Global Warming
WHAT'S THE PROBLEM?
"Global warming has emerged as the most serious environmental threat of the 21st century...Only by taking action now can we insure that future generations will not be put at risk."
Excerpt from a letter to the US President from 49 Nobel Prize winning scientists.
"When carbon dioxide, methane and nitrous oxide are released into the air they blanket the earth, trapping heat inside the atmosphere - this is known as the greenhouse effect, and it is this that keeps our planet at a temperature at which life can thrive. The problem is that the massive increase in the output of these and other greenhouse gases since industrialisation has caused the effect to intensify. "
The 1990s was the hottest decade on record. The Intergovernmental Panel on Climate Change (IPCC) estimates that over the course of the 20th century average global temperature rose by around 0.6 deg C. [1] Over the past two decades the earth has been warming at a faster rate than at any point in the last 1,000 years. It is now almost universally agreed that the major cause of this problem is the burning of fossil fuels. The US Environmental Protection Agency estimates that the use of coal, oil and gas to produce energy is responsible for 98% of carbon dioxide emissions.
An increase of 0.6 deg C may not sound like much, but climate scientists predict that this rate of change will have serious, if not disastrous, consequences. Whilst it is difficult to judge how our weather systems will adapt to increased global temperatures, possible scenarios include an increase in freak floods and prolonged droughts, which would have a significant impact on future food production. The melting of the polar ice caps and thermal expansion of the seas are among the most worrying possibilities. The British Meteorological Office's Hadley Centre for Climate Prediction and Research estimates that if nothing is done about greenhouse gas emissions, sea levels will rise by more than 40cm by 2100. [2] Such an increase would have disastrous consequences for inhabitants of oceanic islands and coastal regions.
the Livestock Connection
Livestock production contributes to climate change in a number of ways, with fossil fuel consumption being the major factor. It is also the main source of anthropogenic ('man-made') methane emissions (see figure 3).
Methane is one of the three gases thought to be responsible for global warming. It is second only to carbon dioxide as a contributor to anthropogenic greenhouse gas emissions. The overall contribution of methane to global warming is significant as it is estimated to be 21 times more effective at trapping heat in the atmosphere than CO2. Over the last two centuries, the concentration of methane in the atmosphere has more than doubled.
"Methane is produced by bacteria in the stomachs of ruminants such as sheep, cattle, and goats and is farted and belched out by the animals. Dairy cows have been calculated to produce roughly 30kg more methane per year than free-range beef cattle (84kg and 54kg respectively), largely because of differences in diet and levels of exercise. When manure is kept in anaerobic conditions (as in the liquid systems commonly used on intensive farms), even more methane is produced. Manure is also responsible for 7% of emissions of nitrous oxide (an even more aggressive greenhouse gas)."
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"Emissions from manure were the fastest growing source of methane between 1990 and 1999. [3]
In addition to these direct impacts, animal husbandry also contributes to global warming indirectly, one of the major problems being the felling of forests to provide land to grow food for cattle. This results in there being fewer and fewer trees to absorb carbon dioxide, the major greenhouse gas."
Changing to a vegan diet will not stop global warming, but if you worry about using cars, having baths, turning on the heating, using energy saving light bulbs and so on, you should also be worrying about the amount of damage the food you eat is causing.