Mayors across the U.S. continue to indicate their desire to lead the nation at a municipal level in the struggle to adjust to global climate change. On June 25, the U.S. Green Building Council (USGBC) and the American Institute of Architects commended the U.S. Conference of Mayors for passing 10 new measures to support resiliency, sustainability, brownfield and in-fill development, and economic recovery.

Yet at the launch of the Resilient Communities for America campaign—organized by ICLEI–Local Governments for Sustainability, the National League of Cities, the USGBC, and the World Wildlife Fund—several mayors spoke about the need for greater support from state and federal governments, and from the nation as a whole.

That’s because cities acting alone cannot curb global climate change—though cities can do a lot. Bloombergreports that the C40 Cities Climate Leadership Group has enacted a plan to cut carbon emissions by 1 billion metric tons by 2030, equivalent to the annual output of Canada or Mexico. Further, cities are increasingly facing consequences of global climate change that require them to look for resources and support from beyond their municipal boundaries.

Mayor John Cook of El Paso, N.M., for example, told an assembly at the press launch for Resilient Communities for America that the border city, which experiences an extreme climate under normal conditions, has experienced a variety of severe climate phenomena. In 2006, the city experienced three years’ worth of rain in two days—to the tune of $450 million in damage to public infrastructure. Then, in 2011, the desert city endured five days of below-zero temperatures, causing brownouts and bursting pumps.

Now, Mayor Cook says, “We’re in year 15 of a seven-year drought.”

The Rio Grande divides El Paso and its much larger city sister, Ciudad Juárez, and both cities draw on the river for nearly all of their drinking water. So climate change poses an international problem for Mayor Cook—who says that the city cannot even look to its state for leadership in terms of sustainability or resiliency.

Des Moines, Iowa, Mayor T.M. Franklin Cownie says that water pollution, a severe problem in Iowa, illustrates a parallel point about cities and environmental regulation. Much water regulation regards source-point polluters, he says, such as the city of Des Moines. But other polluters—principally farms—account for 85 percent of the mineral pollution in the state’s rivers.

It was Washington, D.C., Mayor Vincent Gray who spoke most to the role of design in counteracting climate change in cities. The District regularly leads the nation’s cities in LEED-certified building space, with just short of 40 square feet of LEED-certified space per capita. Even as powerful storms called derechos continue to plague the city, it has worked to grow its tree canopy. The city continues to lead as a purchaser of renewable energy.

The Resilient Communities for America campaign aims to draw attention to four factors driving the successes and struggles of cities today: extreme weather, energy security, crumbling infrastructure, and economic certainty. Neither city policy nor design alone can curb the effects of severe climate—but this campaign’s leaders say that cities must lead if states, and the nation, are to follow.