CAMBRIDGE, Mass.--City governments' response to climate change ranges from cutting-edge distributed energy to adding more bike lanes and trees.
Climate change experts from four cities--London, Toronto, Chicago, and New York--spoke about the connections between sustainable urban design, energy, the economy, and human health on Monday at the Mass Impact Symposium, organized by the Boston Society of Architects and the Massachusetts Institute of Technology.
The cities' climate action plans, some of which have yet to be fully rolled out, call for aggressive goals to measure, reduce, and monitor greenhouse gas levels--on the range of 50 percent to 80 percent in the next three decades.
Under that over-arching goal are dozens of programs, including promotion of green technologies to lower energy consumption in transportation and buildings.
"We can't just do one thing," said Ariella Maron, deputy director of New York's Office of Long-Term Planning and Sustainability. She said the city's plan covers clean energy, efficient buildings, transportation, and avoiding sprawl--all of which impact water, land use, and air quality.
Called PlaNYC, the program stems from simple demographics: another 1 million people will join its current population of 8.25 million by 2030.
It's not just New York. Urbanization is rapidly accelerating around the world. That means the "tipping point" toward greenhouse gas reductions will come from making cities more sustainable, particularly in developing countries, said John Fernandez, an associate professor at MIT's architecture department.
More than half of the world's residents now live in cities, and 85 percent of the world's population growth will be in urban areas in the coming decades, mostly in Asia, Africa, and Latin America, Fernandez said.
Top on the list of these cities' programs is building energy efficiency. Overall, energy use in buildings is about one-third of the U.S.' energy use but it can be a lot higher in cities--in New York, it's 80 percent of energy use and rising.
Chicago requires city buildings requesting funding to meet the U.S. Green Building Council's Silver-level LEED certification.
But while cities can make visible commitments to environment stewardship, it's typically a drop in the bucket when it comes to carbon emissions. That's because 80 percent of buildings that exist today will still be around in two decades, making technologies to retrofit existing buildings more important, city representatives said.
There are also opportunities for individuals or neighborhoods to generate their own energy. Toronto is experimenting with a program called SolarCity to encourage communities to purchase solar hot water systems.
At the end of this month, the PlaNYC program will announce details of a program to lower buildings' carbon emissions 30 percent by 2017 by promoting micro-power generation and waste-to-power technologies, Maron said.
London, meanwhile, is exploring more futuristic approaches, where whole neighborhoods would generate their own energy.
Nicky Gavron, the former deputy mayor of London, said city planners envision replacing natural gas production either by producing bio-gas from organic wastes in anaerobic digesters or using waste to make synthetic gas through plasma arc gasification.
The energy from waste would be used in either individual or neighborhood combined heat and power systems. "We have an opportunity to usher in a new era of municipally owned enterprises around low-carbon technologies," said Gavron, who was member of a hydrogen committee.
Not keeping pace with technology?
City governments are eager to show leadership by adopting green technologies in their own operations.
Toronto's LightSavers pilot is testing to see whether more efficient LED lighting with controls can be used for street lights, parking garages, and pedestrian areas.
And the FleetWise plug-in hybrid pilot has allowed the city government to improve its fuel economy by 50 percent, said Philip Jessup, director of the Toronto Atmospheric Fund. In Winnipeg, Canada, already 70 percent of taxis are hybrids.
Water treatment is an important feature of climate change response, according to planners.
With more extreme precipitation, New York is enlisting trees to try to capture run-off and pollutants. The city is trying to add more green spaces to its streets and change the tree pit specifications so that they are big enough to retain more water, Maron said.
It's also looking to reestablish its mussel and oyster industry, which will filter pollutants from storm water run-off--a move that stresses energy-intensive treatment plants, she said.
"We are already feeling the impacts of climate change," with higher levels of precipitation and higher temperatures, she said. "If a category 3 hurricane hit New York, it's catastrophic."
Despite the good intentions, representatives from these cities said that politics--particularly with regard to funding--make climate change all the more challenging.
To get different sources of revenue, London has taken a minority stake in an energy services company that uses savings from energy efficiency to offset upfront investments.
Toronto's Atmospheric Fund was created and sustained by the savings from building energy retrofits.
Another challenge is that political institutions are falling behind the technology advances in areas like lighting and transportation, said Toronto's Jessup.
"The job descriptions, the bureaucracies, have not changed fast enough for these new technologies so they just don't get it," he said.