It rather depends by what you mean by end.
Scenario 1. The earth is hit by meteorite, 1.5 km in diameter on impact. One second after impact an area the size of Yorkshire wil be vapourised in temperatures of 1000's degrees C as meteorite is travelling at 1,500mph. Blast will completely destroy everything within 500 miles of impact as winds of upto 700 miles per hour flatten everything in its path. Shockwaves and firestorms will travel another two thousand miles causing massive damage to all buildings and infrastructure. A subsequent dust cloud will collect in atmosphere and completely enshroud the earth within days. Normal civilisation and technology will cease functioning as the earth is plunged into a severe ice age.
Assuming the meteorite impacted on say Berlin, then virtually half the population of Europe will be wiped out in minutes. Many millions more will die in the following hours. The ensuing 'winter' will wipe out another 3 bilion on earth in months. Fortunately this is very unlikely to happen within the next 100 years. We are somewhat overdue for such an occurrence but overdue means several thousand years.
Scenario 2 The sun runs out of hydrogen and in a final fling sheds it outer layers, it's core becomes super critical and turns into a super nova. The entire solar system out to Jupiter will be vapourised within minutes. THIS WILL HAPPEN. Fortunately as the sun is very, very big indeed (although not that big as stars go) it will take a very long time for it to use up all it's fuel. We can expect the sun to shine for around another 5,000,000,000 years according to astrophysicists.
Sleep well
Bounty
