Climate Change for Dummies.

     With regard to climate change: Since 1978, output from the Sun has been precisely measured by satellites. These measurements indicate that the Sun's output has not increased since 1978, so the warming during the past 30 years cannot be attributed to an increase in solar energy reaching the Earth.

     In another area, however variations in the earth's orbit over long periods have been shown to contribute to changes in average temperatures. The problem when considering this contributor to climate change (it works both ways) is that, while orbital cycles vary slowly over tens of thousands of years, they at present are in an overall cooling trend which would be expected to lead towards a glacial period within the current ice age, but the 20th century instrumental temperature record shows a sudden rise in global temperatures. This would imply that other contributory causes  are causing warming at a rate which offsets the cooling  expected if orbital cycles were sole determinants of global temperature change.  

     A third area for consideration which should also, if a sole contributor, cause a decrease in overall global temperatures is concentration of atmospheric particulates such as volcanic ash, soot, and other man made pollutants. This phenomenon is sometimes referred to as "global dimming," since the effect is to allow less solar radiation through the atmosphere.

    The problem with global dimming is that it is also largely man made, but the atmospheric contaminants are hazardous to human life. One need only look at Beijing's constant state of smoggy haze and a population forced to wear respiratory protection to see the problem. This does not take into account long term effects of carbon combustion such as the litany of carcinogens produced by burning coal. While in the US, stack scrubbers and better burning have seriously reduced stack pollutants (and, therefore acid rain and carcinogens), China is more than making up for it, with 2014 Beijing's atmosphere reminiscent of London's worst period during the industrial revolution or Pittsburgh's in 1900!

   Those products of combustion which become wet particulates and contribute to dimming have a half life in the atmosphere - that time required for half of a given quantity to be "washed out" of about a week and a half. Unfortunately, the invisible by-product of the same combustion which produces these particulates in either man made (stack gasses) or natural (volcanic) processes is carbon dioxide.  Unlike all the other causes, carbon dioxide is strictly a product of man's burning  of fuels which produce it as an unwanted by-product. Unlike the other causes which might actually result in global cooling, CO2  trapped in the atmosphere causes increased retention of the heat caused by solar radiation. This balance is already unbelievably fine, and its precision is one of the key reasons why life as we know it exists on  earth and nowhere else in the solar system.  Solar radiation at the frequencies of visible light largely passes through the atmosphere to warm the planetary surface. How much of this energy is retained is the key.

     Unfortunately, as this solar radiation is absorbed by various things on earth, its wavelength becomes longer (or frequency becomes less, and its energy reduced, same thing).  This reflected energy is emitted at these lower energy levels as  infrared thermal radiation and some (just enough, mind you if all is well) escapes back, maintaining the earth's mean temperature , as baby bear said, "just right."   Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection.

    Earth’s natural "greenhouse effect" makes life as we know it possible. If there were no greenhouse effect, we'd freeze, or rather more likely, life on earth would never have existed. However, human activities, primarily the burning of fossil fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming. The understanding of this is not new, or theoretical, as some on the far right (generally) would have you believe.  It was proposed 190 years ago by Joseph Fourier, shown to be real in 1860 by John Tyndall, was first quantitatively  investigated  by Svante Arrhenius in 1896, and was developed in the 1930s through 1960s by Guy Stewart Callendar.

     On earth, naturally occurring  greenhouse gases have an average  warming effect of about 59 °F.   Without the Earth's atmosphere, the temperature across almost the entire surface of the Earth would be below freezing. The major greenhouse gases are water vapor, which causes about 36–70% of the greenhouse effect; carbon dioxide (CO2), which causes 9–26%; methane (CH4), which causes 4–9%; and ozone (O3), which causes 3–7%.  

     Human activity, since the Industrial Revolution led to a huge increase in the use of fossil fuels for production, has increased the amount of greenhouse gases in the atmosphere, leading to increased levels of   CO2, methane, tropospheric ozone, CFCs and nitrous oxide. According to one study completed in 2007,  the concentrations of CO2 and methane have increased by 36% and 148% respectively since 1750.  These levels are much higher than at any time during the last 800,000 years. We know or can determine this because ice cores taken  from glacier borings  can show us snapshots of climate conditions at a given time in the past back a considerable distance. There is absolutely no disputing that fossil fuel burning has produced about three-quarters of the increase in CO2 from human activity over the past 20 years. The rest of this increase is caused mostly by changes in land-use, particularly deforestation, since trees, which absorb CO2 and emit Oxygen, are an integral part of the cycle. )  "It's the Circle of Life"

     Methane increases since 1750 reflect the huge increase in beef and dairy production over that period, since cattle are essentially methane generators, as are pigs to a lesser extent. Cows eat grass, fart methane - a lot!

      Estimates of global CO2 emissions in 2011 from fossil fuel combustion, including cement production and gas flaring, was 34.8 billion tons,  an increase of 54% above emissions in 1990. Coal burning was responsible for 43% of the total emissions, oil 34%, gas 18%, cement 4.9% and gas flaring 0.7% In May 2013, it was reported that readings for CO2 taken at the world's primary benchmark site in Mauna Loa surpassed 400 ppm. According to professor Brian Hoskins, this is likely the first time CO2 levels have been this high for about 4.5 million years.!

     Over the last three decades of the 20th century, gross domestic product per capita and population growth were the main drivers of increases in greenhouse gas emissions. CO2 emissions are continuing to rise due to the burning of fossil fuels and land-use change.  Emissions can be attributed to different regions, e.g., see the figure opposite. Attribution of emissions due to land-use change is a controversial issue.

     As I earlier pointed out, the particulate by products of combustion last in the atmosphere at a "half life of about 10-11 days.  Unfortunately the CO2 produced by these same processes lasts about 100 years! The implication being that even if man stops using fossil fuels now, it will be quite a while until its effects are diminished.

      So what of the future?   Emissions scenarios, estimates of changes in future emission levels of greenhouse gases, have been projected that depend upon uncertain economic, sociological, technological, and natural developments. In most scenarios, emissions continue to rise over the century, while in a few, emissions are reduced.  Fossil fuel reserves are abundant, and will not limit carbon emissions in the 21st century. Emission scenarios,  have been used to produce estimates of how atmospheric concentrations of greenhouse gases might change in the future. Using six "marker" scenarios (contributors weighted per their impact on CO2 formation, retention and deletion), models suggest that by the year 2100, the atmospheric concentration of CO2 could range between 541 and 970 ppm. This is 90–250% above the concentration in the year 1750!

    The popular media and the public often confuse global warming with ozone depletion, i.e., the destruction of stratospheric ozone by chlorofluorocarbons. Although there are a few areas of linkage, the relationship between the two is not strong.  Ozone depletion allows more dangerous Ultra-violet (high frequency, short wavelength, high energy) solar radiation in through the atmosphere, resulting in greater damage to humans by the sun in some areas, "Oz", for example. Unfortunately, the "hole in the Ozone layer" doesn't let much infra-red, the other end of the radiation energy scale, out, since CFC's don't deplete greenhouse gasses like CO2 and Methane.

     So: why is there even any discussion regarding this phenomenon, let alone deniers claiming that it's all some "Liberal invention?" I think perhaps the answer to that lies in four places.

    First is the fact that Global warming is slow and invisible to the vast majority of people on the planet. Relatively few humans witness polar bears unable to go to sea until a month after they used to be able to do so. Even fewer measure glacial recession.  Only scientists analyze atmospheric conditions over time  and many Americans (especially) are dismally ignorant when it comes to understanding Science and its role in society, unless it has  an immediate impact on their lives, like the Salk vaccine, Lasik surgery,  bariatric gastric reduction  or the "Lifestyle Lift."

     Second is the fact that taking steps on an individual level to reduce greenhouse emissions seems like an inconsequential thing, not to mention a damned nuisance. Why, Hell, I might even have to trade the Hummer for a Prius! Take the train and leave the car home, surely you jest! Next thing they'll (it's always "they," isn't it) make me use different light bulbs. A corollary to that is that while there are alternate energy sources (and we will have energy, how else can I use Facebook?) , they are relatively expensive, have a very long payback time and are just, well, just a pain in the ass; I mean,  who's got time to set up a windmill or put solar cells on the roof, anyway?  

     

     Which leaves us with the third and perhaps most significant real reason, so well outlined by my dear nephew. John,  earlier - money! Not our money, spent to conserve or use alternate energy sources, but the incredible wealth represented by the Energy industry fat cats  who seem to have an attitude of "Fiddle dee-dee,  I'll worry about that tomorrow." If there is no financial incentive for the energy industry to look elsewhere for alternate power sources which don't effect the greenhouse gas inventory, then they simply won't. These companies will wait until the last barrel of oil has been pumped and their coffers filled, and then say "Don't blame us. you all bought it, even when it costs $10 per gallon."    

     A great example is the current enthusiasm for fracking, which is now being shown to cause quakes in hitherto quake free Ohio, as well as in some areas resulting in citizens having natural gas issue from their kitchen sink taps. No mind, though, Rep. Joe Barton (R-TX), chairman emeritus of the House Committee on Energy and Commerce, received the most contributions from the fracking industry, raking in $509,447 between the 2004 and 2012 election cycles — over $100,000 more than the next closest recipient, Senate Minority Leader Mitch McConnell (R-KY), who received $384,700. While serving as chairman of the committee, Rep. Barton sponsored the Energy Policy Act of 2005, which exempted fracking from the Safe Drinking Water Act. Overall, nearly 80 percent of fracking industry contributions went to Republican congressional candidates.

   As long as supporting the continued dependence on fossil fuels is this profitable for politicians (of both parties, the energy industry is an equal opportunity briber), Global warming will be real and worsening. Science denying conservatives will be the last to truly see the disastrous results, since it's already warm and moist where they have their collective heads!

     Finally, and most pathetic are the true believers for who the meaning of Global Warming, if real, would be that we humans have the power to degrade something that "God made." At some level this must be the huge denial factor for these zealots, since we see the Palin, Bachmann, Perry camps all waving the "It ain't so" banner. One wonders what Neanderthals believed they had done to piss off their particular supernatural sky-God and precipitate the last ice age. Modern Neanderthals (including a fair number of members of Congress, sucking up to their fundamentalist voter bloc) have the same attitude. Science is not anti-religious. It isn't "anti" anything.  That perspective belongs to persons of the same caliber as those who persecuted Galileo, burned "witches", and drank the Kool -Aid at Jonestown.