Tropical Forests -- Earth's Air Conditioner

Planting and protecting trees--which trap and absorb carbon dioxide as they grow--can help to remove carbon dioxide from the atmosphere. But a new study suggests that, as a way to fight global warming, the effectiveness of this strategy depends heavily on where these trees are planted. In particular, tropical forests are very efficient at keeping the Earth at a happy, healthy temperature.

The researchers, including Ken Caldeira of Carnegie's Department of Global Ecology and Govindasamy Bala at Lawrence Livermore National Laboratory, found that because tropical forests store large amounts of carbon and produce reflective clouds, they are especially good at cooling the planet. In contrast, forests in snowy areas can warm the Earth, because their dark canopy absorbs sunlight that would otherwise be reflected back to space by a bright white covering of snow.

The work simulates the effects of large-scale deforestation, and accounts for the positive and negative climate effects of tree cover at different latitudes. The result, which appears in this week's early online edition of the Proceedings of the National Academy of Sciences, makes a strong case for protecting and restoring tropical forests.

"Tropical forests are like Earth's air conditioner," Caldeira said. "When it comes to rehabilitating forests to fight global warming, carbon dioxide might be only half of the story; we also have to account for whether they help to reflect sunlight by producing clouds, or help to absorb it by shading snowy tundra."

Forests in colder, sub-polar latitudes evaporate less water and are less effective at producing clouds. As a result, the main climate effect of these forests is to increase the absorption of sunlight, which can overwhelm the cooling effect of carbon storage.

However, Caldeira believes it would be counterproductive to cut down forests in snowy areas, even if it could help to combat global warming. "A primary reason we are trying to slow global warming is to protect nature," he explains. "It just makes no sense to destroy natural ecosystems in the name of saving natural ecosystems."

eight things you can do to make our planet cleaner and greener

1. Turn off the darn lights! You've heard your Mother say it and you've heard your father say it. Now we are telling you too. Turn off lights and other appliances when you leave a room. Don't leave the refrigerator door open. Don't run hot water with no one in the shower and turn the thermostat up or down a couple of degrees depending on the season to save power.
Electricity comes at a high Global Warming cost. If we use less juice we create fewer carbon emissions to create that power. Plus your parents will save plenty on their energy bill.


2. Save cans, bottles and paper.It is far less expensive to make new products from old ones. Aluminum cans are a perfect example. It takes only 10% as much power to melt down old aluminum cans to make a new one as it does to mine and refine Bauxite into fresh aluminum. Some plastic bottles can be melted down to make new plastic and even the ones that can't can be ground up and used as raw materials for other products. Refined petroleum based oils in products like Jelly Bracelets and Shoes can be squeezed out and used to make… Guess what? More Shoes! Paper products are the easiest of all to recycle. Old newspapers and school paper are 100% recyclable. You can directly recycle too simply by folding up cardboard boxes until the next time you need one and reusing them.


3. Piggyback a rideDon't wait until your parents have already been out and back to tell them you need a ride somewhere. Plan your travels so as to save gas by consolidating family trips. Find out where your parents will be going and coordinate the place you want to be with their destinations. Of course you may need some dark glasses for days when your Mom is going to the mall the same time you are. But the greenhouse gases your family car creates can be cut in half with a little planning. Also have your parents pick up friends along the way to places like the movies so that their parents won't need to make a separate trip.


4. Donate your outgrown clothes.Like most kids you are constantly growing. You clothes don't grow with you and usually don't wear out before you are too big for them. Sure your little brother or sister may not want to wear your icky clothes. But there are people in your home town and around the world that need clothing and shoes desperately. Handing down clothes to a younger relative is direct recycling, the most efficient kind of sustainability there is. Don't leave clothes you no longer wear hanging in your closet for years. Bring them to agencies that will give them to people without.
There are programs like Soles 4 Souls that give your gently worn shoes to children all around the world who have none.





Click here to go to Soles4Souls.org


5. Walk, Bike and Ride the busFor short trips there is one means of transportation that never seems to grow old. This of course is walking. In fact people have been using their feet to get around for at least a million years (Homo Erectus). True our great great great great great great great great great great great ancestors didn't have to get to the Cineplex before the price increase at 4PM, but we don't have to look out for Saber Toothed Tigers.
There are over a billion bicycles in the world. That is twice as many bikes as there are cars. Obviously this machine, first invented over 150 years ago, is a great way to get around. Wear a helmet and use the buddy system. You can safely travel anywhere you want without using a drop of gasoline. Plus the exercise from cycling is a low impact high aerobic workout. You can stay fit and get to wherever you want.
Sometimes the places we want to go are just too far to walk or ride a bike. Most towns and cities have bus routes and bus passes available at great prices for kids.





6. Plant a tree, or two or threeEvery 6 seconds the Earth loses an acre of rainforest. Trees play an essential role in climate. They extract ground water through their roots and evaporate that water into the atmosphere through their leaves. Without the precipitation created by trees areas of major deforestation are prone to drought. This is how rainforests become deserts.

How can the one, two or three trees you plant help? Eventually that tree will grow tall enough to provide shade. The air conditioner in your house won't have to run as much. Your little tree will also draw Carbon dioxide from the air and replace it with oxygen. One tree can consume 48 pounds of CO2 per year and create enough oxygen to support two people. Plus your little city tree reduces fossil fuel consumption enough to save 15 trees in the forest.





7. Refill and reuseOn a cold day there is nothing that can make you feel as warm and comfy as some hot soup. You don't need to nuke a container of soup in a microwave to get some. Pack your lunch with a thermos and fill it with hot soup or beverages in cold weather and ice cold drinks in summer. Pack your sandwiches and snacks in resealable plastic containers that get washed and reused. Refilling and reusing is direct recycling, the most efficient way to save the Earth's resources.


8. Read a book!Not just any book, try reading an eBook. EBooks are inexpensive and don't require the sacrifice of a tree to make them. You will find all your favorite books, magazines and newspapers are available online and many of them are free. Visit the openlibrary.org and you will be amazed at all the wonderful books there are for you to read that are absolutely free. It won't use any gas to get there and as with all libraries once you start reading you are free to travel the world.

Global Warming May Increase the Capacity of Trees to Store Carbon

One helpful action anyone can take in response to global warming is to plant trees and preserve forests. Trees and plants capture carbon dioxide during photosynthesis, thereby removing the most abundant greenhouse gas from the atmosphere and storing some of it in their woody tissue.

The paper summarizes the results of a 7-year study at Harvard Forest in central Massachusetts, in which a section of the forest (about one-quarter of an acre) was artificially warmed about 9^oF above ambient, to simulate the amount of climate warming that might be observed by the end of the century without aggressive actions to control greenhouse gas emissions from fossil-fuel burning and deforestation.Yet global warming may affect the capacity of trees to store carbon by altering forest nitrogen cycling, concludes a study led by Jerry Melillo of the Marine Biological Laboratory (MBL), published recently in Proceedings of the National Academy of Sciences.

The study confirmed, as others have, that a warmer climate causes more rapid decomposition of the organic matter in soil, leading to an increase in carbon dioxide being released to the atmosphere.

But the study also showed, for the first time in a field experiment, that warmer temperatures stimulate the gain of carbon stored in trees as woody tissue, partially offsetting the soil carbon loss to the atmosphere. The carbon gains in trees, the scientists found, is due to more nitrogen being made available to the trees with warmer soil.

"Tree growth in many of the forests in the United States is limited by the lack of nitrogen," Melillo says. "We found that warming causes nitrogen compounds locked up in soil organic matter to be released as inorganic forms of nitrogen such as ammonium, a common form of nitrogen found in garden fertilizer. When trees take up this inorganic nitrogen, they grow faster and store more carbon."

Melillo says that the biological processes that link soil warming, increased soil organic matter decay, increased nitrogen availability to trees, and increased tree growth will likely operate together in many temperate and boreal forests -- forests found in North America, Europe, Eurasia and much of the developed world. Tree growth in tropical forests is often limited by factors other than nitrogen, so lessons from this new study are not widely relevant in the tropics.

While Melillo thinks that the carbon-nitrogen interactions he is studying at Harvard Forest will help us to make predictions of carbon storage in forest over the coming decades, he adds that "the carbon balance of forest ecosystems in a changing climate will also depend on other factors that will change over the century, such as water availability, the effects of increased temperature on both plant photosynthesis and aboveground plant respiration, and the atmospheric concentration of carbon dioxide."