Cross-posted from Sightline Daily.

In the Seattle suburb where I grew up, the main transportation choice most residents face is what kind of car to buy. I moved to the city after college and, inspired by the “car-lite” lifestyles of several friends, decided to give cycling a try.

I fell in love with it. Urban cycling freed me from slow buses, parking meters, and mind-numbing elliptical machines. I arrived at work with more energy. I lost weight. I discovered charming neighborhood restaurants. I could smell fresh laundry and dinners in the oven while I pedaled home through residential streets. Getting from A to B on my bike became the best part of my day.

Recently, I won a fellowship and got to spend six months living life on two wheels in the world’s most bike-friendly cities. I brought home 10 lessons for us here in the States:

Given how valuable space is in New York City, the city's rooftops are strangely empty. But a proposal from the city's planning department could change that by making 1,200 acres of commercial rooftops available for urban farmers to open greenhouses across the city.

City law imposes restrictions on how tall buildings are allowed to be in different areas, which is one reasons why rooftops stay empty -- developers often build to the maximum height possible. The planning department's proposal would allow buildings to add rooftop greenhouses above regular height restrictions. And according to a study from the Urban Design Lab, that would mean 1,200 acres of empty, flat rooftops would be eligible for green penthouses.

Remodeling an old pad like these ones, in Baltimore, is more eco-friendly than building a new one. (Photo by cinderellasg.)

Looking for the ultimate earth-friendly bungalow? No need to engineer some LEED certified space pod. Buy an old house and gird yourself for an eco-friendly remodel.

A study released Tuesday finds that in almost every instance, remodeling an old building is greener than building a new one. Beyond that, it shows that reusing old buildings provides immediate results in the fight against climate change, while a relatively energy efficient new building won’t pay climate dividends for decades.

Taken to the scale of the city, the study has some fascinating implications. Cities, it turns out, serve as a sort of carbon sink -- the existing buildings hold a tremendous amount of “embodied energy.” Conserving that energy by sparing these buildings from the wrecking ball does a lot of good for the planet, too.

Because it takes longer to fill up an electric vehicle than to fill a gas tank, and because EV infrastructure is still limited, the most common criticism of EVs goes something like "OMG RANGE ANXIETY." And, sure, no one wants to get stuck in their big metal bucket on the side of a highway until a tow truck can haul your ride to the nearest charger. But two Columbia Ph.D. students have parsed real actual data (from the National Household Travel Survey) to show that, in the daily lives of most people, range anxiety just shouldn't be a thing.

It’s not news that utilities can be budget-killers, and apparently people are getting wise to the fact that energy-efficiency means lower utility bills. A recent Yahoo survey found that energy efficiency is the one feature everyone can agree on when they imagine their "dream home" -- ahead of water views, a custom build and all the other things Americans usually aspire to.

In Sweden, city planners and the country's traffic authority are looking into building a four-lane bike superhighway between the university town of Lund and Malmö, Sweden's third-largest cities and one of its most diverse.

Cities like London have invested in protected lanes that they call “bike superhighways,” but this one would be one of the first to connect two cites (you know, like an actual highway). The designs for the trail have it following the path of railway tracks, protected from wind by fences and hedgerows.

Passive Houses are homes so well insulated that they require no heating at all, even in winter. They're super popular in Europe, because it’s a magical land where everything is made out of chocolate and any sexual encounter that ends in fewer than three orgasms is immediately reported to the happiness police. Journalist Charlie Hoxie realized that most people in America have never heard of the Passive House (or Passivhaus in the original, economical German) building movement, so he embarked on a documentary to spread the word. What follows are a series of excerpts from that film. You can also …

No matter how strong a cyclist's legs are, a bike cannot go as fast as a car. Duh, right? But traffic lights are not as smart as humans, and they do not instinctively understand that. So they’re programmed to assume leg-powered vehicles can make it safely through lights in the time allotted to things with engines. Luckily, some human was smart enough to invent the Intersector --  a traffic light that respects the difference between bikes and cars. A few California towns are installing these suckers, which measure the speed and dimension of objects rolling towards them in order to …

Photo: Steve JurvetsonThis story is excerpted form a longer piece in Urbanite. Imagine if someone concocted a method for turning cities inside out, so we could view their inner workings -- their strengths and shortcomings, how they grow and thrive and die -- at an almost cellular level. By analyzing a vast sweep of data, everything from how much money the city's residents make to the numbers of miles in its sewer lines, this system could tell us just how successful a city has been, where it falls flat, and how it stacks up to other cities of its size. …

Jason Griffiths is an assistant professor of design at Arizona State, and apparently living in the middle of all that desert sprawl got to him after a while. In the early aughts he jumped into a car, drove all over the country, and made a discovery so banal it’s practically a tautology: Suburbia is the same everywhere. Except, because he's a photographer and he's been steeped in design thinking and this is what artists do, Griffiths managed to turn his sojourn into a book called Manifest Destiny: A Guide to the Essential Indifference of American Suburban Housing. It's a collection …