Energy, Environment, and Industrial Development

1. Energy, Environment, and Industrial Development Frederick H. Abernathy Michael B. McElroy Lecture 9 March 6, 2006

5. Figure 3.1 The radiation budget of Earth’s surface-atmosphere system. Source: Peixoto and Oort 1992

6. Classification of terrestrial ecosystems • Tundra. No trees, grasses, mosses, lichens. Low rainfall, low temperatures • Taiga or boreal forests. Dominated by conifers – spruces, firs, larches, pines. Trees less than 30m high. Covers much of Canada and Northern Eurasia • Temperate deciduous forests. Maples, beeches, oak. Source of hardwood. China, Japan, western Europe, United States, southern Canada • Temperate rain forests. Moderate temperatures and high precipitation. Redwoods, Douglas firs, western cedars. Western US, western New Zealand • Temperate woodlands. Temperature similar to deciduous forests but drier. New England to Georgia. Parts of Caribbean • Temperate shrub lands. Dry, temperate, low stature, chaparral

7. Classification of terrestrial ecosystems • Temperate grasslands. Regions too dry for forests. North American prairies, steppes of Eurasia, pampas of Argentina. Fire and grazing necessary for persistence of grasses • Tropical rain forests. High average temperature relatively constant over year. High, frequent, rainfall. Amazon basin, Indonesia, Malaysia. • Tropical seasonal forests and savannas. High relatively constant average temperature. Abundant, but seasonal, rainfall. Savannas dominate at lower rainfall. • Deserts. Rainfall < 0.5m/year

8. http://edcdaac.usgs.gov/glcc/gifs.asp

9. http://edcdaac.usgs.gov/glcc/gifs.asp

10. Spring, Feb. 21-Apr. 21, 2001 Summer, May 21-Jun. 21, 2000 Winter, Nov 21- Jan. 21, 2001 Fall, Aug 21-Oct. 21, 2000 http://earthobservatory.nasa.gov/Newsroom/EVI_LAI_FPAR/

13. Perfectly dry wood (0% moisture) can provide as much as 8660 BTU/lb • Live wood contains a large amount of H2O. Even when well seasoned, the moisture content is significant ~ 20% • Significant heat is expended to evaporate the water content of the wood and to raise its temperature to the typical stack gas temperature (~ 400 F). Energy required to evaporate 1 lb of water = 1050 BTU • A realistic estimate of the energy available from well seasoned wood is about 6050 BTU/lb or 13,367 BTU/kg • Approximately half of the wood is represented by carbon. Thus, energy available is 12,100 BTU (lb C)-1 or 26,734 BTU (kgC )-1 = 2.67x104 BTU (kgC )-1

14. The photosynthetic processmay be represented as Light + CO2 + H2O  CH2O + O2 • Respiration (or decay) describes the reverse process CH2O + O2  CO2 + H2O + energy • Gross uptake of C by photosynthesis at Harvard Forest today amounts to about 11 tons C ha-1 yr-1. 1 hectare (ha) = 2.47 acres • Most of the carbon taken up is respired. Only about 25% is converted to organic matter, half of which is above ground, half below. This constitutes the net uptake. • Carbon available for sustainable harvest: tons C ha-1 yr-1 = 1.4 tons C ha-1 yr-1

15. Abernathy estimated that in 1800 people used about 5.5 cords of wood per person per year. • Energy content of a cord he took as 20x106 BTU • Implies energy use per person per year of 5.5 x 20 x106 BTU = 110 x106 BTU • Carbon required to supply this energy • Each person required 4.1 metric tons of C per year, equivalent to about 8 metric tons of dry wood or more than 15 tons of wood harvest • To apply needed carbon by sustainable harvest each person would need

16. Approximately 11% of the total global land area is devoted to crops: about 15x106 km2 = 1.5x109 ha • If all of this land were devoted to sustainable forestry with yields quoted here, the carbon yield would amount to 2.1x109 tons C yr-1 • At a consumption rate of 4.1 tons C (person)-1 yr-1, this could supply 512 million people

17. There are indications that mid-latitudes of the N. hemisphere are currently accumulating carbon at a rate of about 2x109 tons C yr-1 • Taking the 1800 per capita demand as 4.1 tons C yr-1, it follows that this would be sufficient to supply (2/4.1) x 109 people or 487 million people at the 1800 consumption rate. • Current fossil fuel use is about 6x109 tons C yr-1 or about 1 ton C/person • US consumption per capita is about 4 ton C yr-1 (person)-1

18. Nutritional energy requirement for a typical human  40 kcal day-1 (kg of body wt)-1 • Energy requirement per unit of body mass for an insect is about 10x higher than for a human or about 20x higher for a small bird • Nutritional energy requirement for a typical 70 kg adult human  70 x 40 kcal day-1 = 2.8x103 kcal day-1; 1 kcal = 4 BTU • Nutritional energy requirement for a typical 70 kg adult  1.1x104 BTU day-1  1.1x104 x 3.65x102 BTU yr-1 = 4x106 BTU yr-1. Allowing for domestic animal feed  ~ 15 x106 BTU yr-1 • This compares with the energy demand for wood per person per year in 1800 of 110x106 BTU • Energy/food factor = 28 or ~ 7 allowing for animals

20. Estimate for carbon incorporated globally in trees  3x109 tons C yr-1 • How many people could this support at utilization rate in 1800 New England? About 0.7 billion (3x109/4.1) • Current global consumption of carbon in fossil fuel is about 6x109 ton C/yr, roughly twice the carbon potentially available from trees • But, large amount of energy required to harvest the trees. Plus transportation and seasoning

21. What is the better economic choice, to grow food or timber? • Timber is sold in units of board feet • 1 board foot = 1 foot x 12 inches x 1 inch • Assuming a density of 1 g cm-3, the mass of a board food is about 0.25 kg • Price for softwood: $35~$305/1000 board feet; price for hardwood: $230~$580/1000 board feet • Take $300/1000 board feet as average  timber worth $1200/metric ton • Rice costs $0.48/lb  $1.10/kg  $1100/metric ton • It would appear that wood and food are comparable as investments!

22. Wood in English History A Forest Journey, John Perlin, Harvard Univ. Press, 1991 • England was industrially relatively backward in early 1500s. Henry VII built only four ships for the Royal Navy during his reign (1485-1509) • Imported salt, iron, dyes, glass and arms from continent • Change in 1530s. Concern about Spanish/French intention to depose Henry VIII (1509- 1547) • Development of arms industry in Sussex. England is forefront of arms race to 1550 • To produce 1 ton of bar iron required 48 cords of wood. Beginning of English deforestation

23. Wood in English History A Forest Journey, John Perlin, Harvard Univ. Press, 1991 • Prior to Elizabeth I, England’s ships were mostly made elsewhere or were hired. • Elizabeth took steps to promote domestic industry. Subsidies for large ships, fishing, policies on wine importation • To build a large warship took 2000 oaks which had to be more than 100 years old. Increased wood demands for iron, copper, glass, construction. Wood becomes scarce. • James I prescribes permissible uses of timber (houses, glass etc) • English reach to Ireland for new sources of wood • Great fire of London, 1666

24. Wood in English History A Forest Journey, John Perlin, Harvard Univ. Press, 1991 • John Houghton proposed a strategic timber reserve: “in times of peace, enough might be laid up for war and I believe that once a ten-year store was gotten, we never need fear the want of timber…when we are so prepared, we need care for nobody” • Growth in use of wood for rail carriages, mining, canal building, mills, water wheels • Abraham Darby develops method to use coked coal rather than charcoal for metal smelting. First coal-fired iron furnace in 1754 • England moves from wood to coal age

25. Diamond’s view of factors that can lead to the collapse of a society Collapse, Jared Diamond, 2005, Viking Penguin, member of Penguin Group • Damage people inadvertently inflict on their environment • Climate change • Hostile neighbors • Decreased support by friendly neighbors • Society’s response to problems