New Scientist- A new model of the way the Earth interacts with the solar wind indicates that a replacement field will form in the upper atmosphere during the switch.

Scientists had previously thought that the planet would be left without a protective shield to stop lethal radiation from space reaching the surface.

The strength of the Earth's magnetic field is known to drop during "magnetic reversals", when the north and south poles swap places. Records of the field direction, frozen into sediments laid down on the seabed, show that the magnetic field has reversed hundreds of times in the past 400 million years.

In normal circumstances, the magnetic field protects the Earth's surface from dangerous high-energy particles, including particles from the sun and cosmic rays from deep space.

But as the field switches polarity, it can drop to below 10 per cent of its normal strength for thousands of years. Such a weakened field would allow lethal radiation to reach the Earth's surface, with potentially disastrous consequences for the atmosphere, the climate and particularly for life.

Their simulations show that the solar wind - the million-kilometre-an-hour stream of hydrogen and helium nuclei from the sun - wraps itself around the Earth in a way that induces a magnetic field in the ionosphere as strong as the original field.

Source

So, what's supposed to happen, the north pole becomes the south pole? Will it effect the climates for the rest of the world? When is this supposed to happen?

it is happening isn't it? i've found a lot of people who think it'll just happen in a snap. it's crazy

The orientation of the earth’s magnetic field has reversed hundreds of times in the past. On average they have happened every 250,000 years but their have been long stretches without. Even the current weakening may not mean it will flip because sometimes it gets very weak then bounces back without flipping poles.

Many biologist wonder how severely it will impact animals that use the magnetic field to navigate on long distance migrations.

At least now they think we won't get bombarded by solar radiation when the field weakens. Hope their right about that.

More information on field reversals

If animals have been around for millions of years, then this polar flip won't bother them at all

wow, that's pretty neat.

i learned something new, woo.