Category: LM_COMMUNITY_MN

Cities are on the front lines of the growing physical risks associated with climate change. ¹ They are home to more than half of the world’s people, and by 2050, that figure is projected to rise to 68 percent. ² Urban areas are often located in places of particular climate risk, such as on coastlines, floodplains, and islands. Moreover, modern urban infrastructure and its operating systems are closely connected. A failure in one part of a network can affect another, multiplying the damage.

A lot of cities have ambitious goals to reduce greenhouse gas emissions. But to achieve those goals, they first need to know exactly how much carbon pollution they produce now and where it comes from.

As part of a global effort to limit the extent of climate change and stave off its worst impacts, many nations, regional jurisdictions, and cities have set the goal of emitting zero net greenhouse gases by 2050. Getting there involves not just a major shift from fossil fuels to renewable energy, but also managing the benefits and costs of this sweeping transition in a way that distributes them fairly.

Bobby Outten, a county manager in the Outer Banks, delivered two pieces of bad news at a recent public meeting. Avon, a town with a few hundred full-time residents, desperately needed at least $11 million to stop its main road from washing away. And to help pay for it, Dare County wanted to increase Avon’s property taxes, in some cases by almost 50 percent.

At least 48 U.S. cities are under-counting their carbon dioxide pollution by nearly 20%, according to a new study that compares local disclosures against a national database that can now estimate the same information. The new analysis could create confusion about how much cities emit—and therefore how much pollution they must cut—at a time of increased attention to climate change from the White House, state capitals, and city officials.

Scientists are taking aim at a commonly-overlooked problem in the fight against climate change: what to do about cities.

Whichever side of the subjective city-versus-rural debate you’re on, the objective laws of thermodynamics dictate that cities lose on at least one front: They tend to get insufferably hotter, more so than surrounding rural areas. That’s thanks to the urban heat-island effect, in which buildings and roads readily absorb the sun’s energy and release it well into the night. The greenery of rural areas, by contrast, provides shade and cools the air by releasing water.

Both a pandemic and a climate crisis make planning for the future difficult. How do we design our lives around ever-increasing hurricanes or wildfires?

Burning fossil fuels in densely populated regions greatly increases the level of the greenhouse gas carbon dioxide. The largest carbon dioxide sources are cars, trucks, ports, power generation, and industry, including manufacturing. Urban greenery adds CO₂ to the atmosphere when vegetation dies and decomposes, increasing total emissions. Urban vegetation also removes this gas from the atmosphere when it photosynthesizes, causing total measured emissions to drop. Understanding the role of urban vegetation is important for managing cities’ green spaces and tracking the effects of other carbon sources.