This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (Credit: Vostok ice core data/J.R. Petit et al.; NOAA Mauna Loa CO2 record.) originally via http://climate.nasa.gov/evidence/
“Scientific evidence for warming of the climate system is unequivocal.”
While we always support debate, and there is still much debate about the climate projections, solutions to climate mitigation and adoption and even geoengineering, the one thing that should not be debated here due to the overwhelming consensus which is that climate change as understood by common global warming terminology should not be disputed at this stage. As the US President Obama said.
“Look, if anybody still wants to dispute the science around climate change, have at it,” “You’ll be pretty lonely, because you’ll be debating our military, most of America’s business leaders, the majority of the American people, almost the entire scientific community, and 200 nations around the world who agree it’s a problem and intend to solve it.
Consensus is no proof of scientific validity and many of the scientific revolutions have been against the popular tide of opinion. Science never explicitly proves anything but finds the current best fitting theory that explains real world data, and that has lead to the current assertion of the validity of the anthropogenic climate-change scientific theory. 
Debate is always welcome but in the context of this forum, it is more helpful to proceed as though climate-change is real, partly man-made, and potentially quite threatening to building a sustainable world populated by a large hungry consumer driven citizenry.