While there are many competing theories on why such a drastic change in climate are taking place within the past 5-10 years, there is no arguing against what impact spewing millions of lbs a day of extra CO2 has on our environment.
Our drastic changes could have to do with a coming "pole shift". We've had them in the past. For example take the Wooly Mammoth they found in the Arctic Circle with tropical fruits frozen in its stomach. This is evidence of a VERY sudden pole shift. One so fast that Animals didn't even have time to migrate. Some other evidence, like the cyclical nature of warm/cold cycles in recent winters might support the evidence for a coming pole shift.
If we experience a pole shift in this day and age it will be nothing short of catyclismic. A pole shift would cause violent tectonic plate shifting, all sorts of violent wind phenomona, massive tidal waves and a host of other "apocolyptic" events ALL over the globe.
Given the nature of earth's ability to purge itself of life, I find it hard to believe humans ALONE are causing ALL of this climate change. There is something else in play somewhere because now the scientists forecast models have become so wrong due to the fact that the melting of the polar ice caps and glaciers around the world have sped up so much in the past two years. We need to find out what is speeding all of this up. Is it solar activity? Is it wobble in the axis of the earth? There is an anomoly somewhere. They just have to figure out what it is.
Edit: There seems to be a lot of people on here downplaying the significance of human impact on the earth's natural systems. I guess they must be thinking of indigen people of places like borneo and the amazon. They have NO impact. So, yes, there ARE humans who have no impact. However the vast majority of us use products which contribute to straight up pollution and contamination of the environment in certain areas. There is NO doubt this behavior is spreading throughout developing countries as much as it is here.
The REAL problem humanity faces is population. While there are some cases, such as in China's case, where government policy dictates only one child per family. Which has created an environment which will cause a population implosion and subsequent industry suffering due to lack of man power. However, the vast majority of humanity has no such limitations. It is considered our God given right to reproduce as we see fit. This simply cannot go on if we hope to enjoy sustainability. If there is not a population correction in a major way we will continue down our current path of inevitable self destruction.
Like I said before, the nature of the universe has special power in that it can, given the right circumstances, eliminate whole planets let alone a lowly race of sentient beings.