06/10/2015 11:17 BST | Updated 06/10/2016 06:12 BST

The 5p Plastic Bag Versus The Steak on Your Plate

The Climate Change Act 2008 gave the government a mandate to impose a fee for plastic carrier bags in an attempt to cut down on waste and global warming. In England this measure has now been implemented. While the step in itself is laudable, its environmental benefits will be negligible.

The UK is the first country in the world to have a legally binding, long-term framework in place to cut greenhouse gas (GHG) emissions by at least 80% on 1990 levels in 2050. Yet one of the biggest contributors is frequently omitted from debate and left off the policy agenda: the farming of animals. Globally, at least 14.5% (FAO, 2013) of all greenhouse gases are caused by the livestock industry,) and some have estimated this figure to be as high as 51% (Goodland and Anhang, 2009).

Leaving aside the tremendous negative impacts from plastic bags on fauna generally, the carbon emissions from individual carrier bags compared to cotton bags, for example, are miniscule: A cotton bag will need to be re-used over 170 times to put it on the same level as a single use plastic bag made from recycled material.

The UK food system emits around a fifth of current estimated consumption GHG emissions. (Audsley et al., 2009). Over half of these arise from the production of animal products. When land use changes are taken into account, such as deforestation to grow crops to feed to animals rather than using them to nourish people, food consumption emissions rise to 30% of total consumption emissions. Meat and dairy have the greatest impact, accounting for approximately half of food-related emissions. A better environment starts with taking more responsibility at an individual level.

A few more staggering figures: Rearing animals for meat is responsible for 37% of all methane emissions. Of these emissions, around three quarters are caused by ruminants (sheep, cows, etc.) emitting gases, and another 20% is released from manure. Methane warms the atmosphere much more strongly than CO2. In addition, 65% of all nitrous oxide emissions are caused by manure and urine from grazing animals, and this gas has a global warming potential of almost 300 times that of CO2. Finally, 64% of gaseous ammonia, which can cause acid rain, is caused by rearing animals for meat. The environmental impact of a steak is therefore many hundred times larger than that of a plastic carrier bag.

People don't like to be told what (or what not) to eat or how to farm. Fair enough. However, more and more people now choose to replace animal products with plant-based alternatives, or go vegan. The government ought to help farmers to protect their livelihoods. Not by propping up failing dairy industries, or beef farming, both of which cause not only untold suffering and death to millions of animals, but also immeasurable depletion of natural resources such as land and water, and these industries have, as we've seen, a very substantial negative impact on climate change.

What is needed is political leadership, so we call on the government to provide subsidies and other incentives to farmers wishing to move away from livestock farming to growing crops. A new report, Grow Green, explains what needs to be done to tackle climate change, and how a policy and financial intervention can achieve improvements in public health, the environment, and of course, reduce animal suffering. Engage with your MP or local Councillor to put the environmental impact of food back on the political agenda. We cannot afford to lose any more time; the climate clock is ticking...