Laura Wellesley
Research Associate, Energy, Environment and Resources
Urgent action to address unsustainable levels of meat consumption is needed if governments are to meet internationally agreed targets to limit global warming.
Burger sales in Hong Kong grew 6.4 per cent last year, more than double the rate of US growth, and are forecast to grow another 6 per cent this year. Photo by Getty Images.Burger sales in Hong Kong grew 6.4 per cent last year, more than double the rate of US growth, and are forecast to grow another 6 per cent this year. Photo by Getty Images.

A growing body of evidence shows the impact that unsustainable levels of meat consumption – particularly of meats like beef and lamb – have on the planet. As shown in a recent Chatham House report, the livestock sector contributes nearly 15 per cent of all greenhouse gas emissions, roughly equivalent to those from transport. Yet minimal attention has been paid to the unsustainable manner in which we produce and consume meat, and public awareness of the impact of dietary choices on our environment is low.

The UK Department for Energy and Climate Change recently launched an interactive web tool that allows users to explore various lifestyle choices and energy uses, and their effect on global greenhouse gas emissions and subsequent temperature rise by the end of the century. The ‘Global Calculator’ provides a striking visualization of what experts already know: if adopted globally, the Western diet is incompatible with staying below the limit of two degrees above pre-industrial levels, deemed necessary to avoid dangerous climate change.

The results are compelling. If the energy sector is successfully decarbonized by 2050, our diets can make the difference between the two-degree scenario in which dangerous climate change is averted and the four-degree scenario described by the World Bank as one of ‘cataclysmic’ climate change.

If current consumption trends continue, with meat consumption in emerging and developing countries increasing but remaining considerably below Western levels, we will stay on track for a global temperature rise of two degrees.

But if the Western diet becomes the norm by 2050, even with cleaner energy and ambitious action in other areas of our lifestyles, we are headed for a global temperature rise of four degrees. Such a scenario implies a considerable escalation compared with current trends but is not inconceivable: consumption in emerging and developing economies is rising rapidly, and China, Brazil and India are among the world’s largest and fastest growing meat-eating countries.

If this scenario were realized, additional emissions resulting from the growth in global consumption of beef, lamb and other meats would be significant enough to derail successful mitigation efforts in other sectors. Put simply, the Western diet is a four-degree diet. The rest of the world cannot afford to converge around such levels of excess.

Thankfully, there is a positive side to this sobering conclusion. Unsustainable consumption represents a significant and untapped area for relatively low-cost mitigating action that, if harnessed, would offer grounds for more ambitious international climate goals. As the ‘Global Calculator’ demonstrates, if decarbonization is accompanied by a push to curb unsustainable levels of emissions-intensive meat consumption, a 1.5 degree world – which offers the best chance of avoiding drastic climate impacts and ensuring the survival of low-lying island states − begins to look like a very real possibility.

A shift towards less meat-intensive, emission-intensive diets would also realize important co-benefits. The average European today consumes over twice as much meat as is recommended by the World Health Organization. A move to promote a diet that is less rich in meat, and that has a greater share of chicken and pork as opposed to beef and lamb, would bring significant benefits to public health, including reduced incidence of heart disease, cancers and diabetes associated with over-consumption of meat.

Shifting diets will not be easy. A recent survey commissioned by Chatham House and undertaken by Ipsos MORI revealed a marked lack of public awareness of the impact of meat consumption on climate change. Furthermore, it outlined the importance of awareness as a precondition for behaviour change. Addressing this awareness gap will therefore be a critical first step in legitimizing interventions at the national and international level.

As consumers around the world look to experts and environmental groups to inform them about climate change and its causes, communication tools like the Global Calculator could be an invaluable means of broadcasting a message that has gone largely unheard. And with such powerful evidence, the need for urgent action on diets will be difficult to ignore.

The impact of diet on the International Energy Agency’s two-degree and four-degree scenarios can be explored further through Chatham House’s high-meat and low-meat pathways, available for selection within the Global Calculator.

In 2015, Chatham House and Ipsos MORI will continue our research into public awareness and understanding of the links between diet and climate change. This will be published in the autumn.

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