Global Warming: Now’s the Time to Act

Image Gallery Rising sea levels due to global warming threaten to displace millions of people who live along seacoasts, such as this shoreline in Honolulu. ISTOCKPHOTO.COM

The debate about global warming is over. In a survey published in Science of nearly 1,000 papers on climate change that appeared in scientific journals between 1993 and 2003, none of the papers’ authors disagreed with the position that the Earth’s climate is being affected by human activities.

From National Geographic, Time and thousands of national and local newspapers to prime time television, this scientific consensus finally is being echoed in the media. And many religious groups and local governments are establishing initiatives aimed at stemming the tide of human-induced climate disruption.

This acceptance of global warming has permeated American public opinion, too. Numerous recent polls confirm it: An overwhelming majority of Americans now think that the Earth’s climate really is warming, that humans are responsible for the situation and that it’s time to do something about it.

So just how did we get here? By burning coal, oil and natural gas at rates much faster than these fossil fuels were created, we disrupt the natural carbon cycle, the delicately balanced system by which carbon is exchanged among air, oceans and land. Over the last century, human activities have released enough carbon dioxide and other gases into the atmosphere to raise the temperature of the Earth by about 1 degree. (Americans shoulder the responsibility for a quarter of that pollution.)

So what should we do now? Many experts think global warming is the biggest challenge current and future generations will face. The minimum warming forecast for this century is more than double what already has occurred. The most recent report by the Intergovernmental Panel on Climate Change predicts that the Earth’s temperature will rise 3 to 10 degrees by the end of the century, causing a dramatic rise in sea levels and increasingly severe “natural” disasters such as hurricanes, floods and droughts.

Warmer temperatures are melting the protective polar ice that moderates climate by reflecting about 90 percent of the solar energy striking it. Ocean water, on the other hand, would absorb about 90 percent of that heat. Melting ice and expanding warm water will likely cause unprecedented shifts in the wind and ocean currents that create seasonal weather patterns, and will endanger already precious freshwater supplies worldwide.