Between 8.30pm and 9.30pm we are asked to turn off all our lights for a time when we can think about how climate change is affecting our planet, and what we can do about it as individuals and communities.

This year the theme for Earth Hour concerns the impact of climate change on biodiversity.

Organisers are inviting Australians to #Connect2Earth, so that we can all work towards better understanding and appreciating the values of biodiversity and the current critical condition of our home and our planet.

Our country is famous for its diverse and beautiful landscapes and its iconic wildlife, but like many other parts of our planet, climate change represents a massive threat to these landscapes and the  plants and animals contained within them.

An example is the koala, perhaps our best loved native Australian animal. Over millennia koalas have evolved to obtain their nutrition and moisture requirements from the eucalyptus leaves they eat.

Climate change has reduced the moisture and nutrition content of the leaves in the koalas' diet, forcing them to leave the protection of their trees and travel overland in search of food and water.

This renders them vulnerable to predators and traffic. The koala is just one of our many unique species to be affected by climate change.

Additionally, climate change also threatens vast natural systems, such as the Great Barrier Reef, our fields of sea grass, and the phytoplankton, which forms the basis of the food chain throughout our oceans.

While we are sitting in the dark, we may wish to think about what each of us can do to help reduce threatening climate change.

Most of us know what we can do as individuals to reduce our carbon footprint. What we can do during Earth Hour is to commit to actually doing it.

At a community level, we can join a local environment group and be prepared to become involved in any climate change initiatives they may be contemplating.

Orange residents can help by finding out about, and supporting the Cities Power Partnership which was adopted by Orange City Council in 2017 and involves developing a range of strategies to reduce Orange's emissions.

Finally, we can all use the power of the pen and the ballot box by contacting our political representatives to demand real action on climate change, and voting  for political parties who have sensible policies for reducing emissions.

Politicians need to know that we care about climate change.