Beginning in the 1960s, a growing number of people felt that something ominous was approaching. Scientists began warning that the global natural environment was degrading to unsafe levels, and that critical resources were at risk of overconsumption. Use of tools designed to model complex systems revealed that this jeopardized the survival of civilization and even the entire human species. While a majority of proposed solutions focused on acquiring more resources (especially energy) in less damaging ways while accelerating economic growth, a minority argued for reducing overall consumption – even at the expense of economic growth.
After 1990, economic growth in Timeline 2 generated noticeably less wellbeing than people expected based on previous decades, despite acceleration of economic activity that reached a peak in 2006. Attempts to increase that acceleration by promoting consumption had the opposite effect because of its newly significant slowing effect on population growth, and in 2017 the rate of economic growth began dropping for the last time.
A third timeline was born of this last event. Its inhabitants had a better chance of surviving because a critical number of them simultaneously came to understand that an alarming degradation of social order in recent years was inextricably linked to the degradation of their world's natural environment, of which pollution-linked global climate change was only the most obvious manifestation. Their number was critical because radical change on a world-wide scale was needed immediately, and they had just enough influence to pull it off.
With only two years left before population reached its own peak and more people started dying than being born, stopping the growth of global consumption was the most effective strategy to use. This artificial peak in consumption would similarly require a decrease in consumption by some people that was equal to any increase in consumption by the rest. Ideally, to reduce pain and suffering (as well as social tension that could result in violence and death), the difference between the two would have to be small, and could be aided by avoiding replacement of people who died of old age. But since the passing of several geophysical tipping points had all but ensured that the amount of available resources would diminish without any additional consumption, everyone would still need to learn how to – and agree to – decrease their consumption to match the supply.
Without voluntary initiation of the strategy, the practical difficulty of social engineering required in its absence was too much for Timeline 2 to avoid catastrophe, and humans there would be effectively extinct by 2038. Immediately following the trigger that started the "Fix" timeline, current Gross World Product grew at a rate one-twelfth of what it did in Timeline 2, and within ten years fell to an annual increase of only half a percent.
Facing the threat of a rapidly uninhabitable planet if they kept living the way they had, more and more of the people in the Fix timeline split their newly "free" time between finding ways to survive that had lower impact on natural systems and removing or rendering harmless as much toxic material as possible. Those who insisted on doing otherwise were steadily deprived of the resources that enabled that behavior, isolated themselves, and then died off.
As natural disasters multiplied and people in the Fix timeline became more familiar with their artificial and natural environments, it became clear that most of the built infrastructure existing until 2018 could no longer serve its intended purposes. Useful and safe material was salvaged for use in new structures resembling Earthships, while the rest was rendered as harmless as possible before being abandoned. Various "hot zones" remained, such as nuclear power plants and weapons stockpiles, which were staffed by volunteers who worked on decommissioning them at high personal risk using what technology was necessary and could itself be rendered safe in the process.
Several fundamental shifts occurred organically as the population of the Fix timeline learned to survive in the long term. One was decoupling the economy from ecological impact. Historically, economic activity was a function of the number of transactions of resources, which depended on both the number of people and what was traded between them; all such activity was measured the same way, without regard to its individual qualities. As restricting both individual consumption and the number of people became more intrinsically valuable, this measure became useless. As people learned to reduce their experience to its essentials as a price for survival, they came to treat interactions with others as part of an almost artistic collaboration whose value was in the result rather than their individual contributions. Like their replacement of largely useless physical infrastructure from the past, they developed new ways to efficiently coordinate their activities based on net benefit, maximizing prioritized qualities over time at all conceivable scales, with survival having the highest priority.
Another fundamental shift was a reshaping of group identity. Taken globally, the world's many nations, cities, and smaller groups behaved as one composite population. The global environment was likewise a composite of ecosystems with their own subpopulations of myriad species with functional elements common to the rest. As physics inexorably moved energy and matter around the planet to create temporarily stable states independent of artificially defined boundaries, members of all species – including humans – had to be able to move to regions that improved their chances of survival, and then interact with others in those regions to get what they needed. If a small group of individuals or species attempted to dominate a region, it took the risk of being unable to adapt to specific conditions within the region that others could, and might otherwise assist them to do the same. The people of the Fix timeline were aware of these facts, and organized their groups to improve their chances of survival by maximizing adaptability. This meant that most groups would need a mix of knowledge, abilities, and environmental affinities that could be applied to a variety of places they might need to go. Emphasizing respect within those groups, and applied to other groups of people and species, would reduce the possibility of local population collapse in any given environment.
At the moment, we have the most in common with Timeline 2, and still barely have the option of branching onto the Fix timeline. To the extent that we can apply insights that come from imagining that timeline, we might gain more time for ourselves.