Hey Isybub- can I get a citation for that fact? I am almost positive that is false.
The fact is, you are just wrong here. I'll actually cite my work- http://news.mongabay.com/2011/1205-hanc ... human.html
In case you are unwilling to actually read that(it's only like 2 paragraphs), I'll sum it up. It says that a recent study by National Geoscience ( a scientific journal), confirms that human-produced emission has contributed to a .85 degrees celsius increase in GLOBAL temperatures.
Also, about the SO2 volcanic sulfur- Scoobywhru's facts are correct, and you guys are wrong to disregard his facts just because it might 'sound' outrageous. The same study that I mentioned before says that aerosols(the smoke from volcanoes included) have actually cooled global temperatures by .45 degrees celsius. That leaves about a .4 degree temperature rise in the past 50 years. Oh yea, forgot to mention, that rate is unseen before in the history of humankind- coincidence? No.
One more thing that you guys might not know about is a positive feedback mechanism that is natural in our environment. While sometimes useful, it can also be very bad.
Allow me to qoute renowned physicist Michio Kaku(you may have heard of him):
We could have a greenhouse effect that feeds on itself. For example, the melting of the tundra in the Arctic regions may release millions of tons of methane gas from rotting vegetation. Tundra covers nearly 9 million square miles of land in the Northern Hemisphere, containing vegetation frozen since the last Ice Age tens of thousands of years ago. This tundra contains more carbon dioxide and methane than the atmosphere, and this poses an enormous threat to the world’s weather. Methane gas, moreover, is a much deadlier greenhouse gas than carbon dioxide. It does not stay in the atmosphere as long, but it causes much more damage than carbon dioxide. The release of so much methane gas from the melting tundra could cause temperatures to rapidly rise, which will cause even more methane gas to be released, causing a runaway cycle of global warming.
Maybe your thinking, 'hey, a .4 degree celsius perhaps doesn't seem like a lot'. So, let me put this into perspective. .4 degrees celcius is about a 1 degree change farenheit. But this is GLOBAL change. That means that places in the world can rise as much as 4 or 5 degrees celsius each (considering the global temp is an average). As Kaku says, just a degree or two could trigger a snowball effect that could kill humanity as we know it.
I'd also like to ask that if we are to have further discussion on this issue that you actually have facts and scientific evidence, otherwise this conversation is super-vacuous and is just a garble of incorrect 'facts'.
Ps: Speaking of venus, I found an interesting qoute on wikipedia : "Studies have suggested that several billion years ago the Venusian atmosphere was much more like Earth's than it is now, and that there were probably substantial quantities of liquid water on the surface, but a runaway greenhouse effect (just like the one kaku mentions!!)
was caused by the evaporation of that original water, which generated a critical level of greenhouse gases in its atmosphere."