Sidney Stevens is a writer and editor for magazines, websites, and books, with a focus on health and environmental issues. Some 400 billion birds share the planet with us, each with its own abundant ...

ULEV is an acronym for Ultra Low Emission Vehicle. ULEVs release emissions that are 50 percent cleaner than the current average year's models. ULEVs take the LEV, Low Emission Vehicle, standard a step ...

A solar tree is a structure resembling a tree that generates solar energy using photovoltaic (PV) panels. It employs principles of biomimicry, using a natural system—in this case the form of a tree—to ...

Steve Nix is a member of the Society of American Foresters and a former forest resources analyst for the state of Alabama. These conifers are not native and for the most part have not naturalized to ...

Katherine Gallagher is a writer and sustainability expert. She holds a B.A. in English Literature from Chapman University and a Sustainable Tourism certificate from the GSTC. Denali—no longer called ...

It's a Treehugger's dream come true. Leafsnap is a free app that identifies plant species of all kinds, from flowers and bark to fruit and trees. Go for a walk, take a shot of a leaf, and this little ...

Ever wonder why males and females of the same species can sometimes look radically different from each other? It's all thanks to a condition known as sexual dimorphism, which is generally triggered by ...

Katherine Martinko is an expert in sustainable living. She holds a degree in English Literature and History from the University of Toronto. Wrapping paper may have "paper" in its name, but that ...

Jerry James Stone is a food blogger, vegetarian chef, activist, and internet personality who started writing for Treehugger in 2004. Peacocks are known and loved for their brilliant, ornamental ...

Mary Jo DiLonardo has worked in print, online, and broadcast journalism for 25 years and covers nature, health, science, and animals. Fast fashion describes cheap, stylish, mass-produced clothes that ...

Lisa has been writing for People Inc. since 2005 and works with a wide range of educational publishers, conservation nonprofits, and research institutions. She has written for science museums, nature ...

Solar air conditioning is any air conditioning powered by the sun's energy. Solar air conditioners have no emissions and supply their own energy, so customers can lessen their carbon footprint and ...