In the past century the earth's human population has quadrupled, growing from 1.5 billion in 1900 to about 6 billion today. By 2050, it is estimated that the global population will reach 9 billion. In 1968, a young biologist named Paul Ehrlich wrote a best-selling book called The Population Bomb, which sparked an ongoing debate about the dangers of overpopulation. He argued that population growth was destroying the ecological systems necessary to sustain life. So just how worried should we be? Is population growth a problem or not? And if so, what should we do about it?

During the 2000 presidential campaign, George W. Bush said, "Prosperity will mean little if we leave future generations a world of polluted air, toxic lakes and rivers and vanished forests." So after two years in office, how has President Bush done as the chief steward of our nation's air, water, and land? Is the Bush environmental record the disaster that critics contend? Or has the administration just done a poor job of articulating its vision for new ways of caring for the environment?

Global warming, population, deforestation, mass extinctions—according to environmental groups and environmental scientists, the earth is in ever more dire straits. Should we heed these warnings and take steps to mitigate our impact on the global ecosystem? Danish statistician Bjørn Lomborg has come forward to say, not so fast. He claims the environmental state of the world is actually improving, not getting worse. His claims have generated a firestorm of condemnation in the scientific community. Why? And how can we in the general public separate ideology from fact in this debate?

This year we mark the anniversaries of two environmental catastrophes...

On the last weekend in May, Gov. Jerry Brown traveled to a cabin on the Russian River to help spread the cremains of Peter Finnegan, one of his oldest friends.

Stephen Haber, the Peter and Helen Bing Senior Fellow at the Hoover Institution and a professor at Stanford University, discusses, with Carol Massar and Matt Miller on Bloomberg Television's Street Smart, his research into the impact rainfall may have on the development of governments. Haber and Victor Menaldo, a professor at the University of Washington, found that countries where rainfall averages between 50 and 100 centimeters (39.4 inches) a year are more likely to be democratic.

Delivering his first State of the Union address to a Democratic-controlled Congress, President Bush hopes to balance a rebuke of his Iraq policy already promised by lawmakers with a high-profile invitation to cooperate on vexing domestic problems...