Question: If the sun heats up to much what will happen to the earth?

Ciarán O'Brien answered on 11 Nov 2014:

It won’t be pretty.

As the temperature increases, the weather will get nastier (all the wind and rain is ultimately powered by the sun’s heat), skin cancer will become more common, and there’ll be a lot of water shortages as rivers and lakes get smaller.

Eventually the heat will be too much for plants and animals to bear, and they’ll die off leaving the world a barren wasteland.

If the heat becomes greater again, the planet’s atmosphere will just boil away into space, including the oceans.

That last part will probably happen in 7 billion years when the sun starts to run out of fuel and goes nova, the sudden jump in heat will just blast the atmosphere away, might even destroy the planet completely!