online, we have more from the combat photographer tom bearden profiled. kwame holman has the details. kwame? >> holman: air force sergeant pearsall describes the firefight that ended her military career. watch that video on the rundown blog. we explore the challenges and benefits of earth's growing population. find a chart showing the rapid rise on our world page. all that and more is on our web site: newshour.pbs.org. margaret? >> warner: and that's the "newshour" for tonight. i'm margaret warner. >> brown: and i'm jeffrey brown. we'll see you online and again here tomorrow evening with mark shields and david brooks, among others. thank you and good night. major funding for the pbs newshour has been provided by: moving our economy for 160 years. bnsf, the engine that connects us. >> and by the bill and melinda gates foundation. dedicated to the idea that all people deserve the chance to live a healthy productive life. and with the ongoing support of these institutions and foundations. and... this program was made possible by the corporation for public br

newshour correspondent tom bearden updates the story from nebraska. >> hi, everybody. thanks for coming. >> reporter: hundreds of land owners, environmentalists and union members jammed into high school gyms, community hall and rec centers in six states last week. they were trying to persuade state department officials that proposed pipeline will either create thousands of jobs or will destroy the life and livelihoods of family farmers throughout the midwest. >> creating jobs, enhancing energy independence, improving national security, the keystone pipeline will do all of these and more. >> all this is good for is big oil. and at our expense. with our life blood at stake.... >> reporter: a canadian company called trans-canada wants to build the keystone excel pipeline. the $1 billion system would carry crude oil from the so- called tar sands region in alberta to houston texas for refining. the 1700-mile pipeline would cross six states and go through the heart of nebraska farm country. one of the largest aqua fers in the world lies just beneath the sand hills of nebrask