1. Engineering solutions for ocean cleanups

At 19, I was struggling with basic things like filing my taxes and attending my more boring lectures. At 19, Boyan Slat drafted plans for an Ocean Cleanup Array, a floating structure that could consolidate and sort plastic drifting in the ocean, storing it for later recycling. The structure consists of a network of booms which would accumulate floating debris and guide it towards a central processing unit that would separate it from plankton and sort it.

Slat adds that his project has another dimension, one that brings the public’s attention to a growing issue: "One of the problems with preventive work is that there isn’t any imagery of these ‘garbage patches’, because the debris is dispersed over millions of square kilometres. By placing our arrays, however, it will accumulate along the booms, making it suddenly possible to actually visualize the oceanic garbage patches. We need to stress the importance of recycling, and reducing our consumption of plastic packaging."

The project is currently raising money for a feasibility study.

2. Bikeshares in the world’s most famous city

Bikeshares exist in many places: Paris, Montreal, Washington DC. The system is incredibly simple: There are numerous bike stands around the city. You find the one nearest you, swipe your credit card, which is charged a modest fee, unlock a bike, bike to where you’re going, then drop off your bike at the stand nearest your destination. Your credit card, of course, acts as insurance should you fail to return the bike.

In my home of Montreal, the city bikeshare (called Bixi) is both useful to workers, many of whom use Bixi for their daily commute, and popular among people who would like to stay out later than midnight, which is when the metro closes. The 5am cavalcades of happy people on Bixis are quite a sight. (Friendly reminder: Drunk biking could be a bad idea.)

Now this idea, in its largest-yet iteration (6,000 bikes, to be expanded to 10,000), is coming to the most famous city in the world. Despite naysayers who worry that the city is “too mean” for bikes, seeing local sustainable transport on two wheels in NYC is pretty exciting.

3. Millennium Seed Bank Project

Seed banks, large libraries that house the seeds of various plant species, provide both a living catalog of plant biodiversity and a form of insurance against extinction. The latter is an important mission in the face of what researchers deem a global biodiversity crisis.

Housed in Sussex, England, the Millenium Seed Bank Project is one of the most famous seed banks globally. Since the year 2000, it has been collecting seeds of plants that grow in the wild, gathering its billionth seed in 2007. Another seed bank, the Svalbard Global Seed Vault, is located in northern Norway and serves as a sort of neutral backup to other banks. It was listed as #6 on the Time “Best Inventions of 2008″ list.

4. Milan’s vertical forest skyscrapers

Imagine a skyscraper that contains a hectare of forest. What sounds like a detail from one of George Lucas’s more creative set designs is rapidly becoming a reality in the Italian city of Milan. Construction of the Bosco Verticale (Italian for “vertical forest”) is set to complete later this year.

The towers, both over 80 meters high, serve both as residential areas and as office buildings, and their terraces together hold over 900 trees. What seems at first like a flashy idea has practically sound aspects. Besides adding a strikingly unique design perspective to the urban landscape, the trees help filter air to ameliorate the problem of urban air pollution. Photovoltaic energy systems will reduce the buildings’ energy dependency on Milan’s infrastructure.

5. Tool lending libraries

Imagine going to your local library to borrow, say, a book on the Aztecs, the latest issue of Vogue, and a lawnmower. That’s more or less the idea behind tool libraries—just like you don’t need to own every book you want to read once in a while, you don’t need to own every tool you want to use once in a while.

One of the first tool lending libraries was the Berkeley Public Library Tool Lending Library, which was founded in 1979 and still exists today. However, the libraries are found all over the States and in Europe, and their inventories can be quite extensive. (At a tool lending library in Ohio, for example, you can borrow a power planer, a water pump, a hatchet, and, uh, safety scissors.)

These community projects are environmentally sound because they reduce consumption (not every home desperately needs to own a chainsaw) and foster a DIY ethic that has conservation principles at its core. Also, you get to borrow a cement mixer.

6. Community Supported Agriculture (CSA)

Embodying the old hippie adage of “think globally, act locally,” Community Supported Agriculture is a living link between farmers and their communities. Members sign up for regular deliveries of farm produce at a previously decided rate. The price is set based on the budget of the farm and the produce delivered depends on the harvest of the farmer, making CSA members actively invested in their farms.

The project, which began in the 1960s in Europe, has been growing in popularity: America now has over 13,000 CSA farms. CSAs have been widely lauded for obvious (and valid) reasons: supporting small local business, farming less harmfully, avoiding buying food that’s flown across oceans, eating more vegetables.

Also, it’s great fun: In some respects, it’s a bit like having Christmas every Tuesday, except instead of socks the presents end up being beets and exotic (yet locally grown!) leafy greens you’ve never heard of. (Do you know what celtuce and Swiss chard are? Yeah, I missed that part of the “vegetables” unit in elementary school, too. It’s okay.)

7. Canadian tree planters

Any ecologist will somewhat balk at the idea that the mass reforestation operations that take place every year in northern Canada should be called environmental initiatives, and in fact they aren’t environmental initiatives—they’re simply a way to mitigate the adverse effects of Canada’s massive logging industry.

The general scheme goes like this: Canada has vast forests that it logs for profit. Laws about sustainably managing natural resources mandate that these forests be replanted, and the only way to do that with any sort of effectiveness is by hand. The end result is that every spring, legions of sinewy people in boots and fleece and spandex take to the hills of northern Canada with shovels and go do this, carrying baby trees on their backs and planting them one by one according to specific and arcane rules.

They do not, by any means, negate all of the effects of the logging industry, which ultimately destroys complex forest ecosystems with machines as big as houses and replants them with a few types of nursery-grown seedling. However, the sheer scope of activity is awesome to behold: Last year, Canadian tree planters collectively planted somewhere between 300 million and 500 million trees. By hand. That’s a lot of biomass, a lot of carbon fixed, and a lot better than nothing.

8. Bikes made out of cars

A bike chain out of a car transmission belt? Car door metal welded into bike tubes? Engineering can be pretty cool. Bicycled and the Carma Project are two design projects that recycle junk cars and turn them into bikes.

Though neither is ready to produce its recycled bikes for a wider market yet, both showcase beautiful small-scale design while making an original (and utilitarian) statement about sustainable transit. Though I suppose you can’t put one of those ubiquitous “One Less Car” stickers on one.

9. Rooftop farming

Rooftop farming reutilizes otherwise empty space for the purpose of growing plants. Besides the obvious benefit of produce, urban gardens can sequester carbon and act as stabilizers of their environments through transpiration.

The largest rooftop farm in the world, the Brooklyn Grange, was founded in 2010 and has gone on to create a total of 2.5 acres of rooftop farming space, on which vegetables are grown and bees are kept. It’s a fully functioning commercial farm that succeeds in making a profit. There are also rooftop farms in Boston, Montreal, Hong Kong, and many other places.

Though my friends who worked as urban farmers point out that the world of urban farming is not without its own procedural complications, the tomatoes they used to bring me were delicious.

10. Ancient tree archive

Ninety-eight percent of the old-growth forest in the United States has been cut down. This is the urgent motivation behind the Archangel Ancient Tree Archive, which was started in 1996 by a father-son team from Michigan and now counts multiple distinguished botanists and geneticists among its members.

The group collects, archives, and plants seeds from ancient trees, some 2,000 years old, with the mission of studying and propagating their genetics before they are gone. Through the project, the seeds of giant oaks and coast redwoods find new homes across the globe, thanks to a small group of unabashed treehuggers. The hope of the project is that they’ll keep growing for some time to come.

This story originally appeared on Matador Network, a Dwell partner site.