Wednesday, July 25, 2007

10 THINGS YOU CAN DO AT HOME TO CURB GLOBAL WARMING



Courtesy of Conservation International
Do your part to ensure a healthy planet by incorporating these ten simple actions into your everyday life.


1) Replace your incandescent light bulbs with compact fluorescent lights (CFLs). Look closely at labels when buying light bulbs. Those marked as CFLs last 10 times longer and use 66 percent less energy than incandescent bulbs while delivering the same light levels. As a result, CFLs accrue net savings between $30 and $45 over their lifetimes, depending on your cost of electricity, the wattage size of the CFL, and the lamp's lifespan (manufacturers make CFLs that last 6,000, 8,000, or 10,000 hours). The return on investment is 15 times higher than leaving your money in a bank account or the average return on Dows-Jones stock investments. CFLs also reduce the release of greenhouse gas emissions and are safer because they burn at a lower temperature (160° F or less) than incandescent and halogen lights, which can burn at temperatures up to 500° F.


2) Turn down the thermostat just three degrees in the winter and up three degrees in the summer. You can prevent the emission of nearly 1,100 pounds of carbon dioxide annually.


3) Inflate your car tires. When walking or biking isn't feasible, you can do something to better protect the Earth while driving. Take a step in the right direction by inflating your car tires. Pumping them up can improve your gas mileage by about 3.3 percent -- a savings of about 7 cents per gallon. It's the right thing to do for your wallet and the right thing to do for the Earth.


4) Turn down the hot water heater. Set your water heater to 130° F. While you're at it, turn down your house thermostat during the winter to 55° F when you go to bed or leave home. These simple actions can have enormous positive consequences, preventing the emission of more than 1,100 pounds of carbon dioxide over the course of the year, while cutting your energy bill by more than 10 percent. And that's just from you! Get your friends on board, and the benefits will multiply.


5) Choose your seafood wisely. We can't afford to wait until 2008. The world's seafood will be entirely depleted by 2048, according to an early November report in the journal Science. That means the moment to shape up is now. By buying and eating certain types of seafood, you can discourage harmful fishing practices and avoid the more depleted or threatened species. Take a look at Seafood Choices Alliance or Seafood Watch to make smart choices.


6) Purchase EnergyStar-labeled appliances. EnergyStar products are among the top 25 percent most efficient and can provide a 30 percent return or better through lower utility bills.


7) Wash and rinse in cold water. If everyone in the United States alone switched to cold water with their washing machines, we could save about 30 million tons of carbon dioxide each year -- and more than $3 billion in energy costs, collectively. And what's more? Cold water cleans your laundry just as well as hot water.


8) Buy locally produced meats and produce. Sounds like a good idea, but you don't know where to start? Just type in your zip code on Local Harvest's website to see a list of farms and farmers' markets close to home, as well as nearby restaurants committed to supporting their neighbors. Buying locally produced food cuts out the middlemen and the vast amounts of energy required to get your products onto store shelves. Most produce in U.S. supermarkets travels an average 1,500 miles before it is sold!


9) Drink more water from reusable glassware. It's great for your bank account, your health, and your planet. The average American consumed more than 400 beverage bottles and cans in 2006, leaving behind wasted glass, plastic, steel, and aluminum. That adds up to excessive amounts of fossil fuels and hydropower for mining, processing, refining, shaping, shipping, storing, refrigerating, and disposing of those materials. Of course, changing your drinking habits both at home and at work is applicable to just about every other habit, as well. You've heard it before and you'll hear it again: Reduce, reuse, and recycle.


10) Walk, bike, and carpool. In the United States, the car represents one of the largest sources of greenhouse gas emissions. However, you don't have to give up your car for a healthier planet, just expand your transportation options. You can significantly reduce your emissions by commuting to work. Try combining trips to minimize emissions, which are greatest at the beginning of a journey before the engine has reached optimum temperature and efficiency. When purchasing your next car, make it a fuel-efficient one. Hybrid cars can get twice the fuel efficiency of the average new car, cut greenhouse gas emissions by half or more, and reduce urban air pollutants. Carpooling saves energy, cuts on additional pollution, and allows you to take a turn as a passenger instead of driving everyday. Car-sharing (not pooling) is available in numerous U.S. cities. Car-sharing enables you to rent a car just when you need it. Each car-share vehicle displaces four to eight privately held cars, requiring less parking area and creating less road congestion. If you live within an hour's bicycle ride to the office (~10 miles), consider biking to work one or more days a week.

Tuesday, July 24, 2007

NOT THE SUN



By Brian Handwerk for National Geographic NewsJuly 12, 2007
Cyclical changes in the sun's energy output are not responsible for Earth's recent global warming, a new study asserts.
Instead the findings put the blame for climate change squarely on human-created carbon dioxide (CO2) and other greenhouse gases -- reinforcing the beliefs of most climate scientists.
The sun's output waxes and wanes due to a variety of mechanisms. Its power rose during much of the 20th century, but it has declined over the past two decades.
"Up until 1985 you could argue that the sun was [trending] in a direction that could have contributed to Earth's rising temperatures," said study author A. Mike Lockwood of the University of Southampton in Britain.
Two decades ago, "it did a U-turn. If the sun had been warming the Earth, that should have come to an end, and we should have seen temperatures start to go the other way," Lockwood said.
Yet Earth's temperatures have continued to climb since that date -- making a strong solar role in warming appear unlikely. (What is global warming?)
"I think it's quite conclusive," said Lockwood, who co-authored the report appearing in the current issue of the U.K. journal Proceedings of the Royal Society A.
Ancient Climate Change
For centuries scientists have pondered an intuitive link between the sun's intensity and Earth's climate. When global warming became an issue in recent years, the debate heated up. (Related: "Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says" [February 28, 2007].)
Recently one hypothesis suggested that cosmic rays from the sun could be responsible for significant warming. The star's cosmic rays deliver particles to Earth's atmosphere, around which cooling clouds may form.
During periods of high solar strength, the Sun's magnetic field blocks some of these rays, which in turn could hamper cloud formation on Earth and cause the planet to warm. (Explore a virtual solar system.)
But the new data seem to be at odds with that theory.
"In terms of the last 30 years I'd have to agree that there's nothing in these records that suggests solar variability could be giving rise to warming global temperatures," said Carl Wunsch, a climate expert at the Massachusetts Institute of Technology in Cambridge, who was not involved in the study.
"Nobody can show that there is no solar/Earth climate connection," he added. "But having said that, if there is one and if these records are representative, whatever connection exists is weak."
In the latest study, co-author Lockwood does report evidence for a past solar role in shaping Earth's preindustrial climate.
"I even believe that you can detect in the climate record a solar influence up until about 1940," he said.
"The trouble is that [in] about 1960 solar variability started to become dominated by fossil fuel burning and greenhouse gases."
Gavin Schmidt, climate scientist at NASA's Goddard Institute for Space Studies and an editor of the blog http://www.realclimate.org/, agreed.
"Basically, there simply isn't a trend in solar activity that would explain the rapid warming that has occurred in recent decades," said Schmidt, who was unaffiliated with the study.
That isn't to say that there isn't a solar influence on climate change in the past, or that there isn't still uncertainty in possible mechanisms, he added.
"But for what we are concerned about now, the sun is not too blame.
"Think of the sun as a criminal suspect who has a long record, but a cast iron alibi for the latest crime," Schmidt said.
"And meanwhile, the fingerprints of CO2 are all over the murder weapon."

Tuesday, July 17, 2007

GLOBAL WARMING



The Planet is Heating Up—and Fast
Glaciers are melting, sea levels are rising, cloud forests are drying, and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.
We call the result global warming, but it is causing a set of changes to the Earth's climate, or long-term weather patterns, that varies from place to place. As the Earth spins each day, the new heat swirls with it, picking up moisture over the oceans, rising here, settling there. It's changing the rhythms of climate that all living things have come to rely upon.
What will we do to slow this warming? How will we cope with the changes we've already set into motion? While we struggle to figure it all out, the face of the Earth as we know it—coasts, forests, farms and snow-capped mountains—hangs in the balance.
Greenhouse effect
The "greenhouse effect" is the warming that happens when certain gases in Earth's atmosphere trap heat. These gases let in light but keep heat from escaping, like the glass walls of a greenhouse.
First, sunlight shines onto the Earth's surface, where it is absorbed and then radiates back into the atmosphere as heat. In the atmosphere, “greenhouse” gases trap some of this heat, and the rest escapes into space. The more greenhouse gases are in the atmosphere, the more heat gets trapped.
Scientists have known about the greenhouse effect since 1824, when Joseph Fourier calculated that the Earth would be much colder if it had no atmosphere. This greenhouse effect is what keeps the Earth's climate livable. Without it, the Earth's surface would be an average of about 60 degrees Fahrenheit cooler. In 1895, the Swedish chemist Svante Arrhenius discovered that humans could enhance the greenhouse effect by making carbon dioxide, a greenhouse gas. He kicked off 100 years of climate research that has given us a sophisticated understanding of global warming.
Levels of greenhouse gases (GHGs) have gone up and down over the Earth's history, but they have been fairly constant for the past few thousand years. Global average temperatures have stayed fairly constant over that time as well, until recently. Through the burning of fossil fuels and other GHG emissions, humans are enhancing the greenhouse effect and warming Earth.
Scientists often use the term "climate change" instead of global warming. This is because as the Earth's average temperature climbs, winds and ocean currents move heat around the globe in ways that can cool some areas, warm others, and change the amount of rain and snow falling. As a result, the climate changes differently in different areas.
Aren’t temperature changes natural?
The average global temperature and concentrations of carbon dioxide (one of the major greenhouse gases) have fluctuated on a cycle of hundreds of thousands of years as the Earth's position relative to the sun has varied. As a result, ice ages have come and gone.
However, for thousands of years now, emissions of GHGs to the atmosphere have been balanced out by GHGs that are naturally absorbed. As a result, GHG concentrations and temperature have been fairly stable. This stability has allowed human civilization to develop within a consistent climate.
Occasionally, other factors briefly influence global temperatures. Volcanic eruptions, for example, emit particles that temporarily cool the Earth's surface. But these have no lasting effect beyond a few years. Other cycles, such as El NiƱo, also work on fairly short and predictable cycles.
Now, humans have increased the amount of carbon dioxide in the atmosphere by more than a third since the industrial revolution. Changes this large have historically taken thousands of years, but are now happening over the course of decades.
Why is this a concern?
The rapid rise in greenhouse gases is a problem because it is changing the climate faster than some living things may be able to adapt. Also, a new and more unpredictable climate poses unique challenges to all life.
Historically, Earth's climate has regularly shifted back and forth between temperatures like those we see today and temperatures cold enough that large sheets of ice covered much of North America and Europe. The difference between average global temperatures today and during those ice ages is only about 5 degrees Celsius (9 degrees Fahrenheit), and these swings happen slowly, over hundreds of thousands of years.
Now, with concentrations of greenhouse gases rising, Earth's remaining ice sheets (such as Greenland and Antarctica) are starting to melt too. The extra water could potentially raise sea levels significantly.
As the mercury rises, the climate can change in unexpected ways. In addition to sea levels rising, weather can become more extreme. This means more intense major storms, more rain followed by longer and drier droughts (a challenge for growing crops), changes in the ranges in which plants and animals can live, and loss of water supplies that have historically come from glaciers.
Scientists are already seeing some of these changes occurring more quickly than they had expected. According to the Intergovernmental Panel on Climate Change, eleven of the twelve hottest years since thermometer readings became available occurred between 1995 and 2006.