Johannesburg residents have been encouraged to save power as part of the Earth Hour Challenge.

“As residents of the City of Johannesburg, we need to change our way of life by constantly thinking of ways of reducing our carbon footprint, cutting emissions and limiting our electricity and water usage,” Johannesburg Member of the Mayoral Committee for Environment and Infrastructure Services, Councillor Matshidiso Mfikoe, said.

The City is vying for top honours in the Earth Hour City Challenge on Saturday.

Cities across the world will be judged on what steps they have taken to ensure that they and their residents reduce their carbon footprint by accessing their power through energy-efficient appliances and from renewable sources.

According to the City, millions of people in more than 7 000 towns and cities in 162 countries will spend an hour in self-imposed darkness.

“Johannesburg and its residents will join the rest of the world in switching off their lights and non-essential appliances between 8.30 pm and 9.30 pm in support of the World Wide Fund for Nature’s fight against climate change,” the City of Johannesburg said.

How you can contribute to the fight against climate change:

• Replacing just one 100W globe by 20W CFL can reduce carbon dioxide emissions by 84kg annually;
• Switching off electrical appliances at the plug, instead of using a remote control, can reduce emissions by 106g in each household annually;
• Reducing wastage of water by 100 litres a day cuts emissions by between 24kg to 63kg in each household annually;
• Using pressure cookers instead of pots and pans without lids can reduce emissions by at least 125kg in each household annually;
• Reducing usage of gas by 20 minutes a day each household can cut emissions by 62kg annually;
• Switching from desktops to laptops can reduce an individual’s annual carbon dioxide emissions of between 205kg and 279kg;
• Turning off one fan and incandescent light bulb when not in use, each household can reduce emissions by 28kg; and
• Using a solar water heater instead of a 25 litre geyser can prevent emissions of about 687kg of carbon dioxide a year.