Science fiction writers construct an imaginary future; historians attempt to reconstruct the past. Ultimately, both are seeking to understand the present.
Let's imagine a future historian and a mud core sample expert looking back 6,000 years to our present and (possible) future. The occasion is the tercentenary of the end of Western culture (1540 – 2073); the dilemma being addressed is how we – the children of the Enlightenment – failed to act on robust information about climate change and radioactivity with knowledge of the damaging events that were about to unfold.
Our future historian concludes that a second Dark Age had fallen on Western civilization, in which denial and self-deception, rooted in an ideological fixation on “free” markets, disabled the world's powerful nations in the face of tragedy. Moreover, the scientists who best understood the problem were hamstrung by their own cultural practices, which demanded an excessively stringent standard for accepting claims of any kind – even those involving imminent threats.
In my sci fi take on the future, our future historian, living in the Second People's Republic of China, recounts the events of the Period of the Penumbra (1988 – 2073) that led to the Great Collapse and Mass Migration (2074). The scientist studying core samples found a layer of trash and radiation thicker than any asteroid impact and mass extinction.
All language from that era was lost to the ages because digital data does not last as long as etched stone. The theories that accumulate are incredibly (laughably) far fetched compared to the knowledge that the reader who is currently living in this time prior to the collapse already happening in 2019.