THe Earth....?

Question

How would the Earth be affected if

Earth had no oceans ?

Earth's spin axis were perpendicular to the plane of the Earth's orbit (no tilt) ?

Earth's spin axis were tilted 50 degrees to the plane of the Earth's orbit? (today it is tilted 23.5 degrees)?

Answer 1

There are several changes that would occur from a lack of oceans.  Barring the changes on biology and ecology, some of the basics are:

The Earth would have less precipitation; solar evaporation is partially dependent on the surface area of the water heated.

The climate would also change due to the change in water vapor in the air (clouds), as well as the change in planetary albedo from more land surface.  With less reflection, the Earth would absorb more heat.  Although, with less water vapor in the air, it might not -hold- that heat as long.  Hotter days and colder nights.

If the Earth's spin axis were perpendicular to the plane of orbit, we would have no seasons; it is the change in apparent angle of solar incidence at any specific point that helps determine how much heat is absorbed by the Earth instead of reflected away.  Minor seasonal changes would still exist, since the orbit of the Earth is not a perfect circle; in the Northern Hemisphere "winter" months, we are actually closer to the Sun; those would become the warmest months of the year due to the more "average" solar incidence.  Likewise, the Northern Hemisphere "summer" months would be the new "winter" months; that would be the farthest point in the Earth's orbit from the Sun.

If the Earth's spin axis was tilted at fifty degrees from the plane of orbit--roughly doubling the current amount of tilt--the seasons would be far more drastic than they are.  The "winter night" and "midnight sun" of the Arctic and Antarctic Circles would extend much farther toward the equator.  The incident angles of solar radiation for a fixed point on the Earth's surface would vary more widely, causing much greater temperature variations.  While the actual extremes of temperature for the planet as a whole might not vary all that much, the changes in temperature at any specific point would certainly fluctuate much more widely.