Read here, here and here. The UN's IPCC political leaders, bureaucrats and the Climategate scientists have said for years that today's temperatures are "unprecedented." They also claim that all temperatures to the right of the black-dash line on the graph below are natural; and, all temperatures to the left of the black-dash line are unnatural, due to human CO2. The past visible history (as shown) of temperature records makes both these claims flat-out lies. The historical record also indicates that temperatures fluctuate up and down without any relationship to the CO2 level. (click on image to enlarge)
It could well be that for highly urbanized metropolitan areas of the world that temperatures are "unprecedented" but for the vast majority of global areas, they are not. As the latest Greenland ice core research finds (and other research), multiple historical and ancient periods were significantly warmer than current temperatures, despite lower atmospheric CO2 levels. The temperature history the ice cores record reveal are not only temperatures that are both substantially cooler and warmer than current ones, but that temperatures naturally have periods of "accelerating" movement over extended periods. Finally, the Greenland ice sheets that the ice cores came from obviously survived much higher temperatures without sliding into the sea, as global warming alarmists claim will happen by 2100.