One thing that only seems to be understood to a limited extent in most quarters is the degree to which humanity faces very serious long-term climatic challenges, even in the absence of human greenhouse gas emissions. This is simply because there is no reason to believe that the kind of climate that has existed for most of human history is one that is uniquely probable and likely to persist. Ongoing forces like plate tectonics, the development of carbon-rich rock through the weathering of mountains, and orbital variations (Milankovitch cycles) all have marked and overlapping effects in the long term. Paleoclimatological evidence shows a world that has differed considerably in temperatures, weather patterns, and continental layouts. Oxygen only emerged in the atmosphere 1.7 billion years after the Earth formed (though because of biological developments, rather than climatic ones). During the late Precambrian period, Earth was essentially a giant snowball. At times, evidence suggests that Antarctica hosted deciduous forests rather than an ice sheet. It seems that sometimes the forces that caused transitions from one state to another were relatively minor in and of themselves: they just pushed the overall climate system in a self-sustaining direction.
Of course, long-term natural climatic variation on the scale of hundreds of thousands or millions of years is a much less immediate concern than the consequences of humanity’s continued use of the atmosphere as a carbon dioxide dump. The latter is a real and massive immediate threat, while the latter is more of an academic consideration for the moment. That being said, it does seem important to understand that our present conditions are not some robust preference emergent from the fundamentals of the climate system; rather, it is one equilibrium among many. In a manner somewhat akin to learning that our planet/solar system/galaxy is just one of a vast multitude, this should prompt humanity to re-examine some of our beliefs about our own importance and about the stability and habitability of the planet we inhabit.