The state of our planet has never been more urgent -- for one, 2014 was the hottest calendar year on record, suggesting that the earth is getting increasingly warmer.

In New York City, sustainable and green initiatives big and small are helping to raise awareness about climate change and eco-friendly living, from recycled fashions to vegetarian schools to energy-saving on a stadium scale.

As we mark the 45th anniversary of Earth Day on April 22, here's a look at ways New Yorkers are leading the city toward a greener future -- one non-carbon footprint at a time.

 

Urban farming

 

Green rooftops are growing across the city. One of the largest of its kind is Gotham Greens' 60,000-square-foot greenhouse being developed atop a Jamaica building. It is set to start growing greens and herbs later this year and is expected to produce more than 500 tons of fresh vegetables each year. This is Gotham Greens' third rooftop greenhouse, with others currently operating in Greenpoint and Gowanus. Brooklyn Grange is also flourishing, with two vegetable gardens in the city producing more than 50,000 pounds of produce a year that goes to markets, retailers and restaurants. Some restaurateurs have taken things into their own hands; Rosemary's operates a rooftop garden of fresh greens and herbs atop its West Village restaurant that help flavor its Italian dishes.

 

Parks and rec

 

Caring for the city's parks has gotten a big boost. In March, the U.S. Department of Interior announced plans to increase volunteerism in public parks across the country, choosing NYC as its starting point. The project strives to raise the annual number of volunteers in American parks from 322,000 to 1 million by 2017. Prospective volunteers can contact NYC's parks department for opportunities in protecting the more than 29,000 acres of city park land.

 

Vegging out

 

A vegetable-based diet can be a nutritious -- and sustainable -- one. And P.S. 244 in Flushing is paving the way as the first school in the country to serve all-vegetarian meals. Since 2012, the school has served vegetarian breakfasts and lunches every day. The concept seems to have caught on -- Lower Manhattan's Peck Slip School became the country's second school to turn vegetarian in 2013.

 

Environmental shopping standards

 

From recycled plastic to organic cotton, NYC retailers are selling items to help protect the planet. Love, Adorned in the East Village offers organic items for men, women and children. Catering to men's fashion, Red Hook's Three Leaves only carries items that meet strict criteria of environmental standards, paying special attention to reducing the amount of shipping materials in each delivery. Sustainable NYC is an East Village staple for biodegradable cleaning products, upcycled bags and jewelry, Fair Trade chocolate and more. The store's wallpaper, paint and solar-powered outdoor sign are also eco-friendly.

 

Reduce, reuse, recycle, rewear

 

Fashion designer Kristen Alyce's favorite material is trash. From empty drink bottles to old newspapers, the 28-year-old designer transforms daily garbage into glamorous outfits for her eco-conscious company, Garbage Gone Glam, which recently opened an office in Brooklyn. The high-fashion pieces start at $500, and customizable designs are also offered.

 

Green team

 

The Bronx Bombers are hitting it out of the park when it comes to going green. When the Yankees rebuilt its stadium, it integrated sustainable initiatives throughout, from purchasing more than 33 million kilowatt-hours of renewable energy certificates and adopting C-Neutral, which neutralizes greenhouse gas emissions, to reducing water consumption and recycling cooking oil. In total, the Yankees' sustainable efforts are equivalent to taking more than 4,700 cars off the road for one year.

 

Eco-hospitality

 

When 1 Hotels makes its NYC debut this July near Central Park, it'll provide a sustainable option to tourists. The unique hotel chain offers triple water purification systems in all guest rooms (you won't find any plastic water bottles in the rooms), integrates a chalkboard tablet in place of pads of paper in all rooms and serves several organic options in its in-house restaurant, including a once-a-week meatless menu. Employees are also encouraged to commute eco-consciously: The hotel also provides Citi Bike reimbursement and free bike parking in its garage.