The United Nations is once again pleased to support Earth Hour, a global awareness campaign on climate change that spans thousands of cities around the world.

This year is also the International Year of Biodiversity. Despite international commitments to slow the global rate of extinctions by 2010, the Earth's species and ecosystems on which we depend for sustenance, economic development and cultural well-being continue to decline. Climate change is a significant cause.

The message of Earth Hour is simple. Climate change is a concern for each of us. Solutions are within our grasp and are ready to be implemented by individuals, communities, businesses and governments around the globe.

Earth Hour is both a warning and a beacon of hope. By switching off non-essential lights for an hour, people will join a symbolic display that can inspire the change we so urgently need. As we watch the lights go out from continent to continent, let us reflect on the fragility and importance of our natural heritage and pledge to protect it for a sustainable future for all.