The Why Files -- whyfiles.org

Photo: Don Fellows NPS

Global warming: Obama’s decisions add heat to the battle

Even before president-elect Barack Obama accedes to the highest office, he's placing green energy near the center of his plan to stabilize the economy, create jobs, and battle global warming. In an Nov. 18 statement, Obama said "my presidency will mark a new chapter in American leadership on climate change."

This is a welcome change from years of inaction. And although the recession and the vanishing price of oil have undercut the short-term allure of green energy and a low-carbon economy, on Dec. 12 the United Nations convenes a conference in Poland to set further action against global warming.

The greenhouse gas carbon dioxide, the central player in global warming, is released whenever something containing carbon burns. Human activities -- mainly burning fossil fuels -- spew about 7.2 billion tons of carbon dioxide into the atmosphere each year, where it remains for decades.

A good number of scientists think that by 2050 we will need to cut carbon dioxide pollution to 20 percent of 1990's level if we want to avoid an environmental calamity.

Photo: House of Representatives

Mass transit saves energy, but can a light rail system, like this one in Houston, compete in a world of automobiles?

Big changes needed

Photo by Mikhail Povarennykh, Vernadsky State Geological Museum. USGS

In terms of greenhouse gases, coal is one of the dirtiest sources of energy. According to climate expert James Hansen "the most critical action for saving the planet at this time, I believe, is to prevent construction of additional coal-fired power plants without CO2 capture capability," (without the ability to sequester carbon dioxide.