100% CORRECT ANSWERS
Despite the general stability of the Thermohaline Conveyor at present, future climate
changes could alter the temperature and salinity dynamics of the world's oceans amidst
rising sea levels, thereby leading to more extreme weather events. What do most
scientists point to as the cause for the projected rise in sea level and extreme weather?
- Answer-Scientists have projected higher sea levels and increases in extreme weather
in the coming decades as a result of estimated future global emissions of greenhouse
gases, primarily CO2.
Why might ocean floors be better than continental locations for studying long-term
changes in the size of ice sheets? - Answer-Continental records are fragmented and
discontinuous, missing parts of the climate record.
How does the analysis of forams in ocean sediment cores reveal climate change? -
Answer-The presence and relative dominance of different species of forams reveal
different global climate conditions.
Generally, what has been the pattern of global temperature change during the past 70
million years? - Answer-Earth's average temperature is approximately 15° cooler now
than it was 70 million years ago.
What did the discovery of tillite in South Africa reveal about southern Africa's past? -
Answer-An ice sheet covered southern Africa 300 million years ago.
Radiocarbon dating of organic material may provide a climate record for up to ________
years before present. - Answer-50,000
Which of the following statements is not correct about the description of changes in
greenhouse gas concentrations and temperature? - Answer-In the late 20th century,
carbon dioxide and nitrous oxide had almost the same concentration.
During the last century, sea level - Answer-rose 17 to 21 cm (6.7 to 8.3 in.).
The 16O evaporates ________ than 18O, and condenses ________. - Answer-more
easily; less easily
Changes in the orientation of the Earth's axis over a 26,000-year cycle is known as -
Answer-precession
, The ________ is a graph which plots monthly averages of CO2 concentrations since
1958. - Answer-Keeling Curve
Annual mass balance of glaciers worldwide from 1980 to 2012 - Answer-shows a
negative cumulative annual mass balance.
Mineral deposits within caves and caverns are known as - Answer-speleothems.
Changes in Earth's elliptical orbit around the Sun (eccentricity) varies over a ________
year cycle. - Answer-100,000
Over the span of 70 million years, the Earth's climate - Answer-was much warmer 70
m.y.a. compared to the present.
Which of the following has a negative radiative forcing (i.e. cools the planet)? - Answer-
stratospheric ozone (O3)
Since the Industrial Revolution, - Answer-global temperatures have continued to warm
at accelerating rates.
What natural mechanism is accepted as the cause for patterns of long-term climatic
fluctuations over tens of thousands of years? - Answer-Milankovitch cycles
Since 1880, the years with the highest land surface temperature were - Answer-2010,
2014, and 2015.
Scientists use ________ to study past climates, using ________ to reconstruct climates
that extend back further than our present instrumentation allows. - Answer-proxy
methods; climate proxies
Which proxy data source for past climate conditions examines mineral deposits in
caves?
View Available Hint(s) - Answer-speleothems
Which of the following is correct regarding Arctic sea ice? - Answer-Since 1979,
summer sea ice minimum extent and winter sea ice maximum extent have declined.
Which of the following is incorrect? - Answer-Scientists can say with 100% certainty that
current climate change can be solely attributed to anthropogenic causes.
In the case of radiocarbon dating of organic material, the half-life of 14C is - Answer-
5,730 years
Since 1880, global land-ocean temperatures have shown - Answer-a warming trend