Earth 2100 begins on June 2nd, 2100, with Lucy narrating some of the most significantly horrific things she's seen. Lucy then tells her entire life story, during which we see the world go from a relatively OK state where she lives in a suburban home with a well-watered lawn to a Crapsack World in which humanity has been plunged into the Dark Ages.
- After the End: The time at which Lucy is telling her story, on June 2nd, 2100.
- Apocalypse How: Class 2: Outside of a few walled cities, civilization collapses into anarchy.
- Despair Event Horizon: Lucy hits this when her husband Josh dies trying to close the floodgate.
- Downer Ending: The government has pretty much disintegrated, the Caspian Fever epidemic has killed more than half of the human population, while other parts of the world have wiped themselves out over wars over resources, and most technology has broken down, with only the elite able to use it. Society has become the Cyberpunk equivalent of the Dark Ages as cities become fortress communities, and the environment will likely take centuries to heal. Lucy herself laments what kind of knowledge to pass onto her grandson in this new world.
- The End of the World as We Know It: What has happened by Lucy's 91st birthday.
- Extinct in the Future: Many species end up this way as the years pass, with Lucy specifically mentioning the extinction of the albatross and other seabirds.
- Exty Years from Now: An interesting variation where, instead of having the work take place in a year of a round figure based on the year of release, they have it take place on the same date a certain number of years into the future.
- Foregone Conclusion: We already know that by June 2nd, 2100, The End of the World as We Know It has already happened. The plot is basically a matter of finding out how it got to that point.
- Gaia's Lament
- Green Aesop: Earth is our home, our only home, and we should treat it accordingly, otherwise we will lose everything.
- Hope Spot: Several communities in the later years of the 21st century are able to achieve sustainability- but by then its too late to make a difference.
- Just Before the End: Basically the whole 21st century. Over 91 years, we see multiple signs that the world is going to hell in a handbasket that only get worse as time goes on. The world's descent into the Crapsack World that Lucy lives in at the age of 91 gets so progressively bad that the line between "Just Before" and the actual End is kind of blurry.
- Methuselah Syndrome: While the world is steadily growing into one of the Crapsack kind and almost everyone is dying off from diseases and starvation, Lucy has managed to live to the ripe old age of 91, which is longer than the present average life expectancy, even when you're going by that for women. Most amazingly, she still seems to be going strong and is in a physical condition adequate for leaving New York City to find her daughter and grandson, who are both alive.
- Justified in that whomever she's telling her life story to had presumably sought her out because she was so old, and could recall times nobody else remembers.
- Together in Death: In 2050, a terrible flu epidemic occurs. Among the fatalities are Lucys parents, who die together.
- Trauma Conga Line: Everyone in the world goes through this, but we see Lucy's especially long one.