All sides of this issue accept that humankind has some input into the current global warming scenario on this planet. The issue is just what percentage of this climate change is mankind responsible for? For example, if it is 5% then in reality we have had such little effect as to render our input meaningless, if it is 50% the we have made a major and dangerous contribution to this phenomena.
Hillary:
Just a note that the issue you raised needs to be clarified about human involvement. In what way do you mean, CO2 contributions or the fact that we are here as an integral part of an ecosystem? Even the excrement from 6 billion people will produce greenhouse gases such as methane and CO2.
As far as CO2 is concerned we represent 0.78- 0.98 % of the total CO2 on our planet. We generate 6.5 Gt annually to a total of 750 Gt (+/- 10% or 75 Gt). Other natural contributors of CO2 such as off gassing oceans, volcanic venting etc is approximately 200 Gt per year. We represent about 3% of that total.
At the same time the amount of CO2 as high as it may seem is actually stable as the earth has been undergoing a greening period over the last 40 years, partly due to mans agricultural endeavors as well as conservation policies. 1992 was flat line CO2 levels and 1998 saw a decrease even though it was the hottest year in the last decade.
So according to your 50% comment we are not even close, and being lower than the 5% contributor you suggest, the levels of <1% and 3% depending on what perspective you look at (either the total global amount or total global annual output from natural sources) makes our role in CO2 levels very small.
But as I have tried to show CO2 is not related to rising temperature (at least as a forcing) nor is it a large component of what are called Greenhouse gases either. (I believe less than 3% is CO2, so if Greenhouse gas is behind Global Warming then our <1% of that 3% is minuscule)
In fact water vapour is one of the largest components of Greenhouse gas at 30%. If we are contributing to that percentage then the cry should be against taking hot showers, wave pulls at water parks or those water misiting systems at outdoor malls in the summer time! Can you see the protests now!
None of the 'global warming hysteria' contributors who have laid down the challenge on this thread have provided any scientific evidence that indicates that mankind’s input into the global warming scenario is actually negligible,
Ok here goes:
On global forces of nature driving the Earth’s climate. Are humans involved?
L. F. Khilyuk1 and G. V. Chilingar1
Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089, USAAbstract The authors identify and describe the following global forces of nature driving the Earth’s climate: (1) solar radiation as a dominant external energy supplier to the Earth, (2) outgassing as a major supplier of gases to the World Ocean and the atmosphere, and, possibly, (3) microbial activities generating and consuming atmospheric gases at the interface of lithosphere and atmosphere. The writers provide quantitative estimates of the scope and extent of their corresponding effects on the Earth’s climate. Quantitative comparison of the scope and extent of the forces of nature and anthropogenic influences on the Earth’s climate is especially important at the time of broad-scale public debates on current global warming. The writers show that the human-induced climatic changes are negligible.
Likewise there are numerous studies that point to increases in global CO2 levels and even a warmer climate in general being positive in nature even desirable! See posting on page 5 of this thread.
Global Warming is the issue of the day that effects us all, it is a natural cycle taking place which we will just have to learn to survive as best as we can and that man's input into the problem is far less than is being touted in some quarters. On a geologic timescale, which takes place over hundreds of thousands of years, what is happening is not unusual, though even the little that mankind is contributing to the problem is not helping the situation.
First part is partly true (but there are many more serious issues than this issue which amounts to a tempest in a tea pot) although that idea that "natural cycles" are backed up by science is very unpopular with fundy's who believe that God placed us here on the perfect earth 6000 years ago.
When confronted with two ideas, such as Science on one hand pointing to a geological history of 100's of millions of years consisting of upheaval after catastrophe, warming periods followed by extreme cold and Ice Age after Ice Age, and the other being Apocalyptic expectation that confirm their superstitions, the resulting hysteria is what we see happening. We all like a good conspiracy and this one is as good as any. That is what I see through all of this.
We will see change in the future and some of that will be catastrophic in nature as our planets history proves. We will either adapt and survive or perish. The only thing we can do in the mean time is make the best of our time here and our place in the biosphere. That means taking better care of natural resources, managing forests, wildlife and our oceans and being more responsible in practical ways to make the best of our time as species here.
Frank75