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Global Warming is Real and is Manmade!

In ROUND 3 I will continue my ROUND 2 response, where I will show the link between carbon dioxide emitted by human activity and the increase in global surface temperatures. In the final ROUND I will go over the effects of climate change caused by global warming. Carbon Dioxide (and Other Green House Gases) are Causing Global Warming and Climate Change With the advent of the industrial revolution, human-induced global warming--through such actions as the burning of fossil fuels and deforestation--has led to an unprecendented increase in CO2 concentrations and other green house gases [1][2]. However, climate scientists overwhelmingly pin the blame of global warming on carbon dioxide because it is the most widely and most abundantly emitted green house gas of human activity [3]. According to the Intergovernmental Panel on Climate Change (IPCC), carbon dioxide and methane are responsible for more than 84% of the warming being inflicted on our planet because of green house gases [3]. The remaining percent of warming can be attributed to green house gases like nitrous oxide and flourinated gases [3]. By itself, the IPCC has affirmed that carbon dioxide is reponsible for 54.7% of the global warming caused by green house gases; that's because it is the most abundantly produced green house gas of human activity and because it has an enormous radiative impact compared to other green house gases when accounting for its abundance in the atmosphere, its indirect heating effects, and because of the CO2 molecule's long lifetime in the atmosphere [3][4]. In fact, only water vapor has a stronger green house gas effect than carbon dioxide in our atmosphere, but unlike CO2 water vapor isn't being emitted naturally by any known source at a large enough scale to be blamed for global warming [4]; water vapor does contribute to global warming, but this is because of a feedback loop caused as other green house gasses in our atmosphere increase in concentration and heat up the Earth's lower atmosphere [5]. As the Earth's atmosphere and surface become warmer because of green house gas emissions, this drive's more water vapor to be absorbed into the air, further heating our planet; this water vapor loop is well-understood and contributes to anthropogenic (human induced) global warming [5]. However, other green house gases emitted by human activity drive this loop and are primarily responsible for global warming. As the statistic above shows, carbon dioxide is responsible for 54.7% of the warming being inflicted on our planet because of human activity. As I demonstrated with the graph on carbon dioxide concentration in our atmosphere in ROUND 2 (and as I reported in ROUND 1), never in the last 400,000 years has the CO2 concentration been quite so high as it is today! Ice core analysis shows that in the last half-million years the peak concentration (the highest concentration) of CO2 was almost 300 parts per million--and that was 300,000 years ago [1]. Today the concentration of atmospheric CO2 is 398 parts per million! Nearly 33% higher than it has ever been in the last half-million years [1]! This unprecedented increase in atmospheric carbon dioxide can be attributed almost entirely to human activity, such as through large-scale deforestation, land use changes (such as methane emission from ammonia-based fertilizers), and the burning fossil fuels (which include coal and gasoline) [2]. The IPCC reports that in the last 150 years, human activity has increased atmospheric carbon dioxide levels from 280 parts per million to 398 parts per million today [2]! According to the United States Environment Protection Agency (EPA), humans largely emit carbon dioxide and other green house gases from the production of electricity and from transportation; in the U.S. these two behaviors contribute to 60.8% of all the nation's emitted green house gases in a single year [3]. Other behaviors, such as those of industry, businesses, of agricultural, and of energy use in homes, contribute to the remaining 39% of the nation's green house gas emissions [3]. Global warming is produced when green house gases in the atmosphere--water vapor, carbon dioxide, methane, nitrous oxide--accumulate in the atmosphere and act as a thermal blanket for the Earth, absorbing the sun's radiative heat and warming the Earth's surface [2]. Nature uses green house gases to facilitate heat trapping from the sun's rays to warm the Earth and make biological life on the planet possible. But if the concentrations of green house gases in the atmosphere become excessive, this can overheat the planet, alter the Earth's climate system, injure natural ecosystems, and make it harder for biological processes to take place and be maintained. This is exactly what's happening now and generating planet-altering climate change (these effects will be explicated in the final ROUND). Volcanes and Changes in the Sun's Solar Output are Not Contributing to Global Warming Some skeptics claim that erupting land and submarine volcanoes are causing global warming. But reports by the U.S. Geological Survey (USGS) shows that volcanoes primarily emit gases, like sulfur dioxide, at high enough concentrations so as to encourage global cooling [6]. In fact, the USGS takes the position that erupting volcanoes typically emit gases that are more likely to lead to global cooling[6]! The USGS asserts that CO2 emission by human activity dwarfs the output of CO2 by all volcanoes worldwide [6]. Some opponents of manmade global warming claim that the Sun's solar output is responsible for the current rise in atmospheric temperatures--that humans are not responsible for the modern warming trend. But this is a view that the scientists firmly dispute, based on a variety of evidence (2): --Scientists point out that, since 1750, the average amount of energy coming from the sun either remained constant or increased only slightly. --If the warming were caused by increased radiation coming from the sun, then scientists would expect to see warmer temperatures in all layers of the atmosphere. Instead what they observe is a cooling in the upper atmosphere, and a warming at the surface and in the lower parts of the atmosphere. Scientists say that this is a strong indication that green house gases are responsible for global warming, because they trap heat in the lower atmosphere. --Computer climate models that include solar irradiance changes can't reproduce the observed temperature trend over the past century or more without including a rise in green house gases. All of these bits evidence demonstrate that solar irradiance is not responsible for the rise in Earth's surface temperatures over the last century or more. Elevations in Atmospheric Carbon Dioxide Concentrations have been responsible for Prehistoric Rises in Global Surface Temperatures Scientists that study prehistoric ice ages and warming ages point out that carbon dioxide released into the atmosphere by geologic activity or other natural events has consistently led to warming trends in Earth's history. For example, the Ice Age that stretched during most of the Cryogenian Period (840 - 635 million years ago) had the potential to cover the entire globe and would have been a major setback for biological life and evolution in general had it been this severe. Scientists that study the period point out that this extreme condition never occured because, as the Earth froze, atmospheric oxygen was forced into the oceans, which oxidized organic matter and released CO2 into the atmosphere, preventing temperatures from falling any lower [7]. Presently scientists have no other plausible model to explain how the atmosphere was able to maintain warmth while the Earth froze [7]. Scientists also point out that a rise in atmospheric CO2 concentrations have led to prehistoric Warming Ages. 55 million years ago, the Earth entered a sudden and rapid global warming event, which scientists call the the Paleocene-Eocene Thermal Maximum (PETM). Analysis firmly demonstrates that the quantity of carbon and carbon dioxide in the atmosphere rose significantly at the beginning of this period [8] [9]. The increasing concentration of CO2 is considered the chief reason why the atmosphere warmed so rapidly during PETM [8] [9]. Ice core analysis also attributes the end of the last ice age to an increase in atmospheric CO2 levels[10]. That carbon dioxide is a heat-trapping greenhouse gas is sound; its heat-trapping effects have been studied in laboratories throughout the world. Its contribution to prehistoric global warming has long been understood, even before the concept of man-made global warming entered the imagination [11]. [1] (http://climate.nasa.gov...) [2] (http://climate.nasa.gov...) [3] (http://www.epa.gov...) [4] (http://en.wikipedia.org...) [5] (http://www.nasa.gov...) [6] (http://volcanoes.usgs.gov...) [7] (http://news.softpedia.com...) [8] (http://en.wikipedia.org...) [9] (http://smithsonianscience.org...) [10] (http://www.livescience.com...) [11] (http://en.wikipedia.org...)