One of the trickiest things about making projections about climate change is that what it will end up being like is intertwined with the question of how a number of other important trends develop. For instance, there is the question of how long conventional reserves of coal, oil, and gas will last. Related to that is the question of whether prices of those conventional fossil fuels will increase considerably with scarcity, fall as they are eclipsed by new forms of energy, or something different. Tied to those questions is the unknown future development pathways of all the world’s major economies. Will rapid growth continue in China? If so, what implications will that have for climate and energy? What will the pace of development and deployment be for renewable energy, particularly given different potential policy approaches.

It is possible to imagine many possible global trajectories. In some, climate change impacts prove serious earlier. In others, effects only emerge later. In some, those effects are concentrated in some geographic areas. In other scenarios, different parts of the world experience the largest changes.

We will not be able to ‘wait and see’ how major trends develop, before making our choices about how to deal with climate change. Rather, we need to choose in the face of layered uncertainty. Given that inevitable situation, I would argue that the only prudent approach is to pursue a set of strategies that would prevent disastrous outcomes from occurring, regardless of which predictions prove accurate on various important questions. We cannot, for instance, simply assume that renewable energy, or nuclear energy, or some other energy source will automatically become inexpensive and widely deployed enough in time to prevent the worst effects of climate change. We must also be prepared for scenarios in which conventional fossil fuels become scarce more rapidly than expected, unconventional sources prove uneconomical or slow to deploy, and prices rise substantially.

Avoiding disastrous outcomes requires pursuing a resilient approach that can deal with surprises. It requires investing in numerous technologies and approaches, with the knowledge that not everything will work and the humility to recognize that we cannot know in advance which technologies will be successful and which will not be. That means driving investment and innovation in every major energy source that has the potential to serve humanity’s energy needs in a low-carbon or carbon-neutral way. This clearly includes renewables and nuclear fission. It also includes biomass for stationary power generation and biofuels for vehicles. It includes basic research into promising but speculative technologies like nuclear fusion and space-based solar power. It includes continued and expanded work on energy efficiency.

In addition to all of those things, we need to stop assuming that the world of the future will basically be like the world of today. It may not be the case that energy use will be at the same level fossil fuels have allowed us to reach, either in absolute or per-capita terms. It may not be the case that the most energy-intensive aspects of our current lifestyle will be able to continue. At the same time, there are many benefits that could be realized though the transformation of our energy systems. Fossil fuels produce large quantities of deadly air and water pollution. They also contribute to conflict and geopolitical instability.

If we succeed in moving from a world that runs on dirty, climate-altering fossil fuels to a world that operates much more efficiently using energy that largely comes from renewable sources, we will have achieved one of the most remarkable and positive transformations in the broad sweep of human history. We will also have set humanity up to endure indefinitely, without undermining the relatively stable climate that has accompanied and facilitated the emergence of human civilization. Exactly how we can do that remains unknown, but it will require us to confront layered uncertainty and develop portfolios of effective strategies that allow us to progress to that goal.