[Europan Ocean (OP)]

Good day, I wanted to ask about the liquid metal core of the Earth and if it is cooling? How long would this take? Will we lose our magnetosphere?  Are we losing Ozone?

["Is the sun heating so fast that within 2000 years life as we know it on Earth will not be possible?" has been split off into a separate topic: "Solar heat and storms increase?" - moderator]

[HellsMascot]

The Earth's core is basically just liquid iron-nickel, which means that it will expand and cool over time. It is indeed doing so, at a calculated rate of ~100 C every billion years. This cooling and expansion does indeed infinitesimally affect the earth's 'magnetosphere.' If you want more information I can explain. However, I would be more concerned about two things: Geomagnetic Reversal http://en.wikipedia.org/wiki/Geomagnetic_reversal [nofollow] and another Carrington Event http://en.wikipedia.org/wiki/Solar_storm_of_1859 [nofollow].  And yes, we are losing ozone at an alarming rate. Ozone is extremely reactive in terms of atmospheric compounds so the ozone layer is very fragile indeed; there is a multitude of studies on human activity's affect on the ozone layer, with very conclusive implications about how quickly we may find ourselves without protection from all the types of highly energetic particles hitting us from space.

[evan_au]

Study of seismic waves suggest that the Earth has a solid nickel-iron core, surrounded by a liquid nickel-iron layer. It is thought that the temperature of the core is a combination of heat left over from Earth's formation and radioactive decay.

Heat is being continually lost to space through the surface of the Earth, but the temperature of the core is probably kept fairly constant by heat released as liquid iron progressively crystallises onto the solid core at around 1mm per year. At this stage, we have about 2,000km radius of liquid iron which will maintain the current temperature. Geologists would be able to tell if this reserve was being used up at a rapid rate.

It is thought that Earth's magnetic field is produced by churning of the liquid iron layer, producing electrical currents. This churning action is chaotic, resulting in a randomly reversing magnetic field. Some geologists suggest that the Earth's core rotates at a slightly different rate than the Earth's surface, which may contribute to this churn.

See: http://en.wikipedia.org/wiki/Structure_of_the_Earth#Core

[syhprum]

There are various opinions as to the Earths centre temperature

http://phys.org/news/2013-04-earth-center-degrees-hotter-previously.html#ajTabs