How will life on earth end?
No one knows for sure but we know about certain theories theories. Astronomers believe that the sun will hydrogen and will become a red giant . It will produce a lot of heat , the earths oceans will evaporate and lands will be scorched . This is how life on earth will end .
If, after this stage, suddenly we don't have seasons, life on earth will end. Because, as you know, that life on earth is a cycle. Everything needs everything to live. So, if there are no seasons, which is practically not possible, then the life will end. And if from beginning of time, the earth wouldn't have had seasons, then life on earth would have molded itself to the change or climate.
It's not a matter of *IF* but WHEN the earth will end. Eventualy the sun will burn itself out and blow up (that's how all stars end) but long before that it will be too cold for life to exist on earth. The fact is human life on earth may end much sooner than that, it's only a matter of time before a lage commet strikes the earth and the dust cloud it produces will…