Answer to Question 1
Answer: Air pressure decreases with elevation in the atmosphere. This occurs because air pressure is caused by the weight of air molecules. With increases in atmosphere, there are fewer air molecules and therefore less weight.
Answer to Question 2
Answer: No; some greenhouse warming is good for the planet, making climate conditions more favorable for our species. In the past, when CO2 levels were significantly lower than today, low CO2 levels contributed to a glacial climate. However, too much of the greenhouse effect results in significant warming, which can result in climates that are too hot for many species currently existing.
Blood Pressure Chart
Focusing Jets by Pressure
Nonlinear increase in saturation vapor pressure with increase in temperature.
Natural Causes of Climate Change
Reaction at constant-pressure
Blood pressure measurements: Palpable blood pressure