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Green Lantern: Can hemp help the environment, or isit just marijuana?April 11, 2011April 11, 2011

I keep hearing about how beneficial hemp is for the environment and what a shame it is that U.S.I keep hearing about how beneficial hemp is for the environment and what a shame it is that U.S.

farmers arent allowed to grow it. Is hemp really that eco-friendly?farmers arent allowed to grow it. Is hemp really that eco-friendly?

With the possible exception of soy, no plant has managed to spawn as many different products and as muchWith the possible exception of soy, no plant has managed to spawn as many different products and as much

controversy as hemp. You can buy hemp clothing, hemp paper, hemp milk, hemp oil .controversy as hemp. You can buy hemp clothing, hemp paper, hemp milk, hemp oil .... the list goes on. A. the list goes on. ACanadian company has even built an Canadian company has even built an electric car out of hempelectric car out of hemp. Advocates talk about the leafy plant like its going. Advocates talk about the leafy plant like its going

to reverse global climate change. Opponents think its merely a Trojan horse packed with potheads hoping to getto reverse global climate change. Opponents think its merely a Trojan horse packed with potheads hoping to get

your kids stoned.your kids stoned.

The legal problem for hemp is that its taxonomically identical to marijuana. Both are classified as The legal problem for hemp is that its taxonomically identical to marijuana. Both are classified as CannabisCannabis

sativa Lsativa L, and the only difference between them is the concentration of delta-9-tetrahydrocannabinol (THC), the, and the only difference between them is the concentration of delta-9-tetrahydrocannabinol (THC), the

psychoactive substance in pot. Marijuana contains at least 3 percent THC by weight, whereas hemp falls belowpsychoactive substance in pot. Marijuana contains at least 3 percent THC by weight, whereas hemp falls below

that threshold.that threshold.

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Some hemp advocates think there are also visible differences. But Some hemp advocates think there are also visible differences. But Uncle Sam seems to believeUncle Sam seems to believe that the only way that the only way

to distinguish marijuana from hemp is by taking it to the lab (or, presumably, rolling it up and smoking it).to distinguish marijuana from hemp is by taking it to the lab (or, presumably, rolling it up and smoking it).

The plant is a The plant is a Schedule 1Schedule 1 controlled substance in the United States, which means you need special permission to controlled substance in the United States, which means you need special permission to

grow it regardless of THC content. Canada and several European countries allow their farmers to grow hempgrow it regardless of THC content. Canada and several European countries allow their farmers to grow hemp

with THC content below 0.3 percent one-tenth as strong as the weakest marijuana. The United States has heldwith THC content below 0.3 percent one-tenth as strong as the weakest marijuana. The United States has held

off, largely because a government helicopter that flies over a farmers field cant tell the difference between hempoff, largely because a government helicopter that flies over a farmers field cant tell the difference between hemp

and marijuana. For this reason, raw ingredients for all U.S.-manufactured hemp products must be imported.and marijuana. For this reason, raw ingredients for all U.S.-manufactured hemp products must be imported.

Hemp is so versatile in part because it can be grown for either seed or fiber. The seeds yield milk, oil and otherHemp is so versatile in part because it can be grown for either seed or fiber. The seeds yield milk, oil and other

food products, and are particularly popular among vegans, who have trouble food products, and are particularly popular among vegans, who have trouble working omega-3sworking omega-3s into their diets. into their diets.

The fiber is used for paper and clothing. Sailors have been using hemp rope and sails for centuries, and the The fiber is used for paper and clothing. Sailors have been using hemp rope and sails for centuries, and the cropscrops

abundanceabundance was valued during the Revolutionary War era. was valued during the Revolutionary War era.

So is hemp the answer to all our environmental problems, or is it just pot? It depends on what you want to use itSo is hemp the answer to all our environmental problems, or is it just pot? It depends on what you want to use it

for, and what you compare it to. For now, lets focus on textiles, the most traditional and common use.for, and what you compare it to. For now, lets focus on textiles, the most traditional and common use.

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A A 2005 report2005 report by the Stockholm Environment Institute compared the water, land and energy requirements of by the Stockholm Environment Institute compared the water, land and energy requirements of

cotton, polyester and hemp textiles, among others. While the study is the most comprehensive investigation ofcotton, polyester and hemp textiles, among others. While the study is the most comprehensive investigation of

this issue, the results were unsatisfyingly mixed.this issue, the results were unsatisfyingly mixed.

Producing the raw ingredients for any textile consumes more energy than any other part of the process. DifferentProducing the raw ingredients for any textile consumes more energy than any other part of the process. Different

production techniques, however, can significantly affect that consumption. Since pesticides and herbicidesproduction techniques, however, can significantly affect that consumption. Since pesticides and herbicides

account for more than half of the energy used in growing hemp or cotton, organic methods for raising these twoaccount for more than half of the energy used in growing hemp or cotton, organic methods for raising these two

crops produce lower carbon-dioxide emissions. Organic cotton required less energy than organic hemp, but thecrops produce lower carbon-dioxide emissions. Organic cotton required less energy than organic hemp, but the

difference was fairly small. Polyester, a petroleum-based synthetic fabric, was the clear loser because it takes sodifference was fairly small. Polyester, a petroleum-based synthetic fabric, was the clear loser because it takes so

much energy to extract the oil required to make it.much energy to extract the oil required to make it.

Cotton needs approximately twice as much territory as hemp per ton of finished textile. Further complicatingCotton needs approximately twice as much territory as hemp per ton of finished textile. Further complicating

matters is the inverse relationship between chemical use and land requirements. While organic farmers save onmatters is the inverse relationship between chemical use and land requirements. While organic farmers save on

energy consumption, their yield per acre is lower than that of cotton and hemp growers who use syntheticenergy consumption, their yield per acre is lower than that of cotton and hemp growers who use synthetic

pesticides and herbicides. Polyester does almost as well as hemp on land use. And apparently you can get morepesticides and herbicides. Polyester does almost as well as hemp on land use. And apparently you can get more

fabric from an oil field than a cotton field.fabric from an oil field than a cotton field.

Cotton is again the big loser when it comes to water. The cotton plant needs around 50 percent more water perCotton is again the big loser when it comes to water. The cotton plant needs around 50 percent more water per

season than hemp, which can grow with little irrigation. More than half of the worlds cotton fields rely onseason than hemp, which can grow with little irrigation. More than half of the worlds cotton fields rely on

irrigation, because it is raised in some relatively dry regions, including Egypt, Chinas Xinjiang province,irrigation, because it is raised in some relatively dry regions, including Egypt, Chinas Xinjiang province,

California and Texas.California and Texas.

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When you add processing into the equation, cotton uses more than four times as much water as hemp. PolyesterWhen you add processing into the equation, cotton uses more than four times as much water as hemp. Polyester

is difficult to compare, because its not an agricultural product. But some studies suggest it is the least water-is difficult to compare, because its not an agricultural product. But some studies suggest it is the least water-

intensive of the bunch, using just 1/1,000th as much water as cotton. (In fact, water is a byproduct of polyesterintensive of the bunch, using just 1/1,000th as much water as cotton. (In fact, water is a byproduct of polyester

processing.)processing.)

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So where does all this leave us? Without a clear winner, unfortunately. Theres a case to be made for polyester,So where does all this leave us? Without a clear winner, unfortunately. Theres a case to be made for polyester,

but the nonrenewability of synthetic textiles raises serious concerns. Overall, hemp appears to be slightly easierbut the nonrenewability of synthetic textiles raises serious concerns. Overall, hemp appears to be slightly easier

on the environment than cotton, superior on water and land requirements, and only slightly worse for energyon the environment than cotton, superior on water and land requirements, and only slightly worse for energy

use. But is the Drug Enforcement Administration responsible for all of our environmental woes? Hardly.use. But is the Drug Enforcement Administration responsible for all of our environmental woes? Hardly.

The Green Lantern is produced by the online magazine Slate and can be read at The Green Lantern is produced by the online magazine Slate and can be read at www.slate.comwww.slate.com..