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Carbon Footprints

Information from How Bad Are Bananas? By Mike Berners-Lee

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Carbon Footprint• Best estimate of full

climate change impact of something– Carbon – Usually talking

about CO2e (CO2-eq) not actually just carbon

– Footprint – Total impact

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CO2e• Total climate change impact of all greenhouse gasses caused

by item or activity

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Direct vs. indirect emissions• Direct emissions of an item– Manufacturing process – Transportation of item to retailer

• Indirect emissions – Everything else– Example: offices in the factory use

paper clips made of steel that were mined and have their own carbon footprint

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Context for numbers• 1 gram of CO2e would be

produced if you burned a pea sized blob of gasoline

• 1 Kilogram (2 lbs) of CO2e would be produced if you burned 2 cups of gasoline

• 1 Ton of CO2e would be produced if you burned 60 gallons of gasoline

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Context for numbers

• The average American has a carbon footprint of 28 tons CO2e / year

• World GHG emissions are 34 Gt CO2e / year

• The global average carbon footprint is ~6 tons CO2e / year / person

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Carbon footprint of items• A pint of beer• Cycling a mile • Manufacturing a car• A web search • Walking through the door• A banana • Spending 1$• Road trip (NY to Niagara falls)• 10 lbs of trash

• Leaving the lights on • Having a child • A forest fire • A Burger• A bottle of water• 2.5 acres of deforestation• Using a cell phone • A computer • International flight (LA-

Barcelona)

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Which type of beer would have the highest carbon footprint per pint?

Loca

lly brewed at t

he bar

Store bough

t, locally

b...

Store bough

t, bottled ...

0% 0%0%

1. Locally brewed at the bar 2. Store bought, locally

bottled3. Store bought, bottled

elsewhere, imported long distances

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Pint of beer• Locally brewed at the bar – 300g CO2e

• Store bought, locally bottled– 500g CO2e

• Store bought, bottled elsewhere, imported long distances– 900g CO2e

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Which food would produce highest carbon footprint for cycling a mile?

Air-fre

ighted ...

Bacon

Bananas

0% 0%0%

1. Air-freighted asparagus

2. Bacon3. Bananas

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Cycling a mile• Powered by bananas

– 65g CO2e• Powered by cereals with milk

– 90g CO2e• Powered by bacon

– 200g CO2e• Powered by cheeseburgers

– 260g CO2e• Powered by air-freighted

asparagus– 2,800g CO2e– A hummer has a lower carbon

footprint per mile

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The carbon footprint of manufacturing a new car is ____ compared to the carbon

footprint of driving that car over its lifetime

Very sm

all

Roughly

equiva...

Very large

0% 0%0%

1. Very small2. Roughly equivalent 3. Very large

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A new car• Citroen C1, basic spec – 6 tons CO2e:

• Ford Mondeo, medium spec – 17 tons CO2e:

• Land Rover Discovery, top of the range – 35 tons CO2e:

• The CO2e emissions associated with producing the car are comparable to the CO2e emissions out of that car’s tailpipe over its lifetime

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A web search• Goggle estimates 0.2 g CO2e

for the electricity it uses when you enter a search term

• 0.1g CO2e for 20 seconds of use from an efficient 20 watt laptop

• Local network and servers would use 0.1 g CO2e

• Maintenance on the whole system (replacing parts ect.) doubles the above figures

• Total = 0.8 g CO2e

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A web search• Desktop computers are

more power Hungary – ~150 watts– 0.75 g CO2e for 20 seconds

of use– Increases in maintenance

and network CO2e – Total = 4.5 g CO2e• Google accounts for just 0.2

g CO2e of that (4%)

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A web search• Searching the web non-stop

for a year – 5 tons CO2e

• Does not include – Wearing clothes– Keeping warm– Burning calories – Getting closer to your next

need for medical attention – Living in a building that

needs maintenance– Ect.

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Walking through a door• Automatic door– 6.5 feet wide by 8 feet high – Stays open for 18 seconds

• Power from electric motors to open door is 1 g CO2e– If the temperature inside is

equal to that outside then this is the entire carbon footprint

– If it's cold outside (say 20°f) then the footprint jumps to 84 g CO2e because of the energy required to heat that air

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Bananas• Bananas have very low carbon

footprints compared to other foods – Grown in natural sunlight (not in a

heated greenhouse)– They don’t spoil quickly• So instead of shipping them by

plane, you can ship them by boat (1% the carbon footprint of flying)

– No packaging • Total = 80 g CO2e if shipped from

across the world

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Spending 1$• In our current energy

system it is very difficult to spend a dollar without it adding to your carbon footprint

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Spending $1• Exception would be

spending on something that reduces net emissions–Minus 220 kg (485 lbs)

CO2e on a well executed rainforest preservation project –Minus 2 kg (4.4 lbs) CO2e

on solar panels

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Spending $1• In the middle of the spectrum

would be spending on groceries– 620 g (1.37 lbs) CO2e per $1

• Flying is among the worst activities for carbon emissions– 10 kg (22 lbs) of CO2e per $1

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Road trip• San Francisco to LA and back

(~800 miles)– Banana powered bike

• 53 kg (117 lbs) CO2e– Bus

• 66 kg (146 lbs) CO2e– Small efficient car

• 330 kg (728 lbs) CO2e– Plane

• 500 kg (1,100 lbs) CO2e– Large SUV

• 1,100 (2,530 lbs) CO2e

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10 lbs of trash• The average US citizen sends 1,250 lbs of

garbage to landfills each year • The average US citizen recycles 640 lbs of

garbage each year• Landfill emissions are produced when

the garbage decomposes (methane)• Sending metals, glass, plastics and paper

to landfills (rather than recycling them) forces new materials to be produced for future products – It takes much more energy to make a new

product from raw materials than it does to make one from recycled materials

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10 lbs of trash• Garden waste – 910 g (2 lbs) CO2e

• Average trash contents– 3.1 kg (7 lbs) CO2e

• Aluminum and copper– 41 kg (90 lbs) CO2e

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Leaving the lights on• Light on continuously for 1 year• Depends on where you are – Iceland produces almost all of its

electricity from fossil fuel free geothermal and hydroelectric power plants

– The US produces much more of its electricity from fossil fuels

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Leaving the lights on• Assuming US electricity

generation – Low energy bulb• 1 year• 90 kg (198 lbs) CO2e

–100-watt incandescent bulb• 1 year• 500 kg (1,100 lbs)

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Having a child • The decision to reproduce ends up

being one of the biggest carbon choices people ever make– Assuming that the child lives to 75 – Assuming the child lives a

nationally typical lifestyle – Assuming that GHG emissions are

reduced in the coming decades • 700 tons CO2e– 150 tons for a carbon conscious

child– 2,000 tons for high-impact child

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A forest fire• If you chose to start a forest fire – One of only decision you could

make that has a larger carbon impact than having a child

– Your lifetime carbon footprint would increase by 1000s of times

• 2008 California forest fires – 231 million tons CO2e

• A certain portion of the carbon releases will be taken back over time as the forest regrows

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A bottle of water• Most emissions come from

packaging and transport – 80 g CO2e just from the plastic

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A bottle of water• Locally sourced and using local

distribution – 110 g CO2e

• Traveling 600 miles by road – 215 g CO2e

• Bottled water is 1000X more carbon intensive than tap water

• The world consumes 53 billion gallons of bottled water a year which accounts for 1/6th of a percent of TOTAL world GHG emissions

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• 32 million acres of rainforest are cleared per year– 17 percent of all human emissions

• Why?– 35-45% Small farms – 20-25% for cattle grazing – 15-20% Intensive agriculture – 10-15% logging– ~5% other (urbanization, mining,

roads, ect.)

2.5 Acres of Deforestation

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2.5 Acres of Deforestation• 2.5 acres = 1 Hectare –500 tons of CO2e• Equivalent to

driving the average car 28 times around the world

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A Burger

The energy that you use to live and move around came from the sun. Which is a more efficient way to transfer energy from

the sun to you?

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: :

1 and 2 are equal

10%

30%

60%

1.:2.:3. 1 and 2 are equal

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A Burger• Animal products tend to be

more carbon intensive than vegetables and grains because animals consume a lot of energy just to keep themselves warm and move around

• Converting animal feed into meat and milk is inherently inefficient

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A Burger• In addition to being inefficient…– Cows/sheep are ruminants • They belch out methane (CH4) • Beef/lamb has double the

carbon footprint (per kilogram of meet) of pork

– Excessive demand for meat provides an incentive for deforestation to provide more grazing land

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• Beef cheeseburger – 2.5 kg (5.5 lbs) CO2e

• Veggie Burger – 1 kg (2.2 lbs) CO2e

• If you ate nothing but cheeseburgers for a year, your carbon footprint from food alone would be 4.6 tons CO2e

A Burger

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Using a cell phone • Depends on how often you use it• Components of footprint – Manufacturing of phone • 16 kg (35 lbs) CO2e

– Power over 2 years • 6 kg (13 lbs) CO2e

– Energy required to transmit calls across network • 66 kg (146 lbs)

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Using a cell phone • 1 minute cell-to-cell phone call has the same

carbon footprint as an apple

=

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Using a cell phone • As of 2009 there were 2.7

billion cell phones in use (almost half the world)

• Cell phone calls account for about 125 million tons CO2e–1/4th of a percent of global

emissions • Texting is a much lower

carbon option

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Using a cell phone • A year’s typical usage of just

under 2 minutes per day – 47 kg (103 lbs) CO2e

• A year’s usage of 1 hour per day– 1,250 kg (2,760 lbs) CO2e

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A Computer• Machine itself – 2010 21.5-inch iMac• 720 kg (1,590 lbs) CO2e

• Electricity consumption – 2010 21.5-inch iMac• 69 g (0.2 lbs) CO2e per hour

• Use of servers and networks – 55 g (0.1 lbs) CO2e per hour

• Overall computing may be only a few % of your carbon footprint

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A Computer (and using it) • Most of the manufacturing

footprint comes from the microprocessor

• The electricity emissions typically equal the footprint of manufacture after 15,000 hours – 9 hours every day for 5 years

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An International Flight• Economy class– 3.4 tons CO2e

• Average – 4.6 tons CO2e

• First class– 13.5 tons CO2e

• One trip is equivalent to 340,000 disposable plastic bags

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An International Flight• First class tickets are

particularly high in impact because the seat uses up more of the plane and by paying more money you provide more of a commercial incentive for the flight

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• When a 747 takes off about 1/3 of its weight is fuel

• As the fuel burns, it creates 3 times its weight in CO2

An International Flight

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Carbon footprint ranking1) Forest fire – 100 million tons

CO2e2) Having a child – 700 tons CO2e3) 2.5 Acres deforestation – 500 tons

CO2e4) A new car – 17 tons CO2e5) Flight (LA to Spain) – 4.6 tons

CO2e6) A new computer – 720 kg CO2e7) Road trip: SF to LA – 500 Kg CO2e8) Light on for a year – 400 kg CO2e9) $100 on groceries – 62 kg CO2e10) Moderate cell phone use (year) –

47 kg CO2e11) 10 lbs of trash – 3.1 kg CO2e

12) Beef cheeseburger – 2.5 kg CO2e

13) A pint of beer – 500g CO2e14) Bottle of water – 200g CO2e15) Cycling a mile – 100g CO2e16) Banana – 80g CO2e17) Walking through a door –

10g CO2e18) A web search – 2g CO2e