If the presence in greenhouse gases in earth's atmosphere continues to increase at the present rate, scientists predict that in the next 50 to 100 years, atmospheric temperatures could rise by 2oc.

all of these could be consequences of global warming except
a) an increase in arid and semi-arid areas on earth.
b) permanent flooding of low-lying coastal wetlands.
c) an increase in square miles of polar ice covering earth.
d) a rise in the amount of vegetation found in tundra and taiga regions.

1. the geologists have established a set of principals that can can be used o determine the relative ages of rock. this principal is applied to sedimentary and volcanic rocks. the rocks exposed to wall of grand canyon has layers and by studying the number of horizontal layers in the rock(strata) the relative age can be determined. the layer first formed will appear at the bottom and the the layer of strata last formed appear at the top. by using this information the approximate age of rocks can be determined.

2. carbon dating is used to find the relative age of rock in numbers which means for the rocks that has age between 1-70,000 years.

3. for the rocks of age range between 1,000 - billion of years potassium-argon dating is used.