dathwampeer said:
Yeah... sure.
I guess all the drastic climate changes that happened before we even existed. Never mind before our industrial revolution just never happened ay?
"DAMN YOU PERMIAN EVIDENCE... for foiling my clever strawman!!!!!!"
Climate reacts to whatever forces it to change at the time. Humanity is now the dominating force. It is obviously true that past climate change was caused by natural forcings. However, to argue that this means we can?t cause climate change is like arguing that humans can't start bushfires because in the past they have happened naturally. Greenhouse gas increases have caused climate change many times in Earth's history, and we are now adding greenhouse gases to the atmosphere at a increasingly rapid rate.
Did we have an effect on Natural climate change? Hmmmm debatable. But possible.
What? debatable? Source [http://tigger.uic.edu/~pdoran/012009_Doran_final.pdf]
"
It seems that the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes. The challenge, rather, appears to be how to effectively communicate this fact to policy makers and to a public that continues to mistakenly perceive debate among scientists."
Did we cause it? Fuck no. What hippie world do you live in?
Reality? Here's a nice simple picture to sum it up:
[EDIT for clearity]
The first four pieces of evidence show that humans are raising CO2 levels:
1. Humans are currently emitting around 30 billion tonnes of CO2 into the atmosphere.
2. Oxygen levels are falling as if carbon is being burned to create carbon dioxide.
3. Fossil carbon is building up in the atmosphere. (We know this because the two types of carbon have different chemical properties.)
4. Corals show that fossil carbon has recently risen sharply.
Another two observations show that CO2 is trapping more heat:
5. Satellites measure less heat escaping to space at the precise wavelengths which CO2 absorbs.
6. Surface measurements find this heat is returning to Earth to warm the surface.
The last four indicators show that the observed pattern of warming is consistent with what is predicted to occur during greenhouse warming:
7. An increased greenhouse effect would make nights warm faster than days, and this is what has been observed.
8. If the warming is due to solar activity, then the upper atmosphere (the stratosphere) should warm along with the rest of the atmosphere. But if the warming is due to the greenhouse effect, the stratosphere should cool because of the heat being trapped in the lower atmosphere (the troposphere). Satellite measurements show that the stratosphere is cooling.
9. This combination of a warming troposphere and cooling stratosphere should cause the tropopause, which separates them, to rise. This has also been observed.
10. It was predicted that the ionosphere would shrink, and it is indeed shrinking. As a consequence of greenhouse warming, which we are the dominating source of.
Souce [http://www.skepticalscience.com/10-Indicators-of-a-Human-Fingerprint-on-Climate-Change.html]