Meet the companies tackling nine of humanity's biggest problems -- and making millions saving us from ourselves.
Problem #4: Dirty Air
Problem #4: Dirty Air
The background: Three billion households worldwide depend on wood and charcoal to prepare food, but a person cooking over an open fire that's burning wood or kerosene inhales the equivalent of the smoke from two packs of cigarettes a day. Respiratory infections are the leading cause of death in children under the age of 5 and kill 1.6 million people overall each year.

The solution: Sun Ovens International, based in Elburn, Ill., sells a family-size solar oven for $259 that's used in 130 countries. A much larger solar cooker, including a trailer and a set of pots and pans, sells for $10,500 and is designed for schools, hospitals, and orphanages. The solar oven uses mirrors to redirect the sun's rays into an insulated box.

The ovens have been popular in Haiti; the United States and Canadian militaries will use them for humanitarian projects in Afghanistan, and they'll soon be available in Uganda and Nepal.

The payoff: Sun Ovens has sold about 32,000 of its family-size ovens and 260 institutional units. Last year it generated $720,000 in revenue.

The opportunity: Sun's CEO estimates there's a worldwide market for more than 300 million family-size solar ovens, which would generate at least $75 million in revenue annually.

Global Warming

Oil Dependency

Hunger and Malnutrition

Dirty Air

Dirty Water

Overfishing

Epidemics

Drug-Resistant Infections

Waste Disposal
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Market indexes are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer LIBOR Warning: Neither BBA Enterprises Limited, nor the BBA LIBOR Contributor Banks, nor Reuters, can be held liable for any irregularity or inaccuracy of BBA LIBOR. Disclaimer. Morningstar: © 2014 Morningstar, Inc. All Rights Reserved. Disclaimer The Dow Jones IndexesSM are proprietary to and distributed by Dow Jones & Company, Inc. and have been licensed for use. All content of the Dow Jones IndexesSM © 2014 is proprietary to Dow Jones & Company, Inc. Chicago Mercantile Association. The market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. FactSet Research Systems Inc. 2014. All rights reserved. Most stock quote data provided by BATS.