Assume that you have 100 years of continuous temperature records from your local weather service office. Discuss some of the difficulties you might have trying to determine whether average temperatures have increased during this period. Our book indicated that one of the difficulties is that reporting systems have changed so much over time. Other things to consider are things such as time of observation adjustments, adjustments for changing equipment, and adjustments for changing site locations. Understanding the slight differences in global records between groups at NCDC and NASA. Each group calculates global temperature year by year, using slightly different techniques.
What are meant by the terms positive and negative feedback mechanisms? Give an example of a process that would be considered a positive feedback mechanism during a period of warming on the earth? There are many climate feedback mechanisms in the climate system that can either amplify (positive feedback) or diminish (negative feedback) the effects of a change in climate forcing. For example, as rising concentrations of greenhouse gases warm Earth’s climate, snow and ice begin to melt. This melting reveals darker land and water surfaces that were beneath the snow and ice, and these darker surfaces absorb more of the Sun’s heat, causing more warming, which causes more melting, and so on, in a self-reinforcing cycle. This feedback loop, known as the ice-albedo feedback, amplifies the initial warming caused by rising levels of greenhouse gases.
Can you think of a negative feedback mechanism?
A good example of a negative feedback mechanism will be if the increase in temperature increases the amount of cloud cover. The increased cloud thickness or extent could reduce incoming solar radiation and limit warming.
Discuss the significance of a predicted increase in global temperatures of 3 C, as opposed to a predicted increase of 1 C. Even if greenhouse emissions stopped overnight the...
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