NASA and the National Oceanic and Atmospheric Administration, NOAA, have been tracking global temperatures since 1880. Last year (2014) has been Earth's warmest year since record keeping began. The planet is actually on track to beat that record this year. According to NOAA, October 2015 " has marked the sixth consecutive month a monthly global temperature record has been broken."
NASA states that "Since 1880, Earth’s average surface temperature has warmed by about 1.4 degrees Fahrenheit" and furthermore attributes the rise to be directly related to human interaction. "The long-term trends are attributable to drivers of climate change that right now are dominated by human emissions of greenhouse gases" - Director Gavin Schmidt, NASA's Goddard Institute of Space Studies.