Global warming is happening now. The planet's temperature is rising. The trend is clear and unmistakable.
Every one of the past 37 years has been warmer than the 20th century average. The 12 warmest years on record have all occurred since 1998. The hottest year ever recorded for the contiguous United States occurred in 2012.
Globally, the average surface temperature has increased more than one degree Fahrenheit since the late 1800s. Most of that increase has occurred over just the past three decades.