If you care to get analytic, it's related to the insulation factor of the atmosphere, fairly consistent amounts of sunlight in (subject to know solar variation and orbit) that heats land and sea surface radiating thermal energy out to space with a "small" amount trapped to maintain a globally mean amount of energy that powers climate cells and cascades into other forms.

The global amount of coal use in the 1880s was non zero, sure, but overall the CO2 emissions from those tonnages were minuscule compared to modern emissions within the past 50 years .. and we have direct libraries of atmosphere created since the early years of the Cold War and many pocket captures for the past 200 years, with proxies (such as ice core bubbles) going back far longer.

ENSO predates heavy coal use - so it's not something created by human activity, and as noted the first uses of coal were barely enough to move the needle (recall that collieries kept records so we have a fair handle on tonnages extracted).