Carbon dioxide forest fires

The growth of woody biomass in one year s annual increment represents the quantity of material that can be harvested without affecting the productive capacity of the forest in subsequent years. The gross annual increment (GAI) is the yearly increase in woody biomass, whereas the net annual increment (NAI) is the GAI adjusted for natural losses such as fire, insect damage and so on. The NAI is often referred to as the allowable cut . In boreal and temperate zones, the removal of woody biomass is lower than the NAI, and thus these forests are presently acting as net sinks for carbon dioxide (Figure 1.6). If all of the NAI was harvested, then the forests would no longer act as sinks for CO2, but would be in balance with the atmosphere. 

The actual proportion of carbon dioxide in the air varies very considerably according to circumstances. Whalley reported that in a Scottish mine the carbon dioxide in the air near the coal face reached T21 per cent., whilst on the pavement it was no less than 4-56 per cent. Levy,1 in discussing the abnormal air of New Granada, points out that owing to forest fires the percentage of carbon dioxide in the air would often rise to 0-49 per cent. These cases, however, are abnormal. 

Volcanos send sulfur dioxide and carbon monoxide into the air. Forest fires also add carbon monoxide. Tiny living creatures remove some of these poisonous gases from the air. Human activity adds many different gases into... 

A fire that is 100% efficient in the combustion of organic material emits all carbon as carbon dioxide. Most forest fires in the Southeast Asian sub-region are not this efficient and emit carbon in other forms, such as carbon monoxide, as a result of... 

M., Milyokova, I., Wirth, C., Ltihker, B., Lloyd, J., Valentini, R., Dore, S., Marchi, G., Schulze, E.-D. (1999). Exchange of carbon dioxide and water vapour between the atmosphere and three central Siberian pine forest stands with different aged trees, land-use and fire history. Agric. For. Meteorol. (submitted). 

As pollutants go, carbon dioxide might be considered a relatively innocuous component of our atmosphere. After all, every breath we exhale contains about 4% carbon dioxide even though the inhaled air is only about 0.04% carbon dioxide. Fossil fuel combustion and natural decay processes combined with forest and grassland fires release billions of metric tons of carbon dioxide into the atmosphere annually. At the same time, trees, grasses, and other plants remove equivalent quantities of carbon dioxide from our atmosphere each year. Carbon dioxide is constantly being dissolved in and released from the ocean and other bodies of water as their temperature fluctuates. In other words, carbon dioxide is constantly being added to and removed from our atmosphere by a variety of processes, some natural and some of human origin. 

Decaying vegetation releases carbon dioxide. Rice paddies release methane. Forest fires and volcanoes release a variety of greenhouse gases. 

A particularly important consequence of the release of gaseous pollutants into the atmosphere is the local acidification of the environment. Rainwater reaching Earth s surface has a pH of about 5.6 (it is lower than 7 because of the dissolved carbon dioxide). In some parts of North America, Europe, and even Asia, however, acidic rainwater of pH < 5.6 is quite widespread. This is believed to be due to the presence of acidic gases, particularly oxides of sulfur (SOjc) and oxides of nitrogen (NO ) in the atmosphere. The contribution of HCl, if any, is relatively minor. A biogenic contribution to acidification caused by emissions from volcanos or forest fires also exists, but is relatively small. 

Forest fire—an undesirable exothermic reaction. The models show some simple combustion products carbon monoxide, carbon dioxide, water, and nitric oxide. The last compound represents nitrogen-containing compounds. 

Carbon dioxide 1 Fossil fuels, deforestation, road vehicles, forest fires... 

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