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 concentrations already in the atmosphere would still mean a global rise of between 0.5 and 1C. An average increase of one degree across its entire surface means huge changes in climatic extremes. America suffered a short reprise during the dust- bowl years of the 1930s, when the topsoil blew away and hundreds of thousands of refugees trailed through the dust to an uncertain welcome further west. A three degree increase in global temperature would throw the carbon cycle into reverse. Instead of absorbing carbon dioxide, vegetation and soils start to release it.
More areas would experience droughts the human race would suffer and there is also a possibility of extinctions for the species that fail to adapt. Not to mention the increase in Hurricanes and higher sea levels which would erase several cities off the map The hottest places on earth are not found near the equator in tropical wet climates but rather in arid climate regions. Why is this true? The hottest places on earth tend to occur in the subtropical deserts of the Northern Hemisphere, where clear skies and sinking air, coupled with low humidity and a high summer sun beating down upon a relatively barren landscape, produce extreme heat
What meteorological information is the primary basis for climate classification using the Köppen system? Give Examples. The Köppen system classifies a location’s climate mainly using annual and monthly averages of temperature and precipitation and Köppen also related the distribution and type of native vegetation to the various climates. The Koppen features is a short hand code of letters designating major climate groups, sub-groups within the major groups and further sub-divisions to distinguish particular seasonal characteristics of temperature and precipitation. Five major climate groups are designated by capital letters as follows:
A–Tropical Rainy Climate: Average temperature of every month is above 64.4oF (18oC). These climates have no winter season. Annual rainfall is large and exceeds annual evaporation.
B–Dry Climate: Potential evaporation exceeds precipitation on the average throughout the year. No water surplus; hence no permanent streams originate in B Climate Zones.
C–Mild, Humid (Mesothermal) Climates: Coldest month has an average temperature under 64.4oF (18oC), but above 26.6oF (-3oC); at least one month has an average temperature above 50oF (10oC). The sea climates have both a summer and a winter season.
D– Snowy Forests (Microthermal) Climates: Coldest month has an average temperature under 26.6oF. Average temperature of warmest month is above 50oF.
E–Polar Climates: The average temperature of warmest month is blow 50oF. The climates have no true summer.
Courtney from Study Moose