Right wing websites have been promoting fake, or at least deceptive, news about alleged global cooling.
- Don't Tell Anyone, But We Just Had Two Years Of Record-Breaking Global Cooling
- Inconvenient and unreported weather fact: we just had two years of record-breaking global cooling
- Did You Know the Greatest Two-Year Global Cooling Event Just Took Place?.
The explanation is that 2016 was the hottest year on record. As the NASA Goddard Institute for Space Studies reports (https://www.giss.nasa.gov/research/news/20180118/):
Earth's global surface temperatures in 2017 ranked as the second warmest since 1880, according to an analysis by NASA.
Continuing the planet's long-term warming trend, globally averaged temperatures in 2017 were 1.62 degrees Fahrenheit (0.90 degrees Celsius) warmer than the 1951 to 1980 mean, according to scientists at NASA's Goddard Institute for Space Studies (GISS) in New York. That is second only to global temperatures in 2016.
So, the fact that things have cooled off a bit from the record highs of 2016 doesn't mean there's a significant trend of global cooling. The temperatures since then are still unusually high.NASA