There are many ways to defrost a freezer. You can just switch off the power and wait for room temperature to permeate the ice. You can use a heat source such as a hair-dryer or hot air gun. Or you could chip away the ice and dump it where it will melt naturally due to local atmospheric temperature.
As I write this, Britain is shivering in its worst winter for 30 years. A temperature has been measured in Scotland insignificantly different from the current temperature at the South Pole. Supplies of grit, salt and gas are being rationed.
A large number of comments have been posted on newspaper websites claiming that our current U.K. weather disproves the theory of global warming.
It does no such thing.
The snow and ice that have fallen on the U.K. in the past few days would normally have fallen in the Arctic circle, adding to the polar ice cap. Snow and freezing rain that fall on the U.K. do nothing to replenish the polar ice that melted during the summer. In effect, the winds from the Arctic that bring snow to the U.K. act as an automatic defrosting mechanism for planet Earth. The snow and ice in the U.K. will soon melt and drain into the sea. Just like the auto-defrost in a modern freezer, the current U.K. / Arctic weather system is preventing a build-up of ice in the planet's freezer.
I am not a meteorologist, but I think my basic idea is sound. Unfortunately, we may well come to know the truth about global climate change only when it is pitching to hurt us most.