Friday, July 26, 2013

Respiration vs. Combustion Global Warming Footprint

Source 1: From one news group: "Humans exhale about 1kg of CO2/day"

Source 2: from post below *** 145.6 kg/year/person ** or about 1/2 kg per person per day for a 300 day year ***
http://www.abovetopsecret.com/forum/thread278647/pg1
www.abovetopsecret.com/forum/thread278647/pg1
About 5 billion people in the world gives us 1.4ee(11) kg/year CO2 produced by human respiration. That's 140 billion kg/yr That's 140 million metric tons/yr

Source 3:
http://barryonenergy.wordpress.com/2010/08/18/human-breathing-and-co2-carbon-dioxide-as-anthropogenic-causes-of-climate-change-and-global-warming/
• per year, the entire U.S. population produces 5% as much CO2 as all the electrical generation power plants in the U.S., [20x respiration]
• per year, the entire World population produces 116% as much CO2 as all the electrical generation power plants in the U.S. 
• per year, the entire U.S. population produces 8% as much CO2 as all the passenger vehicles in the U.S., [13x respiration]
• per year, the entire World population produces 189% as much CO2 as all the passenger vehicles in in the U.S.
Perspective: 
US population of 300 million is about 6% of world population of 5 billion
US produces about 33 times more CO2 from combustion for power and driving than respiration
The entire world population of humans produces as much CO2 as US electricity generation, or twice as much as cars
The US produces about 1.5 times the amount of CO2 for power and cars as the rest of humanity by breathing)
A 10% or even 50% reduction in US CO2 emissions would have a negligible effect on global emmissions.


Source 02: CO2 loading from respiration, page 1 - AboveTopSecret.com ..
http://www.abovetopsecret.com/forum/thread278647/pg1
www.abovetopsecret.com/forum/thread278647/pg1
About 5 billion people in the world gives us 1.4ee(11) kg/year CO2 produced by human respiration. That's 140 billion kg/yr That's 140 million metric tons/yr

Just out of curiosity I performed numerous internet searches to determine the annual CO2 loading to the atmosphere from human respiration. I could not find one single resource that provided this statistic so I tried to calculate it myself. I was interested in this to get an idea of the ratio of CO2 loading between fossil fuel combustion and respiration.

Global CO2 loading per year based on hydrocarbon use and cement production is 22.8 billion metric tons.

www.nationmaster.com...

Some basic figures for calculating CO2 loading from human respiration:

Average human respiration rate = 3 l/min air
CO2 content of atmosphere = 0.038%
CO2 content of exhaled breath = 4.7%

The average human inhales 0.0009 l of CO2/min and exhales 0.141 l CO2/min. Net exchange = (+) 0.1401 (say 0.14 l)

What's the mass of 0.14 l of CO2? From any Chemistry book we find that at STP the density of gaseous CO2 is 1.98 kg/M3. This converts to 0.00198 kg/l. So one average human exhales 0.14 l of CO2 per minute @ 0.00198 kg/l. This gives 0.00027 kg/min/person =

*** 145.6 kg/year/person ** or about 1/2 kg per person per day for a 300 day year ***

About 5 billion people in the world gives us 1.4ee(11) kg/year CO2 produced by human respiration.

That's 140 billion kg/yr
That's 140 million metric tons/yr

That's alot of CO2 however its miniscule in comparison to hydrocarbon combustion emissions.

source 03.

http://barryonenergy.wordpress.com/2010/08/18/human-breathing-and-co2-carbon-dioxide-as-anthropogenic-causes-of-climate-change-and-global-warming/

The question is: in the U.S. and the world, how much CO2 is produced, per year, by an average man and women through the life-giving function of breathing?
Per the EPA, the average person, through the natural process of breathing, produces approximately 2.3 pounds (1 kg) of CO2 per day or 365 kg per year. (Source:http://www.epa.gov/climatechange/fq/emissions.html#q7)
Using population figures of:
309.4 million for the U.S. (Source: http://www.census.gov, May, 26, 2010)
6,823.4 million for the World (Source: http://www.census.gov, May, 26, 2010)
This calculates to:
• the U.S. population produces 112.9 million metric tons of CO2 per year by breathing,
• the World population produces 2,603.5 million metric tons of CO2 per year by breathing.
COMPARISON TO ELECTRICAL GENERATION POWER PLANTS
To put this in perspective, these numbers are compared to “Carbon Dioxide Emissions from the Generation of Electric Power in the United States.” (Source:http://www.eia.doe.gov/cneaf/electricity/page/co2_report/co2emiss.pdf, July 2000).
In 1999, estimated emissions of CO2 in the United States resulting from the generation of electric power was 2,245 million metric tons, includes all coal, petroleum, natural gas, and non-fossil fuel burning power generation stations.
Therefore:
• per year, the entire U.S. population produces 5% as much CO2 as all the electrical generation power plants in the U.S.,
• per year, the entire World population produces 116% as much CO2 as all the electrical generation power plants in the U.S.
COMPARISON TO PASSENGER VEHICLES
Doing the same sort of analysis with passenger vehicles in the U.S., the annual emissions from a typical passenger vehicle was determined to be 5.5 metric tons of carbon dioxide equivalent (Source: http://www.epa.gov/oms/climate/420f05004.htm, February 2005).
According to the US Bureau of Transit Statistics for 2006 there are 250,844,644 registered passenger vehicles in the US.(Source:http://en.wikipedia.org/wiki/Passenger_vehicles_in_the_United_States)
This equates to 1,379.6 million metric tons of CO2 produced by all passenger cars per year.
Therefore:
• per year, the entire U.S. population produces 8% as much CO2 as all the passenger vehicles in the U.S.,
• per year, the entire World population produces 189% as much CO2 as all the passenger vehicles in in the U.S.
Notes:
1. Analysis includes only humanity and does not include any other oxygen breathing and CO2 emitting life forms.
2. Analysis includes passenger vehicles in the U.S. only and does not include planes, trains and other fossil-fueled vehicles in the U.S. and other countries.
3. U.S. autos account for half of global warming linked to cars worldwide. (Source: environment.about.com/od/…/a/autoemissions.htm).
CONCLUSION
As we were taught in grade school, humans breathe to live and correspondingly produce CO2. Though in today’s socio-political landscape, one can say humanity is an emitter of CO2, a GHG, which is a concern to some as it relates to climate change and global warming.
Nevertheless, it can be said that the worldwide human population produces almost twice the amount of CO2 emissions than all the passenger vehicles in the U.S.
In closing, the environmental impact of human-breathing related CO2 emissions is left to your beliefs and best settled by debate.





for comparison cars range from 3-to-6 miles/kg

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