Global Warming 101 - Part I

Human-induced global warming is taking the planet into a zone of no return.  The scientific evidence is overwhelming.  The only questions now are: how bad will the damage be, when will it come, and what can we do to mitigate it?

So what exactly is happening with atmospheric greenhouse gases and why should it be of concern?  The three most prevalent greenhouse gases are water vapor, carbon dioxide and methane.  Water vapor comes and goes quickly.  It's in the atmosphere for a matter of days before condensing into rain or snow.   Methane lasts 10-15 years breaking down in time to water vapor and carbon dioxide.  A good portion of the carbon dioxide is removed naturally by being absorbed in plants and forests and dissolved in oceans and lakes. However, what carbon dioxide cannot be removed persists in the atmosphere for hundreds of  years.  And that is the heart of the problem.

Before the start of the fossil-fueled Industrial Revolution, the Earth was more or less in carbon dioxide "balance".  What was being emitted by natural sources was being absorbed by natural "sinks" such as plants and oceans. As we burned more and more fossil fuels and simultaneously cleared forests and jungles for development, we created an imbalance.  Prior to 1750, CO2 levels (determined from ice core samples) held at 260-280 parts per million (ppm) for the previous 10,000 years.  The July 2011 reading at the Mauna Lua (Hawaii) Earth System Research Laboratory was 392 ppm - an increase of 30-35%.  Coincidence?  I think not. 

These atmospheric levels of carbon dioxide have not been seen for at least 650,000 years according to a 2008 report.  The same report also noted that the rate at which carbon dioxide is accumulating is faster than had been estimated by the computer models.  Scientists at UCLA then applied the ice core sampling technique to study the period from 800,000 to 20 million years ago. Science Daily reported on the research in a 2009 article.  The researchers concluded that the last time carbon dioxide was sustained at this level for a long period was 15 million years ago.  Temperatures back then were 5 to 10 degrees Fahrenheit warmer than today.  This would result, among other things, in a melting of the polar ice caps, a dramatic rise in the level of the oceans, and the complete destruction of sea level cities globally - from New York to London to Singapore. And that's the good news...some scientists believe the carbon dioxide levels will rise to 600-900 ppm if nothing is done now to reverse the disturbing trend. 

(to be continued)