The world is counting on an international climate agreement in Paris next month to stop the rising fossil fuel and biofuel emissions that are warming the planet. Creating an international agreement is an admirable goal, but it is interesting that countries are not racing to zero emissions on their own. It is even more amazing that no country has performed a study on the benefits and costs of going to 100 percent clean, renewable energy.

Fortunately, scientists have done the analyses. They show that switching to an entirely renewable energy system would save money and lives while making international climate agreements unnecessary.

We recently developed road maps showing how each of the 50 states in the U.S. could abandon nuclear and fossil fuels and change their all-purpose energy infrastructures (that includes electricity, transportation, heating/cooling and industry) to ones powered 100 percent by wind, water and sunlight by 2050. The details of the plan vary from state to state. Overall, however, by 2050 it would be possible to meet 100 percent of power and fuel demands in the U.S. with a mix of approximately 30.9 percent onshore wind, 19.1 percent offshore wind, 30.7 percent utility-scale photovoltaics, 7.2 percent rooftop photovoltaics, 7.3 percent concentrated solar power with storage, 1.25 percent geothermal power, 3 percent hydroelectric power and less than 1 percent wave and tidal power. Installing this capacity would require less land than one might expect: By our calculations, approximately 0.42 percent of U.S. land would be devoted to the footprints of these generators, and 1.6 percent would serve as open space between wind turbines.

A 100-percent renewable energy system would still need to continuously meet the power demands of consumers—even when the sun isn’t shining or the wind isn’t blowing. This is a solvable problem. Our analysis found that it is possible to stabilize a renewable power system with low-cost solutions including storing excess energy generated when the sun and wind are strong in ice, water, concentrated solar power with storage, pumped hydropower and hydrogen; and by using a smarter power grid to lessen periods of excess demand. In our simulations biomass, nuclear power, natural gas and batteries (with the exception of those in electric vehicles) were unnecessary.

The benefits of switching to this entirely renewable mix would be significant. The mean cost of energy in 2050, accounting for storage transmission, distribution, maintenance and array losses, would be 10.6 cents per kilowatt hour for electricity and 11.4 cents per kWh for all energy (2013 dollars)—comparable with energy costs today. Yet each state’s end-use power demand would drop by a mean of 39.3 percent by 2050. Nationwide, the conversion would produce a net increase of two million 40-year jobs, eliminate 48,000 premature deaths due to air pollution per year in 2050 and save $3.3 trillion per year in 2050 global climate costs. Each American would save $260 per year in energy costs and $1,500 per year in health costs.

Most recently, we developed similarly detailed road maps showing how 139 countries could switch to 100 percent renewables. These studies suggest that, in aggregate, converting entirely to renewables would create a net of over 22 million jobs while preventing as many as seven million premature air-pollution deaths each year. The conversion would use little land. It would stabilize energy prices and reduce international conflict over energy—after all, each country will be largely energy independent. And it would reduce the risk of terrorism by replacing big, centralized power plants that are tempting targets with many small ones dispersed nationwide. Finally, it would do exactly what world leaders aim to do when they meet next week in Paris: nearly eliminate any additional global warming.

Mark Z. Jacobson is a professor of civil and environmental engineering and director of the Atmosphere/Energy Program, at Stanford University.