At the beginning of 2007, the United Nation’s Intergovernmental Panel on Climate Change (IPCC) reported that global temperatures will probably rise by between 1.8 and 4°C by the end of this century (the possible range being between 1.1 to 6.4°C)*11. This may not sound like a lot but the polar ice caps are already melting and the report predicted that these temperature changes would cause rises in sea levels and increases in the number of hurricanes and tropical storms. When the sea level rises, low lying land around the world is threatened and over time, things just get worse as the expanding oceans increase further, thanks to the melting of ice sheets covering Greenland and Antarctica.

Many scientists and world leaders believe that climate change is the most serious issue facing the whole human race.

The most important greenhouse gases are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The atmospheric concentrations of all three have increased phenomenally in modern times. Comparing figures from 2005 with pre-industrialised levels (measurements from 1750), carbon dioxide has increased from around 280 parts per million (ppm) to 379ppm, methane has increased from 715 parts per billion (ppb) to 1774ppb and nitrous oxide has increased from 270 ppb to 319 ppb*11. The increase in carbon dioxide is due mostly to the use of fossil fuels and changes in the way we use land.

Increases of methane and nitrous oxide, however, are primarily caused by agriculture*11.

Farmed animals produce more greenhouse gas emissions (18%) than the world’s entire transport system (13.5%). Cows’ flatulence, alongside animal excrement, makes the headlines due to both of them being extremely damaging. However, farming animals also generates gaseous emissions through the manufacture of fertilisers (to grow feed crops), industrial feed production and the transportation of both live animals and their carcasses across the globe*8.

9% of human-related CO2 emissions are caused by the livestock sector, mostly due to changes in land use (e.g. forests being cleared for grazing or growing animal feed) and the use of fossil fuels for farm operations*12.

Methane has 23 times the global warming impact of CO2*8 and ruminant mammals (cows and sheep) are responsible for 37% of the total methane generated by human activity.

There are approximately 1.5 billion cattle and 1.7 billion sheep on the planet. A single cow can produce as much as 500 litres of methane per day*13.

Nitrous oxide is almost 300 times as damaging to the climate as carbon dioxide with 65% of the total quantity produced by human activity coming from livestock (mostly their manure).