During my time in Seattle I spent a lot of time listening to large cargo jets fly low overhead, over a bedroom community late at night or very early in the morning, with over 16 miles to go before arriving at SeaTac Airport, with hills, harbor cranes, and the Seattle downtown skyline in between. This made me wonder about the impact that organized stalking activities were having on the environment. These thoughts were further stimulated by the phalanx of vehicles that would descend upon my route every time I ventured out of my residence, most with their headlights on during the daytime. When I moved from Seattle to Arizona in October 2009, and drove along remote highways through Eastern Oregon and Nevada, I encountered numerous vehicles, the vast majority from California and a higher than expected number from Washington, Idaho, Utah, and Arizona. In contrast, I encountered relatively few vehicles registered in Oregon, and then Nevada, as I drove through. I suspect most people would have chosen to drive down Interstate-5 to Interstate-10, and then head east. This experience made me wonder whether all these California cars went east just to keep me company as I drove to Arizona, and what the environmental impact would be if this were true.

So, I decided to play around with some numbers and apply them to the recently-released stalking statistics from the US Department of Justice showing that approximately 450,000 Americans believe they are being stalked by 3 or more people (possible organized stalking victims).

1.   DOJ reported 13.1% of stalking victims in 2006 believed they were being stalked by 3 or more people, suggesting 450,000 Americans could be victims of organized stalking. This number is probably an underestimate because many victims report that they were stalked for years prior to becoming aware of the existence of organized stalking. (www.ojp.usdoj.gov/bjs/pub/pdf/svus.pdf)
2.   A gallon of gasoline produces approximately 8.8 kg of CO2, by far the most prevalent greenhouse gas and the primary byproduct of transportation emissions, and the average passenger vehicle produces 5.5 metric tons of CO2 per year. (http://www.epa.gov/OMS/climate/420f05004.htm#step1).
3.   Since 1 kg = 0.001 metric tons, then 5.5 metric tons = 5500 kg. 5500/8.8 = 625 gallons of gasoline used per year per passenger vehicle, or 1.7 gallons per day. This results in each passenger vehicle in the US producing 15.1 kg of CO2 per day on average.
4.   Based on my observations, anywhere from 20 to 100 vehicles are mobilized to ‘accompany’ me on my outings. If we assume the distance traveled during an organized stalking victim’s outing is no different from anyone else’s, then each time I go to work or shopping I personally use 1.7 gallons of gasoline on average. If we include the vehicles involved in organized stalking then I ‘use’ approximately 36 to 170 gallons of gas (approx. 20 or 100 stalker vehicles x 1.7 gallons of gasoline per vehicle), thus producing between 317 and 1500 kg of CO2. The fuel costs range from 100 to 500 dollars given an average price of $2.56 per gallon.
5.   On an annual basis, assuming one trip per day for a single organized stalking victim, between 13,000 and 62,000 gallons of gasoline could be used, generating between 115 and 550 metric tons of CO2, and costing between 35,000 and 170,000 dollars (assuming $2.65/gal.).
6.   If we assume there are 450,000 stalking victims in the United States, then annually organized stalking activity burns between 6 and 28 billion gallons of gasoline, generates between 52 and 250 million metric tons of CO2, and costs between 16 and 77 billion dollars (assuming $2.65/gal.).
7.   Total CO2 emissions for all passenger cars and light trucks was 1100 million metric tons for the year 2007. Organized stalking activities could therefore represent between 4.7 and 22.7% of total annual CO2 emissions for this class of vehicles. http://www.deq.state.or.us/aq/committees/docs/november09/emissionstransportationsubsector.pdf
8.   Total CO2 emissions from all activities in the US in 2007 were 6103.4 million metric tons, and organized stalking activity could represent anywhere from 0.9 to 4.1% of this total. Since CO2 accounts for 85.4% of all greenhouse gas emissions, organized stalking activity could be responsible for up to 3.5% of all greenhouse gases produced within the United States.
9.   Based on my observations, most vehicles driven by persons involved in organized stalking activities drive with their headlights on, I assume to make them recognizable to the person being targeted and to increase the intimidation effect. The estimated fuel penalty is between 0.5 and 1.5% (http://auto.howstuffworks.com/fuel-efficiency/fuel-economy/drl-gas-consumption.htm). This results in a small increase in CO2 emissions on an annual basis, between 0.26 and 1.25 million metric tons at the 0.5% level, and between 0.8 and 3.75 million metric tons at the 1.5% level. These estimates are probably low because they are based on low wattage running lights. What I’ve noticed is that vehicles involved in stalking activities typically use regular low beam headlights, and occasionally high beam headlights, which consume more power and thus produce more greenhouse gas emissions.
10.  These estimates do not take into account CO2 emissions from aircraft, heavy-duty trucks, and motorcycles involved in stalking activities, or emissions from vehicles on ‘stake-out’ duty idling their engines to stay warm on cold nights.

Conclusions: Each year an estimated 16 to 77 billion dollars is spent on fuel for passenger cars and light-duty trucks involved in organized stalking activities, generating between 52 and 250 million metric tons of CO2 emissions. This represents between 4.7 and 22.7% of total CO2 emissions for this class of vehicles, up to 4% of all CO2 emissions and up to 3.5% of all greenhouse gases produced within the United States.