AUBURN - Global warming is a hot topic, so Brian Aldrich, an agriculture resource educator at Cornell Cooperative Extension of Cayuga County, found someone who shared his interest in it.

In his discussion Tuesday titled “Climate Change: The New Urgency of Emission Reduction and How to Make a Difference,” Sylvester Johnson, Ph.D. of applied physics, took guests through a brief history of global warming and looked at its continuing impact.

“I heard him speak at Cornell in November,” Aldrich said. “This is a topic I've been following and studying for over a year and I thought it would be good to bring him here to share this information.”

Johnson said global warming has been steadily rising for at least the past three decades.

Johnson said that the earth's temperature has increased .4 degrees Fahrenheit every decade for the past 30 years.

“This may not seem like much,” Johnson said. “But in the long run we are overheating the planet.”

While arguments have been made that these increases are a part of the natural cycle of the planet, Johnson and many others disagree and point to man-made emissions such as burning fossil fuels, which give off carbon dioxide. Other gases such as methane and water vapor also contribute to the greenhouse effect.

“During the last decade alone these trends have accelerated beyond any known possible natural cause,” Johnson said. “Therefore the climate is being changed by people's activities.”

Johnson went on to explain the dangers of these emissions into the atmosphere, which create what Johnson termed feedback cycles.

In a feedback cycle, emissions are released into the atmosphere and collect as greenhouse gases, these gases essentially create a blanket that traps heat, leading to increased temperatures, which lead to more evaporation of water, which thickens the blanket, trapping more heat, until a state of equilibrium can be achieved.

This rise in temperature has led to a significant impact on ice shelves around the world, which has increased water levels.

Rising temperatures have also had an impact on weather patterns, perhaps most prominently with a recent increase in hurricanes and tropical storms.

“Hurricanes are driven by heat energy,” Johnson said. “The increased temperature over the Gulf (of Mexico) has led to greater evaporation and that turns into bigger storms and this drives the storms more fiercely.”

According to Johnson, it is estimated that in 2005, more than $200 billion dollars of damage related to weather disasters was caused in the United States.

Johnson said this is an urgent issue that needs to be addressed.

Greenhouse effects impacting the planet will also carry with them secondary effects that may affect the earth for generations. Some of the effects that may follow include an increased strain on freshwater supplies and increased evaporation which will impact food supplies. Carried out to its farthest extreme, this will impact all life on the planet.

But Johnson said there are means to reduce and delay these effects that are already set in motion.

He pointed to decreasing dependency on fossil fuels through the use of hybrid cars and alternative and renewable energy sources such as hydro, solar and wind. He pointed out they also have the added benefit of creating savings for those who use them and at the same time reducing further greenhouse emissions.

Johnson urged the audience to use what he termed the most powerful tool available, the ability to speak out and vote and use that power to change.

“I've heard it said that future generations can deal with this,” Johnson said. “But it is up to us. We are the generation that has been put on the spot with this emerging crisis and it is up to us to do something about it.”