Subject: Re: [permaculture] So what do you really think about long term climate change due to pollution-related global warming
Date: Sun, 25 Mar 2007 21:41:16 -0700
lawrence asked,
Can we, acting collectively, actually make any difference?
Is it for generations hence to deal with or should we start now?
What do we do?
The number-one thing everyone can do is to eat lower on the food
chain. We could reduce greenhouse gases by about half within a year
or two by stopping the breeding and eating of livestock.
A New Global Warming Strategy: How Environmentalists are Overlooking
Vegetarianism as the Most Effective Tool Against Climate Change in
Our Lifetimes
by Noam Mohr
Summary
Global warming poses one of the most serious threats to the global
environment ever faced in human history. Yet by focusing entirely on
carbon dioxide emissions, major environmental organizations have
failed to account for published data showing that other gases are the
main culprits behind the global warming we see today. As a result,
they are neglecting what might be the most effective strategy for
reducing global warming in our lifetimes: advocating a vegetarian
diet.
Global Warming and Carbon Dioxide
The environmental community rightly recognizes global warming as one
of the gravest threats to the planet. Global temperatures are
already higher than they've ever been in at least the past
millennium,1 and the increase is accelerating even faster than
scientists had predicted.2 The expected consequences include coastal
flooding, increases in extreme weather, spreading disease, and mass
extinctions.
Unfortunately, the environmental community has focused its efforts
almost exclusively on abating carbon dioxide (CO2) emissions.
Domestic legislative efforts concentrate on raising fuel economy
standards, capping CO2 emissions from power plants, and investing in
alternative energy sources. Recommendations to consumers also focus
on CO2: buy fuel-efficient cars and appliances, and minimize their
use.3,4
This is a serious miscalculation. Data published by Dr. James Hansen
and others5 show that CO2 emissions are not the main cause of
observed atmospheric warming. Though this may sound like the work of
global warming skeptics, it isn't: Hansen is Director of NASA's
Goddard Institute for Space Studies who has been called "a
grandfather of the global warming theory."6 He is a longtime
supporter of action against global warming, cited by Al Gore7 and
often quoted by environmental organizations, who has argued against
skeptics for subverting the scientific process.8 His results are
generally accepted by global warming experts, including bigwigs like
Dr. James McCarthy, co-chair of the International Panel on Climate
Change's Working Group II.9
The focus solely on CO2 is fueled in part by misconceptions. It's
true that human activity produces vastly more CO2 than all other
greenhouse gases put together. However, this does not mean it is
responsible for most of the earth's warming. Many other greenhouse
gases trap heat far more powerfully than CO2, some of them tens of
thousands of times more powerfully.10 When taking into account
various gases' global warming potential-defined as the amount of
actual warming a gas will produce over the next one hundred years-it
turns out that gases other than CO2 make up most of the global
warming problem.11
Even this overstates the effect of CO2, because the primary sources
of these emissions-cars and power plants-also produce aerosols.
Aerosols actually have a cooling effect on global temperatures, and
the magnitude of this cooling approximately cancels out the warming
effect of CO2.12 The surprising result is that sources of CO2
emissions are having roughly zero effect on global temperatures in
the near-term!13
This result is not widely known in the environmental community, due
to a fear that polluting industries will use it to excuse their
greenhouse gas emissions. For example, the Union of Concerned
Scientists had the data reviewed by other climate experts, who
affirmed Hansen's conclusions.14 However, the organization also cited
climate contrarians' misuse of the data to argue against curbs in
CO2.15 This contrarian spin cannot be justified.
While CO2 may have little influence in the near-term, reductions
remains critical for containing climate change in the long run.
Aerosols are short-lived, settling out of the air after a few months,
while CO2 continues to heat the atmosphere for decades to centuries.
Moreover, we cannot assume that aerosol emissions will keep pace with
increases in CO2 emissions.16 If we fail to start dealing with CO2
today, it will be too late down the road when the emissions catch up
with us.
Nevertheless, the fact remains that sources of non-CO2 greenhouse
gases are responsible for virtually all the global warming we're
seeing, and all the global warming we are going to see for the next
fifty years. If we wish to curb global warming over the coming half
century, we must look at strategies to address non-CO2 emissions. The
strategy with the most impact is vegetarianism.
Methane and Vegetarianism
By far the most important non-CO2 greenhouse gas is methane, and the
number one source of methane worldwide is animal agriculture.17
Methane is responsible for nearly as much global warming as all other
non-CO2 greenhouse gases put together.18 Methane is 23 times more
powerful a greenhouse gas than CO2.19 While atmospheric
concentrations of CO2 have risen by about 31% since pre-industrial
times, methane concentrations have more than doubled.20 Whereas human
sources of CO2 amount to just 3% of natural emissions, human sources
produce one and a half times as much methane as all natural
sources.21 In fact, the effect of our methane emissions may be
compounded as methane-induced warming in turn stimulates microbial
decay of organic matter in wetlands-the primary natural source of
methane.22
With methane emissions causing nearly half of the planet's
human-induced warming, methane reduction must be a priority. Methane
is produced by a number of sources, including coal mining and
landfills-but the number one source worldwide is animal
agriculture.23 Animal agriculture produces more than 100 million tons
of methane a year.24 And this source is on the rise: global meat
consumption has increased fivefold in the past fifty years, and shows
little sign of abating.25 About 85% of this methane is produced in
the digestive processes of livestock,26 and while a single cow
releases a relatively small amount of methane,27 the collective
effect on the environment of the hundreds of millions of livestock
animals worldwide is enormous. An additional 15% of animal
agricultural methane emissions are released from the massive
"lagoons" used to store untreated farm animal waste,28 and already a
target of environmentalists' for their role as a primary source of
water pollution in the U.S.29
The conclusion is simple: arguably the best way to reduce global
warming in our lifetimes is to reduce or eliminate our consumption of
animal products. Simply by going vegetarian (or, strictly speaking,
vegan), 30,31,32 we can eliminate one of the major sources of
emissions of methane, the greenhouse gas responsible for almost half
of the global warming impacting the planet today.
Advantages of Vegetarianism over CO2 Reduction
In addition to having the advantage of immediately reducing global
warming, a shift away from methane-emitting food sources is much
easier than cutting carbon dioxide.
First, there is no limit to reductions in this source of greenhouse
gas that can be achieved through vegetarian diet. In principle, even
100% reduction could be achieved with little negative impact. In
contrast, similar cuts in carbon dioxide are impossible without
devastating effects on the economy. Even the most ambitious carbon
dioxide reduction strategies fall short of cutting emissions by half.
Second, shifts in diet lower greenhouse gas emissions much more
quickly than shifts away from the fossil fuel burning technologies
that emit carbon dioxide. The turnover rate for most ruminant farm
animals is one or two years, so that decreases in meat consumption
would result in almost immediate drops in methane emissions. The
turnover rate for cars and power plants, on the other hand, can be
decades. Even if cheap, zero-emission fuel sources were available
today, they would take many years to build and slowly replace the
massive infrastructure our economy depends upon today.
Similarly, unlike carbon dioxide which can remain in the air for more
than a century, methane cycles out of the atmosphere in just eight
years, so that lower methane emissions quickly translate to cooling
of the earth.
Third, efforts to cut carbon dioxide involve fighting powerful and
wealthy business interests like the auto and oil industries.
Environmental groups have been lobbying for years to make
fuel-efficient SUVs available or phase out power plants that don't
meet modern environmental standards without success. At the same
time, vegetarian foods are readily available, and cuts in
agricultural methane emissions are achievable at every meal.
Also, polls show that concern about global warming is widespread, and
environmental activists often feel helpless to do anything about it.
Unless they happen to be buying a car or major appliance, most people
wanting to make a difference are given little to do aside from
writing their legislators and turning off their lights. Reducing or
eliminating meat consumption is something concerned citizens can do
every day to help the planet.
Finally, it is worth noting that reductions in this source of
greenhouse gas have many beneficial side effects for the environment.
Less methane results in less tropospheric ozone, a pollutant damaging
to human health and agriculture.33 Moreover, the same factory farms
responsible for these methane emissions also use up most of the
country's water supply, and denude most of its wilderness for
rangeland and growing feed. Creating rangeland to feed western
nations' growing appetite for meat has been a major source of
deforestation and desertification in third world countries. Factory
farm waste lagoons are a leading source of water pollution in the
U.S. Indeed, because of animal agriculture's high demand for fossil
fuels, the average American diet is far more CO2-polluting than a
plant-based one.34
Recommendations
l Organizations should consider making advocating vegetarianism a
major part of their global warming campaigns. At a minimum,
environmental advocates should mention vegetarianism in any
information about actions individuals can take to address global
warming.
l Government policy should encourage vegetarian diets. Possible
mechanisms include an environmental tax on meat similar to one
already recommended on gasoline, a shift in farm subsidies to
encourage plant agriculture over animal agriculture, or an increased
emphasis on vegetarian foods in government-run programs like the
school lunch program or food stamps.
ENDNOTES
_____________________
1 Some examples: U.S. PIRG's global warming site
(http://uspirg.org/uspirg.asp?id2=5235) advocates increasing fuel
efficiency standards, capping CO2 from power plants, shifting
investments from fossil fuels, and ratifying the Kyoto Protocol. The
Sierra Club global warming site
(http://www.sierraclub.org/globalwarming/overview/solutions.asp)
advocates energy efficiency in cars, power plants, and increasing
solar and wind energy. The Natural Resources Defense Council
(http://www.nrdc.org/globalWarming/gsteps.asp) recommends
energy-efficient appliances, fuel efficient cars, compact fluorescent
light bulbs, planting trees, weatherizing your home, and contacting
your representatives. The Union of Concerned Scientists' site
(www.ucsusa.org) recommends curbing our consumption of fossil fuels,
using technologies that reduce emissions, and protecting the world's
forests.
2 It's worth noting that buying fuel efficient cars and light trucks
do not directly reduce carbon dioxide emissions. Because auto
manufacturers are bound only by fleet-wide averages, every
low-gas-mileage car sold simply allows them to sell another gas
guzzler. However, choosing efficiency is not for naught: demand for
fuel efficiency may help drive technological innovation and reduce
industry opposition to improved fuel economy standards. Moreover,
since cars have stricter standards than light trucks, it is always
better to buy the former.
3. Hansen, James E. et al., "Global warming in the twenty-first
century: An alternative scenario," Proceedings of the National
Academy of Sciences, vol. 97, no. 18, 29 Aug. 2000, p. 9876, 5.
4.Llanos, Miguel, "'Alternative' view offered on battling climate
change; NASA scientist: CO2 still a factor but other gases are key",
MSNBC News - Environment, 31 Aug. 2000,
http://www.msnbc.com/news/447151.asp.
5. Gore, Albert, Earth in the Balance, Houghton Mifflin Co., 2000, p. 176.
6. Hansen, James E., "The Global Warming Debate", NASA Goddard
Institute for Space Studies Education,
http://www.giss.nasa.gov/edu/gwdebate/.
7. Moser, Susi, "Review of Hansen et al.: 'Global warming in the
twenty-first century: An alternative scenario'", Information Update,
The Union of Concerned Scientists, September 2000, p.2,
http://www.ucsusa.org/documents/reviewofalt.pdf.
8. SF6 has a global warming potential 23,900 times that of carbon
dioxide. HFC-23 has a global warming potential 11,700 times that of
carbon dioxide. "Global Warming Potentials", National Emissions, U.S.
Environmental Protection Agency,
http://www.epa.gov/nonco2/econ-inv/table.html.
9. Hansen, James E. and Makiko Sato, "Trends of measured climate
forcing agents", Proceedings of the National Academy of Sciences,
vol. 98, no. 26, 18 Dec. 2001, p. 14778-14783,
http://www.pnas.org/cgi/content/full/98/26/14778. The estimated
climate forcing of carbon dioxide from 1850 to 2000 is 1.4 W/m2,
while the combined forcings of methane, CFCs, nitrous oxide, and
tropospheric ozone is 1.6 W/m2 when indirect effects via water and
ozone are taken into account.
10. Hansen and Sato, supra note 11. Estimated climate forcing of
aerosols from 1850 to 2000, is -1.5 W/m2, larger than the positive
forcing of carbon dioxide. Admittedly, estimates of aerosol forcing
have large uncertainties; however, there are as likely to be too low
as too high. Among aerosols, black carbon warms the atmosphere, both
by absorbance and through semi-direct dirty cloud and snow effects,
while sulfates, nitrates, and organic aerosols have a cooling effect,
both by directly reflecting sunlight and by indirectly making clouds
less bright and reducing cloud cover. Hansen, et al., supra note 5.
11. However, Hansen points out that "Offsetting of global mean
forcings does not imply that climate effects are negligible." Hansen,
et al., supra note 5.
12. Moser, p. 1-2, supra note 9.
13. Moser, p. 4, supra note 9.
14. Hansen, et al., supra note 5.
15. Animal agriculture is also a major source of nitrous oxide
emissions, another important greenhouse gas 310 times more powerful
than carbon dioxide. 73% of U.S. emissions of nitrous oxide come from
animal grazing, manure management, and crop growing practices-with
half of U.S. crops grown for livestock feed. Agricultural emissions
of nitrous oxide in the U.S. increased 9% from 1990 to 2002.
"Inventory of U.S. Greenhouse Gas Emissions: 1990-2002," EPA
430-R-04-003, U.S. Environmental Protection Agency, 15 April 2004, p.
ES-16, http://www.epa.gov/globalwarming/publications/emissions.
16. Hansen and Sato, supra note NOTEREF _Ref90104934 \h 11.
Estimated climate forcing of methane from 1850 to 2000 is 0.7 W/m2,
while estimated forcing of CFCs, tropospheric ozone, and nitrous
oxide combined is 0.9 W/m2.
17. "Global Warming Potentials", supra note 10.
18. Atmospheric CO2 concentrations have risen from 278 parts per
million (ppm) in 1750 to 365 ppm in 1998. Atmospheric concentrations
of methane have increased by 149% since 1750, from .700 ppm to 1.745
ppm. "Emissions of Greenhouse Gases in the United States 2002",
Chapter 1, Energy Information Administration, U.S. Department of
Energy, October 2003, http://www.eia.doe.gov/oiaf/1605/ggrpt.
19. Natural sources emit 770 billion metric tons of CO2, and 239
million metric tons of methane, compared to 23.1 billion and 359
million, respectively, for anthropogenic sources. "Emissions of
Greenhouse Gases in the United States 2002", supra note 20.
20. Hansen, et al, supra note 5. It is also possible that warming may
dampen natural sources of methane by drying out wetlands.
21. Animal agriculture is responsible for 32% of global methane
emissions from human activity, including 28% from domesticated
livestock and 4% from livestock manure. Natural gas is the second
largest source, accounting for 15% of emissions. Kruger, Dina, "The
Role of 'Other Gases' in Addressing Climate Change", U.S.
Environmental Protection Agency, 12 Feb 2004,
http://www.iges.or.jp/en/cp/output_all/
workshop/usjapan/pdf/06Kruger.pdf.
22. "Emissions of methane from livestock", Climate Change Fact Sheet
32, Information Unit on Climate Change (IUCC), UNEP, 1 May 1993,
http://www.unep.ch/iucc/fs032.htm.
23. World meat production reached 242 million tons in 2002, from 122
million tons in 1977, and from 44 million tons in 1950. Additionally,
per capita meat consumption has more than doubled since 1950, from 17
to 39 kg per person. Vital Signs 2003, Worldwatch Institute, May
2003, p.30-31, http://www.worldwatch.org/pubs/vs/2003. The majority
of the meat is consumed by developed countries. Delgado, Christopher
et al., Livestock to 2020: The Next Food Revolution, "Food,
Agriculture, and the Environment Discussion Paper 28", International
Food Policy Research Institute, May 1999,
http://www.ifpri.org/2020/dp/dp28.pdf.
24. "The Role of 'Other Gases' in Addressing Climate Change", supra
note 23. Methane emissions come particularly from ruminant animals,
like cows, sheep, buffalo, and goats, but also from non-ruminants
like pigs and horses. "Emissions of methane from livestock", supra
note 24.
25. Not including methane released from manure, an adult cow produces
80-110 kg of methane a year. "Frequent Questions", Ruminant
Livestock, U.S. Environmental Protection Agency,
http://www.epa.gov/rlep/faq.html.
26. "The Role of 'Other Gases' in Addressing Climate Change", supra note 23.
27. "Water Quality Conditions in the United States", U.S.
Environmental Protection Agency, August 2002,
http://www.epa.gov/305b/2000report.
29. Herein, the term "vegetarian" is used to refer not just to a
meatless diet, but to one free of animal products, i.e. a "vegan"
diet. Dairy cows, for example, produce even more methane per animal
than beef cattle. Logically, the same concerns extend beyond diet to
the consumption of other consumer goods derived from livestock, like
wool and leather.
30. Because ruminant livestock produce far more methane than
non-ruminant livestock, reductions in agricultural methane can also
be achieved by shifting consumption away from cows and sheep in favor
of chickens and pigs. However, the benefits of such shifts are not
simple; for example, in the U.S., manure from pigs produces more than
five times as much methane as manure from beef cattle. ("Inventory of
U.S. Greenhouse Gas Emissions: 1990-2002", p. 181, supra note 17.)
Moreover, the large scale production of these animals in concentrated
animal feeding operations (CAFOs) is associated with numerous other
environmental harms already extensively documented by environmental
organizations, making the trade of one environmental danger for
another a Faustian bargain.
30. The U.S. Environmental Protection Agency's efforts to address
methane from livestock amount to encouraging changes in feed and
increasing the amount of product (meat, milk, offspring) per animal.
Even at best such efforts are unlikely to achieve large reductions in
emissions per animal, and any such reductions are easily swamped by
increases in the number of animals raised overall. Methane emissions
from manure can also be captured and used to produce energy.
31. Hansen, et al, supra note 5.
32. Pimentel and Pimentel estimate that the production of animal
products requires more than 10 times as much fossil fuel as the
production of plant foods, averaging 25 kcal of fossil fuel input per
kcal of animal protein, compared with 2.2 kcal of fossil fuel input
per kcal of plant protein. Pimentel, David and Marcia Pimentel,
"Sustainability of Meat-Based and Plant-Based Diets and the
Environment", American Journal of Clinical Nutrition, Vol. 78, No. 3,
September 2003,pp. 660S-663S. On CO2 see Tidwell, Mike, "Food and the
Climate Crisis: What You Eat Affects the Sky", Sierra Club Redwood
Chapter Newsletter, Dec./Jan. 2005,
http://www.redwood.sierraclub.org/articles/
December_04/FoodClimateCrisis.html.
Re: [permaculture] So what do you really think about long term climate change due to pollution-related global warming,
yarrow, 03/26/2007