To answer this question, we need to know how much of different types of meat the global population will consume in the coming decades, and what greenhouse gases (GHGs) are emitted during the production, processing, retailing and preparation of these meats.
We also need to understand whether changing demand for meat will involve new land being brought into agriculture resulting in GHG emissions, and whether there are opportunity costs in using land to produce meat that might be used to reduce the amount of carbon in the atmosphere by; for example, might the land be used for planting trees that would lock up carbon for decades and help prevent warming.
Consider the first question: how will demand for meat increase in the future if current trends continue. We know that global populations are increasing (though the rate of increase is declining) so this in itself will lead to greater demand for meat. The global population today is a little over seven billion people and human demographers are confident that it will be about 40% bigger, around 10 billion, by mid-century. A first approximation would be that demand for meat would rise in line and be 40% greater over the same time period.
Not only will there be more people but very likely they will also be wealthier. This has been the trend throughout the last century and barring major economic catastrophe it will continue. This matters for meat consumption because wealthier people tend to have more meat-rich diets – there are exceptions but the overall relationship is clear. We cannot know exactly what the future will hold but when LEAP researchers try to estimate meat consumption in the future they typically assume a “mid-range” scenario of economic growth that has been developed by the Organisation of Economic Cooperation and Development (OECD) in Paris.
Given population and economic growth there are a number of ways to estimate future meat consumption though they all give broadly similar results. At LEAP we use an economic model that can track how changing demand for meat affects meat prices which in turn affects consumption. The model is able to follow the consumption of different types of meat in different countries, and so can take account of regional differences and how, for example, future projections for beef consumption might differ from chicken. But lumping all kinds together, if there are no changes to policy or behaviour, we expect meat consumption to be 60-70% higher by 2050.
So what does this mean for GHG emissions? To answer this question we need to know the GHGs associated with each meat production system. These figures are obtained through “life-cycle analyses” of which a large number have now been conducted and catalogued. Of course, not all possible ways of producing meat and meat products have been studied, but data are now available for the most important. A further issue is that meat production produces several different types of GHGs while many other activities only produce carbon dioxide. We shall explore some of the issues this raises in a separate article.