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Global Warming is Real and is Manmade!

In this ROUND--the final ROUND--I will explain what it is about carbon dioxide, water vapor, and methane that allow them to be heat-trapping greenhouse gases. I will also briefly explain how global warming facilitates climate change and then go over the various effects of climate change that are occurring because of rising surface temperatures. Carbon Dioxide (and other Green House Gases) Generate the Greenhouse Effect by Absorbing and Emiting Infrared Radiation (a.k.a. Heat) Atoms and molecules can absorb electromagnetic radiation, but only at certain energies (wavelengths) [1]. The electromagnetic spectrum is illustrated directly below. When the sun emits energy it principally does so in the form of electromagnetic radiation. Our human eyes can only detect radiation between 300 and 800 nanometers in wavelength (1 billion nanometers = 1 meter); this is called the "visible portion" of the spectrum [1]. Radiation of a different wavelength can also be detected, but not visibly by our eyes. Radiation that falls between 700 nanometers to 1 millimeter is infrared radiation, and it can be detected indirectly as heat, or the vibrational-rotational movements of molecules [2]. (Other wavelengths of the electromagnetic spectrum also contribute to heat.) Carbon dioxide (illustrated below) is special because it absorbs and emits electromagnetic radiation in the infrared portion of the spectrum [3]; this means that it has an inclination to trap heat radiation coming both from the sun and bouncing off the Earth's surface [1]. Because CO2 absorbs heat radiation (which is a form of energy), that means the molecule will rotate and vibrate fiercely to contribute to heating (kinetic motion) and the greenhouse gas effect [1]. CO2 absorbs infrared "heat" radiation at 4.26 micrometers and 15.0 micrometer wavelengths; this causes the molecule to vibrate in several possible ways (illustrated directly below) [1]. When the molecule absorbs a photon of radiation at 4.26 micrometers wavelength, this causes it stretch either symmetrically (A in the picture above) or asymmetrically (B); when it absorbs a photon of radiation at 15.0 micrometers wavelength, this causes it to undergo one of two bending vibrations (C or D) [1]. It's this molecular phenomena that contributes to the greenhouse gas effect and to gradual global warming, as carbon dioxide and other other green house gases increase in concentration in the atmosphere [1][3]. Water vapor, methane and other greenhouse gases have identical methods of trapping heat [3]. Even though there are a variety of natural "sinks" to take up carbon dioxide and remove it from the atmosphere, the molecule continues to accumulate because of human activity and is forcing the current global warming trend [3][4]. Carbon dioxide is regarded as the fiercest driver of global warming because it is the most emitted green house gas by human activity and because it remains in the atmosphere far longer than the other major global warming gases [4]. Where it takes methane a decade to leave the atmosphere (unfortunately it converts to carbon dioxide), it takes carbon dioxide about a century to exit the atmosphere, though 20% of what is emitted will remain 800 years from now [4]. Water vapor on the other hand only stays in the atmosphere for a couple of days before it falls to Earth; this is why it's rarely discussed as a driver of global warming [4]. The Link Between Global Warming and Climate Change Rising global temperatures caused by human activity are having a drastic impact on physical and biological processes across the Earth. Besides those effects I went over in ROUND 2, there are numerous other consequences that are occurring as a result of global warming. Increasing global temperatures are causing polar sea ice and worldwide land ice to melt, which is causing oceanic sea levels to rise and coastal land to disappear. But global warming is having other adverse effects on the globe too, which includes alterations to the Earth's climate systems, changes in bird migration, greater intensity in forest fires, and a reduction in local freshwater supplies throughout the planet. According to two recent independent studies--one conducted by NASA in collaboration with the University of California, Irvine and the other by the University of Washington--the rate of sea level rise is accelerating and the oceanic sea level should be expected to rise by as much as 10 feet within the next two centuries [5]. The reason for the acceleration, the researchers say, is because the West Antarctic ice sheet is melting and it now appears to be unstoppable. The source of the problem is that warmer water (generated by anthropogenic global warming) stirred by Antarctic winds is melting the underside of the ice sheet, which is causing it to retreat and become thinner over time [5]. A 10-foot rise in sea levels would force much of Southern Florida under water (picture below) and it would cause large swathes of New York city's densely populated areas to become swamped [5]; 20 percent of Los Angeles would also find itself under water [6]. Just recently, on March 20th, NASA announced that sea level rise is threatening most of its launch pads and multi-billion dollar complexes; currently the space agency is building sea walls and moving some buildings further inland to avoid the rising sea line [7]. As the picture directly below illustrates, global warming is altering physical and biological processes in numerous ways. Global warming is generating less snow and land ice, which is resulting in a reduced freshwater supply in numerous locations around the world (including the U.S.) [8]; it is also changing rain and snow patterns and resulting in stronger storms [9]. Scientists say this is because storms feed off of latent heat energy; extra heat in the atmosphere or in the oceans (generated by global warming) nourishes storms and strengthens them [9]. There is some speculation that global warming may be decreasing the frequency of storm systems, but there is also strong evidence that storms are becoming more severe and developing more rapidly than just a few decades ago [9][10]. Besides increasing global temperatures, the current manmade warming trend is also resulting in more heat waves, more frequent droughts and intensifying wildfires [11]. Says geoscientist Jonathan Overpeck at the University of Arizona: "The [recent] fires in [Southern] California and here in Arizona are a clear example of what happens as the Earth warms, particularly as the West warms, and the warming caused by humans is making fire season longer and longer with each decade. It's certainly an example of what we'll see more of in the future" [11]. Global warming is also making seas and oceans warmer, damaging natural coral reefs [12], and melting permafrost [13]. As global temperatures rise and the oceans get warmer and become more concentrated in carbon dioxide, natural corals erode which diminishes biodiversity in the planet's oceans; global warming poses a direct threat on the coral reefs surrounding Florida, Puerto Rico, and Hawaii [12]. Global warming and climate change are having a major effect on animal and plant life around the world. Researchers with NASA's Goddard Institute for Space Studies show that trees are now leafing earlier and that some species are retreating into higher latitudes as the Earth warms [13]. Among the alarming findings [13]: polar bears are seeing their numbers plummet and their sources of food become scare, which is causing them to resort to cannibalism; earlier breeding and migration of birds worldwide; earlier peak migration of Atlantic salmon; earlier spring flight of butterlies and mollusks in California; earlier breakup and later freezing dates in lake and river ice cover; marmots are emerging 38 days earlier in the Rockies; earlier egg-laying of birds; long-term changes within fish communities; earlier pollen release in some plant species; a rapid decline in the Emperor penguin population in Antarctica; long-term decline in krill stock in the Southern Oceans; rising plankton abudance in cooler ocean waters, the opposite in warmer waters. Global warming and climate change clearly has a large array of effects [13]. The effects on human life are numerous, but global warming is also currently transforming agricultural yields around the world; the picture below illustrates the long-term impact of global warming on agricultural output around the world [14]. [1] (http://www.wag.caltech.edu...) [2] (http://en.wikipedia.org...) [3] (http://en.wikipedia.org...) [4] (http://www.ucsusa.org...) [5] (http://www.thestreet.com...) [6] (http://www.businessinsider.com...) [7] (http://news.yahoo.com...) [8] (http://news.mongabay.com...) [9] (http://earthobservatory.nasa.gov...) [10] (http://www.accuweather.com...) [11] (http://news.yahoo.com...) [12] (http://www.nwf.org...) [13] (http://www.giss.nasa.gov...) [14] (http://www.imf.org...)