Global Warming is Happening!

My opponent failed to respond to my arguments in ROUND 2. Though I was expecting a lively debate, I totally understand his position. It's difficult to argue with a variety of scientific evidence - collected and evaluated by renown global institutions - that point to the same conclusion: global warming is happening, and it is gradually alterning life on this planet.In ROUNDS 1 and 2 I presented evidence, collected by various atmospheric-, geographic-, and oceanic-researching institutions, that demonstrates the Earth's surface temperatures are increasing, that ocean sea levels are rising, that land and sea ice are disappearing. Now I will show the human connection to global warming. I will demonstrate that, since the boom of the industrial revolution, humans have increased the concentration of carbon dioxide - a heat-trapping green house gas - in the atmosphere, to levels never reached before on Earth in the last 400,000 years! I will also show that, historically, whenever CO2 levels have risen in the Earth's atmosphere, it has typically been accompanied with a global warming spell - and that this link between warming and elevated CO2 levels is the current model used by climatologists to explain many prehistoric warming ages.Let's begin.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 [1]. Presently scientists have no other plausible model to explain how the atmosphere was able to maintain warmth while the Earth froze [2]. 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 [3] [4]. The increasing concentration of CO2 is considered the chief reason why the atmosphere warmed so rapidly during PETM [5] [6]. Ice core analysis also attributes the end of the last ice age to an increase in atmospheric CO2 levels[7].That carbon dioxide is a heat-trapping greenhouse gas is sound; its heat-trapping effects have been studied in laboratories throughout the world [8]. Its contribution to prehistoric global warming has long been understood, even before the concept of man-made global warming entered the imagination [9].But with the boom of the industrial revolution, which continues to expand into and dominate new countries on a yearly basis, human-induced global warming - through such actions as the burning of fossil fuels and deforestation - has led to an unprecendented increase in CO2 concentrations. Never in the last 400,000 years has the CO2 concentration been quite so high. As I reported in ROUND 1, ice core analysis shows that in the last half-million years the peak concentration of CO2 was almost 300 parts per million - and that was 300,000 years ago [10]. Today the concentration of atmospheric CO2 is 396 parts per million! Nearly 33% higher than it has ever been in the last half-million years [11]!Nine in 10 scientists agree that human activity is responsible for today's global warming trend [12].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 [13]. In fact, the USGS takes the position that erupting volcanoes typically emit gases that are more likely to lead to global cooling[14]! The USGS asserts that CO2 emission by human activity dwarfs the output of CO2 by all volcanoes worldwide [15].[1] [2] http://news.softpedia.com...[3] [5] http://en.wikipedia.org...[4] [6] http://smithsonianscience.org...[7] http://www.livescience.com...[8] http://en.wikipedia.org...[9] http://en.wikipedia.org...[10] [11] http://climate.nasa.gov...[12] see Round 1[13] [14] [15] http://volcanoes.usgs.gov...