Mid-century cooling was primarily anthropogenic
Debate Rounds (3)
One of my first global climate change debates my opponent brought up the mid-century cooling trend. Stating that a lot of oil was burned during that time period and that since there was cooling in that time period fossil fuels don't generate Co2. The time period was 1945-1975.
I knew there was something wrong with the logic, but I couldn't tell what. Anyways, here's the answer. Sulfur emissions
Just to explain, the mid century cooling period Stupidape and I are referring to is a time period from 1940-1975 where temperatures fell despite increased emissions of Co2 due to a major global economic boom after world war 2.
Mid century cooling: http://www.ofcomswindlecomplaint.net...
Co2 emmisions: http://a-sceptical-mind.com...
For my argument (that I posted in the comments):
NASA says that sulfate aerosols only cause regional cooling. I quote, "...the cooling effect of pollution aerosols will be somewhat regionally dependent, near and downwind of industrial areas."
This means that global cooling could not have been caused by sulfur emissions because sulfur caused cooling is only regional
More evidence would be that the northern hemisphere, which was generally more industrialized then the southern hemisphere, would cool faster if the cooling was due to sulfur emissions. By looking at the temperature trends of the northern and southern hemispheres, we can see that this is not the case.
Temp trends: http://www.giss.nasa.gov...
Overall, sulfur could not be responsible for the cooling mid century because sulfur only causes regional cooling and the area that we would expect to cool faster did not.
My quotes of sources in italics, opponent's arguments in bold and italics, and my arguments in plain text.
"Hansen and others show that sulfate aerosols can significantly cool the climate, raising confidence in models showing future greenhouse warming. " 
"The net effect of aerosols is to cool the climate system by reflecting sunlight. " 
Above is additional evidence that sulfate aerosols caused global cooling.
My opponent has made a major contradiction of his/her own statements.
"NASA says that sulfate aerosols only cause regional cooling. I quote, "...the cooling effect of pollution aerosols will be somewhat regionally dependent, near and downwind of industrial areas."
This means that global cooling could not have been caused by sulfur emissions because sulfur caused cooling is only regional" epidexipteryx
Somewhat regionally dependent doesn't not equal regionally dependent.
"More evidence would be that the northern hemisphere, which was generally more industrialized then the southern hemisphere, would cool faster if the cooling was due to sulfur emissions. By looking at the temperature trends of the northern and southern hemispheres, we can see that this is not the case." epidexipteryx
There was also increased industrial activity in the northern hemisphere that could have heated the northern hemisphere unevenly. Also, the word "downwind" is in your quote, perhaps the southern hemisphere was downwind from the northern hemisphere.
"Overall, sulfur could not be responsible for the cooling mid century because sulfur only causes regional cooling and the area that we would expect to cool faster did not." epidexipteryx
Somewhat regional cooling, as opposed to only causing regional cooling. One more note your, last source is a graph with tempatures. Yet, this graph does not tell us where the tempature is being measured. For example is the upper atomsphere, lower atomsphere, land, ocean surface, deep ocean, or a mean of all these. Without knowing where the tempature is being measured I can only assume that you cherry picked the data.  Please use scholarly peer reviewed sources to make sure your data is credible, accurate, and impacts the resolution.
Btw I couldn't get the http://a-sceptical-mind.com... link to load.
I have used a peer reviewed source that is in contradiction of your statements. When the debaters cannot agree on the facts, the side with the more credible sources win. Voters give me the source points at the very least. Thanks for debating.
My opponent then says that the southern hemisphere may be downwind of the northern hemisphere but this is speculation and in the link I provided, NASA gave the example of regional cooling as measuring a smokestack from a ship. The most significant cooling was at the smokestack and then as the sulfur aerosols were blown away the cooling became less significant.
My opponent then attacks my last graph saying it is not from a peer reviewed article. While it is not from an article, it is from NASA which is peer reviewed.
To answer my opponents question, according to Geophysics Fluid Dynamics Laboratory, the graph shows the annual mean surface temperature data from the northern and southern hemispheres.
My opponent says, " When the debaters cannot agree on the facts, the side with the more credible sources win" yet this is just untrue. If two debaters disagree on facts the side with the better argument wins, whether the other side has been convinced or not. The sources only matter if one side is using false information or sketchy websites that may have incorrect data. If you cant prove that the sources data is incorrect or manipulated then sources should have very little effect on the argument.
Overall, I have shown that sulfate aerosols cannot be responsible for a global cooling event. I have described how the sulfate aerosols have a larger effect in the area they were released and how the data from the northern and southern hemispheres do not support the idea of sulfur caused warming. While my opponent uses no evidence to rebut my claims and resorts to attacking sources, I have shown beyond a doubt that sulfur caused cooling is not global and therefore did not cause the mid century cooling period.
"To answer my opponents question, according to Geophysics Fluid Dynamics Laboratory, the graph shows the annual mean surface temperature data from the northern and southern hemispheres." epidexipteryx
The above is the weak point in my opponent's argument. My opponent has not shown that surface tempatures are a reliable way to determine global cooling. Therefore, my opponent's argument can be dismissed as a red herring and as a cherry picking fallacy.
Considering that my peer reviewed article contradicts my opponent's premise while proving my own I have met my burden of proof and should win the debate. I recommend that my opponent stick to peer reviewed journals. My opponent has taken a graph and put his/her own interpretation on the graph.
Thanks for debating.
1. The whole globe is cooling (definition of global: of or relating to the whole world; worldwide) The surface is part of the whole world so you would expect it to cool
2. The way sulfur causes cooling is by altering the albedo (reflectivity) of a planet. This means that the sunlight is reflected back into space preventing it from reaching the surface and warming it. In fact, you would expect to see the most cooling at the surface of the planet.
How sulfur causes cooling: http://earthobservatory.nasa.gov...
Now I have proven that sulfur caused cooling would be severe on the surface. This goes back to my graph showing how the northern hemisphere warmed slower then the southern (on the surface) indicating a non-sulfur caused cooling effect for the northern hemisphere is more industrialized and if sulfur caused cooling is regional you would expect the most cooling there.
Sulfur cooling is regional: https://www.nasa.gov...
My opponent, yet again, resorts to attacking sources to try and win the debate. They point out that they have used peer reviewed articles that contradict my arguments and that I have not. The problems with this are:
1. My opponents articles don't contradict my arguments. The only article that is relevant to atmospheric aerosols is this:
and it doesn't even address one of my claims nor does it even explain how the mid century cooling period was due to aerosols.
2. All of my sulfate aerosol related links are from NASA which is peer reviewed and trustworthy so my opponents claims of me using untrustworthy sources is false
In conclusion, my opponent has given up this debate for he resorts to calling my data cherry picking instead of disclaiming it (even though it is not cherry picking as I explained above you would expect the surface to cool from sulfate aerosols). My opponent has run out of arguments and again tries to attack my sources instead of properly debating my claims. My opponent has not proven anything because I have disproven all of their claims while all of mine go untouched. While this debate was fun, I expected more from my opponent and was disappointed by their "arguments".
Thank you for reading
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