The U.S. Forest Service just peered into the future, and it's kind of freaking out. It released its Future of America's Forests and Rangelands Report (pdf) today, and, surprise, it brings some grim tidings. Not just for the nation's ecosystems, but for the hundreds of millions of people that happen to rely on their services to survive.
It's worried that accelerating land development will raze forests, endanger species, and transform some of our most important carbon sinks into carbon emitters. But perhaps most of all, it fears that the impact of climate change on our water supply is going to put a major strain on society.
In the report, the Forest Service estimates that urban and developed land area may expand by 77 percent by 2060, taking 34 million acres of forest down in the process. That means a 77 percent increase in cities, suburbs, and developed industrial land. And it means trouble.
"The loss of forest land contributes to reduced growth in total forest inventory, reduced forest carbon stocks, and reduced tree canopy cover," the report explains. "Carbon stocks are also projected to decrease … as a result of declining forest land area and changes in carbon stored per acre. The result is that forest land becomes an emissions source in future decades."
In other words, forests are important because they suck down major portions of all that carbon we spew into the atmosphere. When we cut them down and convert them into developed land, those carbon sinks become carbon emitters–part of the problem. Meanwhile, development continues to threaten endangered species, which get kicked off their land when the human steamroller moves in.
"Given the projected land use changes, biodiversity in the United States is expected to continue to erode," the report grimly concludes.
Most of this forest destruction will take place in the South, where populations are booming the fastest. Up to 21 million acres of forest are expected to be razed. Over the next half century, that region will lose up to 8 percent of its forest cover. But the South's true problem isn't forest loss–it's water loss.
Just check out this alarming projection:
"water withdrawal would increase from 2 to 42 percent from 2005 to 2060. The result of the combination of increasing water demand and declining water yields is an increase in vulnerability of the U.S. water supply to shortage, especially in the larger Southwest and Great Plains."
A bump from 2 percent to 42 percent is pretty massive. Because climate change is making those regions more arid and drought-prone, the Forest Service expects that we'll need to withdraw a hell of a lot more water to irrigate crops and, get this, meet "landscape watering" needs in desert towns like Phoenix and Las Vegas.
All in all, the nation's forests and rangelands look to be in a something of a jam. Sure, we're still razing and developing those forests that dared wander too close to our metropolises. But worse, the changing climate and thirsty, foolhardy, desert-city-building man is going to dry them out.