Ask Extension

Recent Articles


Tuesday, August 26, 2008

Hurricanes and Climate Change

Mary Campbell, Pinellas County Extension Director, Urban Sustainability Agent

Hurricanes are on everyone’s minds in Florida right now. Since 1995, Florida has experienced some of the most active and intense hurricanes. There are reports that indicate climate change or global warming may play a role in the number and strength of hurricanes. Meteorologists use the term "tropical cyclone" for a closed atmospheric circulation that forms over a tropical or subtropical ocean. Once maximum sustained wind speed exceeds 74 miles per hour these storms are called hurricanes in the Atlantic Ocean, typhoons in the Pacific Ocean, and cyclones elsewhere. Let’s review what we know to date about the link between storms and climate change.

Sea level is rising and will continue to rise as oceans warm and glaciers melt. Rising sea level means higher storm surges, even from relatively minor storms, which increases coastal flooding and subsequent storm damage.

With rapid population growth in coastal regions placing many more people and structures in the path of these tropical cyclones, there is a much greater risk of casualties, property damage, and financial hardship when these storms make landfall.

Two factors that contribute to more intense tropical cyclones -- ocean heat content and water vapor -- have both increased over the past several decades. Human activities such as the burning of fossil fuels and the clearing of forests have very likely elevated carbon dioxide (CO2) levels in the atmosphere which contributes to global warming and these two factors.

The link between stronger hurricanes and global warming is a theory and is not a conclusion of the Intergovernmental Panel on Climate Change (IPCC). It is reasonable to theorize that some human contribution is responsible for the increase in strong hurricanes in the Atlantic since 1970, since this increase does correlate so well with the observed increase in sea surface temperatures. However, it is difficult to make a strong statement saying that global warming is responsible for stronger hurricanes, due to the high natural variability of these storms and the poor observational record.

There are no definite conclusions on the link between storms and climate change. Climate change is an evolving theory that will be the focus of scientists for many years to come. Preparation for storms is an important process for everyone living in Florida.

Intergovernmental Panel on Climate Change
Hurricane Season: Be Prepared

Wednesday, August 20, 2008

Vigilance Needed to Help Our Water Resources Recover

By Neil Combee
Governing Board Chair
Southwest Florida Water Management District

The Southwest Florida Water Management District's 16-county region has weathered more than two and a half years of drought. And, unfortunately, there are no guarantees that this summer's rainy season will finally put an end to this long dry spell.

That's why the Southwest Florida Water Management District's Governing Board voted unanimously to continue the one-day-per-week water restrictions through Sept. 30, which traditionally signals the end of our summer rainy season.

You may be wondering why the Governing Board would extend the water restrictions when it's raining almost every afternoon and most lawn and landscapes are beginning to look lush and green again. The Governing Board chose to extend the restrictions because although the recent rainfall has been beneficial, we have not seen nearly enough improvements in our water resources to lift the restrictions.

For the 24-month period of June 2006 through May 2008, the District accumulated a 17.2-inch rainfall deficit that we still need to make up. As a result of this lack of rainfall, our lakes, rivers and aquifer levels are far below where they should be. Some lakes in the District are as much as five feet below the bottom of their normal levels.

The summer rainy season, which normally runs from June through September, is when we rely on Mother Nature to provide 60 percent of our rainfall for the entire year. But because of our rainfall deficit and our below-normal water resources, we need above-average rainfall throughout the entire summer for our water resources to have a chance to recover.

In addition to extending the water restrictions, the Governing Board is also asking for your assistance to help our water resources recover this summer by continuing to conserve water. The Board is asking residents to limit their lawn watering as much as possible during the summer rainy season. Now is the time to turn off your irrigation systems and let Mother Nature do the work for you.

Continuing to water your lawn during the rainy season can actually be detrimental. Overwatered grass has short roots that make it harder to survive pest attacks, disease and drought.

The Governing Board recognizes and appreciates everyone’s conservation efforts during this drought, but we must all continue to be vigilant by using our water resources as efficiently as possible. We can't afford to waste this precious, limited resource. If we all work together to conserve, our water resources may finally have a chance to recover this summer

For more information and free materials about water restrictions, the drought and how you can conserve water both outdoors and indoors, I encourage you to visit the District's web site at

Friday, August 1, 2008

Climate Change Basics

by Mary Campbell, Pinellas County Extension Director, Urban Sustainability

Climate change and global warming are both used as terms to describe the effects of greenhouse gas emissions on our environment. They are both used to describe the environmental changes due to the build up of gasses that trap heat and warm the Earth. These gases are primarily from the burning of fossil fuels that give off carbon dioxide and other gases. Climate change has been described as both a natural and unnatural process. There is the natural variation in the Earth’s global or regional climates over time. Natural global climate change over time has occurred in response to fluctuations in the amount of solar energy reaching the Earth, changing ocean currents, formation or loss of ice sheets and many other causes.

Global warming refers to an increase in the average global temperature of the entire Earth’s atmosphere. Regional and seasonal variations can occur within that average and so we may experience cooling in local areas. Scientists now think that it is very likely (90% probability) that humans are contributing to global warming. Some of the impacts of global warming include sea level rise, droughts, floods and more severe weather events. As the science on climate change gets more accurate, we will be able to better predict the impacts and use technology to reduce those impacts.

“Warming of the climate system is unequivocal, as is now evident from observations of increases in the global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.” Fourth Assessment of the Intergovernmental Panel on Climate Change

Intergovernmental Panel on Climate Change