Tropical wetlands store 80 percent more carbon than temperate wetlands, reports a new study that compared ecosystems in Costa Rica and Ohio.
William Mitsch of Ohio State University and colleagues found that the tropical wetland in Costa Rica accumulated around 1 ton of carbon per acre [2.63 t/ha] per year, while the temperate wetland in Ohio accumulated 0.6 tons of carbon per acre [1.4 t/ha] per year.
“Finding out how much carbon has accumulated over a specific time period gives us an indication of the average rate of carbon sequestration, telling us how valuable each wetland is as a carbon sink,” said Mitsch. “We already know wetlands are outstanding coastal protection systems, and yet wetlands continue to be destroyed around the planet. Showing that wetlands are gigantic carbon sequestration machines might end up being the most convincing reason yet to preserve them.”
Mitsch says that while wetlands are a natural source of methane – a potent greenhouse gas – from decomposition, CO2 sequestration appears to balance net carbon emissions.
“A big issue in wetland science is how carbon sequestration balances against the release of greenhouse gases,” Mitsch said. “Methane is a more effective greenhouse gas than is carbon dioxide in terms of how much radiation it absorbs, but it also oxidizes in the atmosphere. Carbon dioxide does not degrade – it is an end product. If you take that into account, I think wetlands are very effective systems for sequestering carbon.”
Mitsch conducted the study with graduate student Blanca Bernal, who presented the findings Wednesday at the Geological Society of America meeting in Houston.
The carbon footprint calculators make no sense to us when it comes to the calculations for Jet travel.
Lets run some numbers.
A Boeing 737 burns 800 gallons of fuel per hour
A gallon of jet fuel weighs just less than 7 pounds
In a five-hour flight that is 4000 gallons of fuel weighing 28,000 pounds
Or 14 tons of jet fuel
The 737 will carry up to 162 passengers.Lets assume 80% capacity or 130 in a typical flight
Here is what does not make sense to us:
That works out to 0.107 tons of fuel per person (about 200 pounds of fuel per person)
Yet according to their Carbon Calculators that same 5-hour flight produces the following TONS of carbon per person:
ZeroFootPrint.com2.71 Tons p/ person(24 times the weight of the fuel)
CarbonFootPrint.com.496 Tons p/person(2.5 times the weight of the fuel)
Green.yahoo.com2.0 Tons p/person(20 times the weight of the fuel)
How can this possibly be?Certainly the vast majority of the fuel is converted to energy.How is it possible that the jet fuel produces many more times as much carbon as the weight of the fuel itself? Never mind the question as to why all of these calculators give us such wildly different calculations. Something is wrong here or are we missing something?
( We would to thank everyone at Treehugger.com that contributed to this series. We are grateful for your insights and ideas.)
At Eco Preservation Society we advocate two common sense long-term goals:
Common Sense Goal #1:Within thirty years we must replace fossil fuels as an energy source.
Common Sense Goal #2: Over the next one hundred years we must sequesteredthe excess carbon that has been added to the atmosphere over the last one hundred years.
As important as it is to reduce our CO2 emissions, it is also important to remove the excess CO2 that we have already put into the atmosphere.Certainly over the next 30 years we will be producing much more CO2 before we begin to produce less.To suggest that we should choose emissions over sequestation is a false choice.We must focus on both.
Further, when talking about Carbon Neutral or Carbon Offsets, reforestation is not only a “viable option”; it is our “only option”.Investing in future technologies to reduce emissions does NOTHING to remove the CO2 that we have already dumped into the atmosphere. There is only ONE viable and proven way to remove CO2 from the atmosphere and that is through the growth of trees and vegetation.
Common sense must prevail.The notion that planting trees is detrimental to the cause of protecting our environment does not pass the common sense test.Critics correctly note that as carbon sinks a forests ability to sequester carbon may follow a saw tooth pattern.However it is a fallacy to suggest that because carbon retention in our forests does not follow a linear pattern that it is somehow diminished in importance.This is non-sense! Simply because our understanding of these processes may be more complex than once thought, that does not mean that these processes are any less important to our future.
Those that argue that reforestation efforts are only “feel good” solutions because an individual tree may not permanently sequestered the carbon in its biomass are presenting an overly simplistic argument.An analogous argument could be made that one should not open a bank account because not ALL of the money that you deposit into that account remains there permanently.The concept of effectively managing a bank account does not require that every dollar you put into the account remain there forever.The concept is that money flows in and out and over time successful money manager will grow that account.This is how we need to look at our forests, as a renewable resource that plays an unparalleled and unique role in sequestering carbon from our atmosphere.
There is a danger that when we grasp at headlines like “Reforestation Contributes to Global Warming” that we promote an overly simplistic view of the problem.The headlines garnered by the Livermore Study were so seductive for so many, particularly those that have an interest in the emission reduction side of the Carbon Offset debate.However carbon cycle is only one factor in the equation of protecting our environment.Along with reducing CO2 emissions and removing the excess CO2 that has already been emitted, we should not loose sight of the role that trees play in the water cycle and in the production of the oxygen that we breath.The notion that environmentalist can make blanket statements like: “planting trees north of the Canadian bordered contributes to Global Warming” and to have so many accept these findings without serious scrutiny should be cause for great concern within the environmental community.It is no wonder that those in the business community look at us environmentalist as a bunch of flakes.
We must do better
At Eco Preservation Society we believe that we need to re-examine all of our options in sequestering carbon. Today there are many web sites that feature Carbon Calculators that tell us about our individual Carbon Footprint.Yet in all of the Carbon Footprint Calculators, none take into account the amount of carbon that an affluent family has sequestered in their 4000 square foot wood structured home. We must do better!
Looking at the wood products industry as a possible solution to Global Warming problem is a politically incorrect discussion within the environmental movement.We must to take a fresh look at reforestation and forestry as a sustainable resource.
In the past the forestry industry has given us mono-habitats and clear cutting.These are obvious negative impacts and we must do better.How much more engineering and planning would it really require to manage these resources in a more diverse manner?
In the future we can do better and we need to take a fresh look at how we approach these issues.
Clearly the Lawrence Livermore study is not the final word.It only serves to awaken us to the fact that the complexities of the problems that we face are much greater than we once imagined.It is fair to conclude from the Livermore Study that overly simplistic monolithic solutions such as “Universal Tree Planting” are not viable.At the same time, overly simplistic conclusions drawn from the Livermore Study are equally inappropriate.
As leaders in the environmental movement it is important that we are responsible with the information that we feed to the public.We loose credibility with the public when we grasp at sensational headlines and do not deliver on thoughtful and meaningful examination of these critical issues.
Solutions Moving Forward:
Perhaps it is time for us to reexamine the concept of deforestation, both in terms of methods and importance.Deforestation occurs in nature, it serves a purpose in nature’s cycles.Without question our last remaining old growth forest and primary rain forests must absolutely be protected.However when it comes to the management of lands that have already been deforested there are other options that have not been considered.For those interested in this topic see our article on the Resource Revolution.
Over the last century there have been vast amounts of lands that have been deforested and converted to pasturelands and croplands that should be converted back to forestlands and wildlife habitat.The key to realizing this goal is to provide economic incentives for landowners to covert these lands back to forests.
We see 3 sources of revenue incentives for conservation minded landowners.
First, financial incentives can come in the form of selective harvesting of trees in a diverse forest environment.Instead of planting a “mono crop” of trees that would be harvested all at once, a diverse environment could be created with a variety of trees that grow at different rates.Trees could be harvested in a selective manner at different times based on a variety of factors.Instead of wiping an entire habitat, trees can be harvested in a manner that preserves the habitat.
Second, this staggered harvest approach means that the forests will retain their value not only as a habitat, but as recreational areas as well.Recreational activities would be an additional source of revenue for the land owner:hiking trails, cross-country skiing, canopy tours, horseback riding, GPS tracking games, trail biking, ATV tours, ect, ect.
Finally, with the ability to sell carbon credits, there is a third possible source of revenue for the landowner.
Conclusions
It took us a century to create our problems with the environment; we need to take a long-term view at solving them.Realistically it is going to take us 30 years to phase out fossil fuels; there will be more damage to correct during that time. We need to start now and reforestation is the answer. We are conditioned to seek immediate gratification and we are not satisfied unless we achieve instant results. Instant results are not a realistic expectation for solving our environmental problems.From our view a longer-term approach is required.The key is for our generation to initiate the process and to raise our children with understanding that this will be the biggest challenge facing their generation.We need to provide our children with the values and the education so that they will have the tools and the imagination to solve these problems within their lifetime.The future belongs to our children and it is up to us to provide them the means to make their future a bright one.This is a living legacy that is our responsibility to deliver upon for future generations. This is the goal of the Eco Preservation Society.
A new revolution has begun. As with all changes of great magnitude, the status quo is resisting for as long as it can, but inevitably, the Resource Revolution will push aside the old way of life and bring in the new.
When the world stopped having to rely on manual power and animal power, the result was the Industrial Revolution. Until that time, if you wanted a horseshoe, you would ask a blacksmith to make one for you and he would custom make it to fit your horse. When industry could make thousands of horseshoes per day, the price dropped and often the quality increased, helping create a market for the thousands of horseshoes. Much of the affluence of the modern world is due to the efficiency of industry. Each revolution sows the seeds for the next. For example, without the Industrial Revolution, the Microchip Revolution would have been impossible, because manufacturing at the micro level cannot be done by hand. And without cheap computers and the microchip, the Information Revolution or Information Superhighway would never have happened, with its profound impact on the world. Now a smaller company can compete effectively against large companies because of the efficiencies brought about by computers and the Internet.
There are people left behind in the Information Revolution, as in any revolution. There are jobs that have gone away, just as blacksmithing became nearly an extinct occupation as a result of the industrial revolution. No longer does someone dictate to a secretary who takes shorthand. Draftsmen who did not learn to use CAD systems lost their jobs. In the publishing industry, in the early days, computers helped tremendously by replacing old typesetting processes. But now, because of the Internet, most old-style publishing companies are feeling the pressure. No longer do you need a publisher to get your ideas out, just a website. I can be sitting in Costa Rica typing this while those who will read it can be anywhere. The amount of time invested for me to write and disseminate this is very little compared to the time and cost of publishing it. The Information Revolution has permitted us to have a global perspective like we’ve never experienced before, helping bring us into the Resource Revolution, wherein for the first time we are starting to view the earth as a closed system. Now that we can see the world as a closed system, we have to learn how to treat it like one. With few exceptions, man has removed the easily available resources, and when those were depleted, we moved on to the next place. Land was left fallow to recover from the wastes.
Our species always migrates toward resources. In the USA there is a grave problem with illegal immigration. In truth, there may not be a political solution. This is because we are dealing with the fact that it is always easier to migrate toward resources than to create them. It is the perception in many countries that the USA has an abundance of resources still remaining and all that is necessary to have a better life is to get there. You might as well try to hold back the waves with your hands as to try to stop a migration to easily available resources. Much of the tropics have been deforested in recent years due to slash-and-burn farming (). A farmer stakes out land and removes the forest. After a few years, the soils and fertility have been used up and so he moves to the next section of land. It angers the average farmer when I try to explain why this is a problem, because I’m attacking what they perceive as their only means of earning a living. Besides, if it was good enough for dear old dad, it’s good enough for them. I can remember a time when it was considered okay to dump your trash in the nearest stream. The ability for the streams and rivers to accept it seemed inexhaustible until rivers started to catch fire and fish started dying. In many ways, we as a species have functioned like children. Leave children with no training alone in a home, and they will eat whatever is in the refrigerator and the pantry and, if you are lucky, fill up the trash baskets. We have been doing the same; we have been consuming all the resources of the planet without being worried that someday we would run out. The magic refrigerator and pantry were filled with all manner of good things and we have eaten like there was no tomorrow. We didn’t think about the need to deal with the trash pile growing up around our ears. Mother Earth has been like the adult who comes home to replenish the larder and tell the kids to take out the trash, but we are rapidly running out of easily available resources, untapped frontiers, and places to dump the garbage. Those who do not learn how to treat the world as a closed system will be left behind in the Resource Revolution.
Much of the profitability of old-style companies is based on resources whose only cost is that of extraction. This has left other costs not calculated. For example, to be healthy, a company needs to calculate the cost of resource replacement and the cost of cleanup of any unwanted byproducts of using the resource or creating products with the resource. As resources become more and more dear, the nature of business is changing. Since I am in the business of wood and reforestation and it is a subject I know well, I’ll use it as my example. Before the Industrial Revolution, if you wanted to use wood, you went out and cut the tree down yourself. Since you literally created your home from the sweat of your brow with the power of your body, you built small unless you were very rich. Log cabins required very little wood processing. The only planks that were necessary were for the floor, if you didn’t just have a dirt floor. The roof was made by splitting wood for shakes. It was a challenge to make much of a dent in the forest. The population was relatively small, and the time involved to take a tree and make wood from it was long. In truth, most of the time the forest recuperated faster than trees could be removed. Most of the clearing for farms was done with fire, not with ax. When the Industrial Revolution came about, not only did saws and axes become of better quality and cheaper, but motorized means of cutting trees came into play. Sawmills were invented that could process thousands of board feet of wood a day. If you wished to build a home, you could merely go and buy the processed wood. About this time the USA moved away from post and beam construction that produced homes and barns that lasted for hundreds of years to homes built using framing construction that do not last nearly as long. But it was faster to build with precut framing wood than to build post and beam, and if the homes didn’t last as long, at least they were easier to repair or replace, since there was always more wood available down at the sawmill or lumber store. Now we have machinery such that a single crew can clearcut a square mile of forest per day. In the past, for a person to drop ten large trees in a day would be a good day’s work; now tens of thousands is more normal. This is considered progress. But now we are seeing something: All of this great productivity has destroyed streams, rivers, and the land itself in runoff, degradation of soil, and erosion. Where before was an ecosystem that could easily regenerate itself, now it gets harder and harder to regrow the forest. We’ve tried replacing trees in monocrop plantations, but this has created very serious disease and pest problems in many areas. Not only that, as the supply dwindles, there is not enough wood to keep the very expensive sawmills and harvest equipment busy. The nature of a large capital investment in equipment is that it only makes sense if it is used at nearly full capacity. It is hard to pay the bills on a million dollar piece of equipment if it is sitting idle because there are no trees to cut. Yet as sawmills are closing, for example, in many parts of the USA, there are people elsewhere who are doing very well in wood today. They are revolutionary thinkers who have taken the long view, treating the world as a closed system and buying land with trees on it that had very little value because others had already taken all the good trees. These people have gone out and selectively harvested just the bad trees. Instead of only taking the best, they took the worst. Even though it is not as profitable to process poor quality wood, when you do it with smaller equipment and use it to make flooring, moldings, and such, you can make more than enough to survive while you allow the forest to recover. Instead of year by year the forest being worse off, it actually improves. This means the owner, instead of being poorer every year, actually is getting wealthier. It is like having a magic pantry that every time you open it, the amount of food as well as the quality increases. The secret to this business model is to always have a view to the future, because if you destroy the resource, you will destroy your business and your livelihood. You also have to be careful of your waste, because no more can we assume that there is yet another frontier to exploit just over the hill. If you poison your environment, it will be you that you poison, not your neighbors. The good part is that if you have your own source of resources, your business is not held hostage by availability of the resource nor by price fluctuations of that resource. There is a book worth reading called Collapse by Jared Diamond. Diamond shows how civilizations have collapsed due to various factors, often including abuse of their environment. The author might agree with me that in the coming years, no longer can we view a society as civilized that plunders resources. After all, do we think of societies that are based on robbing and plundering as being civilizations? No, we think of them as barbaric forces against civilization. Now has come a time that if we are not to suffer a collapse of the civilization we have, we must understand that exploitation of anything is not civilization because such action is not sustainable. In the future, we may view companies who exploit resources as no different from a thief who supports himself by stealing. It is not producing to merely take from a common pool of resources. The resources of the world belong to all of us, and those who take and do not replenish are enriching themselves by making all of us poorer. This is not being civilized. You will notice that those who are against the Kyoto agreement often state that adopting it would wreck our economy. Think about what they are saying: If we have to pay for the damage we cause, our businesses will not be profitable. In reality, since we know that there is no “magic pantry” and no “magic trash can,” businesses like that are showing themselves profitable only because they are not calculating the full costs and are leaving the rest of them for all of us to pay. It’s like transferring your expenses to another department to appear profitable. This is considered fraud in business, and we should consider it fraud in civilization as well. When we think of the businesses that have taken resources without putting back and have left the trash for the public to deal with, we need to understand that we are really the culprits. Any time we buy their products, we are benefiting from their short-term gains, and when we place our money in their companies via investments, we are granting them our agreement with their practices. Unfortunately, it will not be them who pay the piper at the end, but all of us. We are starting to see new companies that not only do not rape the planet for resources, but manage to actually turn a profit while turning back the clock on resource consumption. We at Finca Leola believe we have managed to create such a company. The reason, I think, is simple: We were never driven by a need for short-term profit and so were able to take the long view, the revolutionary view. In much of Latin America, the way people outside of the cities earn a living is often by raising cattle. They have chopped down or burned the rainforest, planted grass, and put cattle on the land. Much of the meat is purchased in order to supply cheap beef for the northern markets. There is a problem with this model. First of all, if you have to buy the land, you cannot survive this way – it is better to put the money in the bank and receive the interest. So, raising cattle in Latin America is based on having a free resource: land. Secondly, the longer you have cattle on the land, the poorer becomes the land. I constantly hear stories of how rich the land here in Costa Rica was in the past. When the forest was first removed, all that was needed to raise corn or beans was to cast the seeds on the ground and you would have a great harvest! But after a few years of doing this, you have to start adding fertilizer or you will not have a harvest at all. Finca Leola buys cattle farms and plants trees on them. You can own trees on Finca Leola plantations, and your money will bring back rainforest, improving the world and your bottom line. We raise trees that are pioneer species in order to quickly protect the land and produce a return for the tree owners. After a while, we plant the permanent rainforest trees among the pioneer trees, using them like a nursery. As the forest returns, its products will sustain its protection as well as provide work for the locals so that they value the forest. The forest will be considered a partner, not a free resource to be robbed. This creates many very good and permanent jobs, because the permanent forest is productive, whereas raising cattle in the tropics is a cycle of poverty for all except a few large landowners. Every year our lands are more productive and the future looks brighter. The streams and rivers on our land are cleaner and flow with more water. The wildlife is much more abundant, and amazingly, much more comfortable around people. All our workers have health insurance and retirement, uncommon among rural Costa Rican laborers. They have better jobs that pay better than average in the area. We now have a woodshop that is producing products from the plantations. Since we own the woodshop and sawmill, we use nearly all the tree, not just the easiest part to process. This is because we take the closed-system view that no resource is to be wasted. It takes a lot of effort to grow a tree, and we don’t want to throw away any of it. True, it would be more profitable in the short term if we took the best of the tree and left the rest as waste, but in the long run, it is better to use as much as we can. And since we don’t have many layers (loggers, sawmills, wood brokers, lumber yards, etc.) we can use wood that normally would not be considered profitable. We also use sheep, small cattle, and horses to keep down the grass between the trees. This produces revenue while reducing our cost to care for the trees. When we have to create a bridge for access, at times we create a pond for fish as well. This produces food for our workers and for ourselves and perhaps some for market. We don’t run like an assembly line but as a complete system. We try to use all resources efficiently while producing more if at all possible. No more can industry use up the resources in one location and move on to where there are more. We have finally realized that resources are not inexhaustible. People who have decided to invest in diminishing resources such as trees instead of investing in old-fashioned businesses not only understand that many of the old-style businesses are facing very serious challenges in the future, but that companies such as ours are allowing investors to benefit in the new way of business. They are finding that the returns from the efficient way we grow trees exceed what they would have received from an old-style plantation. We are entering into a new kind of world where holistic companies are the profitable ones. Green investing is a movement that recognizes this as a market force. Instead of investing in businesses that rape and pillage and are therefore doomed to only short-term success, the smart investor places his money in businesses that work in harmony with the earth and help replenish life. Success in business and in investing is usually due to recognizing emerging trends. Buy low; sell high, because no one thinks what you are investing in is worth much, but when the trend catches on, your initial investment is worth many times more. Sometimes the trend is so large, it becomes a revolution. These are times when the fundamentals of business changes radically, and during such times there are always winners and losers, the losers being those who either do not or will not accept the change. Don’t be left behind in this revolution – invest in companies that treat the earth as a closed system. If we are going to advance civilization, our money needs to do more than just earn more money; it needs to buy back the health of our planet.
( We would like to invite all of those interested in this subject to join our ongoing discussion at Treehugger.com . )
In 2005 Lawrence Livermore Laboratory and Carnegie Institutionproduced a study that sent ripples through the reforestation community and has influenced many of those interested in carbon offsets and carbon neutral programs.Many have embraced the findings from this study and many have concluded that reforestation has limited value in efforts to decelerate the warming of the planet.Dr. Caldeira of the Carnegie Institution referred to tree planting as a “feel good solution”.We feel strongly to the contrary, we feel that a long-term effort at sequestering carbon is vital and that reforestation is the only means presently at our disposal.
This study has been frequently referenced under splashy headlines by bloggers all over the Internet.Many, if not most of these bloggers are within the environmental movement.We feel that they have been led astray with faulty conclutions.
To date there has been little, if any, serious scrutiny of the findings of this study. Indeed many have extrapolated conclusions that are well beyond the scope of what was actually measured.The purpose of this article is to take a closer look at the Lawrence Livermore Study and put its findings into a more meaningful context.
First, by the study’s author’s own admission, the Lawrence Livermore study was predicated on an unrealistic scenario.The modeling was based on the single metric of replacing 100% of ALL grasslands and 100% of ALL croplands with evergreen trees!The modeling techniques did not take into account geological variations, topographical variations, altitude, regional weather patterns or microclimates.What the Lawrence Livermore study accomplishes is nothing more than a broad approximation based on a single variable, with that single variable being latitude.
Second, there is a significant time variable when measuring the “possible Albedo Effect” identified in the report.According to the study, the “possible Albedo Effect” does not come into play until 80 years following reforestation.What the Lawrence Livermore study assumes is that the there is no harvesting of the trees in its conclusions.If reforestation efforts north of 50 degrees are followed with a harvest of the trees prior to year 80 in the project there is no Albedo effect.Within this context a strong argument might be made that harvesting trees for wood products may be a effective way of sequestering carbon.
Third, there is no Albedo Effect with non-coniferous trees that loose their leaves during snowy periods.
Finally, it seems to me that the study assumes that there is no snow covering the trees.I have flown over snow-covered forests many times. While I might not be a scientist Lawrence Livermore, I can attest that at high altitude there is just not that much variation in the reflectivity on a snow covered typography.How much Albedo Effect can there really be if the trees are covered with snow?My understanding of the study is that it is comparing the reflectivity of green trees vs. white snow. Is this realistic of real world condition? I tend to think not.
Conclusion: The Possible Albedo Effect discussed the Livermore Study is limited to 80-year-old stands of evergreen trees north of 50 degrees latitude.Even within this limited conclusion, the results are not proven. It should be noted that this limited finding has not been confirmed by independent research.Nor does the study account for variations in Possible Albedo Effect based on regional weather patterns, geological variations or for conditions when trees are covered with snow. Vast regions of the Canadian plains have never been forested and do not have a climate to support a forest. Why should those areas be included in the measurements of this study? This study took into account only one factor, latitude.
Many of those that have embraced this study would suggest that all of our efforts should be focused solely on reducing our carbon emissions.Certainly technologies that allow us to achieve these reductions are of critical important to our future.However, from our view this is not an either/or proposition when comparing Emission Reductions to Carbon Sequestration, both are vitally important. It is of critical importance that we both reduce our emissions and reduce the amount of additioal CO2 that we have added (and will continue to add for the next 20 or 30 years) to the atmosphere.
( We would like to invite all of those interested in this subject to join our ongoing discussion at Treehugger.com . )
In a report from Reuters (“Trees take on greenhouse gases at Super Bowl”, 30 January 2007), Dr. Ken Caldeira, a Carnegie Institute climate scientist, was reported to say, “It’s probably a nice thing to do, but planting trees is not a quantitative solution to the real problem.” Dr. Philip Duffy of Lawrence Livermore National Laboratory said, “If you plant a tree (CO2 reductions are) only temporary for the life of the tree. If you don’t emit in the first place, then that permanently reduces CO2.” Dr. Caldeira had made similar arguments previously in an op-ed in the New York Times (“When Being Green Raises the Heat, 16 January 2007).
A New Scientist article (“Location is key for trees to fight global warming,” 15 December 2006) reports results from a study by ecologist Dr. Govindasamy Bala of Lawrence Livermore National Laboratory. The model developed by Bala and colleagues indicates that, while trees planted in tropical regions have a clear net cooling effect, trees planted in mid-latitudes may absorb so much heat from the sun that they actually contribute to warming.
These stories fail to capture the complexity of the role that city trees play in fighting global climate change. Trees reduce carbon dioxide in the air, thereby reducing the warming “greenhouse” effect of the gas, in two main ways. First, as they grow, they take carbon dioxide out of the air and transform it into roots, leaves, bark, flowers, and wood. Over the lifetime of a tree, several tons of carbon dioxide are taken up (McPherson and Simpson 1999). In fact, trees are the only known feasible way to remove carbon dioxide from the atmosphere. Even if we were able to switch immediately to fuel sources that do not emit carbon dioxide, the current levels in the air are higher than at any time in the past 400,000 years, according to the UN’s International Panel on Climate Change, and because of the long “lifetime” of carbon dioxide, will remain so for decades or even centuries.
Second, by providing shade and transpiring water, trees lower air temperature and, therefore, cut energy use, which reduces the production of carbon dioxide at the power plant. Two-thirds of the electricity produced in the United States is created by burning a fuel (coal, oil, or natural gas) that produces carbon dioxide–on average, for every kilowatt hour of electricity created, about 1.39 lbs of carbon dioxide is released (eGRID 2002). It is certainly true, as Dr. Duffy states, that not emitting carbon dioxide in the first place is a good strategy. Lowering summertime temperatures by planting trees in cities is one way to reduce energy use and thereby reduce carbon dioxide emissions.
To address the other claims made above: Are carbon dioxide and other greenhouse gas reductions from tree planting temporary? In a sense, yes, greenhouse gas reductions are temporary if trees are removed and not replaced. To achieve long-term reductions, a population of trees must remain stable as a whole. This requires a diverse mix of species and ages so that the overall tree canopy cover remains intact, even as individual trees die and are replaced. Although sequestration rates will level off once an urban tree planting project reaches maturity, the reduced emissions due to energy savings will continue to accrue annually. Dead trees can be converted to wood products or used as bioenergy, further delaying, reducing, or avoiding greenhouse gas emissions.
Dr. Caldeira suggests in the Super Bowl article that tree planting projects are “risky.” They may appear more risky than reducing emissions by building solar or wind farms because the tree-related climate benefits are less easy to document and because the 50- to 200-year life span of a tree seems less permanent than a new power plant. This uncertainty can be offset by legally binding instruments such as contracts, ordinances, and easements that guarantee tree canopy in perpetuity. And, of course, trees and alternative energy sources are not mutually exclusive–both have a place in reducing carbon dioxide emissions.
Will urban tree planting in mid-latitude cities result in zero or even negative climate benefits? Dr. Bala’s study in the New Scientist article describes two main ways trees lower temperature: they remove carbon dioxide from the air, reducing the greenhouse effect, and they release water vapor, which increases cloudiness and helps cool the earth’s surface. But because tree leaves are dark, they also absorb sunlight, which increases the temperature near the earth’s surface. The difference between trees in tropical latitudes and those in mid-latitudes has to do with the difference in how much sunlight forests reflect compared to other possible surfaces, especially during winter. Snow reflects more sunlight back into the atmosphere than forest vegetation, resulting in less heat trapped near the earth’s surface. Large-scale tree planting projects that replace highly reflective surfaces with forests will result in more heat trapped near the ground during winter.
In cities, this fact is less relevant. Asphalt, concrete, and roof surfaces account for 50 to 70% of urban areas, with the remaining area covered by trees, grass, and bare soil. The difference in the solar reflectances, or albedos, of the different urban surfaces is small. Vegetation canopies have albedos of 0.15 to 0.30, the albedo of asphalt is 0.10, that of concrete and buildings is 0.10 to 0.35, and the overall albedo in low density residential areas is 0.20 (Taha et al. 1988). In cities, increasing urban tree canopy cover does not appreciably alter surface reflectance, or increase heat trapping.
At the same time, as described above, a number of field and modeling experiments have found that urban trees reduce summertime air temperatures through evapotranspiration and direct shading (Akbari and Taha 1992, Rosenfeld et al. 1998, McPherson and Simpson 2003). This reduces energy consumption and the emissions related to energy generation. Recognizing the climate benefits of trees, the California Climate Action Team Report (2006) recommended planting 5 million trees in cities to reduce 3.5 million metric tons of carbon dioxide. Since 1990, Trees Forever, an Iowa-base nonprofit organization, has planted trees for energy savings and atmospheric carbon dioxide reduction with utility sponsorships (McPherson et al. 2006). Over 1 million trees have been planted in 400 communities with the help of 120,000 volunteers. These trees are estimated to offset carbon dioxide emissions by 50,000 tons annually.
Do tree-planting projects give people a “feel-good illusion that they are slowing global warming?” The climate benefits of trees in mid-latitude cities are not an illusion, although they certainly feel good. Reductions in atmospheric carbon dioxide are achieved directly through sequestration and indirectly through emission reductions. Still, planting trees in cities should not be touted as a panacea to global warming. It is one of many, complementary bridging strategies, and it is one that can be implemented immediately. Moreover, tree planting projects provide myriad other social, environmental, and economic benefits that make communities better places to live. Of course, putting the right tree in the right place remains critical to optimizing these benefits and minimizing conflicts with other aspects of the urban infrastructure.
Urban Tree Planting and Greenhouse Gas Reductions
Greg McPherson, Ph.D.
USDA Forest Service
Director, Center for Urban Forest Research
Davis, CA
March 12, 2007
( We would like to invite all of those interested in this subject to join our ongoing discussion at Treehugger.com . )
Tropical Forests Air Condition Planet Earth
Lawrence Livermore study has raised questions about reforestation in Northern Snowy regions, the is no question about the importance of our tropical rain forests. According to the Lawrence Livermore study tropical forests are very efficient at keeping the Earth at a happy, healthy temperature.
The conclusions of the study found were that tropical forests store large amounts of carbon and because they produce reflective clouds they are especially good at cooling the planet, a positive Albedo Effect.
In contrast, according to the study, forests in snowy areas my possibly 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.
“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.”
( We would like to invite all of those interested in this subject to join our ongoing discussion at Treehugger.com . )
The Lawrence Livermore study has created quite a buzz among bloggers and those that are concerned in Global Warming, Greenhouse Gas Emissions and Carbon Offset Programs. Acceptance of this report is widespread. To make matters worse and the findings have been consistently misinterpreted for the sake of attention getting headlines.
What those that have embraced this report have failed to realize is that the entire study is based on an unrealistic hypothetical predication.
The Lawrence Livermore/Carnegie Institution study investigated whether converting ALL of the world’s grasslands and croplands to forests would cause warming or cooling. Forests interact with the climate in a variety of ways, in some respects providing a cooling effect and in other respects, a warming one. This study tried to determine which of the effects would dominate.
Albedo
Albedo is a measure of reflectivity, quantified as a percentage from zero to 100. The higher the albedo, the more reflective a body is. A body with a lower albedo absorbs more energy and, therefore, will warm more than one with a higher albedo. Fresh snow has a high albedo-close to 90 percent-while the albedo of a dark object like a forest canopy is low.
Through changing land use patterns, human activities have altered the earth’s albedo from pre-agricultural times. According to the Lawrence Livermore/Carnegie Institution study, previous studies have concluded that by converting forest to cropland, humans have increased the albedo in the temperate (mid-latitude regions), thereby causing cooling in those areas before the twentieth century as compared to pre-industrial times. Other studies have shown that expanding forest cover in boreal (high latitude) regions can lower the area�s albedo and lead to warming, while studies of tropical (low latitude) regions have been inconclusive on the effect of forestation or deforestation on albedo.
The issue of latitude comes into the picture because a body’s albedo depends in part on the angle at which the light strikes it. Thus, the same plant at the same time of year but at a different latitude will have a different albedo. In addition, the ground at different latitudes has different albedo, as the snow typical in boreal regions has much higher albedo than the soil or rock in tropical regions.
Reduction of greenhouse effect through terrestrial sequestration
The removal of CO2 from the atmosphere by trees and plants is one type of carbon sequestration. (Another type is geological sequestration, involving the storage of CO2 underground.) Through photosynthesis, plants grow by converting sunlight and CO2 into carbohydrates. In the process, CO2 is taken out of the air and transformed into sugars and starches. So long as the plant remains intact (i.e., does not decay or get burned), the CO2 is sequestered-it is trapped in the plant rather than remaining in the atmosphere. The removal of CO2 from the atmosphere reduces the greenhouse effect, thereby cooling the earth.
Evapotranspiration
Evapotranspiration is the sum of evaporation and transpiration (the process of water loss from plants through stomata, the small openings used for gas exchange found on the underside of leaves). The U.S. Geological Service estimates that transpiration accounts for about ten percent of the moisture in the atmosphere, with oceans, seas, and other bodies of water (lakes, rivers, streams) providing nearly 90 percent. Evaporation and transpiration are endothermic or energy-absorbing processes, and therefore cool down their surroundings.
Findings‘
The Lawrence Livermore/Carnegie Institution study first looked at whether, in converting all of the world’s grasslands and croplands to forest, the albedo effect (warming) or evapotranspiration (cooling) would dominate. The study found:
Global temperatures rise 1.3° C, as the albedo effect dominates over evapotranspiration.
This effect is more pronounced in the northern hemisphere, where the conversion to forests would lead to a 3.8° C temperature increase.
The warming effect is more dramatic in the boreal (very high latitude) forests as compared to the temperate zone. A modeling exercise that looked only at replacing vegetation in the temperate region with trees showed a warming of only 0.27° C.
Although the albedo effect dominates over evapotranspiration in the temperate zone, leading to warming, this is not true in the tropics. There, the evapotranspiration effect dominates, leading to net cooling (because of the relationship between temperature and saturation water vapor pressure).
Reversing the experiment-i.e., replacing of all the world’s trees with grasslands-would result in a global cooling of 0.4° C.
The main finding-that converting the world’s grasslands and croplands to forests will lead to a 1.3° C temperature increase when only albedo and evapotranspiration are considered-is due to the fact that the albedo effect dominates over evapotranspiration, a result which fuels a self-reinforcing loop. Greater forest cover lowers the albedo, which leads to warming. The increased warming melts more snow (which has a high albedo), uncovering bare soil (which has a lower albedo). The decrease in albedo causes more warming, which melts more snow.
The authors then compared these results with another consequence of growing forests: the fact that trees sequester CO2, thereby reducing the greenhouse or warming effect of the gas. By itself, the lower CO2 levels resulting from tree growth would lead to cooling-by 3.5° C globally, with the replacement of all grassland and croplands by trees. However, as the authors have concluded, the albedo effect of forestation (net of evapotranspiration) leads to warming. So this leaves the question as to whether the change in albedo or the effect of sequestering CO2 would dominate.
The study concludes that the answer depends on the time frame. Over the short term (i.e., decades), planting forests is likely to have a cooling effect on the climate, as the trees sequester atmospheric CO2 and reduce the warming effect of the gas. This cooling overcomes the warming attributable to the decreased albedo (again, net of evapotranspiration) that results from the forest growth-but for only so long. According to the authors, although the albedo effect is permanent, atmospheric CO2 concentrations equilibrate over time (in part because of the interaction of ocean and atmosphere), so that after about 80 years global forestation would produce net warming.
The authors suggest that this study has important policy implications, “since incentives for tree plantations in mid- and high latitudes [i.e., temperate and boreal regions], may, on long time-scales, produce the opposite effect to that desired.” Yet although the study raises questions about the efficacy of planting trees as a strategy to address climate change, it is worth keeping at least three items in mind.
First, as the authors themselves observe, the simulations conducted in this study are entirely unrealistic. They write:
“Our goal here is not to reproduce the observed pattern of land cover change, nor to realistically simulate possible future scenarios, but rather to bracket the magnitude of temperature change that is possible in the climate system due to changes in land cover.”
Second, the study reaches significantly different conclusions as to tree planting in the boreal and temperate zones. The albedo effect appears to result in much more significant warming in the far North than in the temperate zones. The authors recommend further study to evaluate whether forestation in the mid-latitudes can actually mitigate climate change.
Third, the study, like some previous ones, suggests that forestation in tropical zones would lead to cooling because, unlike in temperate zones, evapotranspiration dominates over albedo in these areas, even in the long run. Therefore, even if it turns out that forests in temperate and boreal regions cause warming in the long term, that may not be the case in the tropics.
As counterintuitive as the concept may seem, there is a growing number of environmentalist that believe that reforestation is a contributor to Global Warming. Eco Preservation Society has been researching this issue and will present a series of articles on the topic. In this series of articles we will explore the issues around Reforestation, Carbon Offsets and Albedo Effect.
We would also like to invite all of those interested in this subject to join our ongoing discussion at Treehugger.com .
The first article in this series comes from Mathew Feldman at the Carbon Neutral Digest and lays the groundwork for discussion. The second article will deal more closely with understanding Aldedo Effect and its importance to this discussion.
Trees
Planting trees is the most common way to offset carbon production and is the most controversial. The theory is that one tree over the lifetime of that tree destroy one ton of carbon dioxide.
Here are just a few problems with that theory. What is the lifetime of a tree? Will it take 75 years to remove a ton of carbon? Will it take 100 years to remove a ton of carbon?
A 2005 Lawrence Livermore National Laboratory(LLNL) study using climate models examined the effectiveness of planting trees in different areas as a way to offset carbon production. What they found was nothing less shocking, snow is white and reflects heat. Trees are not white and absorb more heat then snow, hence heating the earth up. As the earth gets hotter more snow melts, more trees grow making the earth even hotter. You can see were this is going. LLNL ran simulation models comparing trees versus shrubs/grassland. Trees were shown to make the earth 1.6 C warmer when planted and grasslands were shown to make the earth cooler by 0.38C. So why would anyone plant trees as a carbon offset project?
There are some exceptions to this idea. The first exception is planting trees in the Amazon rain forest. The idea is that the rainforest works in a synergy and adding more trees to this synergy is beneficial. The other exception is planting trees in an urban area. Trees are cooler then pavement, and will provide a cooling effect to the pavement.
The Australia Institute also took a look at tree planting as an offset project. They found some rather interesting results. The first issue is that forestry projects cannot permanently store carbon. At some point the forest will be cut down or burned, when that happens the stored carbon is released into the environment. The forest soil can hold a vast sums of carbon from decaying leaves, trees, and branches. When the forest is cut down or burned the soil can release that carbon into the environment.
Tree planting can lead to carbon leakage. When trees are planted on land, the land use changes. If the land was being used for farms, houses, or recreational activities people may just clear new land and continue those activities. Where this happens, the apparent emission reductions from a forestry projects could ‘leak’ out of another forest area.
Climate change will have an impact of forestry offsets. With the current environmental change caused by global warming rain fall levels are not the same. Many tree planting offset projects are happening in areas that might not have enough rain to support a forest.
EPS Commentary: There is some controversy among those that are interested in Carbon Offsets as to the value of Reforestation as a means of reducing Carbon in the atmosphere. In order to properly understand the importance of reforestation to reducing carbon in the atmosphere, it is important to understand the concepts of Carbon Sinks and Carbon Sequestration. The information below was taken from the EPA and provides complete analysis of the topic.
Carbon sequestration is the process through which agricultural and forestry practices remove carbon dioxide (CO2) from the atmosphere. The term “sinks” is also used to describe agricultural and forestry lands that absorb CO2, the most important global warming gas emitted by human activities. Agricultural and forestry practices can also release CO2 and other greenhouse gases to the atmosphere.
Sequestration activities can help prevent global climate change by enhancing carbon storage in trees and soils, preserving existing tree and soil carbon, and by reducing emissions of CO2, methane (CH4) and nitrous oxide (N2O). For more information on the science, emissions, and reduction opportunities for these and other non-CO2 gases, please visit our non-CO2 gases page.
The Basic Science: Science
Carbon storage (sequestration) occurs in forests and soils primarily through the natural process of photosynthesis. Atmospheric carbon dioxide (CO2) is taken up through tiny openings in leaves and incorporated as carbon into the woody biomass of trees and agricultural crops. Roughly half of this biomass is carbon. Some of this carbon makes its way into soils when vegetation, litter and roots decay. Carbon in forests and soils can return to the atmosphere as CO2 when agricultural tillage practices stir up soils or when biomass decays and burns. Forests and agricultural soils can therefore act as either a net carbon sink or source. The movement of carbon in and out of trees and soils is part of the Earth’s global carbon cycle.
This section of the Web site provides a basic description overview of these carbon processes at two scales:
·Frequently asked questions (FAQ) about carbon sequestration
·Agricultural & forestry practices that sequester carbon and reduce other greenhouse gases
·U.S. national analysis on current sequestration rates, and the potential for additional sequestration and greenhouse gas reductions in agriculture and forestry
·Project analysis to estimate the climate benefits of agricultural and forestry projects
Mitsch says that while wetlands are a natural source of methane – a potent greenhouse gas – from decomposition, CO2 sequestration appears to balance net carbon emissions.
Eco Preservation Society 
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