Maximum Yield Cannabis USA October/November 2018 | Page 64

the ecological cost
OF A JOINT
Ever wonder what the ecological cost of a joint
is? Ian Ashdown, Maximum Yield advisory board
member and senior scientist at SunTracker
Technologies, did. After referencing several
studies, he came up with the answer and a way
to put it into context.
By Ian Ashdown
I
t was a very pleasant lunch conversation in Victoria,
B.C. with Lisa Jansen van Rensburg of P.L. Lights,
colleague Wallace Scott of SunTracker Technologies,
and Maximum Yield Cannabis editor Toby Gorman that
spurred the question: How much energy does it take to
produce a single joint of cannabis?
TRANSPORTATION
12 %
DRYING 1 %
LIGHTING
WATER HANDELING 2 %
33 %
CO 2 INJECTION 2 %
SPACE HEAT 4 %
“
A TYPICAL CANNABIS JOINT
HAS A CARBON FOOTPRINT
OF 1.4 KILOGRAMS OF CO 2 .”
Surprisingly, the answer was not all that difficult to
determine. We begin with “The Carbon Footprint of
Indoor Cannabis Production” (Mills, E. 2012), which
states “one average kilogram (kg) of final product
is associated with 4,600 kg of carbon dioxide (CO 2 )
emissions to the atmosphere.” The paper provides an
extremely detailed analysis of the production equipment
and its carbon footprint, so this is not just another White
House “fact.” The breakdown is itself interesting (see
graphic). The author also estimated that one kilogram of
final product requires between 5,200 and 6,500 kilowatt
hours (kWh) of electricity (or, an average of 5,850 kWh).
This leaves the question of how many grams (g) of
cannabis in a typical joint. The latest estimate is given
by “Bayesian Inference for the Distribution of Grams of
Marijuana in a Joint,” (Ridgeway, G., and B. Kilmer, 2016),
where the authors calculated 0.32 g per joint (which is
less than previous estimates of 0.43 to 0.75 g).
With this, the answer is: a typical cannabis joint
has a carbon footprint of 1.4 kg of CO 2 and requires
enough electricity to power a 60-watt equivalent
LED lamp for 200 hours.
To put the CO 2 issue into perspective, an average
sedentary person generates about one kilogram
of CO 2 a day just by breathing.
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Maximum Yield
AIR CONDITIONING
19 %
HEAT/VENTILATION 27 %
We can provide reference in another way.
According to the US Environmental Protection
Agency, the average passenger vehicle emits
404 g of CO 2 per mile.
So, if one average kilogram of final product is
associated with 4,600 kg of CO 2 emissions to the
atmosphere, and if the average joint is considered
to weigh 0.32 g, then: (0.32 g marijuana/joint)
x (4,600,000 g CO 2 /1,000 g marijuana)
x (1 mile/404 g CO 2 ) = (3.64 miles/joint)
x (1.609 kilometers/mile) = 5.86 kilometers/joint.
The average passenger vehicle traveling
3.64 miles (5.86 kilometers) emits the same amount
of CO 2 as it takes to produce an average joint.