How does a positive feedback mechanism differ from a negative feedback mechanism? Is the water vapor–greenhouse feedback considered positive or negative? Explain.?
What will be the ideal response?
ANSWER: A positive feedback mechanism is a process which is reinforced by other processes. A negative feedback mechanism is a process which is weakened by interactions among other variables. The water vapor-temperature increase process is a positive feedback mechanism. Assuming that the Earth-atmosphere system has been disturbed to the point that Earth has entered a slow warming trend, over the years the temperature slowly rises, and water from the oceans rapidly evaporates into the warmer air. The increased quantity of water vapor absorbs more of Earth’s infrared energy, thus strengthening the atmospheric greenhouse effect. This strengthening of the greenhouse effect raises the air temperature even more, which, in turn, allows more water vapor to evaporate into the atmosphere. The greenhouse effect becomes even stronger, and the air temperature rises even more.
You might also like to view...
Pastoral nomads
A) are expanding their territory in North Africa and the Middle East. B) occupy only their own territory, moving with the seasons to find forage and water. C) occupy different territory each year to find forage and water. D) consume mostly meat, rather than grain. E) prefer sheep to goats because sheep require less water and will forage on virtually any vegetation.
Shifting cells of subtropical high pressure contribute to the dry-summer conditions in the Mediterranean dry-summer climates
Indicate whether the statement is true or false
Fossil fuels are best described as a(n) ________ energy source
A) environmentally friendly B) clean C) renewable D) efficient E) nonrenewable
The current estimate of the number of languages spoken across the planet is approximately
A) less than 100. B) between 250 and 1,000 languages. C) between 1,500 and 3,000 languages. D) between 3,500 and 6,500 languages. E) over 7,000.