In a first for the US, wind and solar produced more electricity than coal last year, according to a new report from energy think tank Ember. Coal fell to a historic low, generating 15 percent of the country’s electricity compared to 17 percent from solar and wind combined.

But carbon emissions from electricity still climbed. That’s because natural gas also set record levels of generation last year. The burst of new gas pushed up greenhouse gases, offsetting modest carbon declines from coal and establishing gas as the leading source of climate pollution in the power industry — another first.

The two renewable energy sources accounted for 17% of the country’s power mix while coal fell to a low of 15%. Natural gas remains by far the largest source of electricity, accounting for 43%.