Imagine you're a medical doctor, committed to go to a developing country to use your skills and knowledge to potentially save hundreds, if not thousands, of lives.

On your way to the airport to catch the last flight out before a cyclone hits, which may close the airport for days, you witness a car accident in which a person is critically injured.

Do you stop and save the person's life, therefore missing your flight to your new job, or do you continue to the airport, because there are hundreds of people at that destination whose lives you can save?

Invariably, everyone says they would stop and help the accident victim. Why? Because it's right in front of you. Proximity determines action.

Thirty years ago, climate change was a distant spectre of something that would probably happen, but no one was sure what it would look like.

European governments took action on the basis of the 'precautionary principle': the theory that diversionary action is necessary regardless of whether something is conclusively proven.

With the benefit now of three decades of exhaustive research, longitudinal data and a scientific consensus, the proof is incontrovertible. We now know precisely what is happening and what it will look like. The bleaching of coral reefs, melting glaciers and ice sheets, extreme weather events and the frightening statistics on a warming planet are right in front of us.

Yet, bizarrely, the government continues to keep its head in the sand and it's business as usual. That is, business as usual for the 1980s.

Australian novelist and environmentalist, Tim Winton, recently commented that during the Cold War, humanity survived because "no one pushed the button". No one pushed the button that would unleash nuclear war because of the doctrine of MAD: Mutually Assured Destruction (surely the best acronym in the history of international relations!)

We are now facing our own era of MAD, an era where it is action, rather than inaction, that will determine whether humanity as we know it survives. As Winton noted, the button has already been pushed.

Proximity determines action. There are no more excuses for failure to act.