Thursday, April 22, 2010
Wednesday, April 21, 2010
What is the Greenhouse Effect?
The "greenhouse effect" often gets a bad rap because of its association with global warming, but the truth is we couldn't live without it.
What Causes the Greenhouse Effect?
Life on earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet's surface and is reflected upward again as a type of slow-moving energy called infrared radiation.
The heat caused by infrared radiation is absorbed by "greenhouse gases" such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere.
Although greenhouse gases make up only about 1 percent of the Earth's atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.
This phenomenon is what scientists call the "greenhouse effect." Without it, scientists estimate that the average temperature on Earth would be colder by approximately 30 degrees Celsius (54 degrees Fahrenheit), far too cold to sustain our current ecosystem.
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing.
The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.
The Average Global Temperature is Increasing Quickly
Today, the increase in the Earth's temperature is increasing with unprecedented speed. To understand just how quickly global warming is accelerating, consider this:
During the entire 20th century, the average global temperature increased by about 0.6 degrees Celsius (slightly more than 1 degree Fahrenheit).
Using computer climate models, scientists estimate that by the year 2100 the average global temperature will increase by 1.4 degrees to 5.8 degrees Celsius (approximately 2.5 degrees to 10.5 degrees Fahrenheit).
Not All Scientists Agree
While the majority of mainstream scientists agree that global warming is a serious problem that is growing steadily worse, there are some who disagree. John Christy, a professor and director of the Earth System Science Center at the University of Alabama in Huntsville is a respected climatologist who argues that global warming isn't worth worrying about.
Christy reached that opinion after analyzing millions of measurements from weather satellites in an effort to find a global temperature trend. He found no sign of global warming in the satellite data, and now believes that predictions of global warming by as much as 10 degrees Fahrenheit by the end of the 21st century are incorrect.
Scientists agree that even a small increase in the global temperature would lead to significant climate and weather changes, affecting cloud cover, precipitation, wind patterns, the frequency and severity of storms, and the duration of seasons.
Currently, carbon dioxide accounts for more than 60 percent of the enhanced greenhouse effect caused by the increase of greenhouse gases, and the level of carbon dioxide in the atmosphere is increasing by more than 10 percent every 20 years.
If emissions of carbon dioxide continue to grow at current rates, then the level of the gas in the atmosphere will likely double, or possibly even triple, from pre-industrial levels during the 21st century.
Climate Changes are Inevitable
According to the United Nations, some climate change is already inevitable because of emissions that have occurred since the dawn of the Industrial Age.
While the Earth’s climate does not respond quickly to external changes, many scientists believe that global warming already has significant momentum due to 150 years of industrialization in many countries around the world. As a result, global warming will continue to affect life on Earth for hundreds of years, even if greenhouse gas emissions are reduced and the increase in atmospheric levels halted.
What is Being Done to Reduce Global Warming?
To lessen those long-term effects, many nations, communities and individuals are taking action now to reduce greenhouse gas emissions and slow global warming by reducing dependence on fossil fuels, increasing the use of renewable energy, expanding forests, and making lifestyle choices that help to sustain the environment.
Whether they will be able to recruit enough people to join them, and whether their combined efforts will be enough to head off the most serious effects of global warming, are open questions that can only be answered by future developments.
reference:
http://environment.about.com/od/globalwarming/a/greenhouse_2.htm
What Causes the Greenhouse Effect?
Life on earth depends on energy from the sun. About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet's surface and is reflected upward again as a type of slow-moving energy called infrared radiation.
The heat caused by infrared radiation is absorbed by "greenhouse gases" such as water vapor, carbon dioxide, ozone and methane, which slows its escape from the atmosphere.
Although greenhouse gases make up only about 1 percent of the Earth's atmosphere, they regulate our climate by trapping heat and holding it in a kind of warm-air blanket that surrounds the planet.
This phenomenon is what scientists call the "greenhouse effect." Without it, scientists estimate that the average temperature on Earth would be colder by approximately 30 degrees Celsius (54 degrees Fahrenheit), far too cold to sustain our current ecosystem.
How Do Humans Contribute to the Greenhouse Effect?
While the greenhouse effect is an essential environmental prerequisite for life on Earth, there really can be too much of a good thing.
The problems begin when human activities distort and accelerate the natural process by creating more greenhouse gases in the atmosphere than are necessary to warm the planet to an ideal temperature.
- Burning natural gas, coal and oil -including gasoline for automobile engines-raises the level of carbon dioxide in the atmosphere.
- Some farming practices and land-use changes increase the levels of methane and nitrous oxide.
- Many factories produce long-lasting industrial gases that do not occur naturally, yet contribute significantly to the enhanced greenhouse effect and "global warming" that is currently under way.
- Deforestation also contributes to global warming. Trees use carbon dioxide and give off oxygen in its place, which helps to create the optimal balance of gases in the atmosphere. As more forests are logged for timber or cut down to make way for farming, however, there are fewer trees to perform this critical function.
- Population growth is another factor in global warming, because as more people use fossil fuels for heat, transportation and manufacturing the level of greenhouse gases continues to increase. As more farming occurs to feed millions of new people, more greenhouse gases enter the atmosphere.
The Average Global Temperature is Increasing Quickly
Today, the increase in the Earth's temperature is increasing with unprecedented speed. To understand just how quickly global warming is accelerating, consider this:
During the entire 20th century, the average global temperature increased by about 0.6 degrees Celsius (slightly more than 1 degree Fahrenheit).
Using computer climate models, scientists estimate that by the year 2100 the average global temperature will increase by 1.4 degrees to 5.8 degrees Celsius (approximately 2.5 degrees to 10.5 degrees Fahrenheit).
Not All Scientists Agree
While the majority of mainstream scientists agree that global warming is a serious problem that is growing steadily worse, there are some who disagree. John Christy, a professor and director of the Earth System Science Center at the University of Alabama in Huntsville is a respected climatologist who argues that global warming isn't worth worrying about.
Christy reached that opinion after analyzing millions of measurements from weather satellites in an effort to find a global temperature trend. He found no sign of global warming in the satellite data, and now believes that predictions of global warming by as much as 10 degrees Fahrenheit by the end of the 21st century are incorrect.
Scientists agree that even a small increase in the global temperature would lead to significant climate and weather changes, affecting cloud cover, precipitation, wind patterns, the frequency and severity of storms, and the duration of seasons.
- Rising temperatures would raise sea levels as well, reducing supplies of fresh water as flooding occurs along coastlines worldwide and salt water reaches inland.
- Many of the world’s endangered species would become extinct as rising temperatures changed their habitat.
- Millions of people also would be affected, especially poor people who live in precarious locations or depend on the land for a subsistence living.
- Certain vector-borne diseases carried by animals or insects, such as malaria, would become more widespread as warmer conditions expanded their range.
Currently, carbon dioxide accounts for more than 60 percent of the enhanced greenhouse effect caused by the increase of greenhouse gases, and the level of carbon dioxide in the atmosphere is increasing by more than 10 percent every 20 years.
If emissions of carbon dioxide continue to grow at current rates, then the level of the gas in the atmosphere will likely double, or possibly even triple, from pre-industrial levels during the 21st century.
Climate Changes are Inevitable
According to the United Nations, some climate change is already inevitable because of emissions that have occurred since the dawn of the Industrial Age.
While the Earth’s climate does not respond quickly to external changes, many scientists believe that global warming already has significant momentum due to 150 years of industrialization in many countries around the world. As a result, global warming will continue to affect life on Earth for hundreds of years, even if greenhouse gas emissions are reduced and the increase in atmospheric levels halted.
What is Being Done to Reduce Global Warming?
To lessen those long-term effects, many nations, communities and individuals are taking action now to reduce greenhouse gas emissions and slow global warming by reducing dependence on fossil fuels, increasing the use of renewable energy, expanding forests, and making lifestyle choices that help to sustain the environment.
Whether they will be able to recruit enough people to join them, and whether their combined efforts will be enough to head off the most serious effects of global warming, are open questions that can only be answered by future developments.
reference:
http://environment.about.com/od/globalwarming/a/greenhouse_2.htm
How Much Energy Does It Take to Make Bottled Water?
Producing, packaging and transporting a liter of bottled water requires between 1,100 and 2,000 times more energy on average than treating and delivering the same amount of tap water, according to a peer-reviewed energy analysis conducted by the Pacific Institute, a nonprofit research organization based in Oakland, California.
Popularity of Bottled Water is Rising
Bottled water has become the drink of choice for many people around the world, and sales have skyrocketed over the past few years. In 2007, for example, more than 200 billion liters of bottled water were sold worldwide. Americans alone purchased more than 33 billion liters for an annual average of 110 liters (nearly 30 gallons) per person—a 70 percent increase since 2001.
Bottled water has become so popular that it now outsells both milk and beer in the United States. Carbonated soft drinks are the only bottled beverage that U.S. consumers buy in greater quantities than bottled water, and per-capita sales of bottled water are rising while per-capita sales of milk and soft drinks are going down. The irony here, of course, is that a lot of bottled water is little more than tap water, which costs very little and is much better regulated and more rigorously tested than bottled water.
Adding Up the Energy Costs of Bottled Water
For the energy analysis, environmental scientists Peter Gleick and Heather Cooley of the Pacific Institute assessed the energy used during each stage of bottled water production. They added up the energy it takes to make a plastic bottle; process the water; label, fill and seal the bottle; transport bottled water for sale; and cool the bottled water before it ends up in your gym bag or your car’s cup holder.
Writing in the February 19, 2009 issue of Environmental Research Letters [pdf], Gleick and Cooley report that manufacturing and transportation are the most energy-intensive processes involved in putting a bottle of water in your refrigerator.
The two scientists estimate that just producing the plastic bottles for bottled-water consumption worldwide uses 50 million barrels of oil annually—enough to supply total U.S. oil demand for 2.5 days.
Transportation energy consumption is harder to figure, because some water is bottled locally and travels short distances to reach consumers while other brands of bottled water are imported from distant nations, which increases the amount of energy needed to transport them. According to the report, imported bottled water uses about two-and-a-half to four times more energy than bottled water produced locally.
Overall, the two scientists estimate that meeting U.S. demand for bottled-water—assuming the 2007 consumption rate of 33 billion liters—requires energy equivalent to between 32 million and 54 million barrels of oil. The energy required to satisfy the global thirst for bottled water is about three times that amount.
Think Before You Drink
If you imagine that every bottle of water you drink is about three-quarters water and one-quarter oil, you’ll have a pretty accurate picture of how much energy it takes to put that bottle of water in your hand.
reference:
http://environment.about.com/od/greenlivingdesign/a/bottled_water.htm
Popularity of Bottled Water is Rising
Bottled water has become the drink of choice for many people around the world, and sales have skyrocketed over the past few years. In 2007, for example, more than 200 billion liters of bottled water were sold worldwide. Americans alone purchased more than 33 billion liters for an annual average of 110 liters (nearly 30 gallons) per person—a 70 percent increase since 2001.
Bottled water has become so popular that it now outsells both milk and beer in the United States. Carbonated soft drinks are the only bottled beverage that U.S. consumers buy in greater quantities than bottled water, and per-capita sales of bottled water are rising while per-capita sales of milk and soft drinks are going down. The irony here, of course, is that a lot of bottled water is little more than tap water, which costs very little and is much better regulated and more rigorously tested than bottled water.
Adding Up the Energy Costs of Bottled Water
For the energy analysis, environmental scientists Peter Gleick and Heather Cooley of the Pacific Institute assessed the energy used during each stage of bottled water production. They added up the energy it takes to make a plastic bottle; process the water; label, fill and seal the bottle; transport bottled water for sale; and cool the bottled water before it ends up in your gym bag or your car’s cup holder.
Writing in the February 19, 2009 issue of Environmental Research Letters [pdf], Gleick and Cooley report that manufacturing and transportation are the most energy-intensive processes involved in putting a bottle of water in your refrigerator.
The two scientists estimate that just producing the plastic bottles for bottled-water consumption worldwide uses 50 million barrels of oil annually—enough to supply total U.S. oil demand for 2.5 days.
Transportation energy consumption is harder to figure, because some water is bottled locally and travels short distances to reach consumers while other brands of bottled water are imported from distant nations, which increases the amount of energy needed to transport them. According to the report, imported bottled water uses about two-and-a-half to four times more energy than bottled water produced locally.
Overall, the two scientists estimate that meeting U.S. demand for bottled-water—assuming the 2007 consumption rate of 33 billion liters—requires energy equivalent to between 32 million and 54 million barrels of oil. The energy required to satisfy the global thirst for bottled water is about three times that amount.
Think Before You Drink
If you imagine that every bottle of water you drink is about three-quarters water and one-quarter oil, you’ll have a pretty accurate picture of how much energy it takes to put that bottle of water in your hand.
reference:
http://environment.about.com/od/greenlivingdesign/a/bottled_water.htm
New EPA Rule Makes Airborne Drinking Water a Little Safer
Wednesday March 17, 2010
If you've ever gotten sick while traveling by air, you'll appreciate a new rule from the U.S. Environmental Protection Agency (EPA) designed to ensure safe and reliable drinking water for passengers and crew on all flights within the United States.
Top 10 Things You Can Do to Reduce Global Warming
1. Reduce, Reuse, Recycle
Do your part to reduce waste by choosing reusable products instead of disposables. Buying products with minimal packaging (including the economy size when that makes sense for you) will help to reduce waste. And whenever you can, recycle paper, plastic, newspaper, glass and aluminum cans. If there isn't a recycling program at your workplace, school, or in your community, ask about starting one. By recycling half of your household waste, you can save 2,400 pounds of carbon dioxide annually.2. Use Less Heat and Air Conditioning
Adding insulation to your walls and attic, and installing weather stripping or caulking around doors and windows can lower your heating costs more than 25 percent, by reducing the amount of energy you need to heat and cool your home.Turn down the heat while you're sleeping at night or away during the day, and keep temperatures moderate at all times. Setting your thermostat just 2 degrees lower in winter and higher in summer could save about 2,000 pounds of carbon dioxide each year.
3. Change a Light Bulb
Wherever practical, replace regular light bulbs with compact fluorescent light (CFL) bulbs. Replacing just one 60-watt incandescent light bulb with a CFL will save you $30 over the life of the bulb. CFLs also last 10 times longer than incandescent bulbs, use two-thirds less energy, and give off 70 percent less heat.If every U.S. family replaced one regular light bulb with a CFL, it would eliminate 90 billion pounds of greenhouse gases, the same as taking 7.5 million cars off the road.
4. Drive Less and Drive Smart
Less driving means fewer emissions. Besides saving gasoline, walking and biking are great forms of exercise. Explore your community mass transit system, and check out options for carpooling to work or school.When you do drive, make sure your car is running efficiently. For example, keeping your tires properly inflated can improve your gas mileage by more than 3 percent. Every gallon of gas you save not only helps your budget, it also keeps 20 pounds of carbon dioxide out of the atmosphere.
5. Buy Energy-Efficient Products
When it's time to buy a new car, choose one that offers good gas mileage. Home appliances now come in a range of energy-efficient models, and compact florescent bulbs are designed to provide more natural-looking light while using far less energy than standard light bulbs.Avoid products that come with excess packaging, especially molded plastic and other packaging that can't be recycled. If you reduce your household garbage by 10 percent, you can save 1,200 pounds of carbon dioxide annually.
6. Use Less Hot Water
Set your water heater at 120 degrees to save energy, and wrap it in an insulating blanket if it is more than 5 years old. Buy low-flow showerheads to save hot water and about 350 pounds of carbon dioxide yearly. Wash your clothes in warm or cold water to reduce your use of hot water and the energy required to produce it. That change alone can save at least 500 pounds of carbon dioxide annually in most households. Use the energy-saving settings on your dishwasher and let the dishes air-dry.7. Use the "Off" Switch
Save electricity and reduce global warming by turning off lights when you leave a room, and using only as much light as you need. And remember to turn off your television, video player, stereo and computer when you're not using them.It's also a good idea to turn off the water when you're not using it. While brushing your teeth, shampooing the dog or washing your car, turn off the water until you actually need it for rinsing. You'll reduce your water bill and help to conserve a vital resource.
8. Plant a Tree
If you have the means to plant a tree, start digging. During photosynthesis, trees and other plants absorb carbon dioxide and give off oxygen. They are an integral part of the natural atmospheric exchange cycle here on Earth, but there are too few of them to fully counter the increases in carbon dioxide caused by automobile traffic, manufacturing and other human activities. A single tree will absorb approximately one ton of carbon dioxide during its lifetime.9. Get a Report Card from Your Utility Company
Many utility companies provide free home energy audits to help consumers identify areas in their homes that may not be energy efficient. In addition, many utility companies offer rebate programs to help pay for the cost of energy-efficient upgrades.10. Encourage Others to Conserve
Share information about recycling and energy conservation with your friends, neighbors and co-workers, and take opportunities to encourage public officials to establish programs and policies that are good for the environment.reference
http://environment.about.com/od/globalwarming/tp/globalwarmtips.htm?nl=1
Did Global Warming Cause Iceland Volcano to Erupt?
Tuesday April 20, 2010
You can blame climate change for a lot, but not for spoiling your European vacation.
Global warming probably did not cause the volcanic eruption beneath Iceland's Eyjafjallajokull glacier, which has disrupted global aviation and grounded travelers on multiple continents over the past few days--but many scientists believe global warming will trigger future volcanic eruptions in Iceland and throughout the polar regions.
Ice is heavy and exerts enormous pressure on whatever lies beneath it. Under glaciers and other thick ice formations, the pressure is often enough to limit geologic movement, or even to restrict the formation of magma by leaving too little room for superheated rock to expand and turn to liquid. When glacial ice melts, the pressure underneath is reduced, allowing the surface of the Earth to push free of its constraints, a release of energy that sometimes causes earthquakes, tsunamis or volcanic eruptions.
The Icelandic volcano that is currently spewing ash into the atmosphere is located under a small and lightweight ice cap, as ice caps go, so scientists are pretty certain than melting ice did not trigger the eruption.
Size also matters in the question of whether ash from the volcano in Iceland will be enough to slow global warming by creating a kind of reflector shield in the stratosphere to block some of the sun's rays and prevent them from reaching the Earth's surface. Again, the relatively small size of the volcano and the eruption leads scientists to believe that the world will go on warming with no cooling effect from Iceland's geology.
The poet Robert Frost wrote, "Some say the world will end in fire/some say in ice," and then went on to offer his own views on the subject. From what scientists are starting to learn about the relationship between climate change, glacial ice and volcanoes, we may get plenty of both before we're through.
Photo courtesy of NASA
reference:
http://environment.about.com/b/2010/04/20/did-global-warming-cause-iceland-volcano-to-erupt.htm?nl=1
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