| Timmah! said: HUMANS PUT OUT 0.28% OF THE TOTAL GREENHOUSE EMISSIONS ON THE PLANET!!!!! To focus on that minescule output and say it is CAUSING global warming is pure fantasy. |
First, where did you get your numbers from? EDIT: Just looked up the 2nd page of this thread and realised you were using Monte Hieb's personal webpage as reference. Since there was no mention of source for the claim in his page, I ask you to find one yourself. In addition, I wouldn't call water vapour "emissions" (neither does Hieb). Water vapour is a major greenhouse gas, but it works quite differently from CO2 because of its short residece time in the atmosphere. It's rather feedback than forcing, contributing 36-90% of the greenhouse effect, depending on area and the changes in moisture.
When talking about emissions (people see that as a increase in forcing), it's rather misinforming to include the greenhouse gases from the natural cycle (decomposing leaves etc.) to the nature's effect. The problem is that we're adding CO2 outside of the natural cycle. That is the only way the CO2 in the atmosphere keeps cumulating. Biological processes are unable to raise the CO2 level purely by themselves. Volcanoes do emit CO2 outside of natural cycle too, but we have surpassed them long ago in emissions. The CO2 of man vs. volcanoes is something like 100:1. Methane and other gases are important too, but I'm trying to keep this short.
The CO2 levels have risen 30% in the past 100 years, and according to isotope analysis of the substance, humans are to blame for that addition.
It's a physical fact that CO2 is a greenhouse gas. The infrared radiation absorption qualities of CO2 have been measured in laboratory conditions several times. This is what the focus on this debate should be about. According to satellite measurements of the spectrum of the outgoing radiation, greenhouse effect has gotten stronger (which is predicted on the basis of the CO2 knowledge): http://www.nature.com/nature/journal/v410/n6826/abs/410355a0.html
"We find differences in the spectra that point to long-term changes in atmospheric CH4, CO2 and O3 as well as CFC-11 and CFC-12. Our results provide direct experimental evidence for a significant increase in the Earth's greenhouse effect that is consistent with concerns over radiative forcing of climate."
...and so the facts are: 1) CO2 is a greenhouse gas (climate sensitivity about 2.5 C), 2) CO2 levels have risen 30% in the past 100 years due to human activity, 3) greenhouse phenomenon has amplified
Agree?
| Timmah! said: Historically, warm periods with higher CO2 levels lead to a better, greener planet (plants like balmy temperatures and CO2), while cooler periods are called ice ages and are commonly associated with mass extintions, famine, etc. |
To my knowledge there were huge deserts in the times when CO2 levels and temperature were high. IIRC, up to 90% of the land area was deserted in the pre-dinosaur times.
