Participants in the "Global Frackdown" campaign posted photos on social media websites showing mostly small groups.
But organizer Mark Schlosberg said Saturday afternoon he thought the protests were going well and he pointed to photos showing larger demonstrations in South Africa and France as well as higher turnouts in cities in California, Colorado and New York.
"I think it's really the communities all over the world coming together to say, 'We want to protect our water, we want to protect our air, and we want to safeguard our climate future by getting off dirty fossil fuels and saying no to fracking. We need to invest in a renewable energy future,'" said Schlosberg, who is national organizing director for Food & Water Watch, a Washington, D.C., nonprofit that developed the GlobalFrackdown website and campaign.
The immense volumes of natural gas found by fracturing underground shale rock around the country has spurred a boom in natural gas production that has been credited with creating jobs and lowering prices for industry and consumers.
But scientists disagree on the risks of hydraulic fracking, a process that injects large volumes of water, sand and chemicals underground to break rock apart and free the gas. The U.S. Environmental Protection Agency and many state regulators say fracking can be done safely, and the American Lung Association says it can help reduce air pollution.
Opponents say the process can pollute water and sicken residents.
At a park in Pittsburgh, protesters signed a petition calling for a moratorium on shale gas drilling. In Buffalo, N.Y., demonstrators called upon Gov. Andrew Cuomo to ban hydraulic fracturing.
Jennifer Krill, executive director of Earthworks, said about 50 San Francisco demonstrators marched along the waterfront to the Golden Gate bridge, carrying signs and banners. She posted a picture of a 30-foot-long white banner stretched out on the grass that listed chemicals used in fracking.
"I thought it was a very eye-catching way to display one of the key problems with fracking, which is that the public does not know — unless the company chooses to disclose it — what chemicals are involved in hydraulic fracturing," she said.
Kathy Hanratty of Frack-Free Geauga said about 30 to 40 people turned out at a demonstration in the northeast Ohio county, which she said was not bad considering "it's a small county and a rainy morning."
"It is an affected area," Hanratty said. "We just had the seismic test trucks go past my house on Monday."
In Ohio, an injection well used to hold wastewater from the fracking process has been tied to a series of earthquakes in the Youngstown area.
