Opponents of scientists' mounting consensus that human activity is heating the globe have routinely cited the lack of evidence that the southern polar cap is warming.

Although ice is clearly on the retreat in the Arctic, Greenland and mountain glaciers, scientists detected little indication that the vast southern continent of Antarctica containing 90 percent of the world's ice was being affected, other than on a narrow peninsula. In a visit with the Chronicle editorial board, Texas Public Utility Commission Chairman Barry Smitherman cited that lack of data as reason to doubt the validity of global warming concerns.

As it turns out, Antarctica's ice is melting in places no one thought to look. A study just published in the journal Nature Geoscience makes the case that instead of dissolving from the top down, the continent's ice sheet is actually being eaten away at the edges below sea level as surrounding ocean currents heat up. Lead author Eric Rignot, a senior scientist at NASA's Jet Propulsion Laboratory, told National Public Radio that the mass loss of ice in Antarctica increased by 75 percent in the last decade, a doubling of the rate of melting. According to the scientist, "the pace of change of these ice sheets has been largely underestimated by models; things are changing on a much faster pace than models predicted."

In fact, the tonnage of ice loss in Antarctica is nearing that of Greenland. Were the ice sheets in both areas to melt completely, global sea levels would rise hundreds of feet. The United Nations Panel on Climate Change conservatively estimated that global warming could cause sea levels to rise several feet by the end of the century but did not take into account the consequences of major ice sheets disintegrating. In recent reports, the panel acknowledged the strong possibility that oceans could rise higher and faster than it first projected.

The new findings come as meteorologists determined that 2007 was the fifth-warmest year on record for the globe and the hottest ever measured if only land masses are taken into account. It was the 10th-warmest year measured in the United States, with six of those occurring since 1998.

These accumulating red flags have particular relevance to Texas, by far the largest producer of greenhouse gases in a country that leads the world in emissions. With the fourth-longest coastline among states, Texas is also extremely vulnerable to rising seas and stronger storms produced by climate change. Even a rise of a few feet in sea level would imperil Galveston, other coastal communities and low-lying sections of Houston.

Unfortunately, rather than joining a growing movement of coastline states to curb greenhouse gas emissions, Texas Gov. Rick Perry and his appointees continue to support the construction of more coal-fired power plants that will boost pollution and likely require expensive modifications.

Unless state leaders commit to making Texas part of the climate change solution rather than the problem, the next generation of consumers will pay for those shortsighted policies with higher electricity bills, increased damage from coastal flooding and ever higher insurance rates.