How do scientists know how the temperature has changed if atmospheric data from the last several thousand years was not available?

How old is the sun and since it's birth, how has the sun changed?

How will the development of alternative energy sources affect Earth Systems? A.) land and air pollution will be reduced B.) People will have fewer choices of fuels to power their cars C.) the geosphere and biosphere D.

If carbon dioxide is denser than air and can form clouds that displace oxygen, why are we all still alive?

Explain how does a deep current form

Why would countries have low percentage of children

What are the most wide spread Paleozoic fossils?

Less developed nations are to extended families as more developed nations are to nuclear families. matrilineal families. families of procreation.

If star a has an apparent magnitude of - 6 and star b has an apparent magnitude of 5, which star is brighter in our sky?

What is one advantage of free trade?

Explain how the shading of the direct light of the sun causes a lunar eclipse.