The southwestern United States is moving headlong toward an environmental catastrophe of apocalyptic proportions.
The already drought-prone region is almost entirely dependent on a shrinking snowpack and sparse rain in the Colorado River Basin. As the planet’s climate changes, an already overtaxed and volatile water supply is expected to get even more unstable.
“A lot of people say that in global warming there will be winners and losers. In the Southwest, we’ll be in the losers’ category,” University of Arizona climatologist Jonathan Overpeck said at a symposium on global warming’s effect on the Southwest.
Overpeck discussed the latest scientific consensus on climate change at the Feb. 19 symposium, hosted by the Urban Land Institute at the Palms.
He was joined by Southern Nevada Water Authority General Manager Pat Mulroy, who discussed what can be done on a local, national and international scale to head off disaster.
The problem of climate change in the Southwest is fairly complex, but can be summed up in one word: water.
The Southwest is the most persistent hot spot on the globe and has a history of severe drought.
As a region, we depend almost entirely on the Colorado River Basin for our water, and all climate change projections estimate that the basin will be among the most heavily hit by drought as the world warms. Most projections say the region will warm by about 7 degrees by 2050 and 10 degrees by the end of the century.
There is a 10 percent chance the warming in this region could be double that — about 20 degrees warmer by 2100.
At the same time, the region will experience its typical drought pattern. That means it will be hotter and dryer from the mountaintops to the valley floors and we’ll have a lot less water available to deal with it.
The most up-to-date climate models available show that if humans reduce carbon emissions significantly starting now, water flow in the Colorado River Basin will be reduced by 5 percent to 40 percent over the next few decades.
If we do nothing, it will be worse, Overpeck said.
“We’ve had low rain and low snow for many years; there’s no doubt we’re already in a drought,” he said. “The thing is, with climate change, we may never come out of the drought.”
The global scientific community agrees that climate change is occurring and is caused by the activities of humans, mostly from deforestation and growing greenhouse gas emissions.
“We need to adapt to drought and climate change because whether we cause it through global warming or Mother Nature causes it or both, we’re still going to suffer,” Overpeck said.
Much of the responsibility for reversing the emission trend falls on Americans, who create about 25 percent of the carbon being spewed into the atmosphere each year.
“The United States is a voracious consumer of natural resources,” Mulroy said. “Those days are over. We can’t afford to use natural resources at the rate we’re currently using them.”
Much also must be done to halt growing production of polluting fossil fuel-fired power plants in China and India and to fund retrofits or replacement of polluting power plants in poorer nations around the world.
That change has to start at home, Mulroy stressed.
“We need to be part of the solution,” she said. “We can’t be in the eye of the storm and not look at our carbon footprint and energy sources.”
To start, she suggests massive regionwide management and conservation of water resources. This includes regulation of the agriculture industry, indicating what crops can be grown in drought-prone areas, decreases in water consumption by residents and industry, widespread wastewater recycling and more efficient management of snowmelt and rainfall through underground catchment basins.
She also said it’s essential to tap into alternative water sources for urban areas such as Las Vegas.
“The most daunting thing is adaptation, and adaptation has to happen at all levels from large institutional changes to individual behavioral levels,” Mulroy said.
That includes urban and suburban developers.
Mulroy said tomorrow’s neighborhoods need to be more condensed, more sustainable and more community oriented. That means smaller or no yards and no more brick walls, but shared recreation areas are necessary.
Not only would such a design be more efficient, it would also help rebuild a sense of community in places such as Las Vegas.
“We’ve built a community of people who share borders — that’s it,” she said.
She also urged Nevada builders and architects to put pressure on the Green Building Counsel to take a more regional approach to Leadership in Energy and Environmental Design certifications.
Specifically, she wants to see the end of LEED points for gray-water systems in Las Vegas to be replaced by points for sending the water down the drain, where 100 percent of it is recycled and sent back to Lake Mead.
This could encourage other municipalities to recycle wastewater as well.
“Gray-water systems won’t generate a single drop of new water,” she said. “You’re simply replacing a municipal water recycling program with an individual water recycling program.”
The region also needs to take advantage of the opportunity to turn renewable resources into electricity, both speakers
said.
If fossil fuel-fired power plants were reduced and renewable energy were dedicated to charging electric cars, the country could significantly reduce its carbon footprint and slow climate change.
The key is to start working on these solutions now, Mulroy and Overpeck said.
“The Southwest needs a plan to adapt,” Overpeck said. “The longer we wait, the worse it will be and for a very long time.”
http://www.lasvegassun.com/news/2009/feb/27/adapting-water-woes/
