The global atmospheric concentration of heat trapping carbon dioxide jumped 2.67 parts per million in 2012 to 395.5 ppm. The 2012 increase was the second biggest annual increase since records began.
http://www.esrl.noaa.gov/gmd/ccgg/trends/#mlo_full. Global concentrations are likely to exceed 400 ppm in 2014 or 2015 at the latest.
The atmospheric concentration of heat trapping carbon dioxide rose in 2012, as huge carbon emission increases in China, India, and other nations overwhelmed a substantial decline in US energy related emissions that are back to 1995 levels. Indeed, NOAA tracks every year the atmospheric concentration level of carbon dioxide and it has been increasing at an annual rate of a little less than 2 parts per million. The data is there for all to see and to see how human activity is increasing carbon concentrations each and every year.
And not one reputable scientist disputes that carbon dioxide traps heat. If it did not or the atmosphere had too little carbon dioxide, earth would be an ice ball. And the reverse is true too. If carbon dioxide dumped into the atmosphere in amounts that keep raising its atmospheric concentration, then our atmosphere will trap more and more heat.
Atmospheric concentrations of carbon directly affect temperatures, and temperatures have already increased over the last 200 years as the atmospheric concentration of carbon dioxide rises. That's why our climate has already changed and more change is ahead. Denial or pretending otherwise is irresponsible and unwise economically and environmentally.