More than 30 climate change activist organizations from the Greater New Haven area await Mayor Toni Harp’s response to a Wednesday letter calling for updates to the city’s climate action plan.

The activists highlighted the need for climate action at a local level to supplement national and international efforts, specifically the Paris Agreement — an international climate action plan formalized and agreed upon in December by nearly 200 countries. While Sarah Ganong, the media coordinator at Connecticut Fund for the Environment, said the Paris Agreement is a good first step, she and the other activists believe that commitments to climate action from municipal and regional leaders will determine the success of plans crafted on a national or international scope.

“Climate change presents a serious threat to all of us, and it is imperative that we act to address this challenge at multiple levels of government,” Shannon Laun, an energy and environment attorney at CT Fund for the Environment, said in a statement. “We encourage the City of New Haven to take a leading role in ensuring that Connecticut meets its target of reducing greenhouse gas emissions at least 80 percent from 2001 levels by 2050.”

Chris Schweitzer, a program director at the New Haven/Léon Sister City Project, a nonprofit that supports education and sustainability in both cities, said the Elm City has not addressed its climate action plan since 2004. He said he and other signatories would like Harp to present an updated plan by July 1.

In their letter, the signatories asked the city to outline how it will reduce greenhouse gas emissions and to take specific steps, such as investing in solar panels.

According to Lee Grannis, coordinator of the Greater New Haven Clean Cities Coalition, 40 percent of Connecticut’s greenhouse gases come from the transportation sector. To reduce emissions, activists recommended municipal investment in public and alternative transportation. Schweitzer added that improved public transportation could motivate businesses to relocate to the Elm City.

Schweitzer also said the updated plan should offer co-benefits — such as more local jobs, improved public health, reduced air pollution and more parks and gardens — that simultaneously improve the environment and city residents’ quality of life.

Ganong said she thinks an updated climate action plan will attract new businesses to the Elm City. She added that these businesses will be able to create green jobs by adopting green technology, such as solar panels, which will become more of a priority under the new climate plan.

“We’re seeing the world shift toward a greener economy and greener technology,” Ganong said. “New Haven could jump ahead of the curve a little bit.”

Ganong said the coalition will give Harp several weeks to respond to the letter before following up. Schweitzer said he thinks the city should be able to formulate the plan relatively quickly and effectively.

The Governor’s Council on Climate Change, which Gov. Dannel Malloy created on Earth Day in 2015, will submit an initial report in February with recommendations to reduce greenhouse gas emissions by 2050.