Melinda Gates has big plans. (Photo by World Economic Forum)

Can Melinda Gates do for family planning what Al Gore did for climate change? Gates has decided to make birth control her signature issue. “My goal is to get this back on the global agenda,” she tells Newsweek. As co-chair of the richest foundation in the world, she might actually be able to do it.

The contraceptive cause could certainly use a high-profile advocate: 215 million women [PDF] around the world want to avoid pregnancy but aren't currently using modern birth control. As Gates explained last month during a TEDxChange presentation on family planning, "This is a life-and-death crisis. Every year, 100,000 women who don’t want to be pregnant die in childbirth. About 600,000 women who don’t want to be pregnant give birth to a baby who dies in her first month of life. I know everybody wants to save these mothers and babies."

Women need to be on the Rio docket. (Photo by Cintia Barenho.)

In just two months, world leaders will gather in Rio to hammer out a new set of agreements on what sustainable development means, and more importantly, how both rich and developing nations can get there before it’s too late. Day by day, the buzz is building around this historic Earth Summit. But there’s a problem: The big plans being hatched for the occasion -- nicknamed Rio+20 -- leave women out.

Of course there will be scores of women leaders at the Earth Summit. But key issues that matter to women -- reproductive health, gender equality, girls’ education -- are notable for their absence from the agenda. That needs to change.

The fact is, sustainable development isn’t sustainable if it doesn’t include empowering women to control their own bodies, educate themselves and their kids, and have a voice in government at all levels. As long as women continue to die each day because they are denied access to sexual and reproductive health and rights -- such as care during pregnancy and the right to live free of violence and discrimination -- we cannot talk about sustainable development goals.

Throughout the world, many women have little say over their bodies, their land, and their resources. And a huge number of women are unable to protect their livelihoods in the face of climate change. On the flip side, empowering women creates a powerful ripple effect --enabling families and communities to be healthier and more prosperous, and helping to restore balance between people and the air, land, and water we all depend on.

Simply meeting women’s needs for contraception, in particular, would reduce maternal and child mortality, enhance human rights, increase food security, and slow the world’s population growth. In so doing, it would also substantially slow the growth of dangerous greenhouse gas emissions.

What’s the cost? Not much: In Latin America and the Caribbean, for example, fulfilling the unmet need for sexual and reproductive health care would cost less than Americans spent on Valentine’s Day dinners last year.

Rio+20 presents a once-in-a-generation opportunity to ensure that women's needs and women's rights are given top priority in plans for sustainable development. In a time of multiple, interlinked human and environmental crises and very tight funding, inexpensive, multiple-benefit investments like family planning are more important than ever.

So including women and their reproductive health in the Earth Summit agenda is a no-brainer. The possibility that a new set of "Sustainable Development Goals" -- to replace the Millennium Development Goals -- may emerge from the Summit makes women’s full participation and inclusion even more important. Women hold up half the sky, as the old Chinese proverb says, and they must be protagonists in the next chapter of the world’s aspirations for a sustainable future.

Also check out:

• Earth Summit 101: A Jedi’s primer to the meeting in Rio
• Speak up! Young people need to be heard at the Earth Summit

OK, I had always understood that Canadians build tree forts with little tiny fridges in them if, and only if, they have a million dollars. But Vancouver-area software developer Joel Allen built his insanely beautiful HemLoft when he went financially bust. And because he was broke, he built it by hand, illegally, on government-owned land.

Richard White. (Photo by Jesse White.)

You know the feeling: the intoxicatingly fresh air, the crunch of leaves under your hiking boots, and only the chirps, gurgles, and caws of the forest to keep you company as you wander down the trail. Ah, to be free of people and surrounded by untouched nature …

Environmental historian Richard White will stop you right there. This contrast between a hike in the woods and a walk down the city streets, between Yosemite and your office cubicle, is not one of nature versus non-nature. People have lived in, worked in, and even burned these landscapes throughout history, White says, and the idea of pristine wilderness that is “untrammeled by man” -- or so goes the Wilderness Act -- is a myth. “Particularly with climate change,” he says, “we have now touched everything except maybe some of the deepest parts of the ocean.”

I'll admit that I attended one TINY textbook fire as a teenager. It was somebody's math book, and we just stuck it in a park barbecue and then melted some cups over it, nothing particularly Fahrenheit 451. But there are better ways to dispose of textbooks that you hate, or just don't need anymore, but for whatever reason can't sell back. Chinese artist Liu Wei, for instance, does it by making spectacular carved-book cityscapes.

Q. Dear Umbra,

I am sure I am singlehandedly filling up a landfill with all the plastic spray bottles I have purchased in the last 25 years. I make many of my own cleaners, some I have even read about in Ask Umbra. I make my own bug spray, weed killer, linen spray, etc. But I seem to buy at least three plastic bottles for each job, which break and are often not recyclable. I am on a quest to find a spray bottle that would last a long time. Please help me.

Penelope J.
Mariposa, Calif.

Photo by El Finco.

A. Dearest Penelope,

I wish my name were Penelope. I also wish you were not singlehandedly destroying the planet with your penchant for flimsy plastic spray bottles.

I kid, of course. While your bottle habit is not ideal, your DIY habits are admirable. I bet we can find a way to make your vessels match your values.

Photo by Marianne Klock.

Saturday is the night to engage in your moon-related activities -- blow it up, write your name on it, release your singing marmoset creatures, whatever -- because you’ll have a pretty good view. It's a “supermoon,” where the moon is closer to earth in its orbit than normally -- and it's going to be the biggest, brightest full moon of 2012.

It's all very well to talk about the urban jungle, but how often are you supposed to water it? Carmichael Collective's tongue-in-cheek urban plant tags offer care instructions for metropolitan flora like benches, fire hydrants, stop signs, and mailboxes.

Thoreau went to the woods because he wished to live deliberately and suck all the marrow out of life. But if you don't want to go outside to do that, don't worry: The Walden experience now comes in video game form!

The digital Walden Pond will showcase a first-person point-of-view where you can wander through the lush New England foliage, stop to examine a bush and pick some fruit, cast a fishing rod, return to a spartan cabin modeled after Thoreau’s and just roam around the woods, grappling with life’s unknowable questions.

Oh yes, this is going to be the next Mass Effect for sure. As Erik Hayden at Time says, "A video game about a 19th-century philosopher living in a shack, where there’s only one character and nothing happens? Sign us up!"

Photo by Bastien Vaucher.

This year marks the 10th anniversary of our Ask Umbra advice column, and to celebrate, we’re pulling one particularly poignant question or tidbit of eco-advice out of the archives each week. Today, a question from a bicyclist in Berkeley:

"My skirt gets caught in the bicycle chain ... Do you know any wonderful manufacturers out there who can solve my problem?"

Read on to see Umbra’s answer. Plus: She shares a website that’ll show you how to make your own “skirt guard.” And don’t you go anywhere, fellas: It works for kilts and coat tails, too.