This is part 4 of a series on world-building Climate Change scenarios for fiction.
The same climate scenario is going to be profoundly different depending on when you look at it. Like, right now we could be in any number of scenarios.
Worst case or best case.
The immediate future looks almost the same in both. The further we look into the future the more these pathways diverge. All this can get confusing fast.
The problem with our orange tree story having a 30 meter sea level rise was precisely this issue. 30 meters is a plausible value… for a different time period. Putting that value too early is what made that story into a Hell-world. We need to get straight what belongs when.
Just like last time we can simplify.
Instead of thinking of calendar dates, I find it easier to think of points on the “Climate Curve”. If plotted on a graph the warming of the planet will follow a curve. A sharp rise, then a plateau, then a very long long long long (did I mention long?) long long long decline back down.
We can break down this curve into stages. Each stage will be distinctly different. Your story’s setting will be in one of those stages.
1) Immediate future
2) Rising
3) Stabilization
4) The Long Tail
5) Equilibrium
Immediate future
Time scale: a few years, to one or two decades in the future at most.
Like I said, this is the same in all scenarios. You can do a slight extrapolation of what’s in the news today. Done.
Rising
Time scale: a few decades (optimistic), to one or more centuries (realistic and pessimistic) into the future.
This is what we are living through now. Greenhouse gas emissions are being produced, therefore temperatures are climbing rapidly. The world is visibly shifting and transforming. Wild new phenomena are appearing. Various systems are breaking under the strain. The race is on to both adapt and slow down the change. Emissions need to be stopped.
Stabilization
Time scale: occurs whenever the rising phase ends. Might last decades to centuries depending on what factors you care about.
Emissions have now stopped. Maybe we changed technology, maybe civilization collapsed, either way the fossil fuel industry is dead.
After a slight lag the rapid temperature rises have also now stopped or slowed down. Earth is still adjusting, and will do so for a long time, but right now everyone will breathe a sigh of relief. The worst of the transition is over. Temperatures might still being going up, but now the rate of change is much slower.
The Long Tail
Time scale: centuries to millennia.
Many Earth systems will take a ridiculously long time to adjust to our new reality. The temperature rise might have stopped, but the transformation will continue. Ice sheets will still be collapsing, sea levels rising, even individual trees that have life-spans measured in centuries will still be adjusting. This will be a strange world in which certain things unfold unstoppably, while relics of a vanished past yet remain.
In the most optimistic scenarios the tail is short. We bring warming back down to normal levels within one to two centuries, and climate change is over (Note: this is extremely optimistic). Pessimistic scenarios might also have a shorter tail, in the sense that the changes happened faster and more violently.
Equilibrium
Time scale: millennia.
Eventually Earth will have settled down. All the ice that can melt will be gone. All the species that could move will have moved. Everything that was going to die will be dead. The new reality will be established.
On extremely long timescales Earth might be returning to a present day normal. Carbon Dioxide levels will be going down, sea levels might be slowly dropping. But this is long. Tens of thousands of years long. That kind of change would be imperceptible to anyone living there. This return to “normal” might be possible, but will be so far in the future that things like the ice age cycles become relevant.
In the most optimistic scenarios we did get back to normal very fast. Equilibrium here means that whatever lingering wobbles we had from our little experiment have finished. That would still likely take centuries.
In the most pessimistic scenarios we will have pushed Earth into a Hothouse state which hasn’t existed since the time of the dinosaurs, and will now persist on a geological timescale. After about three million years, new species will have evolved to fill the vacant niches left open by Earth’s sixth mass extinction.
A Wrinkle Regarding the Details - Non-linearity
While global temperature might follow this nice climate curve, that doesn’t mean everything else will. Temperature is the driving cause that kicks of multiple other processes: species extinctions, melting permafrost, storm events....
Some of these feedback into temperature itself. Melting polar regions removes reflective ice, meaning Earth absorbs more heat. Wildfires release more Carbon Dioxide. Such things might serve to keep the climate curve rising for some time after us humans finally learn to behave.
At a local level non-linearity mean changes can happen in sharp breaks rather than a gentle transition. An ecosystem might flip from forest to grassland, or vice versa. In these cases it doesn’t much matter precisely which scenario you are in. If you cross the threshold it flips. For factors with low thresholds this means optimistic and pessimistic scenarios end up being the same.
Social behavior is also non-linear. Governments, economies, and cultures could experience abrupt changes. Who knows when and where such things might happen.
The point is, while the general trend is this nice tidy curve, the specific changes on the ground will be a total mess. It all depends on what factors you care about.
Conclusion
Each time period gives a profoundly different story. This general feel is far more important than the precise calendar date. Getting mixed up about what belongs when can make a story into an accidental Hell-world or a naive utopia.
However, this simple Climate Curve could get wildly strange depending on what we will cover next: “Curve-balls”.
Return to menu.