Originally posted by Shuckins
Lukster's graph showing the Vostok Ice Core Temperature Differences over the last 200,000 years point out a couple of interesting facts.
It also shows that warming cycle occurs about every 100,000 years (which BTW is believed to be caused by changes in the earth's orbit), which is about right if you compare the data which goes back further, but the present warming is happening just mere 10,000 years after last cooling period.
So, why is it out of whack so suddenly? Just a short term spike? There have been local variations like Little Ice Age and others, but today warming is global.
I got my hands on Pentagon global warming study and those guys deffinately aren't pro environment. Their main concern is melting ice cap which is important for subs operations. Their conclusion is that north ice cap is shrinking at accelerated rate due to increased surface air and water temps and cause of the increase are greenhouse gases.
The main contributor to greenhouse effect is water vapor, which represents about 3/4 of all greenhouse contributors. CO2 is next with share of about 1/6, followed by ozone and all others.
The fact is, we can not directly influence amount of water vapor, but we can influence it indirectly with controlling the levels of CO2, which is next in the line of.
Increase in CO2 can rise the temperature which will cause creation of more water vapor which again will rice temperature which will create even more water vapor, etc.
Ice core samples show amount of CO2 being pretty stable over the last 10,000 years and its medium was about 270ppm with spikes to about 300ppm.
Those levels have increased to todays value of 380ppm since beginning of industrial age, with 90% of increase after WW2.
In the recent past (million years ago until present), spikes in CO2 levels were mainly due to volcanic activity.
Today, burning of fosil fuels alone releases about 6 billion tons of CO2 per year, in comparison, volcanos release 200 million tons per year.
To argue about existance of warming and its causes is silly. Plenty of hard data.
To argue about what can we do is also silly. We won't do anything, it's human nature, besides, whatever we can do, wouldn't be nearly enough to reverse the warming, the best you could hope for is just a slowdown.
With current climate models, real drama starts sometime after year 2100. I'll be long gone til then...