A number of iconic landmarks around the world went into darkness on Saturday night as they switched off their lights for “Earth Hour”.
Earth Hour is an initiative to raise awareness of climate change in our world.
Monuments including the Sydney Opera House, the Empire State Building, the Kremlin, Big Ben, the Leaning Tower of Pisa, the Eiffel Tower and Egypt’s pyramids were all to “switched off”.
Homes and businesses were also being asked to join in, and individuals could commit to the cause on Facebook.
Last year, scientists recorded the Earth’s hottest temperatures in modern times for the fourth year in a row.
Nations agreed in Paris in 2015 to limit average global warming to two degrees Celsius over pre-industrial temperatures.
That is the level at which many scientists say humankind can still avoid worst-case climate outcomes in terms of rising sea levels, worsening droughts and floods, and increasingly violent superstorms.