Carbon dioxide (CO2), methane and nitrous oxide are gases that are found in the atmosphere. They're like the glass of a greenhouse, trapping the sun’s heat and reflecting it back to earth. It's all completely natural and without it we wouldn't be able to live on this world of ours because it would be too cold. This warming keeps temeperatures about 33ºC/92ºF higher than they would otherwise be.
Farming animals produces more of these gases, which add to those that already exist and makes the planet warm even more. In 2006, the United Nations Food & Agriculture Organisation (UN FAO) worked out just how much farmed animals add to global warming. They are the second-biggest cause at 18 per cent of the total. All the world's different forms of transport added together - cars, boats, planes, trains and so on - account for just 13.5 per cent.
This extra heat is causing polar ice caps to melt and is warming the world’s oceans. As they warm they expand and flooding will become a big problem. Britain’s Hadley Centre for Climate Change reckons that 200 million people will be at risk, with some islands disappearing entirely. About one third of all agricultural land will disappear under waterand so the amount of food that's grown will drop dramatically. People whose land has disappeared will have no choice but to migrate and move on to land that's already occupied. Millions of landless people on the move will be create an environmental and humanitarian disaster as well as threatening serious conflict.
The frozen soil at both ends of the Earth is called permafrost because it never melts - until now! But as temperatures rise, the soil is defrosting and is starting to release the billions of tons of methane that it has held captive for millions of years. The more of this global-warming gas that's released, the more intense global warming becomes. It's a similar story with the sea bed of the Arctic Ocean. which also holds trapped methane.
It's a Gas:
The more the earth warms, the more methane is released - and so it goes on. Called ‘positive feedback’, this could mean that global warming becomes unstoppable and impossible to control.
The most damaging of the three gases is CO2 because of the huge quantities produced. The second most damaging is methane, which is 21 times more effective at trapping heat than CO2 and stays around in the atmosphere for nine to 15 years. Nitrous oxide has 296 times more global warming power than CO2 and and lasts for 114 years.
Ee-Aye, Ee-Aye Oh:
Old Macdonald had a lot of animals on his farm and together with all the world's other farms, it's started to cause problems. All the different processes needed to keep livestock and turn them into meat and dairy - feeding, transporting, killing - produce large amounts of all three gases, according to the UN FAO.
Most of the crops grown across the world are fed to animals and these use large amounts of nitrogen fertilizer to increase yields and this produces nitrous oxide. Just thel fuel used to make the fertilizer gives off about 41 million tonnes of CO2 every year.
Humans produce nitrous oxide in many different ways but manure from animals, even that used for fertiliser, is responsible for 60 per cent of the total.
On the Increase:
The outcome of all this is that there is now more CO2 in the atmosphere than at any time in the last 650,000 years, methane has doubled since the start of the industrial revolution and average temperatures have increased by 0.8ºC (2005).
In 2005, the University of Chicago examined the amount of energy used by different food industries. The worst offender is red meat followed by fish (largely due to industrial methods of catching), dairy, then poultry. Vegan diets are the least harmful.
Threat to Life:
The Washington-based World Watch Institute says:
“It has become apparent that the human appetite for animal flesh is a driving force behind virtually every major category of environmental damage now threatening the human future.”
As countries such as China 'develop' they copy the West, including what we eat. This is now causing big problems according to a group pf academic researchers who make up the Profetas study, set up by the Dutch universities of Twente, Waganingen and VUA:
“This trend must be reversed on a global scale” – by moving from meat protein to vegetable protein alternatives."
Meat or Veg?
A study by Amsterdam University and Loma Linda University in California found that meat, dairy and fish were more damaging to the environmental on every front than growing vegetable protein. Vegetable protein is taken from plants such as soya and wheat.
They found that, on average, you had to feed 10g of vegetable protein to animals to get just 1g of animal protein but some animals were more wasteful than others. In broiler (meat) chickens, it was nearly six to one, for pigs it was 11 to one and for beef it was 17 to one.
By anyone's reckoning this is a highly inefficient way of producing food and it's why farmed animals use up 70 per cent of all the world’s agricultural land to graze on or for growing fodder.
In Europe, most of the energy we use is coal, gas and oil from fossil fuels and animal farming demands large amounts of all of them. It takes between six and 20 times more fuel for meat and dairy than it does for plant protein (a vegan diet). For catching fish and processing it, the difference is between 20 and 44 times more than for vegetable protein.
Soaking it up:
It's an uncomfortable fact that the world is threatened - but not just by increased CO2 and other gases. The planet is losing it ability to absorb C02 and hold on to it in what are called ‘carbon sinks’. Again it's the popor old animals who carry a lot of the blame - or rather those who farm them.
One of the greatest carbon sinks is soil itself and as the hooves, heavy bodies and overgrazing of animals cause its structure to break down, the CO2 it holds is released. Because the soil has become 'degraded', it becomes incapable of absorbing any further CO2. It's much the same with forests - chopping them down releases masses of C02 and as they are not regrown, they never absorb C02 again.
The Global Climate Project in Canberra reckons that 50 years ago, 600kg of CO2 was absorbed for every tonne produced but in 2006 it was only 550kg – and reducing all the time.
The vast majority of scientists now agree that Earth is warming much faster than they predicted it would – three times faster, according to the US National Academy of Sciences.
Scary or What?
The hugely respected journal, Proceedings of the National Academy of Science, says that once average temperatures rise by 3ºC – and that's well within most predictions – plants will give off more C02 than they absorb because the organic matter in the soil that holds them will start to decompose, giving off C02 as it does.
Even some in the meat industry know there are problems and have done for years. A report by European meat industry vets written in 1990 said the unsayable: “We are not able to destroy the Earth but we might change the climate in an unpredictable direction – at worst endangering our survival as a species”. Scary stuff!
But there are plenty of other voices as well. In 2007, Professor Peter Cox of Exeter University told the Royal Geographical Society (another impressive organisation) that global warming could be unstoppable by 2050:
“You cannot mitigate yourself out of this problem… The choice is between a damaged world or a future with a seriously damaged world.”
This damage will include:
- 350 to 600 million people in Africa suffering water shortages;
- a fall in agricultural yields of up to one half;
- a spread of eight per cent in arid areas;
- one billion people in Asia suffering from water shortages as Himalayan glaciers melt and crop yields fall;
- 77 million people in Latin America suffering water shortages as tropical rainforests become savannah;
- storms, tempests and wide-scale flooding happening almost everywhere.