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Daily Life and Global Warming. Gidon Eshel and Pamela Martin Department of the Geophysical Sciences The University of Chicago Chicago, IL 60637. nothing I'll say here will be individually new. but - I'd dare guess - putting it all together will. basic premise:.
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Daily Life and Global Warming Gidon Eshel and Pamela Martin Department of the Geophysical Sciences The University of Chicago Chicago, IL 60637
nothing I'll say here will be individually new but - I'd dare guess - putting it all together will basic premise: Global Warming is about energy. All we need is to simply change the way we do every last thing, to completely rethink every bit of societal infrastructure, and we should be all right.
D. Keeling, SIO, UCSD related?! CO2, ppmv year Energy Information Administration, www.eia.doe.gov
so we consume more, but there's more of us… million BTU $$ Energy Information Administration, Annual Energy Review 2003, www.eia.doe.gov i.e., each person consumes more every little choice we make can make a difference
"… The food production system accounts for 17% of all fossil fuel use in the US…" [in 2002] (Horrigan et al., Env. Health Perspectives, 110(5), May 2002, 445-456; Pimentel and Pimentel (Eds.), Food, Energy and Society, Univ. of Colorado Press, 1996)
an earlier, more conservative, estimate for 1999 Heller and Keoleian, Report No. CSS00-04 of the Center for Sustainable Systems, School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI us total, '99: 96.7x1015 BTU 100x10.2/96.7= = 10.5%
for comparison i.e., food production represents a major energy sink,comparable to the other major sectors
fine, so our collective diet has a significant planetary footprint; but how about an individual?! Are some dietary choices the nutritional equivalent of driving an SUV? let's gather the calculation's building blocks, and find out
Average miles driven per household vehicle in 1997 - 12,100 miles (sustainable Energy Coalition, www.sustainableenergy.org/resources/technologies/transportation.htm) single-person household: '88: 10,800 '94: 11,600 '05 Estimate: ~13,000 chapter 3, Fig. 3.5, Household Vehicles Energy Consumption Report Series: DOE/EIA-0464(94)
so your average adult drives ~13,000 miles a year • At 50:50 highway/city driving: • Honda Insight:13,000 / 63 mpg = 206 gal • Ford Focus station wagon: 13,000 / 30 mpg = 433 gal • Jeep Cherokee: 13,000 / 22 mpg = 591 gal • At 1 US gallon gasoline = 115,000 BTU • (from the Oak Ridge National Lab Bioenergy Information Network, assuming the more appropriate LHV) • Honda Insight: 2.4 x 107 BTU a year • Ford Focus station wagon: 5.0 x 107 BTU a year • Jeep Cherokee: 6.8 x 107 BTU a year
assume a reasonable 2100 Kcal/person/day or 766,500 Kcal/person/year, or According to Heller and Keoleian (Report No. CSS00-04 of the Center for Sustainable Systems, School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI), efficiency of food handling and preparation is ~0.55. Thus, the food energy directly consumed by a person in a year becomes
now recall that i.e., that the efficiency ratio of food production is or 0.14 so,
so car: (2.4 to 6.8) x 107 BTU person-1 year-1 food: 3.9 +/-?? x 107 BTU person-1 year-1 That is, nutritional choices can be just as important to one's planetary footprint as the car one drives, and there's a HUGE latitude in food choices!!
Efficiency: 100 x (energy in protein output) / (energy in input) caloric efficiency? modified from David Pimentel & Marcia Pimentel, Food, Energy and Society, University Press of Colorado, 1996, Tables 8.2, 9.4
Efficiency: 100 x (energy in protein output) / (energy in input) Protein loss through the food chain: Another disadvantage of fish farming is that raising carnivorous fish such as shrimp and salmon requires catching wild fish to sustain them, depriving ocean fish of food and sometimes resulting in a net loss of fish from the sea. It takes 3.1 pounds of wild-caught fish to raise one pound of farmed salmon.
Efficiency: 100 x (total energy in output) / (energy in input) average 10-15% caloric efficiency modified from David Pimentel & Marcia Pimentel, Food, Energy and Society, University Press of Colorado, 1996, Tables 8.2, 9.4
Efficiency: 100 x (energy in output) / (energy in input) average 220% caloric efficiency Don't worry about eating your spinach! David Pimentel & Marcia Pimentel, Food, Energy and Society, University Press of Colorado, 1996, pages 114-134
Let's compare competing diets: caloric efficiency of production 35%
Let's (generously) assume a 15% animal product efficiency, and a run-of-the-mill 50% of calories from animal products such a diet requires 1.96 x 107 BTU a year by contrast, this person's vegan counterpart requires 0.25 x 107 BTU a year the difference, ~1.7 x 107 BTU person-1 year-1, is similar to the difference between owning a Jeep Cherokee vs. a Ford Focus!!!
The added benefit is, of course, health % of US GDP spent on health care: 1960: 5.1% 1991: 13.4% 2002: 14.9% 2003: 15.3% DOE/EIA, World Energy Use and Carbon Dioxide Emissions, 1980-2001, May 2004 OECD countries: Australia,Austria, Belgium ,Canada, Denmark, Finland, France, Germany, Germany, Greece, Iceland, Ireland, Italy, Japan, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Portugal, Spain, Sweden, Switzerland, Turkey, UK, USA
and the health care sector is not particularly efficient Krackler, Schipper and Sezgen (1998), Energy Policy, 26(15), 1137-1152 kwh m-2 weighted averages based on floor area in the U.S., Japan, Canada, France, Denmark and Sweden
American Journal of Clinical Nutrition, 73(4), 722-727, April 2001, Fig. 1 most are aware of the importance of total fat
and only slightly fewer are aware of the importance of the kind of fat ingested American Journal of Clinical Nutrition, 78(3), 544S-551S, September 2003 P for trend = 0.001
American Journal of Clinical Nutrition, 78 (3), 544S-551S, September 2003 mean+/- 95% CIs
American Journal of Clinical Nutrition, 78 (3), 544S-551S, September 2003
American Journal of Clinical Nutrition, 78 (3), 544S-551S, September 2003
total fat intake and breast cancer Int. J. Cancer, 15, 1975, 617-631 age-adjusted death rate per 105 animal fat intake, gr/day animal fat intake and breast cancer
age-adjusted death rate per 105 vegetable fat intake, gr/day but for plant fat intake vs. breast cancer - the correlation collapses!
in California Seventh-day Adventists adjusted for age, smoking, exercise, BMI, hypertension, and food preferences. American Journal of Clinical Nutrition, 70(3), 532S-538S, September 1999 men 95% CIs Relative risk of definite fatal ischemic heart disease frequency of beef consumption
most attribute such results to animal fat intake. While this is certainly important, animal protein intake is probably as important to cancer prevalence as animal fat is to CVDs. activity of the enzyme responsible for turning ingested aflatoxin into the DNA-altering derivative Mgbodile and Campbell, 1972: J. Nutr., 102, 53-60
enzyme activity, as expected, results in less aflatoxin binding to three elements of cell nuclei Preston et al., 1976: Life Sci., 19, 1191-1198
Appleton and Campbell, 1982: Nutr. Cancer, 3, 200-206 Dunaif and Campbell, 1987: J. Nat. Cancer Inst., 78, 365-369 foci response 5% 20% dietary protein level foci response high AF low protein low AF high protein
adequate protein for body growth Dunif and Campbell, 1987: J. Nutr. , 117, 1298-1302 Dunaif and Campbell, 1987: J. Nat. Cancer Inst., 78, 365-369 foci development 20% Protein foci development 5% Protein % dietary protein
Protein type and foci response 20% Casein foci response 20% Gluten 5% Casein Early foci, Lifetime 22% 14% 6% % dietary casein protein type Schulsinger et al., 1989: J. Nat. Cancer Inst., 81, 1241-1245 Youngman and Campbell, 1992: Carcinogenesis, 13, 1607-1613 Youngman, 1990: Ph.D. thesis, Cornell Univ., Ithaca
% casein full tumor response 22% 14% 6% these results hold for actual tumors (as opposed to tumor precursors) Tumor development at 100 weeks Youngman and Campbell, 1992: Carcinogenesis, 13, 1607-1613 Youngman, 1990: Ph.D. thesis, Cornell Univ., Ithaca
liver tumors at death (12-16 month) and animal protein intake % casein 6% 14% 22% 6-to-22 at 8 months 22-to-6 at 8 months and another work Cheng et al. (1997) Hepatology, 26, 1351-1354
22% 14% 6% other species, other carcinogen… Hu et al., 1997: Oncogen, 15, 2795-2801
another dimension of the problem is our export of the "American Way", complete with what is undoubtedly among the world's most awful diets
obesity rate of change patterns in the developing world Popkin (2003), Development Policy Review, 21, 581-597 percent Mexico 88-89 Brazil 74-96 Morocco 85-99 Thailand 91-96 China 89-97
Food and Nutrition Bulletin, 22(4) (supplement) 2001, The U.N. University percent overweight in rural India women men
BMI>30 BMI 25-29.9 60% 40% 20% 0% <1 <1 1-5 1-5 >15 >15 5-10 5-10 10-15 10-15 U.S.-born U.S.-born Sanghavi et al. (2004), JAMA, 292, 2860-2867 adjusted BMI of foreign-born individuals (N=4,631) by years of residency in the U.S. % incidence of indicated BMI category years of residence in the U.S.
So: • what you choose to eat has planetary effects as big as, say, what you choose to drive or where you choose to live • eat less animal-based food