Global temperatures will come off the current plateau into a sustained and significant cooling, beginning 2017 or maybe as late as 2021. The cooling will be about 0.3 °C in the 2020s, taking the planet back to the global temperature that prevailed in the 1980s. This was signaled (though not caused) by a fall in underlying solar radiation starting in 2004, one of the three largest falls since 1610 when records started. There is a delay of one sunspot cycle, currently 13 years (2004+13 = 2017).