was revised in 2009 by World Bank scientists, who put it at 51 per cent. It is not headline-making news; this information has been out there for years. However, given the current economy, the fact that the simple act of reducing our intake of beef burgers could wipe $20 trillion (Dh73.45 trillion) off the cost of fighting climate change makes switching to a veggie burger every now and then seem pretty compelling.

The environmental equation of tracking animal production from feed to table goes like this: to produce a kilogram of beef, farmers have to feed a cow 15kg of grain and 30kg of forage. That grain requires fertiliser, which is energy-intensive to produce. Millions of tonnes of methane, a potent greenhouse gas, would also be saved every year due to reduced emissions from farms; methane has about 21 times more global warming potential than carbon dioxide.

Conversely, according to a widely reported study led by Elke Stehfest at the Netherlands Environmental Assessment Agency, if the global population shifted to a low-meat diet - defined as 70g of beef and 325g of chicken and eggs per week - around 15 million square kilometres of farmland would be freed up. Vegetation growing on this land would mop up carbon dioxide. It could alternatively be used to grow bioenergy crops, which would displace fossil fuels. Greenhouse gas emissions could also fall by 10 per cent due to the drop in livestock numbers. Together these impacts would halve the costs of dealing with climate change by 2050.

Altering our dependence on a "hunter" diet could massively alter the Earth's ability to feed us all. Lovelock estimates that our current diet means that Earth will struggle to feed 10 billion; a vegan-based diet could allow the planet to feed 100 billion. Don't let the digestion of these facts bring on a stomach ache, though. For those who have grown out of youthful activism and a thrift-shop vegan life (myself included), there is a grown-up version of eco-friendly eating available: the so-called environmental vegetarian. Environmental vegetarians call for a reduction of First World consumption of meat, but not the elimination of it, while at the same time campaigning for greener agricultural practices.

While the adoption of a lacto-ovo vegetarian diet or an entirely plant-based vegan diet is probably better for the planet, even modest reductions in meat consumption in industrialised societies would substantially reduce the burden on our natural resources. Ideas such as adding a tax to the cost of meat in terms of carbon emissions per portion is another initiative that may soon hit your shopping bill.

If worries about the planet's future or an environmental tax are not enough to shift behaviour, perhaps we will be left with the fight of fashion. If ordering a burger or a T-bone steak became as un-PC as smoking at the dinner table, then the environmentalists may actually stand a chance at making eco-veggies out of many of us. In any case, we may soon find that meat is effectively priced off the menu anyway.