California already leads to the nation in efforts to limit air pollution and reduce carbon emissions.

The Golden State has promoted electric cars like no other, not to mention efforts to boost renewable energy and other technologies that cut emissions.

But a landmark climate bill recently passed by the California state legislature will require even greater work to meet emissions targets.

DON'T MISS: California bought more electric cars than rest of U.S. combined in June

Senate Bill 32 (SB32) calls for California to reduce greenhouse-gas emission to 40 percent below 1990 levels by 2030.

That represents a major increase from California's current climate-change targets, notes The Mercury News.

SB 32 builds on AB 32, a climate bill signed into law by former Governor Arnold Schwarzenegger in 2006.

Photovoltaic solar panels on roof of Honda Smart Home at UC-Davis, California

Photovoltaic solar panels on roof of Honda Smart Home at UC-Davis, California

The earlier bill required California to cut greenhouse-gas emissions to 1990 levels by 2020.

The state is reportedly on track to meet that goal, having already cut emissions 9.4 percent from the peak reached in 2004, according to The Mercury News.

Now officials must find ways to cut them another 40 percent in just 15 years.

MORE: SoCal Edison to install 1,500 electric-car charging sites; what's your electric utility doing?

In 2014, the most recent year with available data, California emitted roughly 441 million metric tons (486 million tons) of greenhouse gases, according to data from Lawrence Berkeley National Lab.

The current goal for 2020 is 431 million metric tons (475 million tons), but emissions would have to be reduced to 260 million metric tons (286 million tons) to meet the requirements of SB 32.

That will necessitate even more ambitious climate policies, analysts say.

Green vehicles parked across from Honda Smart Home at UC-Davis, California

Green vehicles parked across from Honda Smart Home at UC-Davis, California

California now requires the six high-volume carmakers to sell zero-emission vehicles, and that program will expand to cover more auto companies and start to escalate the required numbers in 2018.

It has also mandated that utilities must produce 50 percent of their electricity from renewable sources by 2030.

To meet the new mandate, California may have to take measures like pushing the renewable-energy requirement beyond 50 percent, significantly increase sales of electric vehicles, and bring electrification into other types of vehicles (such as delivery trucks), analysts say.

Meanwhile, on the other side of the country, Massachusetts is moving toward stronger limits on greenhouse-gas emissions from electric generating plants.

On Monday, Gov. Charlie Barker's administration announced its support for stricter limits under the Regional Greenhouse Gas Initiative (RGGI), a program to reduce power-plant emissions run by nine Northeast and Mid-Atlantic states.

Electric power plant outside Ithaca, New York

Electric power plant outside Ithaca, New York

Massachusetts now supports doubling the rate at which emissions decrease as part of the RGGI, from 2.5 percent to 5.0 percent per year, between 2020 and 2030.

The announcement was made in the midst of a review of the RGGI by member states.

Green Car Reports respectfully reminds its readers that the scientific validity of climate change is not a topic for debate in our comments. We ask that any comments by climate-change denialists be flagged for moderation. Thank you in advance for helping us keep our comments civil, respectful, and fact-based.

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