| |
Lead Papers
Germain Dufour, JHY Katima, S. Augustin, B.
Lyimo and E. Kilawe
S. Augustin, J. Katima, E. Klawe & B. Lyimo
have shown that tropical tree plantations may be an important component of the global carbon cycle because they represent a carbon sink that can be
manipulated by humans and they ca mitigate the effects of tropical deforestation, which is the main biotic source of atmospheric
carbon (Houghton et al., 1983).
Most forest plantations in the tropics are planted with fast growing trees that culminate in volume and biomass production earlier than
natural forests. These high biomass production forests have a high capacity to sequester atmospheric CO2 and hence assist in
mitigating global warming. Sequestration of CO2 in plantations occurs in tree biomass (stems, branch, foliage and roots), forest floor
and as storage in the soil. Young growing forests are one of the best means to removing CO2 (the gas partially responsible for the
greenhouse effect) from the air. Thus planting forests help to reduce the amount of carbon dioxide in the air (by the action of sunlight
on the green chlorophyll organic compound, CO2 is absorbed by trees through the small fissures in the leaves or needless, these gases
are fixed as biomass).
Therefore the model is designed to assess the above ground-biomass for two even-aged, single species plantations with the same site
class (Pinus patula and Eucalyptus saligna) as an attempt to quantify the carbon storage potential of the two species and their possible
roles in carbon sequestration and atmospheric carbon dynamics.
The study shows that establishment of Pines and Eucalyptus plantations is seen as an efficient way to create carbon sinks due to rapid
increment rate soon after establishment. Brown et al. (1985) predict that the sink function to become more significant in the future,
attributed to the increase in the rate of establishment and the large areas of young plantations, which will sequester more carbon as
they develop and grow into older age classes.
Greenhouse Effect (Dufour)
Ever-increasing anthropogenic releases of greenhouse gases are driving the United Nations Climate Change effort. As the atmosphere's concentrations of "greenhouse gases" increase, so too does the atmosphere's ability to retain heat radiated from the earth's surface. This phenomenon, known as the greenhouse effect, is linked by many scientists to a long-term rise in global temperatures.
The greenhouse gases, mainly carbon dioxide, methane and nitrous oxide, are critical to the atmosphere's ability to retain heat and thereby maintain the global temperatures necessary to maintain life as we currently know it.
The increases in concentrations of these gases are produced primarily through the burning of fossil fuels, but also by such activities as deforestation and land clearing, which release the carbon naturally contained in vegetation. Over the past 100 years, humans have caused the release of these gases faster than natural processes can remove them from the atmosphere.
Some scientists predict that average global temperatures will increase 2 to 6 degrees Fahrenheit over the next 100 years if global emissions of greenhouse gases continue unabated. In addition to an increase in ambient temperatures, the other possible consequences of global warming include a speeding of the global water cycle. It is predicted that faster evaporation caused by higher temperatures would lead to drying of soils, exacerbating drought in some areas while increasing precipitation and flooding in others.
Warmer temperatures could melt polar ice caps, leading to what some predict as a rise in sea levels of between 6 to 37 inches over the next century. This, in turn, would endanger coastal populations and island nations and cause the degradation of coastal ecosystems. If these predictions prove true, human health will be affected directly as warmer temperatures increase the chances of heat waves, exacerbate air quality problems and lead to an increase in both allergic disorders and warm weather diseases. Agriculture, forests, natural ecosystems and vegetation patterns would also be adversely affected by both increases in temperatures and changes in the water cycle.
U.N. Efforts
The Kyoto Protocol is the latest step in the ongoing United Nations' effort to address global warming. The effort began with the United Nations' Framework Convention on Climate Change (Convention) signed during the Earth Summit in Rio de Janeiro in 1992. (The Convention entered into force in 1994 upon the ratification by 50 nations) Despite the continuing scientific debate on the likely occurrence of global warming, the nations took action under the "precautionary principle" of international law.
The Convention is intended to stabilise greenhouse gas concentrations at a level that will prevent dangerous interference with the global climate system. The time frame is to be "sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner."
To further that objective, the Convention sought to commit all parties to it to develop and implement programs to mitigate climate change by addressing emissions of greenhouse gases.
The Convention places the first level of commitment to reduce emissions on nations that have developed, prospered and established strong economies through the consumption of fossil fuels since the industrial revolution began. These developed countries are the 38 countries listed in Annex I to the Convention.
Kyoto Protocol
The Convention recognises the importance of preserving and enhancing the earth's natural ability to remove certain greenhouse gases from the atmosphere by FORESTS and other carbon stocks, referred to as "sinks". The removal by sinks is also a key component of the Protocol, which allows countries to meet their commitments by considering the effects of afforestation, reforestation and deforestation since 1990, a provision that is expected to promote cost-effective solutions to climate change and good forestry practices.
Flexibility Mechanisms
The Kyoto Protocol put forward three mechanisms for achieving the targets. These include mechanisms such as emissions trading, joint implementation and the so-called "Clean Development Mechanism" (or CDM), to allow flexibility in achieving the required reductions.
Carbon Offset Verification
Assuming that development and maintenance of sinks will be accepted under CDM, knowledge on the calculation of the amount of Carbon dioxide that can be sequestered by a given project needs to be known. At times this will involve establishing the carbon offset potential of a given forest venture, before the project is in place. Use of mathematical models to predicted the carbon sequestration potential will be important. Our paper is discussing the results of study done in Tanzania.
|
