Earth will not remain Habitable for ever.

Good day ladies and gentle men, I am debating on the topic "Earth will not remain Habitable forever" and anyone that accept this challenge should prove to me How and why Earth will forever be Habitable. However, before going further I would like to define major subject in my debate topic. "The Earth is the third planet from the Sun and it is the only planet known to have life on it. The Earth formed around 4.5 billion years ago. It is one of four rocky planets on the inside of the Solar System . The other three are Mercury, Venus , and Mars ." " remain verb continue to exist, especially after other similar people or things have ceased to do so." "habitable adjective suitable or good enough to live in." Let's face it: The planet is heating up , Earth's population is expanding at an exponential rate, and the the natural resources vital to our survival are running out faster than we can replace them with sustainable alternatives. Even if the human race manages not to push itself to the brink of nuclear extinction , it is still a foregone conclusion that our aging sun will expand and swallow the Earth in roughly 7.6 billion years. So, according to famed theoretical physicist Stephen Hawking, it's time to free ourselves from Mother Earth. "I believe that the long-term future of the human race must be in space," Hawking tells Big Think. "It will be difficult enough to avoid disaster on planet Earth in the next hundred years, let alone the next thousand, or million. The human race shouldn't have all its eggs in one basket, or on one planet. Let's hope we can avoid dropping the basket until we have spread the load." Hawking says he is an optimist, but his outlook for the future of man's existence is fairly bleak. In the recent past, humankind's survival has been nothing short of "a question of touch and go" he says, citing the Cuban Missile Crisis in 1963 as just one example of how man has narrowly escaped extinction. According to the Federation of American Scientists there are still about 22,600 stockpiled nuclear weapons scattered around the planet, 7,770 of which are still operational . In light of the inability of nuclear states to commit to a global nuclear non-proliferation treaty, the threat of a nuclear holocaust has not subsided. In fact, "the frequency of such occasions is likely to increase in the future," says Hawking, "We shall need great care and judgment to negotiate them all successfully." According to some new astrobiological research, our home planet will not be habitable for much longer. As our Sun gets older, it will get larger and warmer, eventually leading to the Earth becoming uninhabitable " first to humans and other complex life in fairly short order, and then, in around 1.75 to 3.25 billion years, to all cellular life as we know it. Due to anthropogenic climate change, and other variable factors, we don"t know exactly when human life will become untenable on Earth, but the conclusion of the study is pretty clear: Our time here on Earth is finite, and we better find our way off it sooner rather than later. The research was carried out by Andrew Rushby and fellow researchers from England"s University of East Anglia. There are many factors that dictate a planet"s habitability, but in this case the astrobiologists focused on how long Earth-like planets remain in the habitable zone (HZ) of main sequence stars. Basically, most stars adhere to the main sequence " an order of events that begins with a star becoming dense enough to fuse hydrogen into helium. Over time, these stars get hotter and hotter, until they start to run out out of hydrogen. As the star gets hotter, nearby planets also get hotter, until eventually they become uninhabitable " usually due to a lack of surface water. (The photo above is of the remnants of a supernova, incidentally; our Sun probably won"t go supernova.) In the case of the Earth, the Sun"s increasing warmth will push our planet out of the HZ in around 1.75 billion years, with an upper bound of around 3.25 billion years, depending on the model used by the researchers. Here they are talking about habitability in absolute terms; for humans, Earth will become very unpleasant much sooner. "Of course conditions for humans and other complex life will become impossible much sooner " and this is being accelerated by anthropogenic climate change," says Rushby. "Humans would be in trouble with even a small increase in temperature, and near the end only microbes in niche environments would be able to endure the heat." As part of the same study, the astrobiologists also investigated the length of the habitable phase for other exoplanets, such as Kepler 22b and Gliese 581d, which are both theorized to be within their parent star"s habitable zone. While 22b"s habitable phase is around the same length as Earth"s (4.3 to 6.1 billion years), Gliese 581d, due to the nature of its orbit around its small home star, is expected to be habitable for around 55 billion years. How long planets remain in the habitable zone, versus host star size. (Smaller stars" habitable zones last longer.) Given the almost impossible-to- fathom scale of the universe, and early analysis of data from the Kepler space telescope, there could be up to 50 sextillion Earth-like planets out there in the cosmos . This is a mind-bogglingly large figure (5 followed by 22 zeroes), but in short, combined with this new data from UEA, it"s very, very likely that there are other planets in the universe that have managed to cultivate lifeforms during their multi-billion-year tenure in the habitable zone. It"s also good news for humans: Assuming we can find a way off this planet in the not-too-distant future, we should have no problem finding a planet that can host us for a few billion years (assuming we don"t ruin it, like we did Earth, of course). [source] [1] http://www.extremetech.com... [2] http://bigthink.com... [3]https://simple.m.wikipedia.org...