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SXSW Eco: Sustainability And The Carbon Zero City, By The Numbers

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Alex Steffen speaks on Tuesday at SXSW Eco, in Austin, Tex. | Lynne Peeples

AUSTIN, Tex. -- Replacing fossil fuels with clean energy alternatives such as wind and solar is an important aim. But if the end goal is sustainability, that swap is simply not enough, according to Alex Steffen, author and former Worldchanging editor.

As the global population continues to multiply, energy demands will become "truly gargantuan" -- beyond any quantity that can be easily or cleanly fulfilled, Steffen told a packed room on Tuesday at the inaugural SXSW Eco conference in Austin.

So Steffen's hope rather rests on how this expanding population is distributed, or more specifically, the lower energy needs that come with the higher influx of people into cities. After all, he said in the conference's opening keynote, it is the kind of communities in which we live that determine our energy use. "The denser places get, the lower the amount of energy people use to get around it," he said.

Urban life affords an array of efficiencies, from public transportation and walkability to shared walls. Other SXSW speakers mirrored Steffen's pro-urban sentiments; so do the numbers -- starting with zero.

Zero -- While "carbon neutral" is a popular slogan for sustainability, Steffen prefers "carbon zero." Also the title for his book, this nomenclature "gives a sense that we're doing an equation," he said. "We know that we're always going to have some emissions. The question is, what are we doing to balance those out?"

350 -- Leading scientists warn that 350 parts per million is the maximum concentration of atmospheric carbon dioxide allowable if we want to fend off runaway climate change, and the consequential human and natural disasters.

500 -- "We need 350," said Steffen. But the roadblocks to reaching this lofty goal are rampant. Current atmospheric carbon dioxide levels are already around 394 parts per million. "If we continue on the path we're on," Steffen said, "we have almost no chance of slowing down any sooner than 500 parts per million."

80 Percent -- A popular stand-in trajectory getting tossed around is an 80 percent reduction in emissions by 2050. Steffen calls this an "absolutely perfect political goal," noting that it "requires us to do nothing" yet still sounds like a "big number." "We need to be thinking much more along lines of 100 percent reduction net by 2030," aka carbon zero, he said.

3 billion -- The global population is expected to rise an additional 3 billion by 2050, noted Mark Tercek, president and CEO of the Nature Conservancy, in Wednesday's SXSW conference keynote. An estimated 2 to 3 billion more people will also start living the middle class lifestyle by that time, further increasing burdens on the planet's land, food, water and energy.

2 -- If we continue with "business as usual," said Steffen, then we can expect energy demands to double by mid-century. He suggests our business model needs some serious revamping.

250,000 -- Every day, the world's cities grow by about 250,000 people -- or the equivalent of a city the size of Seattle every three days. People are flocking to urban spaces for the same reasons our ancestors did, said Steffen. It's where they can find education, job opportunities and health care. "Cities offer this great combination of more wealth and less dying," Steffen said. "And most people will take that opportunity when given it."

90 Percent -- By 2050, approximately 90 percent of the world's people will reside within or near a city. "We live on an urban planet," said Steffen. "if we're going to do anything that changes the overall trajectory of humanity's impact on the climate, it has to change what happens for these folks."

250 million -- There are currently more than 250 million vehicles on U.S. roads, noted Bob Perciasepe, deputy director of the Environmental Protection Agency, during a separate SXSW panel discussion on Wednesday. Every year, a chunk of that fleet is replaced with cleaner vehicles, he told the audience. If we can simultaneously reduce the total miles driven with those cars, then it's a "double win" for the environment, said Steffen. It's also a win for people's health and their pocketbooks. Steffen calls cars "mobile money pits."

1 -- With more stuff consolidated in one place, Steffen calls compact communities the "number one strategy" for tackling climate change. "The most climate friendly trip we are every going to take is the trip we never had to take because we were close to what we wanted," he said.

9 -- The carbon equation need not always be balanced to be favorable for the future. Choosing to travel a mile by train rather than car, for example, is equivalent to driving up to 9 fewer miles, noted Steffen. The reason: the carbon footprint of driving goes beyond just what comes out of the tailpipe to include everything from the manufacturing of that car to the concrete upon which its driven, Further, when your only form of transportation is a car, "everything you need becomes a trip," he said. Meanwhile, people who take transit may tend to plan ahead and consolidate their errands.

71 Percent -- Sales rose 71 percent on New York City streets that were closed to traffic, according to the city's transportation commissioner Janette Sadik-Khan. "People shop more when they slow down," said Steffen. "All of this stuff has economic benefits."

40 -- Slowing down is also an example of how a minor environmental change can bring a major health benefit. As Steffen pointed out, if a pedestrian is hit by a car traveling at 40 mph, they have an 80 percent chance of dying. However, if that same car was going 20 mph, that person has a 5 percent chance of dying. "We need to create spaces where cars understand they share the road," said Steffen. Of course, the health consequences of driving go beyond accidents -- for both driver and pedestrian. "Cars are one of leading causes to almost all of our biggest health problems," said Steffen, nodding to a list that includes obesity and high blood pressure, as well as asthma and other known health effects of air pollution. In fact, a slightly longer walk might save more time in the end than a shorter drive. "That walk adds life expectancy, so the time spent walking is not wasted," Steffen added. "It's time you would've spent dead."

94 Percent -- Young adults with a four-year college degree are about 94 percent more likely to live in close-knit urban neighborhoods than their less-educated peers, according to a recent study. “The goal is no longer dream homes," said Steffen, "It’s dream neighborhoods."

6 -- "We need a different relationship to stuff," Steffen said. His example: the home drill. In its entire lifetime, the tool may be used a total of just 6 to 20 minutes. Every hole it drills, he noted, becomes ecologically -- and economically -- very expensive. Car-sharing programs have tapped into the benefits of more people getting more use, but we've only hit the "tip of the iceberg" in terms of the kindergarten lesson's potential, said Steffen. What's more, the use of smart sensors and meters can push people to use those things they do have differently, added Steffen, especially when their results can be measured relative to others. "Comparison will change behaviors quickly," he said. "No one wants to be the outlying energy hog."

90 Percent -- And if a family wants to compete with the Jones in terms of their energy use at home or work, they could take advantage of the estimated 90 percent reduction in energy use attained by buildings that enlist sunlight for lighting and heating, and breezes and shade for cooling, noted Steffen. With the millions of new buildings that will be needed to accommodate a growing U.S. population, better design and construction could keep a substantial amount of climate-changing carbon dioxide out of the atmosphere.

77 Percent -- San Francisco boasts the highest rate of recycling, composting or reusing in the country: 77 percent. "There's a whole suite of things that make for a sustainable city," said Melanie Nutter of the San Francisco Department of Environment during a discussion panel on Wednesday. The department has been working to help America's greenest city become a Zero Waste city by 2020.

1980 -- The year the entire globe needed to start eliminating carbon emissions, according to Steffen, was 1980. The "second best" time, he added, is now.

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