If the magnetosphere of Earth disappeared

[Nikitin]

Would this noticeably increase the radiation level on Earth?

Or would the atmosphere easily stop the excess solar-wind particles which are now not being deflected away?

 

[Drakkith]

The particles themselves for the most part would be absorbed by the atmosphere. However we would probably start to have a dramatic increase in amount of gas lost from the atmosphere thanks to the solar wind. (Though still an extremely small amount on our timescale)

I don't think the magnetosphere protects vs photon radiation, such as gamma and x-rays, but I could be wrong.

 

[Nikitin]

it indeed does not have any effect on electromagnetic radiation.

 

[mrspeedybob]

So wrapping a giant loop of wire around the equator and hooking it to a battery to neutralize the Earth's magnetic field would not be on the list of evil genius plot ideas...

 

[Drakkith]

So wrapping a giant loop of wire around the equator and hooking it to a battery to neutralize the Earth's magnetic field would not be on the list of evil genius plot ideas...

I don't think we would have to worry about that anyways.