Carbon Footprints
Information from How Bad Are Bananas?
By Mike Berners-Lee
1
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
2
CO2e
• Total climate change impact of all greenhouse gasses caused
by item or activity
3
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
4
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
5
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
6
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 (LABarcelona)
7
Which type of beer would have the
highest carbon footprint per pint?
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1. Locally brewed at the bar
2. Store bought, locally
bottled
3. Store bought, bottled
elsewhere, imported long
distances
8
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
9
Which food would produce highest
carbon footprint for cycling a mile?
1. Air-freighted
asparagus
2. Bacon
3. Bananas
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10
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
11
The carbon footprint of manufacturing a
new car is ____ compared to the carbon
footprint of driving that car over its lifetime
1. Very small
2. Roughly equivalent
3. Very large
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12
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
13
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
14
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%)
15
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.
16
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
17
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
18
Spending 1$
• In our current energy
system it is very difficult to
spend a dollar without it
adding to your carbon
footprint
19
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
20
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
21
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
22
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
23
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
24
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
25
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)
26
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
27
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
28
A bottle of water
• Most emissions come from
packaging and transport
– 80 g CO2e just from the plastic
29
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
30
2.5 Acres of Deforestation
• 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.)
31
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
32
A Burger
33
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?
1.:
2.:
60%
3. 1 and 2 are equal
30%
1a
nd
2
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e
eq
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:
:
10%
34
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
35
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
36
A Burger
• 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
37
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)
38
Using a cell phone
• 1 minute cell-to-cell phone call has the same
carbon footprint as an apple
=
39
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
40
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
41
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
42
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
43
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
44
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
45
An International Flight
• 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
46
Carbon footprint ranking
1) Forest fire – 100 million tons
CO2e
2) Having a child – 700 tons CO2e
3) 2.5 Acres deforestation – 500 tons
CO2e
4) A new car – 17 tons CO2e
5) Flight (LA to Spain) – 4.6 tons
CO2e
6) A new computer – 720 kg CO2e
7) Road trip: SF to LA – 500 Kg CO2e
8) Light on for a year – 400 kg CO2e
9) $100 on groceries – 62 kg CO2e
10) Moderate cell phone use (year) –
47 kg CO2e
11) 10 lbs of trash – 3.1 kg CO2e
12) Beef cheeseburger – 2.5 kg
CO2e
13) A pint of beer – 500g CO2e
14) Bottle of water – 200g CO2e
15) Cycling a mile – 100g CO2e
16) Banana – 80g CO2e
17) Walking through a door –
10g CO2e
18) A web search – 2g CO2e
47