Investors are eager to spend trillions on energy transition, but too much money is piling into mature projects, while high-risk innovations struggle to attract backing. Will there be enough money in the world to save the planet? The answer to this urgent question is not straightforward. Big-picture prognosticators name staggering sums needed to finance a greener future—and equally daunting shortfalls in securing them. Investment in the energy transition must more than double to $4.5 trillion