Last Friday, the Intergovernmental Panel on Climate Change (IPCC) released a summary of its upcoming climate report, “Climate Change 2007: The Physical Science.”

The report synthesizes our current understanding of climate change using the input of more than 1,200 authors and reviewed by 2,500 scientific experts from 130 countries. It represents the view of the world’s top climate scientists who have been working on it for the past six years. One could say that the report represents the current state-of-the-art research in climate science.

The scientists conclude that there is now no question whatsoever that the world is warming, snow and ice are melting worldwide and sea levels are rising. It concludes it is “very likely” — a more than 90 percent chance ­— that the warming is a result of human activity. In the words of Achim Steiner, head of the United Nations environment program, “This day marks the removal from the debate over whether human action has anything to do with climate change.” And though there’s much technical detail in it, the report is fairly accessible to a nonscientist.

So what does warming mean, and is there anything an average person can do about it? The report means that if carbon dioxide concentrations in the atmosphere continue to increase, global climate will probably rise between 3.5 to 8 degrees Celsius. In comparison, the world is currently only around 5 C warmer than during the last ice age! The report also suggests that sea levels will rise between 18 centimeters and 58 centimeters by the end of this century. This rise could increase by as much as 20 centimeters if the recent melting of polar ice sheets continues. Much of our world will change and large areas like southern Florida and Louisiana, or even entire countries, like Bangladesh, will be submerged. Greenhouse gases, primarily carbon dioxide, are already responsible for a series of existing problems, including fewer cold days, hotter nights, intense heat waves, floods and heavy rains, droughts and an increase in the strength of hurricanes and tropical storms.

If you think climate change is a controversial theory, you are among the majority of citizens who believe this. For the most part, when climate change is reported, we see two opposing perspectives presented with the impression that each side has equal support in the scientific community. Nothing could be further from the truth. In fact, a very, very small percentage of qualified scientists deny the facts of climate change. In a nutshell, news reports are striving for what they term “balanced coverage,” which they interpret as showing both sides of the story. This seems fair, but consider this: What if one side of the story is real and the other side is fiction? How is one to decide when there is no accompanying information to that effect?

Another view you may hear is that the report is flawed because it is “consensus” science. That means every phrase has been examined and debated until each word was agreed on. So some scientists may wish it used slightly stronger or more conservative terms. For the majority, though, the language is a consensus view among 3,700 climate change experts. Those who claim it is “too conservative” in its projections feel that worst-case scenarios haven’t been given enough weight. And, in general, they’re right that the IPCC is conservative and understates rather than overstates its position.

So what’s one to do? This is easy to answer. Anything one can do to decrease their use of fossil fuels will help immensely. Not only do fossil fuels pollute our planet, but they are also nonrenewable and unsustainable over the long term. It is our responsibility to leave coming generations sufficient resources to work with. This is part of what being sustainable means, working together to make a difference and purchasing renewable energy for your home.

You can reduce your reliance on fossil fuels by simply changing the light bulbs in your home. Because most energy we use as electricity in the Northeast comes from burning fossil fuels that emit climate-changing gases, changing even one light bulb from a 95 percent inefficient incandescent bulb to a more efficient compact fluorescent bulb can reduce the carbon dioxide emitted into the atmosphere by at least 500 pounds (40 watt bulb). You can also walk, bike or use a more energy-efficient vehicle. Above all, don’t lose hope, because it is not too late for us to have an impact. Remember, it’s your planet to care for.

René Borgella and Jason Hamilton are assistant professors of biology. E-mail them at
rborgella@ithaca.edu or jhamilton@ithaca.edu.