Are Americans more worried about population than climate change?

A recent poll found 29 percent of Americans listing "overpopulation" as a major environmental challenge, while just 27 percent named global warming.

Can we turn mining pits into underground cities?

Architect Matthew Fromboluti designed this inverted skyscraper to make use of abandoned open-pit mining operations in Bisbee, Ariz. The 900-foot underground building (maybe we should call it a mantle-scraper?) wouldn't just be for residences -- it would comprise an entire self-sufficient subterranean city, including crops fed by skylights. 


Talking to my son about sex and sustainability

"Are we going to talk about sex again?!" screamed my 12-year-old son. I had just sat down with him to have one of our father-son talks.

The world's first vertical forest is under construction in Milan

We've pretty much established that trees are awesome -- they make you smart, improve your home's value, filter pollution, provide shade, and produce oxygen. But even in a city that prioritizes green spaces, surface area is at a premium. How do you provide enough trees while still living densely? Milan, Italy, has a creative answer: a forest in the form of a skyscraper.


Ask Umbra: Is banning clotheslines legal?

A reader wonders if neighborhoods can legally hang clothesline users out to dry. Umbra pins down the answer.


Remember when Americans used to care about population? [VIDEO]

These days, when people go out of their way to avoid mention of the P word, it's almost hard to believe that population used to be a mainstream issue.

California will ban BPA from baby cups

California Gov. Jerry Brown signed into law a bill that bans bisphenol A from baby bottles and sippy cups sold in the state, starting in July of 2013. The Environmental Working Group had been pushing the law, which is called the Toxin-Free Infants and Toddlers Act and requires that manufacturers sub in the "least toxic alternative available" for hormone-disrupting BPA.


An indigenous take on family planning and population

A Mayan leader in Guatemala finds hope for the survival of his people in a combination of traditional and modern solutions -- including family planning.

Climate Change

Fighting climate change in the Navajo Nation

A physician-turned-street-artist takes an urban art form to a landscape where most of the walls are eons-old stone.