The sun, like all stars of its type, is gradually getting hotter. A recent study concluded that in just 600 to 700 million years, it would vaporize so much of the earth's oceans that a runaway greenhouse would turn our planet into a second Venus.
But wait! Now there is an even newer study, arguing that this dire end won't come for at least a billion years, and perhaps 1.5 billion. A reprieve!