NEW YORK (CBSNewYork) — Hundreds of climate activists rallied at City Hall and marched Sunday, calling for officials to cut greenhouse gases.

Labor leaders, teachers, students, other community activisits and Bill Nye, the “science guy,” were also in attendance, 1010 WINS’ Carol D’Auria reported.

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Their ideas run the gamut from saving community gardens to making all cars that travel in New York City run on electricity.

Thousands of demonstrations took place around the world Sunday, each with its local focus, WCBS 880’s Stephanie Colombini reported.

Nye pushed the electric car idea. He said the city would generate the electricity for that from the wind.

“There’s enough energy to run the whole place several times over if we all got together and embraced this technology,” he said. “Now, we want to do this by 2030. That’s coming right up.”

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The group has sent a letter to Mayor Bill de Blasio calling for the city to commit to 100 percent renewable energy in 15 years. That’s up by the city’s current pledge to reduce them by 80 percent.

“We cannot wait any longer to tackle the threat of climate change,” Public Advocate Letitia James said.

Nye said it would not only help the environment, but the economy, too.

“You can’t import all wind turbines,” he said. “Somebody’s got to go out there and erect them and run the power lines. All the jobs will be local. It would improve the quality of life of everyone.”

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The environmentalists say the large buildings in the city account for 70 percent of its carbon emissions.