Authors' Summary: There are many systems involved in energy transitions, which makes it difficult to anticipate which factors are most likely to result in higher renewable energy adoption in the future, and the currently available projections of future renewable shares are highly uncertain.

We focus here on wind and solar energy in particular, and use a model that represents a variety of the different systems involved (including energy, agriculture, land use, and water) to create a set of nearly 4,000 scenarios that span a wide range of possible futures. Each scenario is driven by a combination of different parameter inputs chosen based on factors that we expect to impact wind and solar energy shares.

By analyzing this set of scenarios, we can find the most important drivers, and combinations of drivers, globally and in each of the 32 different regions represented in our model. Additionally, we look at the scenarios that produced the highest fractions of wind and solar energy and identify four different combinations of parameters that can lead to these high renewable fractions. For each of the four paths, we explore the implications in terms of outcomes like water consumption, air pollution, and food prices, and discuss the resulting tradeoffs.