‘…Stephen A. Montzka, a NOAA research chemist who worked on the index, said the spike between 2015 and 2016 — the largest incremental increase in greenhouse gases since 1988 — was largely caused by El Niño. The jump between 1987 and 1988, which came in at a slightly higher 2.8 percent, was also linked to an El Niño.’
Source:Â Climate-Altering Gases Spiked in 2016, Federal Scientists Report – New York Times