Marijuana causes global warming

According to a study titled “Energy up in smoke, the Carbon Footprint of Cannabis Production” by Dr. Evan Mills, a scientist with the Lawrence Berkeley National Laboratory, marijuana grown indoors in the U.S. uses as much energy as 2 million homes and produces carbon dioxide emissions equivalent to 3 million automobiles.  If you believe that carbon dioxide is responsible for global warming, then potheads are partly responsible for our hot heads.

Mills estimates that in 2011, national production of marijuana will be 17,000 metric tons, one-third of that produced indoors.  Based on the energy requirement estimates for high-intensity lighting, dehumidification, space heating, water heating, and air conditioning, it adds up to 1% of our national electricity production and produces 17 million metric tons of carbon dioxide emissions.

Read the whole study here.

UPDATE April 18:

Upon reading the many comments to this post, I realize that I should have put a question mark at the end of the title so it would read “Marijuana causes global warming?”

The cited paper is just another example of climate silliness.  For those who believe carbon dioxide has a significant effect on temperature, then the author of the study shows that marijuana grown indoors uses lots of energy which implies the practice can produce carbon dioxide emissions.

Regular readers of this blog should know that I do not believe that human carbon dioxide emissions have a significant effect on global temperature because there is no physical evidence to support that contention, there are only speculations from computer modeling  – garbage in-garbage out.  Go over to the Quick Links page and scroll down to the climate section to see my posts on the matter.



  1. The headline should read “Marijuana criminalization causes global warming.” If it were legal, it could be grown outdoors and actually be carbon neutral. If we used hemp fiber and oil in mass quantities, cannabis would be a net carbon sink and part of the solution to global warming.


    ‘If people let the government decide what foods they eat and what medicines they take, their bodies will soon be in as sorry a state as are the souls of those who live under tyranny.’ ~Thomas Jefferson Was this a problem caused by marijuana or marijuana PROHIBITION? The vast majority of problems attributed to marijuana are actually problems directly and completely caused by marijuana PROHIBITION! How many more lives have to be ruined by marijuana PROHIBITION before We The People step up and legalize marijuana? Why is the most useful plant known illegal? It’s illegal because crooked corporations that buy crooked politicians fear competition from superior, safer and more environmentally friendly hemp products and because our Constitution ignoring Government loves to oppress jail and steal from the people! Alcohol, tobacco, petroleum, cotton, timber, chemical and pharmaceutical companies, just to name a few, all see marijuana as unwanted competition because marijuana/hemp/cannabis produces superior more environmentally friendly products than the overpriced, harmful, toxic, often deadly products marijuana prohibition forces everyone to use. The best way for We The People to regain our Constitutional rights and liberty is to demand to be governed strictly according to the Constitution and to demand a complete ban on corporate lobbying. We are supposed to have Government of, for and by THE PEOPLE, not of, for and by corporations and the crooked Constitution shredding politicians they buy! Corporations are NOT people and unconstitutional is ILLEGAL! Marijuana does not cause aggressive behavior. Marijuana does not cause dangerous driving. Marijuana does not cause cancer, brain damage or any serious health problems. Marijuana prohibition does not keep kids away from marijuana, illegal dealers don’t ask for ID. Marijuana is not a “gateway drug”, there is absolutely NOTHING about marijuana that causes people to use other drugs. Marijuana is not addictive. In fact marijuana is one of the safest substances known! Marijuana is SAFER than many foods we consume and give to our kids all the time! Exactly what good is this prohibition doing and who is benefiting from it? What % of marijuana consumers beat their wife because of the effects of marijuana? What % of marijuana consumers go to a marijuana party and end up in a fight because of the effects of marijuana? What % of marijuana consumers get in a drunken stupor and spend the night in a gutter? What % of marijuana consumers pass out and stay right where they fell long after they soil their pants? What % of marijuana consumers end up choking to death on their own vomit? Exactly 0%! Marijuana is no different than alcohol? Who are you kidding? No one that knows the truth! The cops and the politicians know marijuana is no threat to society but they keep screaming their fear mongering marijuana lies at every opportunity. Did you ever wonder why?  LEGALIZE MARIJUANA AND REGULATE IT LIKE POTATOES, CORN OR ANY OTHER SAFE NATURAL PLANT/CROP! NO NEW TAXES! Legalize marijuana and stop funding criminals, gangsters, illegal aliens and terrorists with hundreds of Billions of $ every year. “When you fund something you get more of it” (Ron Paul). Does anyone really think we need more criminals, gangsters, illegal aliens and terrorists? Why should a substance that is far SAFER than aspirin ONLY be legal for those in a few States that have a serious ailment? Why should people be forced to use FDA approved poisons instead of a far safer more effective natural plant? Why should a plant that is SAFER than potatoes be regulated and taxed as if it was as dangerous as alcohol? Eating a few raw potatoes can give you a toxic reaction but marijuana is nontoxic. Why should people have their kids taken away from them when nontoxic marijuana is found in their home while far more harmful, even deadly substances are all over the house? Why should anyone be concerned about people using NONTOXIC marijuana when they have hundreds of far more dangerous and often deadly LEGAL substances under their kitchen sink, in their kitchen cabinets, in their medicine cabinets and in their garage? If adults can use those dangerous, even deadly substances safely, does any logical person really think they can’t use NONTOXIC marijuana safely and keep their kids safe without Government being involved or a recommendation from a Dr.? Marijuana is one of the SAFEST and most beneficial substances known to mankind! It’s an undeniable FACT that the vast majority of so called “drug-related” violent crime is caused by the prohibition of drugs, rather than the drugs themselves. It was the same during alcohol prohibition. Alcohol prohibition created violent criminal organizations just like every other drug prohibition has. These violent crimes should be labeled PROHIBITION RELATED, not drug related. Ending alcohol prohibition is exactly why you don’t see shootouts over that ILLEGAL drug TRADE any more. THE YEAR ALCOHOL PROHIBITION ENDED VIOLENT CRIME FELL BY 65%! Marijuana accounts for roughly half of the entire illegal drug trade. Legalizing this one nontoxic plant that it is impossible to overdose on will take away HALF of all the illegal money that is funding all the illegal drug dealers and causing VIOLENT CRIME over the illegal MONEY.

    No matter where you stand on the issue of legalizing marijuana everyone should read: MARIJUANA AND HEMP THE UNTOLD STORY, Thomas J. Bouril,


    and  the free online book:

    THE EMPEROR WEARS NO CLOTHES, The Authoritative Historical Record of Cannabis and The Conspiracy Against Marijuana.

    Click the links to those titles on this webpage:Internet Explorer web browser:   All Other Browsers:  If you think marijuana prohibition has anything to do with the imaginary, false, fabricated, alleged harms from using marijuana as a recreational drug, YOU HAVE BEEN DUPED!

  3. What a terribly misleading headline. Without the word “Indoor” proceeding the word “Marijuana” you sort of sound like a foolish twat.

  4. Firstly, the study assumes that all grows take up the whole house and use all the mentioned equipment. A lot of Cannabis is grown by people for their personal use, takes up a small space in one room, requires only one lamp and no other equipment. So the real figure is probably lower than the stated figure.
    Secondly, the study assumes a certain amount of electricity is used and equates from that how much CO2 is produced by that amount of electricity. It then states that all this CO2 is produced in the growing of Cannabis. It fails to take into account the amount of CO2 taken out of the atmosphere by the plants as they grow, which more likely than not, is greater than the amount of CO2 produced by the electricity. Even growing indoors it’s probably a Carbon Neutral hobby.

    1. The study actually assumes a (very small) area of 4x4x8… Which makes it even more offensive. I’ve been around a few articles on this study, and basically, after doing some math, it appears the author used the following assumptions:

      Doubling the amount of light currently deemed SOP for indoor growing
      Using HVAC air-cooling, but using the entire house profile in the math
      Using HVAC de-humidifiers, which are often un-needed, as is A/C

      The author claims the power draw for a 4x4x8 space @ 13,000kWh for an entire year. My math (backed up by 13 years of in/outdoor experience) puts the power usage for a similarly sized operation @ 4,500kWh or LESS. Using the author’s calculations for US% of power, that takes the number from ~1% to just over 0.34%, with directly corresponding reductions in calculated amount of CO2 produced.
      As for your idea of an indoor hydro grow being carbon neutral, it is definitely not the case… But it’s also pretty far from the “reality” the study’s author would have us believe.

  5. If pot was legalized, then marijuana would be grown outdoors in vast fields under the sun, where it is supposed to be grown. Instead of some guys basement where the oxygen stays confined in the room and the lights are on all day every day wasting electricity. Just think about all the oxygen these fields would create for the planet. This story tries to make reefer look bad, but it is actually just making yet another point why marijuana should be legalized.
    Cannabis is a good plant with a bad reputation.

  6. Cannabis can end global warming! It’s our #1 fuel source and has existed before humans… why no global warming then? Oh, because it releases a lot of oxygen that we need! It’s excellent for the environment, in fact it’s one of our best plants for the environment. The prohibition causes this insanity…

  7. It is not a belief that humans are causing climate disruption as the research and facts are how that conclusion was drawn.  No belief is necessary.

    1. Hey Mark, what facts?  There is no physical evidence showing that human carbon dioxide emissions significantly affect global temperature.  If you think otherwise, then prove me wrong and provide the evidence.

      1. But isn’t the point of your posting the article above that growing cannabis indoors, certainly a “human activity”, increases the carbon load?  And doesn’t your headline imply that this activity causes global warming?  I’m not sure what you’re getting at Jonathan.  Are you implying that people who grow marijuana indoors are necessarily the same people who decry global warming?  Perhaps your next article should be about the global warming caused by wearing Birkenstocks or playing frisbee. 

        And Jonathan: “There is no physical evidence showing that human carbon dioxide emissions significantly affect global temperature”.  Come on!  There is plenty of evidence.  Your opinion on the matter puts you at odds with the predominant opinion of the scientific community.  Fairer to say that you disagree with the evidence. 

      2. The wording of the headline made you look.  Again, if you think there is “plenty of evidence” then show some.  Neither the IPCC nor any of the scientists within the “consensus” have been able to produce any physical evidence that human carbon dioxide emissions have a significant effect on temperature.  And, “predominant opinion” doesn’t make something true.

      3. Anyone who reads the IPCC Fourth Assessment Report, Summary for Policymakers and doesn’t see evidence that human carbon dioxide emissions have a significant effect on temperature is either suffering from an intellectual deficiency or is in denial. Overwhelmingly, the view of the scientific community is that human activity is advancing global climate change. I’ll take their word before that of a third-rate blogger with a reckless, wrong-headed political agenda. “The wording of the headline made you look.”  Sir, you have a promising future at The National Enquirer. Thought I don’t know anyone there, I’d be overjoyed to write a letter of recommendation for you.

  8. How about you try using the entire title of the study instead of dropping words in an attempt to completely change the point of the study?

    This is yellow journalism at it’s finest.

    1. to Kaleb: Did you not read the first sentence in which I quoted the entire title?

  9. This article should state “Marijuana PROHIBITION causes global warming”.  This asshat DuHamel needs to get his information correct.  The only reason cannabis is grown indoors is because of prohibition!  Once the feds remove federal restrictions on this natural medicine, which has been safety used for thousands of years, cannabis will again be returned to the outdoors.  Stop unnecessary energy consumption!  Legalize Cannabis for all Americans!

  10. Global warming is a HOAX.  So hinting pot adds to a HOAX makes this report a HOAX!

  11. Right wingers don’t believe in Global Warming anyway, so they can’t use this as an argument against cannabis.
    Of course, the reply is obvious – allow outdoor cultivation and this will not be so prevalent.   However, due to prohibition, growers were forced to grow indoors, which produced superior results, cut the time to harvest, and increased the growing seasons to at least 4 per year.   So, the genie is out of the bottle, thanks to the government.

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