HAS222d

Intro to Energy and Environement: Lecture 17

week 9 Solutions

40% off energy use in US goes into generating electricity

generation efficiency: 33%

electric power loss: plant to consumer

7.2% in US..costs

more than shipping the fossil fuel

US average cost: 8.2 cents per KwH

(up 10% in past year)

http://en.wikipedia.org/wiki/Electric_power_transmission#Losseshttp://www.energetics.com/gridworks/grid.html

US Dept of Energy

10,000 plants

B. Lomborg, Skeptical Environmentalist

We have talked about the 1/10 solution…living with 1/10 our present energyuse in the US (thus, about2 kilowatts per person ratherthan 20 kilowatts).

Alternative energies and optimism: we have looked at solar and wind power in some detail. In Lomborg’s

(The Skeptical Environmentalist) book-keeping they represent roughly 0.04% wind 0.009% solar 0.04% biomass 0.12% geothermal 6.6% hydropower 6.4% ‘traditional’ fuel wood and charcoal

While these are small fractions of the 4 x 1020

Joules per year

(i.e. divide by seconds-per-year, π x 107, and then 1000 to get an equivalent expression, 1.3 x 1010

kilowatts) for the 6.75 x 109

residents of Earth… 2 Kw

per person, 24/7, hydropower and fuel woods are significant and the others are growing very rapidly. Allegedly wind power installations are now cheaper in long term cost than the fossil fuel power generation plants that dominate our electricity production.

Remember that electricity represents about 40%

of our energy use, and that electric motors are vastly more efficient (~90%) than gasoline engines (~20% or less). But if the electricity is generated at ~33% efficiency

in the coal-

or oil fired plants, and transmitted to you at 70% efficiency, then on the face of it, your electric motor may be as poor environmentally as you gasoline engine.

But one hopes to improve the 33% greatly or at least its environmental impact by scrubbing out the CO2 at the smokestack. By localizing the fossil fuel use, the net effect on the environment could be very good. ‘Efficiency’ needs to include the loss of, and damage to, natural capital and the (I would say huge) damage to human capital, the cost of overcrowded roads, road building, noise, health hazards from too many cars. (How often do we see editorials in our now-vanishing newspapers crying for a reduction in the 30,000 automobile fatalities in the US each year?).

Al Gore’s July 2008 call for electrical energy independence in the next 10 years: all electricity to be generated by green energy sources: is it realistic? Watch Al Gore’s speech:

http://www.youtube.com/watch?v=dt9wZloG97U

Natural Capitalism

Hawken, Lovins

& Lovins, 1999

hear lecture at KUOW

Weekday archives (search for Lovins):

http://www.kuow.org/defaultProgram.asp?ID=3749

Capital is: moneygoods …these two are the standards of business

but alsopeoplenatural resources

the problem is that these things that are mined, gathered, harvested from Nature are deemed ‘cost-free’ with a value approximately zero

yet ‘the economy is a wholly owned subsidiary of the environment, not the otherway around’.

ecosystem services like pollination: are bees now in trouble(Albert Einstein: ‘if bees were to disappear, people woulddisappear within 4 years’)

People were once a limiting factor of the economy, with limitless environmental capital..now

it is the other way around.

•

Four principles:•

1. radically increased natural resource productivity–

Factor Ten Club: “Within one generation we can achieve a ten-fold increase inefficiency with which we use energy, natural resources and other

materials”–

defining efficiency ( output per $) => include quality of life, long-term valuation–

vast opportunity for technology development…and for profit–

end of subsidized inefficiency (mining, oil, coal,fishing, forest industries) –

the automobile: 1% efficient as a people mover (20% efficient at

converting gasolineto mechanical energy, but human represents only 1/20 th

of the mass being moved..=> 1%..and that neglects inefficiency in bringing you the gasoline. Incandescent light bulbs are ~ 3% efficient

Electric motors are ~ 90% efficient while gasoline engines are ~20% efficient)cars are 20x too heavy and engines 10x too powerful…yet a UW study shows nocorrelation between efficiency of electric motors and their cost…market price!

20 times your body weight per day of ‘stuff’ is created and 99% disposed–

design whole systems rather than one component at a time: e.g., heating and ventilating in buildings is squeezed into inefficient, small ducts, pipes and vents, making it noisy and inefficient. Windows are still installed without long-term energy efficiency implications.

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2. biomimicry–

estimate that only 6% of materials involved in US industry end up as products; overall, durable goods produced = about 1% of waste

spider webs versus Kevlar: silk made from flies. Nature’s Darwinian evolution has selected low-impact, high efficiency solutions. Abalone shell stronger than our best ceramics assembled at 4C from seawater, no waste. Trees make a sugar called cellulose which is strong as nylon, wood as strong as steel and low toxicity. Paint that cleans itself the way lotus petals stay white as the rise from the mud made in Germany.

Successful companies will take their values from customers, designs from nature and their discipline from the marketplace.

•

3. service and economy flow: continuous flow reckoning –

the economy moves from durable goods to services–

xerox

copiers, air conditioning, elevators; ‘lease a vertical transport service’; Dow’s solvents: don’t sell these toxic things but lease a ‘solvent service’. Why are you trying to sell me this thing, there must be something wrong with it.

–

University of Zurich chemistry class that makes goo

from pure chemicals, run backward: take goo

and separate it into primary chemicals. Closed loop cycle thinking

–

Dupont

plastic films: thinner, recycled, profitable–

Ray Anderson’s INTERFACE carpet company…carpet tiles with invisible seams..eventually

lease a floor covering service»

1000 times less raw material input than conventional carpets!–

beginning-to-end tracking of materials and waste: the carpet factory where the waste water is cleaner thanthe water coming in. The environment comes into the service-flow economy because, if you are renting someone a

copier you may design it to optimize its lifetime and value when

its life is over..its

recycling value. Design and planning come to the foreground, whereas if you sell copiers you

don’t care what happens to them.–

increased employment, continuous need for service rather than big capital purchase

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4. investing in natural capital–

business has not followed its own accounting principles in neglecting value of natural capital–

‘tragedy of the commons’

chapter 7 (Muda…) of Natural Capitalism tells of Interface, a carpet company that has implemented closed cycle,

ingenious, non-toxic thinking into its products.

NY Times24 May 07

Beginning to end thinking: this water pump is 9.5% efficient relative to the fossil fuel input at the electricity generating plant (and less so if you go back up the

chain further to extraction and shipping of coal, and if you include environmental damage by soot, sulfer

and CO2

). Note that these numbers for efficiency should be examined. Elsewhere we read that electrical power

transmission on average has a loss of 30% of its energy in the US, rather than the 9% shown by Lovins

et al. here

from Natural Capitalism

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Natural Capitalism: the Curitaba, Brazil story•

Curitiba

is the largest city in southern Brazil: 1.8M people, GDP of US$

17B.

1972: a new mayor, architect, engineer, planner Jaime Lerner, ‘brain of a technocrat and soul of a poet’ in 12 years ‘redesigned’ the city

–

believed that “trend is not destiny” (after Rene Dubos)–

solutions that are fast, fun and cheap: street malls…garbage removal (pay the people for their garbage in the urban core!)

–

public and private transport: “growing along the trail of memory

and of transport..memory

is the identity of the city, transport is its future:

•

land use and growth patterns, matching population density to the

capability of transport•

single design strategy for land use, flow of food and waste, health and education, jobs and income, culture and politics…..new design for buses and bus stops: 270 passenger Volvos, triple length.

•

land use regulations, urban parks, 1,100 registered private woodlands, 7 sq miles of parks–

everything is recycled solutions that are fast, fun and cheap: street malls…garbage removal (pay the people for their garbage in the urban core!)

•

finds a recent parallel in the Deep Economy movement (Bill McKibben’s

recent book, advocating diverse, local economies and the 100 mile dinner (cooked with food grown within 100 miles).

Curitiba

bus stop, Museu

Oscar Niemeyer, botanical garden (formerly a garbage dump), Universidade

Federal de Peranã

Alternative energies and optimism: we have looked at solar and wind power in some detail. In Lomborg’s

(The Skeptical Environmentalist) book-keeping they represent roughly

0.04% wind 0.009% solar 0.04% biomass

0.12% geothermal 6.6% hydropower

6.4% ‘traditional’ fuel wood and charcoal

•

While these are small fractions of the 4 x 1020

Joules per year(i.e. divide by seconds-per-year, π

x 107, and then 1000 to get an equivalent expression,

1.3 x 1010

kilowatts) for the 6.5 x 109

residents of Earth…

2 Kw

per person, 24/7,

hydropower and fuel woods are significant and the others are growing very rapidly. Allegedly wind power installations are now cheaper

in long term cost than the fossil fuel power generation plants that dominate our electricity production.

Remember that electricity represents about 40% of our energy use, and that electric motors are vastly more efficient (~90%) than gasoline engines (~20% or less). But if the electricity is generated at ~33% efficiency in the coal-

or oil fired plants, and transmitted to you at 70% efficiency, then on the face of it, your electric motor may be as poor environmentally as you gasoline engine. But one hopes to improve the 33% greatly or at least its environmental impact by scrubbing out the CO2

at the smokestack. By localizing the fossil fuel use, the net effect on

the environment could be very good. ‘Efficiency’ needs to include the loss of, and damage to, natural capital and the (I would say huge) damage to human capital, the cost of overcrowded roads, noise, health effects of too many cars.

•

We have argued that an important test of environmental ideas and

trends can be made a few years after a book or research paper has been published. Check the predictions! This needs to be done widely.

–

Lomborg

in 2000 quotes the US Energy Agency in predicting a price for oil at abou

$20 to $22 per barrel through roughly 2010. The price in May 2007 ranged from $50 to $75. So much for ‘no problems with oil supplies’

–

Lovins

in 1999 quotes the CEO of Daimler-Benz as ‘pledging’ 100,000 of their car production to be hydrogen fuel cell powered by 2005. There are no such cars. Toyota in 1998 revealed plans to market fuel-cell cars ‘well before 2002 (later slipped to 2003)’. Only a token, trial vehicle has been developed. He quotes the president of Toyota as predicting 1/3d of the world automobile fleet to be electric/gasoline hybrids by 2005! In fact Toyota is the dominant producer and is doing very well, but the number of hybrid Toyota’s produced in 2004 was 200,000 (of a world new car production of ….0.3% are hybrids). So much for instant environmental solutions with new technologies.

–

Paul Ehrlich, in his books The Population Bomb and The Population Explosianfollowed the tradition of a 1970s book The Limits to Growth in sounding the environmental alarm with numbers that were too pessimistic in some areas. Depletion of energy supplies, metals and minerals has not happened as quickly as predicted. Yet, the basic message is much more important than

prediction of the exact year that oil will be gone.

–

The next slide shows how far off predictions of global energy demand were back in the 1950s-1980s: virtually everyone predicted more energy demand, neglecting increased efficiencies.

We see above that burning wood for cooking and purifying water is a big part of global energy use even today (~6.3%). Much of this occurs in the tropics where sunshine can be abundant. Solar box cookers

are a ‘soft technology’ that can entirely replace wood burning, except in

rainy seasons that accompany tropical monsoons. This is a potentially radical improvement developing nations’ household energetics

for example: solar cooking and water purification

In India, where a reported 90 percent of cooking is done over wood-

and dung-fueled fires, several studies have documented that “indoor air pollution leads to 400,000-550,000 premature deaths … from lower respiratory infections and chronic obstructive pulmonary disease. … The burden falls disproportionately on women and children, who inhale soot and other particles from smoke released by the burning of biofuels.” This soot combines with outdoor air pollution to form atmospheric brown clouds (ABCs) that “envelope most of India and the Indian Ocean … [leading] to a large reduction of sunlight at the ground and … atmospheric solar heating

Solar cookers in Bolivia and Nepal…a soft technology that bakes bread, cooks meals and purifies water, replacing the need for fuel wood

burning (or..yak

dung in Tibet), wherever it’s sunny www.solarcooking.org

communal solar cooker: people are thinking bigger, and regarding

the community

and some are thinking really big

•

Series of Scheffler

Solar dishes/concentrators concentrate light on receivers generating steam.

The steam generated with the salar

dishes in terrace is sent to kitchen via steam pipe lines to kitcchen

to cook food for thousands.

Such Solar Steam cookers are working successfully at Brahma Kumaris

Mt.Abu

Complex to cook for 1000 persons per day, for their Taleti

Complex for 10,000 persons per day and for Shirdi

Sai

Baba Temple(seen

in photo) for 3000 persons per day.

Worlds largest Solar Steam Cooking is being installed by us at Tirumala

Tirupati

Devasthanam

Complex to cook for 15,000 persons per day!!!!

•

www.solarcooking.org

India is well-known for delicious food, and the kitchen is considered to be a sacred place in any Indian home. And now India has something else to be

proud of: the world’s largest solar kitchen. The system has been installed as a collaboration between the

Academy for a Better World

and

Brahma Kumaris

World Spiritual University, with technology from

Solare-Brücke, Germany. With 84 receivers and cooking at 650 degrees, the system can produce up to 38,500 meals a day when the sun is at its peak!

The system generates temperatures of up to about 650 degrees, and 3500-4000 kg of steam per day. The food is cooked in 200-400 liters capacity cooking pots, producing an average of 20,000 meals a day, and up to 38,500 meals per day

during periods of peak solar radiation maximum.A total of $5 million has been spent on this endeavor.

•

Solar Steam Cooking System:With

technical assistance provided by M/s

HTT

GmbH of Germany and funding from GATE/ GTZ

also of Germany, the first solar steam cooking system to cook for 1,000 person was developed and installed at the Brahma Kumaris' Ashram, Mt.Abu

in Rajasthan. In 1997, this was the first Solar Steam Cooking System based on Scheffler

Solar Concentrators in the World. Its success has led to many more systems being installed in India. Schematic

•

Working principle of Solar Steam Cooking System :•

In the focus of each pair of Scheffler

Concentrator (dishes), the sleeping dish and standing dish, are placed heat exchangers called receivers.

•

The Solar rays falling onto the dish

are reflected and concentrated on the receivers placed in its focus. Due to concentration the temperature achieved is very high (between 450-650 degree centigrade) and thus the water in receivers comes to boiling and

becomes steam.•

Above the receiver is an insulated header pipe filled half with water. The cold water enters the the

receiver through inner pipe, gets heated due to the high temperature of the concentrated rays and the heated water goes up.

The cold water again enters through inner pipe and and

the cycle continues till steam is generated. The steam gets stored in the upperhalf

empty portion of the header pipe and pressure keeps on rising. The steam is than drawn / or sent to kitchen through insulated pipe line.

•

Spurred by the success of the above system, with training and jigs provided by Gadhia

Solar, the Brahma Kumari's

installed the world's largest solar steam cooking system at their Taleti

Ashram in Abu Road, Rajasthan. This system installed in 1999, cooks upto

35,000 meals a day.•

Gadhia

Solar has manufactured and installed many solar steam cooking system since than on Turn-Key basis -

starting for system for 500 people per day (1,000 meals per day) to 15,000 persons per day (30,000 meals per day)

The story of Pacala

and Socolow’s

wedges of carbon reduction (see above) goes on and on, and extends to wedges of sustainable building with natural materials

that have a much smaller footprint on the environment. One can build with bamboo, not the thin kind we

know but heavy, thick bamboo trunks that are competitive in strength with traditional wood or

steel framing… from a rapidly growing sustainable forestry site in Columbia or Costa Rica…www.zeri.org

Rancho Mastetal, Costa Rica

Perhaps the most striking contrast of discord I see in thinking about this course is the brilliance of modern technology, next to the growing social and

environmental inequity: ecocide leading to genocide•

Ehrlich’s PAT

Population x Affluence x Technology

is an estimate…theory…idea… of the impact of humanity on the global environment

Population is simple… or is it?… consider the spiky world of Richard Florida

Technology is simple… or is it?.. the inventions that empower us to shape the environment purposefully, and also inadvertantly. It is the ‘inadvertant’ that is particularly dangerous. Recall Thomas Midgely

, inventor of both leaded gasoline and CFCs … chlorofluorocarbons used in refrigerators and spray cans for decades, but both became dangerous global pollutants.

That brings us to Affluence…simple? It seems to mean, really, power and control over resources (natural and human) by one sector of the population. What we see are too many rich and too many poor and not enough in between. MacNeill’s

‘energy slaves’, the energy each of us has at our command (expressed in units of human somatic energy) numbers something like 500 for the average 2 kW Earthling, and 3000 for the 11kW

American+…(compare with MacNeill’s

estimate of 75 slaves)________________________________________________________________________

+(recall that we use the metric of climbing mountains carrying 25 kg loads…suggesting roughly 2000m climb each day, or mgΔh = 25 x 9.8 x 2000 = 4.9 x 105

Joules of work per day. With 5 work days per week this gives an average power of 4.0 watts! Compare this our peak running-upstairs power output of roughly 1 kW and our average food energy intake (say, 3000 kCal/day = 12.6 x 106

J/day = 12.6 x 106/0.864 x 105 J/sec = 145 Watts). So, as work-machines we are about 3% efficient converters of food energy into mechanical energy. Not much better than the 1% efficiency of the automobile as a converter of gasoline’s chemical energy into people-moving mechanical energy.

Two short essays, late-night thoughts about this course, 30 May 2007

P.B. Rhines

Where is the logic of studying Native societies of the Arctic, in the midst of studying energy physics, chemistry, biology, energy flow through the physical world and the world of living things…and in the midst of studying the pressing human predicament of population growth, global warming, finite energy, finite environment?

I believe that the logic is in our

(warm, southern peoples’) complex relationship with these small

native populations. Most obviously, we have cast our shadow on them, if only by studying them and visiting them. But following Knud

Rasmussen and Harald

Sverdrup, explorers/ethnologists with the greatest respect for the societies they visited, came European fur traders and ivory traders, whalers in search of oil for lamps

and baleen for corsets, Americans in search of modern oil in ANWR, Danes in search of shrimp in Greenland, Canadians in search of

minerals brought guns, sugar, European diets and turned hunters into fishermen and oil wildcatters.

Why was it that the ‘warm’ people developed technology, and built the modern world? Because of energy, ample environment for growing and catching food, and easy trade routes. The Industrial Revolution

in England in the 1700s-1800s was fueled by coal and iron and hinged on a few inventions

like the first geologic map of Britain (in 1815; see The Map that Changed the World: Wm Smith and the Birth of Modern

Geology by Simon Winchester), the

steam engine, to pump ground water out of the coal mines. See McNeill’s text, or The Lunar Men

by Jenny Uglow: 5 men who came together on the night of the month with the fullest moon,”for

a little philosophical laughing”, as Erasmus Darwin said. Joseph Priestly, Josiah Wedgewood, James Watt dreamt of canals to transport china without breaking it, electricity.. “warmed by wine and friendship, their heads full of air pumps and elements and electrical machines, their ears ringing with talk, the whirring of wheels and the hiss of gas."

The aboriginal population of Australia, a successful but slowly evolving society for nearly 60,000 years before the coming of Captain Cook and the English prison ships, and the Inuit of Greenland share the burden of smallness and energy-poverty: development of technology seems to require enough people, enough competitive societies nearby, and enough energy and quick enough trade routes to make the pot boil.

More of the logic of studying Arctic natives comes from learning

of their own brand of success…their adaptability, strength, fortitude. Their ingenuity in the most hostile, life-threatening climate on Earth.

They succeeded so well! Their technology was simple but the Greenland kayak is a good example of a highly evolved form, light, fast, economical, carries a lot, built of driftwood and sealskin. Mine

weighs 35 lbs, and it requires no floatation compartments: it does not sink if flooded! I like it better than the $2500 plastic kind. A group of 6 of us built 6 of these in 6 days. Svend

Ulstrap, my building instructor from Denmark and Greenland, said proudly, ‘there’s nothing in this boat that you couldn’t eat’. Wood, cotton thread, #20 duck canvas, linseed oil and chalk. No metal, no nails, no screws. He earnestly wanted his kayaks to disintegrate back to Nature when we are done with them rather than sitting in a land-fill for a thousand years.

Their adaptation to a communal life that involved close isolation for long periods of darkness.Their patience .. squatting motionless by a seal breathing hole for hours, with harpoon poised.Their frugal use of energy and insulation, of somatic heat energyTheir physical strength and endurance.Their fortitude in the face of tragedy: failed hunts, lost family members, outbreaks of disease.Their spirituality. Sila

was the name of Kristin Laidre’s

double ended boat in the waters west of Greenland: Sila

being the weather god or ‘consciousness’. Elaborate mythology, orally transmitted and administered by the shaman, filled the vacuum in their lives when times were hard. It is said that the Inuit love to dream in the long winters, and to promote

this they like to be a bit chilly (which does promote active dreaming…try it). These are qualities that might serve us well in the coming decades. (Build a super-insulated house..or

an apartment building that uses no fossil fuel for winter heating, live close to your work, eat food grown

locally...)

OF REFRIGERATORS AND OTHER THINGS

Refrigerators and freezers have made possible a healthier life with fresh, crisp food, vegetables in winter, fewer trips to the grocery store. In earlier times, the winter was a fallow period with vegetables hidden away in ‘root cellers’, or canned in jars by a hard-working farm-wife. Meats were preserved by using salt to draw out the moisture and bathe the meat in a briny fluid hostile to microbes

and decay. Indeed, salt used to be immensely valuable and used like gold as a currency (‘salary’). But, let’s go a little deeper into refrigerators.

It is cold outside, and to protect us from the cold we have houses made warm by burning oil or gas. Inside them we want a cold box so we burn more fuel to suck the heat out (which incidentally helps to heat the rest of the house). Inside the refrigerator we want our butter not to be too hard so there is a little box that warms it up. And, most of you will not remember the days when refrigerators would cake up with ice and have to be defrosted: that was solved by periodically drawing out the moist air, and warming it to remove the moisture, then chilling it down again.

There are questions of energy, efficiency, many details of engineering design here. Insulation is important; ‘fridges used to have thick walls. Now the ‘slim-wall’ design using solid insulation is the pride of the industry, fits

better in small kitchens, and doesn’t use more electricity than

the old white elephants. In the early 1990s $30 million was given to US manufacturers to improve efficiency; apparently this lead to new models more than 30% improved in efficiency. China put $31 million into such a competition in 1999, leading to better than 40% increase in efficiency (decrease in KwH

used) in new refrigerators. A modern US refrigerator uses about

450 KwH

of electriciy

per year compared with 2000 KwH

per year in 1972.

Deeper still. The refrigerator in our house runs most of the

time. Late at night when all else is quiet it can be heard throbbing away by itself. It has not been opened for hours yet it has to run constantly to hold the air 15

degrees (Celcius) or so below room temperature. What could be wrong? How does a

refrigerator work? It is a heat engine working backwards. A heat engine takes a flow of thermal energy (from input to exhaust) and puts out some fraction

of it as work..mechanical

energy. With the refrigerator instead, we take mechanical energy generated from electricity and move heat with it. The PV diagram comes into play; a fluid is expanded and compressed making a repeating cycle; when when

expanded it cools greatly, and this cold fluid is run through pipes lining the cold compartment. When compressed it is much warmer, and flows in pipes exposed to the air perhaps with metal fins to help conduct away the heat. Now the efficiency is measured just the inverse of the efficiency of a heat engine: the amount of cooling divided by the mechanical energy input. Note that a ‘heat pump’ is such a device set up to air condition your house in summer and, run the other way, heat your house in winter.It miraculously pumps heat one way or the other and in winter this is much more efficient than simply running an electric heater.

Cleaning behind the refrigerator is a Hallowe’en

experience. Cob-webs and sticky puddles. I had a strange compulsion to get back

there and clean it out, thinking it would make it run more efficiently. Air is drawn past coils of metal tubing in which the liquid refrigerant flows, so that the ‘waste’ heat will be carried off. A pleasantly warm airstream

can be felt under and behind. But this mesh of metal tubing was

thick with dust bunnies, so that the air would have a harder time flowing past. The refrigerant would have to be pumped faster to do the same amount

of cooling, than if the dust was cleaned up. So I felt good after this (always strange) experience of sucking mountains of dust into the vacuum (like a video run backwards somehow). I pictured long periods of silence late at night.

2.Did it work? I don’t know, because I didn’t measure anything. I could have timed the ‘duty cycle’ (the fraction of time the fridge is running), or

monitored the electricity use (with a watt-hour meter like the one outside your house or apartment) but of course there are variables: how warm is the room, how moist is the air, how full is the fridge (does it run better

full or empty)? It might seem extreme but there are enough refrigerators in the world that a little more efficiency built into them would save the world a lot of energy.

Cleaning the fridge, inside or out, is not something that everyone does. Some would argue that that human energy is better spent on more important things. Some are fastidiously neat and have to clean everything

around them.

Let’s go one step deeper. I was thinking about

the cob-webbed coils of the fridge, how hard they have to work to do the

same job. In middle age you will begin to be aware that you have lungs and that air passes through them so that oxygen can be extracted and carried by red blood cells to your muscles, heart, brain. Each day we run a lot of air through these passages, and suspended dust, and unwanted gases come along with the oxygen. The lungs are remarkably clever at cleaning themselves out with a steady flow of mucous fluid, yet in the deep, small passages this does not happen, and soot can collect. Even the larger channels of the lung can be overwhelmed by exposure to smoke. There are also many organic chemicals that enter the body this way. Our bodies are wonderfully adaptable, but were not designed to withstand this buildup forever.

Why can’t we vacuum out our lungs the way I did

the refrigerator coils? The other fluid pathways in the body have similar problems, and I imagine that one day we will have a sort of RotoRooter

job done on our veins and arteries, perhaps an out-patient procedure every few years, which will bring back some of our youthful vitality. Medicine has provided cures and relief for a remarkable range of injury and disease. Yet we still see

people suffer and die from what seem just plumbing problems.

Finally, the fridge in your kitchen has a past

and a future…a life cycle if you like. It was born somewhere in

Michigan or Taiwan with a design that has not basically changed in half a century. After a 10 or 20 year lifetime it will end up at the dump, hopefully some the metal recycled. If it is now 20 years or more old, the CFC refrigerant will be released to the atmosphere. These are molecules made (in the case of CFC-11) of one carbon atom at the center with one fluorine atom and three chlorine atoms, arranged around like

chairs round a table. They will rise to the upper atmosphere, where they attack the ozone layer…fortunately CFC’s are now banned in most countries, and the ozone hole may be on the mend. And, the ozone hole has now been shown to greatly intensify the westerly winds round Antarctica, and possibly the ocean circulation beneath, and with that, possibly the primary production biology of the Earth: a very far-reaching change in the global climate system induced by rich humans with their refrigerators. It is about as strange as in Hitchhikers’ Guide to the Galaxy where author Douglas Adams imagines that the world is being run by extragalactic mice, as a computer experiment, and where spaceships were peopled by neurotic computers. Yet, this is not science fiction.

The design of the back side of a refrigerator defies analysis. Looking at how things work is part of this course. There are layers and layers of design and understanding and we can never get to their end: but a functional understanding of the workings of our environment can often be approached. Sometimes a little knowledge is dangerous of course, so beware of becoming a casual expert in the environment, knowing the buzz-words and repeating the news about el Nino or global warming or habitat loss without going one step deeper, confronting some of the uncertainties.

. http://counties.cce.cornell.edu/chemung/publications/replace-old-fridge.pdf

•

Finally, this is all human centered (as McNeill admits in his book). What about the global ecosystem and the impact of air pollution on plants and animals? A complex, multi-dimensional set of issues!

•

Notice, though Nature’s resilience: why are leaves so clean?

tree leaf 400 micron image

water on a tulip

the pollution-prosperity curve:as a society progresses it develops industry, increasespollution as well as wealth. Then,predictably, the society decidesto clean up its nest and airquality improves.