Tuesday, June 15, 2010

Geoengineering: Can Humans Reverse Climate Change?

by: Jasmine Greene


Tags: , , , , Geoengineering techniques have been around since 1965 when scientists suggested spreading reflective material over the ocean to bounce back 1% sunlight back to space [Source: Scientific America]. Unfortunately this idea was complete bunk, but Geoengineering has been gaining traction recently due to rising temperatures. There are currently two different geoengineering techniques: solar radiation management and carbon sequestering.

Solar radiation management, while potentially the fastest way to cool the planet, also is temporary and could potentially have many side effects. One of the proposals currently being discussed is the creation of manmade volcanic eruptions. Sulfide gases would  be injected into the stratosphere every one to four years, providing the earth with a “grace period” of up to 20 years before major cutbacks in greenhouse gas emissions would be required [Source:
UCAR]. Unfortunately, this technique could thin the ozone layer if enough aerosol is injected into polar stratospheric clouds. Other negative effects include changing weather patterns, drought, acid rain and respiratory problems in humans. If done properly, however, this technique could potentially drop average temperatures 0.6 degrees Celsius [Source: 21st Century Challenges]. A less risky solar radiation management plan involves whitening of marine clouds. Ocean spray is released into the atmosphere to increase the reflectiveness of clouds. The extra changes the size of the water particles in existing clouds, making them whiter. This technique can be stopped at any time and is part of the natural process of "ocean spray". It can be deployed quickly and rolled out cheaply and effectively, though it could potentially interfere with wind and weather patterns [Source: Guardian]. This problem also does not address ocean acidification or ways to actually decrease the amount of CO2.

While solar radiation management only looks at decreasing overall temperature, carbon sequestration looks for ways to decrease overall CO2 levels. Iron deposition into the ocean is one method of carbon sequestration. The iron encourages phytoplankton growth, which removes carbon from the atmosphere, potentially on a permanent basis. While this sounds promising, there is no way to predict how this could affect marine life and nutrient balance in the ocean and could lead to poisonous algae spread [Source:
Spiegel]. There are two methods of geoengineering that do not have harmful side effects:reforestation/afforestation and biochar. Reforestation is the process of replanting trees in cleared areas and afforestation is planting trees in areas that were never forest or haven't been for years. Currently, deforestation accounts for 25% of the world's greenhouse gas emissions [Source: Monga Bay]. While planting trees would help to decrease the amount of CO2, the time it takes for trees to regrow and biomass to rebuild is significant. Reforestation could be used alongside biochar. Biochar is charcoal made through pyrolysis of biomass, which is then buried and mixed with normal soil. Not only does it make the soil fertile, it holds potential for long-term carbon storage, possibly for millennia. Craig Sams, founder of Carbon Gold, believes biochar could potentially reduce CO2 levels to pre-industrial levels by 2050 if it were used in 2.5% of the world's agricultural fertilizer [Source: Popular Mechanics]. Biochar is easily measured, making it great to figure out effectiveness of its carbon sequestration and it is at much lower risk of returning to the atmosphere than living organisms since it is mainly inert [Source: Treehugger].


 While many of the "quick-fix" geoengineering proposals have many negative side effects, they are mostly presented in worst-case scenario and are generally temporary. The more long-term solutions like reforestation and the usage of biochar may work better, but it takes longer to see the effects. Either way, no geoengineering technique will be effective if the average global carbon emission does not decrease.



One program using the model of reforestation and biochar is the Enoch Olinga College (ENOCIS) agricultural extension program “New Era Farms” in Panama dedicated to using paulownia to teach peoples oof extreme poverty alternate income sources for their farms.



Read more: reforestation, geoengineering, biochar, environment & wildlife, paulownia, ENOCIS



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Wednesday, June 2, 2010

Study Finds Reforestation May Lower the Climate Change Mitigation Potential of Forests

Tags: , , , , , , , , , ,   Scientists at the University of Oklahoma and the Fudan University in Shanghai, China, have found that reforestation and afforestation - the creation of new forests - may lower the potential of forests for climate change lessening.


Yiqi Luo, professor of ecology in the OU College of Arts and Sciences Department of Botany and Microbiology, and Changzhang Liao, Bo Li and Changming Fang, professors of ecology in the Fudon University Department of Ecology and Evolutionary Biology, examined whether plantations have the same ecosystem carbon stock as natural forests.


By synthesizing 86 experimental studies between plantations and their natural forest counterparts, Luo and colleagues found plantations substantially reduce carbon stock in ecosystems in comparison with natural forests.


'That decrease in ecosystem carbon stock should be accounted for, together with other forest products such as the harvested wood, when the total mitigation of reforestation is evaluated,' said Luo.


This study challenges the idea that planting non-native or native-improved growth species on historical forest land yields greater carbon accumulations rates. They argue against the replacement of natural forests by reforestation, also known as plantations, to help stave off climate change.


Plantations established on non-forested fields such as agricultural lands do help with the control of carbon emissions; however, converting farmland to forests decreases the amount of carbon absorbed by the soil. Another form of gas, methane, also is affected by the conversion. Converted soil loses 80 percent of capability to degrade methane as compared to natural forests when it is developed as a plantation.


To minimize negative effects of plantation, appropriate forest management practices need to be adopted. Site preparation without burning, for example, leads to less soil carbon loss than that with burning. To avoid ecosystem degradation associated with plantations, restoration measures need to be implemented to engineer ecosystems toward their natural potentials.


'The shifts from natural forests to plantations can also generate other ecological problems,' writes Luo. 'For example, soil bulk density, representing the degree of soil compaction, increases, possibly leading to limitation of rooting systems and destruction of soil structure in plantations. Additionally, plantations decrease stream flow.


'On the positive side, plantations can provide commodities for human needs (e.g., timber, biomass). Therefore, we are now facing a great challenge of developing a management policy for plantation practice that minimizes their negative impacts on ecosystems but maximizes their commodity values.'


One project using these techniques in Panama is New Era Farms, the agricultural extension program of the Enoch Olinga College (ENOCIS). To read more about their reforestation efforts with paulownia refer to www.paulownianow.org or to invest in this type of program you can read www.panampro.com



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