White Roof, Green Roof: Cities Share Climate Solutions on the Hill

The green roof at Chicago’s City Hall, with the adjacent Cook County building visible at bottom. (Photo: 2modern)

When Energy Secretary Steven Chu observed that simply painting roofs white would go a long way in reducing emissions, he was mocked by conservatives but hailed by advocates who have long understood the power of small-scale actions to mitigate the warming climate.

Chu may have focused on white, green was the hue of choice today at a Capitol briefing on urban climate strategies sponsored by the Center for Clean Air Policy (CCAP).

Though “honorary co-hosts” Sens. Barbara Boxer (D-CA) and John Kerry (D-MA) were absent, officials from several cities shared their ideas with aides from Congress and the Obama administration. Joyce Coffee, policy director at Chicago’s environment department, made an impression with a slide showing the heat emanating from her city’s government headquarters, which installed a rooftop garden in 2001.

On a 70-degree day, Coffee’s heat map showed Chicago City Hall keeping its rooftop temperature to 74 degrees — saving energy and diminishing the brutal “heat island” effect that can pose serious environmental hazards.

The Cook County administrative building, located just next door to City Hall, had a rooftop temperature of 151 degrees, according to the heat map.

The prospect of using more roofs to mitigate climate change and boost local agriculture took one step closer to reality last week, when Rep. Jay Inslee (D-WA) and 21 co-sponsors offered a bill that would authorize a community-garden grant program at the U.S. Department of Agriculture.

Inslee’s measure does not require that gardens receiving aid be on roofs; but judging from Coffee’s presentation, it could be a way to maximize the benefits of greening infrastructure.