I offer the following scientific charts are evidence:
Chart #1 shows the Earth's temperature trend over the last 12,000 years or so since the Pleistocene era. Al Gore and the scientists that support his theory use this as "proof" of Global Warming. (The Pleistocene era was the end of the last ice age, which began in the Tertiary era and lasted for nearly 2.5 million years. Needless to say, it could take awhile to get back to "normal" temps.)
Chart #2 shows the same chart, but only as a small fraction of the entire Earth's temperature history.
As you can see, while the temp does seem to be rising, it is still far, far below what is normal for our planet. It would appear by the scientific evidence (this chart was produced using findings by paleontologists, climatologists, archeologists, minerologists and many other scientists whose findings prove temperature) indicates the normal temperature of Earth, barring any outside influences (ice age begun by a meteorite strike, for example) usually maintains an average of a rather steady 25 degrees centigrade (77 degrees F). Currently, the average world temperature is roughly 55 degrees. If you doubt these charts, ask yourself why the temps were so much warmer during the Jurassic (dinosaur) and other eras, and why scientists have found tropical fossils beneath the ice sheets of the Antarctic. Man and his machines were nowhere to be found back then.
A 77 degree average temp is found in the area of Phoenix AZ. Now imagine that as the AVERAGE year-round temperature of the planet. That is "normal" for Earth.
So, while we may very well be in a warming trend, overall, the Earth is simply getting back to normal after the last ice age. And, barring any cataclysmic outside influence, there is nothing we can do about it.