(Bloomberg) – US President Joe Biden’s landmark clean-energy law will cost roughly $1.2 trillion — three times more than the official government forecast — and spur trillions more in private-sector investments, according to Goldman Sachs Group Inc.

The Inflation Reduction Act passed last year is intended to encourage investment in renewable energy sources and efficiency technology. As such, it’s crucial to one of the Biden administration’s fundamental priorities: decarbonizing the economy to forestall the worst effects of climate change.

Goldman’s analysts estimate that the $1.2 trillion in government outlays will unleash another $3 trillion in investment by businesses and individuals to build and expand climate-friendly ventures.

–With assistance from Ari Natter.