London: Microwave ovens across Europe alone emit as much carbon dioxide as nearly seven million cars, a study has found.
Researchers from University of Manchester in the UK have carried out the first ever comprehensive study of the environmental impacts of microwaves, considering their whole life cycle, from 'cradle to grave'.
The study found that microwaves emit 7.7 million tonnes of carbon dioxide equivalent per year in the European Union (EU). This is equivalent to the annual emissions of 6.8 million cars.
Microwaves across the EU consume an estimated 9.4 terawatts per hour (TWh) of electricity every year. This is equivalent to the annual electricity generated by three large gas power plants.
Microwaves account for the largest percentage of sales of all type of ovens in the European Union (EU), with numbers set to reach nearly 135 million by 2020. Despite this, the scale of their impacts on the environment was not known until now.
The study used life cycle assessment (LCA) to estimate the impacts of microwaves, taking into account their manufacture, use and end-of-life waste management.
Altogether, the research team investigated 12 different environmental factors, including climate change, depletion of natural resources and ecological toxicity.
They found, for example, that the microwaves used across the EU emit 7.7 million tonnes of carbon dioxide equivalent per year. This is equivalent to the annual emission of 6.8 million cars.
The research shows that the main environmental 'hotspots' are materials used to manufacture the microwaves, the manufacturing process and end-of-life waste management.
For example, the manufacturing process alone contributes more than 20 per cent to depletion of natural resources and to climate change.
However, it is electricity consumption by microwaves that has the biggest impact on the environment, taking into account its whole life cycle, from production of fuels to generation of electricity.
In total, microwaves across the EU consume an estimated 9.4 terawatts per hour of electricity every year. This is equivalent to the annual electricity generation by three large gas power plants.
The study found that, on average, an individual microwave uses 573 kilowatt hour of electricity over its lifetime of eight years.
That is equivalent to the electricity consumed by a seven watt LED light bulb, left on continuously for almost nine years.
Due to their relative low cost and ease of manufacture, consumers are throwing more electrical and electronic (EE) equipment away than ever before, including microwaves.