1) The amount of carbon dioxide in our atmosphere has been increasing rapidly over the last few decades and continues to do so.
2) Historically, the trends in the increase of carbon dioxide started in the late 1700s. This was the approximate time of the Industrial Revolution. At this time, the carbon dioxide concentration was around 270 ppm (pounds per million). Concentrations grew very slowly from this time until the twentieth century. But in the last century, especially in the last fifty years, carbon dioxide levels have grown rapidly.
It is presently around 350 ppm.
3) The Antarctic ice sheet provides a long record of carbon dioxide concentrations. This is done by examining tiny bubbles of air in the ice core at different levels below the present ice surface. The deeper layers in the ice core correspond to times in the more distant past. The air bubbles can be analyzed for the relative abundance of carbon dioxide to estimate atmospheric carbon dioxide levels at times extending back 160 000 years.
Through the ice sheet, we know that 160 000 years ago, carbon dioxide concentrations were about 180 ppm and have presently exceeded 350 ppm.
4) There are mainly 3 major sources of carbon dioxide presently and historically. They are industrial activity, land use change, and cement plants. The carbon dioxide from industrial activity mainly comes from fossil fuel burning and is by far the most abundant of sources. The carbon dioxide from land use change comes mostly from deforestation which occurs mostly in Brazil, Indonesia, and Columbia. The last major source of carbon dioxide in the earth’s atmosphere is the emission from cement plants.
Carbonaceous material used for making cement releases significant amounts of carbon dioxide. This source is fairly large since cement is used for roads, bridges, buildings, and powering and manufacturing plants.
1) A carbon dioxide sink is a storage reservoir that increases in size, and the carbon dioxide sink size or strength is the rate at which the storage reservoir grows.
1) Oceans can regulate carbon in three different ways: physical processes, chemical processes, and biological processes. Physical processes include the movement of carbon by ocean circulation from one location to another. This process is referred to as advection. Another physical process is the diffusive mixing of water from one vertical level to another. On the other hand, chemical processes transform carbon into different molecular forms.
Biological processes include the production and decomposition of organic matter, which are confined to the upper layer of the ocean where photosynthesis can occur. If biological material remains near the surface, it will continue to cycle with the atmosphere. Carbon, such as in the form of phytoplankton that thrives in the surface water of the ocean, is eaten by small fish and eventually larger fish or animals that ultimately die, leaving skeletons of carbonate shells that sink to the ocean floor. This process takes carbon from the rapidly changing part of the cycle near the ocean’s surface to the deep ocean where it may be stored for thousands of years.
Sunlight penetrating the ocean surface is dcarbonepleted as it passes downward, creating what is called the euphotic zone. This is the zone where sunlight is sufficiently intense to promote photosynthesis. Regions below this zone have a negative photosynthetic rate due to the lack of solar energy, resulting in very little biological activity below a certain level. In addition to sunlight, nutrients such as nitrogen and phosphates are needed for biological production. The euphotic zone, where sunlight is sufficient for photosynthesis, tends to lack these nutrients and the deeper zones, where sunlight is not sufficient, tend to have nutrient-rich water. If a mechanism were available to bring the deep water containing nutrients to the euphotic zone, phytoplankton and algae would flourish, as would the marine life that lives on these tiny organisms, thus allowing more consumption of carbon dioxide.
2) The Antarctic Ocean has a limiting factor for the growth of phytoplankton and algae. This is insufficient amounts of iron. With more iron, the growth in ocean marine plants would consume large additional amounts of carbon dioxide from the atmosphere. The “iron solution” was an idea to fertilize the Antarctic ocean with iron increasing the growth of phytoplankton and algae.
3) Near the ocean surface, turbulent motions promote the uptake of atmospheric carbon dioxide by the ocean through the formation of weak carbonic acid. This differs in cold and warm oceans. Approximately twenty-two units per year go from the cold ocean into the atmosphere and about thirty-five units come back, making the cold ocean a net sink for carbon dioxide from the earth’s atmosphere. The warm ocean, however, is a net source because it’s emitting eighty units and taking in only seventy, giving a net change outward of about ten units. Therefore, the cold ocean is a more efficient carbon dioxide sink than the warm ocean.
1) Forests are very important in their role as carbons sink. It is through the plants’ ability to perform photosynthesis that extracts carbon dioxide from the atmosphere. Trees take in carbon dioxide through photosynthesis and release oxygen into the atmosphere.
6CO2 + 12H20 + energy (sunlight)
C6H1206 + 60 2 + 6H2O
2) four major forestry practices can help to maximize the forests’ potential as carbon sinks. The first is conserving native forests or replacing them with plantations. Another practice is choosing species and forest type. A third is the intensity and frequency of forest cutting and the last is the conservation of soil carbon.
The first method to replace forests with plantations will cause a loss of carbon because of the lower age of the trees. This will result in low biomass. This is why it is important to practice the second also. Choosing a fast-growing species will cause plants to accumulate carbon at a faster rate and make up for the clearing of trees. These trees can go through a one-time period of carbon storage. In contrast, with carbon dioxide concentrations predicted to rise, it is more sensible to put in slow-growing trees and think long-term. This process, however, will take a long time, but in the long term, the payoff will eventually be seen.
When talking about the intensity and frequency of forest cutting, there are two important factors to consider. One factor is the lifetime of the wood products that come from the trees. These can be products that are long-lasting and recyclable. The second factor is the time that the forest takes to reach the maximum mean annual increment. If the lifetime of the wood products from the forest is longer than the time needed to reach the maximum mean increment, then the wood should be harvested. If not, then the wood should not be harvested and should be left in the forest.
The last factor is the carbon content of the soil. Soil contains a substantial amount of carbon, and this amount often exceeds the amount found in trees. When forests are cut and the soils are cultivated and converted to agricultural land, the soil is disturbed. This causes a rapid loss of soil carbon. However, there are few significant trends of carbon loss from soil.
3) NEW ZEALAND: New Zealand is experimenting with afforestation to reduce atmospheric carbon dioxide. Afforestation is the planting of forests on land that has not been previously forested. New Zealand has approximately 5.5 million hectares of unsustainable pasture that have the potential to be forested. A typical radiata pine forest on a thirty-year rotation contains approximately 112 tons of carbon per hectare on average. Conversion of all 5.5 million hectares of land to forest will remove about 616 million tons of carbon from the air. This carbon will stay out of the atmosphere for as long as there is a continuous forest cover on that land.
NORWAY: Norway is using a strategy that consists of increasing biomass in managed forests. In the last century, biomass has doubled. Dynamic models are being created and determining sustainability. These dynamic models use optimal control theory from electrical engineering to estimate optimal harvest practices. These models show that cutting trees at a mature stage and selectively harvesting them optimizes ground biomass and also resource income.