When we extract and burn fossil fuels such as coal or petroleum, we cause the release of carbon dioxide (CO2) and other heat-trapping "greenhouse gases" into the atmosphere.
Though natural amounts of CO2 have varied from 180 to 300 parts per million (ppm), today's CO2 levels are around 400 ppm. That's 30% more than the highest natural levels over the past 800,000 years.
We also can tell that the additional CO2 in the atmosphere comes mainly from coal and oil because the chemical composition of the CO2 contains a unique fingerprint.
none. there is no evidence.
All the carbon locked away in fossil fuel reserves were once part of the system when life flourished. In fact one could ask that if all that fossilized carbon plus the carbon currently in the system existed in a global living ecosystem which did not destroy the world in the past then why would it destroy the world now?
Proof humans are responsible for global warming comes when we look at the frequencies of radiation associated with the warming. First we look at the frequencies associated with CO2 absorption. To do this we can go to the following page and select the following options.
http://spectralcalc.com/spectral_browser...
1. Select 'Group by Molecule' if it is not already selected.
2. Select the following in 'Spectral Range': Units - wavenumber, Lower limit - 400cm^-1, Upper limit - 1400cm^-1 (This is the approximate area for the black body radiation curve of the Earth)
3. Select the following in 'Options': 'scale by atmospheric abundance', Atmosphere - standard, Scale - linear, Symbols - sticks
4. From the select menu under 'Species' select the following gasses: H2O, CO2, O3, CH4, N2O (These are the five most prominent greenhouse gasses.)
Further study regarding absorption frequencies can be found in the links in sources below.
After you hit the plot button you can see just how much an effect each gas has as it pertains to it's atmospheric abundance. As you can see the core of the CO2 band is at about 667cm^-1. Now what happens when we increase the amount of CO2 in the atmosphere? To find out we look at a University level text book written by David Archer, a professor at the Department of The Geophysical Sciences at the University of Chicago. If you scroll down to figure 4-5 near the bottom of the following page we can see that, while the middle of the CO2 absorption band remains relatively static after a certain concentration is reached, the band does not get deeper but gets wider with increasing CO2 concentration.
http://forecast.uchicago.edu/archer.ch4....
Next we look at the changes in tropospheric radiation. Griggs published a paper in 2007 that did just that. If we look at the various graphs on the paper in the following link we see a range of measured frequencies from 700cm^-1, the right hand side of the CO2 absorption band and the point where we will see the most change if the increase is due to CO2, and 1200cm^-1. And, in fact, between the years 1970 and 2003, the study period, we see just that.
http://journals.ametsoc.org/doi/pdf/10.1...
This study is an extension of a study by Harries in 2001.
https://workspace.imperial.ac.uk/physics...
Now that we know the warming is due to increases in CO2 we need to find out where that additional CO2 is coming from. Historically during warming periods CO2 concentration has risen after temperatures increase due to what is known as Le Chatelier's Principal, which states if a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the imposed change and a new equilibrium is established. However, as we are currently using fossil fuels from what is known as the geological carbon cycle and pumping them back into what is known as the biological carbon cycle we are throwing that natural balance off. The result being an increase in the partial pressure, or weight, of that CO2 above the surface of the ocean and the oceans trying to maintain equilibrium. They are actually absorbing more CO2 than they are emitting during a warming period, as evidenced by their decreasing pH or acidification, which would not occur naturally.
http://www.bu-eh.org/uploads/Main/doney_...
For more proof we can look at measurements of increasing atmospheric CO2, which is currently rising at an average rate of 2 parts per million (ppm) or 15.6 billion tonnes annually, and estimates of human emissions, which stands at over 33.5 billion tonnes annually.
http://scrippsco2.ucsd.edu/data/in_situ_...
http://cdiac.ornl.gov/trends/emis/perlim...
Here is a couple of things you can use http://globalmicrowave.org...
http://en.m.wikipedia.org...
http://www.youtube.com/ plasmoid in a microwave oven
I am writing an argumentative paper on whether Global warming is causes by human activity or not. I need three different claims to back up what I think ( I believe it is caused by human activity), and under each claim, I need evidence to back it up. The only claim i have so far is that the amount of greenhouse gases has significantly increased in the atmosphere, and under that claim, I talk about fossil fuel emission, deforestation, and man made greenhouse gases. Is there any other claim I can use that has evidence to back it up? It can't be anything about rising sea levels or anything like that because there is no evidence humans caused it, unlike the amount of greenhouse gases.
Thanks!
