Photos: Cities worldwide turn off their lights to mark Earth Hour

Singapore: Cities around the world were turning off their lights Saturday for Earth Hour, with this year's event highlighting the link between the destruction of nature and increasing outbreaks of diseases like COVID-19.

Starting off the event, at 8:30 pm the skylines of Asian metropolises from Singapore to Hong Kong went dark, as did landmarks including Sydney Opera House.

The annual event calls for action on climate change and the environment, and this year, organisers said they want to highlight the link between the destruction of the natural world and the increasing incidence of diseases - such as COVID-19 - making the leap from animals to humans.

A combination picture shows the Grand Palace with the lights on before Earth Hour and with the lights off during Earth Hour, in Bangkok, Thailand.

Experts believe human activity such as widespread deforestation, destruction of animals' habitats and climate change are spurring this increase, and warn more pandemics could occur if nothing is done.

A combination photo shows Akorda, the official residence of Kazakhstan's President, before (top) and during Earth Hour in Nur-Sultan, Kazakhstan.

In Singapore, people at the waterfront watched as skyscrapers went dark and in a nearby park, Gardens by the Bay, a group of futuristic-looking tree sculptures had their lights turned off.

This combination of pictures created on March 27, 2021 shows a general view of the illuminated Pakistan's Prime Minister office building before (top) and after its lights were switched off (bottom) during Earth Hour in Islamabad.

A combination picture shows the India Gate war memorial before (top) and after the lights were turned off for Earth Hour in New Delhi, India.

In Thailand, Bangkok's ultra-popular CentralWorld mall counted down to 8:30 pm before its exterior glass displays went dark for an hour - though inside, the shopping centre appeared to operate as usual.

Other landmarks that were due to switch off the lights to mark Earth Hour include the Eiffel Tower, the Colosseum in Rome and the Brandenburg Gate in Berlin, according to organisers.