Hi Marea,
In response to your question, yes, replacing your old fridge with a newer more energy efficient fridge is the 'greener option, however for most people, buying a newer more energy effiecient fridge is out of the question. If your Fridge is still running perfectly, and has not had any problems, i recomend getting the seals replaced and having the electricals checked, just to make sure that you are really going to get the most out of it.
However, if you are considering buying a new fridge, here are some things for you to think about:
-Refridgerators are the third largest consumer of power in the average household, and are on of the few appliences that are left on 365 days a year.
-Older fridges can generate between 600- 900 kw, where as newer fridges generate up to 200kw less power.
-Fridges need adequate space and ventilation to allow that they do not overheat.
-Obviosly larger fridges consume more power, however it is a much better option to only have one large fridge running in your household, then 2 smaller fridges like most families have.
-These days fridges come with energy saving features, such as warning sounds when the door has been left open for too long, holiday mode (where you can set it to use less power whilst you are away) and better seals, which keeps the cool air in.
-Different types of fridges have different energy efficiencies, such as a 2 door fridge uses more energy then a standard sized fridge with freezer on the top, so looking at the type of fridge that will best suit your needs is a must.
In terms of disposing of fridges, you can take your fridge to any recycling depot/ dump and they will dispose of it correctly, or if it is still in good working condition, donate it to a charity or recycling station to be re-sold.
(When buying a new fridge, most stores will collect your old appliences on delivery of the new ones to ensure they are propperly disposed of.)
I hope this sort of answers your question.
-Kle