Sore throat is a symptom, not a disease. In each case, there was a different cause that dictated a different treatment. The scratchy throat probably was a mechanical problem caused by dry, heated winter air and aggravated by my friend's tendency to breathe through her mouth when she sleeps.
Biogeochemistry includes the history of the great carbon reservoirs in the crust of the Earth, like limestone rocks and the coal deposits, as well as the distribution of nitrate and phosphate in the ocean.
The atmosphere is one of the Earth's major carbon reservoirs and an important component of the global carbon cycle, holding approximately 720 gigatons of carbon. Atmospheric carbon plays an important role in the greenhouse effect. The most important carbon compound in this respect is the gas carbon dioxide (CO2). Although it is a small percentage of the atmosphere (approximately 0.04% on a molar basis), it plays a vital role in retaining heat in the atmosphere and thus in the greenhouse effect.