Scientists probably did not adequately convey to the public that their projections for future warming are based on models that account only for the so-called “forced response” in global mean surface temperatures – that is, the change caused by greenhouse-gas emissions. But what is observed at the surface includes unforced, or natural, variations, such as the El Niño and La Niña fluctuations from year to year, and the 60-70 year cycle from the fluctuations of the Great Ocean Conveyor Belt in the Atlantic.