SYDNEY, Australia — From the street, Alicia Campbell's house looks no different from the others in her suburban cul-de-sac. But it has a secret: It's green — very green.

The four-bedroom home she shares with husband Jason Young and their two sons sucks no water from Australia's drought-stricken reservoirs, recycles everything from food scraps to sewage, and even pumps electricity back into Sydney's power grid.

As the world debates how best to respond to climate change, families such as Campbell's, like others in the U.S. and Europe, are taking the challenge personally.

"It was a moral decision for me," said Campbell, 38, an intensive-care nurse who describes herself as "not hippie, just normal."

When she and Young began building in 2005, they decided that persistent drought made water the first priority. Like thousands of Australians whose homes are too remote to access urban water supplies, they decided to use rainwater for drinking, washing and flushing the toilet.

Under the driveway lies a 6,600-gallon concrete tank with a steel lid. Each time it rains, a network of pipes feeds water from the roof through a flush system and into the tank. The first few gallons are diverted into the garden to eliminate any heavy metals, leaves and bird droppings.

Despite its sunny climate, coal-rich Australia doesn't use much solar power, and its 21 million people are the world's biggest greenhouse gas emitters per capita.

So in February, Campbell installed 18 solar panels on her roof that power the house by day. Excess power is fed back into the city's electricity grid, earning the family a small rebate.

At night, the house switches into the grid rather than store the solar power in high-maintenance batteries. Campbell has yet to receive her first bill from the state energy supplier, but estimates the house has produced more energy than it has used.

A computer monitor shows the panels have produced 1.3 megawatt hours of electricity since they were installed, the equivalent of 1.2 tons of carbon dioxide on the coal-fired system.

At that rate, the family will save around five tons of greenhouse gas from entering the atmosphere over 12 months.

In the yard, the family is experimenting with growing fruit and vegetables. Their chickens, Itchy and Scratchy, pick at vegetable scraps near a big compost heap.

The Australian Conservation Foundation estimates the average household produces 2,160 pounds of garbage a year, about 40 percent of it perishable food, garden or wood matter. Since they started composting, Campbell says her family sends around two garbage cans to the landfill each month, compared to four before.

Even their sewage is treated on site.

After wrangling with local officials worried about odors and leaks, Campbell received permission to install a commercially available waste treatment system in the back yard.

Three 1,320 gallon tanks filled with sand, gravel and bacteria dissolve and purify the waste underground. An ultraviolet filter — similar to those used by Sydney's water authority — then irradiates the water, making it safe for use on the garden.

Similar systems have been used in rural Australia for years, but city officials have been reluctant to approve them because of health risks in higher density areas.

"In an urban environment, there tends to be greater caution," said Simon Hayman, a Sydney University architecture professor who specializes in eco-friendly design.

"As soon as you place responsibility for maintenance of water quality on a homeowner, you are then relying on them looking after themselves which, of course, may or may not happen," Hayman says.

For Campbell, the project hasn't been cheap.

Power- and water-saving devices, plus time spent wrangling with the municipality over the sewage system, have added about $65,000 to the $300,000 it cost to build the house, Campbell estimates.