While some scientists and politicians continue to debate the connection between global warming and intense weather events such as hurricanes and droughts and, the majority of American voters have already made up their minds—a trend that could significantly influence public policy and the outcome of future elections. Hurricanes have grown fiercer in recent decades, spurred by global warming, and even tougher storms are likely on the way, a researcher predicts. In his new study, ocean climatologist Kerry Emanuel of the Massachusetts Institute of Technology, suggests that the power of big ocean storms has increased and will continue to do so, even if their numbers stay the same.

While many view the effects of global warming to be more substantial and more rapidly occurring than others do, the scientific consensus on climatic changes related to global warming is that the average temperature of the Earth has risen between 0.4 and 0.8 °C over the past 100 years. Researchers who study severe weather and climate change studied the effects of global warming on the number of severe storms in the future and discovered a dramatic increase in potential storm conditions for some parts of the United States.

HURRICANES

Hurricanes are storms that form near the equator and gain wind speeds of at least 74 miles per hour. They get their power from warm ocean water. For a hurricane to occur, the surface of the ocean must be at least 80 degrees Fahrenheit. This is why the U.S. hurricane season is from June to November, when ocean waters in the North Atlantic are warmest. As global warming continues, thanks to a buildup of pollution in the atmosphere, scientists project that the oceans will continue to get warmer. Increasingly warmer oceans paint a sobering outlook for future hurricane seasons. In fact, there has been a 75% increase in intensity and duration of hurricanes and tropical storms since the 1970s.

DROUGHT

The percentage of Earth's land area stricken by serious drought more than doubled from the 1970s to the early 2000s, according to a new analysis by scientists at the National Center for Atmospheric Research (NCAR). Widespread drying occurred over much of Europe and Asia, Canada, western and southern Africa, and eastern Australia. Rising global temperatures appear to be a major factor. Even as drought has expanded across Earth's land areas, the amount of water vapor in the air has increased over the past few decades. The average global precipitation has also risen slightly. However, as Dai notes, "surface air temperatures over global land areas have increased sharply since the 1970s." The large warming increases the tendency for moisture to evaporate from land areas. Together, the overall area experiencing either very dry or very wet conditions could occupy a greater fraction of Earth's land areas in a warmer world.

FIRE

Wildfires in the western U.S. now occur more frequently, last longer, and cover more ground than they did in the past. A 2006 study published in Science found that since 1986, the number of major wildfires has increased by 400 percent, and the amount of land these fires burned increased by 600 percent, compared to the period from 1970 to 1986.

Until recently it was often assumed that spiking population growth and expanding land use patterns were mainly to blame for any increase in the number of big fires. But the Science study, which was conducted by researchers at the Scripps Institute and the UC Merced, concluded that these factors have had “relatively little effect.” Instead, the authors wrote, the change has come about mainly because summers have gotten longer, hotter, and drier. “The transition has been marked by a shift toward unusually warm springs, longer summer dry seasons, drier vegetation, and longer fire seasons.”

STORM SURGE

Global average sea level is projected to rise between 9 and 88 cm between 1990 and 2100 for a global average surface temperature rise projected to be between 1.4 and 5.8 degrees Celsius. Coastal storm surges will become an increasing threat to life and property. Ocean warming and thermal expansion will be the largest contributor to sea-level rise during the 21st century, and that's caused by global warming.

FLOOD

A warmer world will deliver heavier rainfalls and more flooding. Floods caused more property damage and fatalities than any other natural disaster in the United States in the twentieth century. The outlook for the next century does not look any better -- either inland or along the coasts. For example, downpours are expected to become more frequent and in many areas, winter precipitation is increasingly likely to fall as rain than as snow.

HEAT WAVES

Global warming doesn't just mean warmer weather. It also means we'll see more instances of extreme warm weather, often in the form of heat waves. U.S. heat waves are generally defined as at least three consecutive days of temperatures over 90 degrees Fahrenheit — and they’re dangerous, particularly in areas less accustomed to hot weather. In the past several decades, the Centers for Disease Control (CDC) says extreme heat has become more deadly than hurricanes, tornadoes, lightning, floods and earthquakes — combined. From 1979-2003, some 8,015 deaths in the United States were attributed to excessive heat. In 2001 alone, excessive heat exposure caused 300 fatalities.

THE FACTS

In an analysis of sea surface temperatures and storms since 1930, researchers found that a combined measure of duration and wind speeds among North Atlantic hurricanes and North Pacific cyclones has nearly doubled since the 1970s.