There is a link between El Nino and carbon dioxide emissions.  Mainly El Nino causes less rainfall over Indonesia/Maritime Continent and, along w/ their annual burning, it can increase CO2 emissions.  I'm not sure how far back that record goes, but we definitely saw it in 1997-98 and in 2015-16 (two huge El Ninos):

http://www.nature.com/news/massive-el-niño-sent-greenhouse-gas-emissions-soaring-1.22440