Big Heat : CO2 in the atmosphere will bring us a back a new carboniferous era.
Big Freeze : rise of global temperature will change ocean streams regulation and will make the Gulf Stream disappear, which in turn will freeze Europe and north America or Universe will expand indefinetely and mid energy level will fall forever until every star burns out and everything freezes to death for ever
Big Crunch : Universe will cease to expand and will contract again, to the Big Crunch and a new Big Bang to come.
Big rip I don't know of.

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.