As children and even adults we are prone to 'browsing' for what might be in the fridge and then choosing based on what has taken our fancy. Well, this isn't the best option for saving the planet, unfortunately. It is better for the environment if you know what you're going to get out of the fridge before you touch the door and best if you can take multiple items out of the fridge at once rather than going back and forward to get single items each time.
Why? Every time you open the fridge door a little bit of room temperature air gets into the fridge. However, your fridge is trying to maintain all your food at a particular temperature (usually much cooler than room temperature) and basically the fridge is fighting with you to keep the food cold every time the door is open. So basically each time you open the fridge the air in the fridge gets a little warmer and the motor then turns on to cool the air in the fridge to its pre-set temperature. The motor uses electricity which in turn means emissions, generally use of a non-renewable energy source, etc, etc.
So next time you're thinking of what you might like from the fridge how about having a mental image of what is in the fridge and deciding whether a big bowl of mousse or a block of chocolate would be the better afternoon treat rather than hanging off the fridge door trying to decide.