California’s greenhouse gas emissions declined by about 1% in 2017, with a continued shift toward renewable electricity keeping the state ahead of schedule in meeting its 2020 climate target, according to a report released Monday by air quality regulators. The state Air Resources Board inventory found 2017 was the first year since the state began tracking planet-warming emissions that electricity generated from solar, wind, hydroelectric and other renewable sources surpassed what was generated by fossil fuels. Clean power provided 52% of the electricity California used in 2017, according to the report. The gains came so heavily from the electricity, environmental policy experts say, that the sector is making up for more lackluster areas of the economy, such as transportation and industry.