The laws of physics will always trump politics. How will Melbourne, let alone an event such as the Australian Open, cope with a global temperature rise of 2 or 3 degrees? Has the facility and the city planned to manage unavoidable climate change? Where are the voices in the world of tennis speaking up for action to avoid unmanageable warming?

Premier Denis Napthine recently announced that the Rod Laver Arena and its precinct would receive a $338 million upgrade. That's no short-term investment and cements the city's desire to keep the global sports event here.

Sport is an integral part of Australian life. In Victoria, about 2.2 million were spectators at live sporting events, mostly outdoors, in 2009-10. The year after, revenues from such events were more than $13 billion, and rising.

Last year a record 686,000 fans attended the Australian Open, making Melbourne the southern hemisphere's mecca of tennis. About 350 million more watched from 200 countries an event that earns Victoria about $240 million. The flow-on benefits for Melbourne businesses in the tourism and hospitality sectors, let alone for the city in terms of public transport use, are incalculable.

Or is it time, sadly, to accept that perhaps tennis should be a winter sport in Australia; a fact forced on us by an increasingly hostile environment-an environment of our making. Heatwaves are more than just uncomfortable for people - heat stress can kill. About 374 people lost their lives in the heatwave immediately preceding the catastrophic Black Saturday fires five years ago. That's twice as many as those who died from the flames. The scars from those fires - physical and mental - of both the fires and the heatwave are still raw for many.

Last year Australia endured its hottest year on record, with the hottest summer, the hottest January, and the hottest September. Fire authorities tell us, in no uncertain terms, that the season is starting earlier and finishing later, with a higher and higher risk of extreme fire weather throughout. At the end of the hose, few question the link between the fires and climate change, even if some of our politicians and their advisers are more short sighted.

In Australia today, the number of record-high temperatures exceeds record lows by about five to one. Scientists at the University of Melbourne recently showed that, with odds of 100 to one against, the record hot weather is hotter than it would otherwise have been if left to its own devices. The trend towards extreme swelters has human fingerprints all over it.

This is a country nearly 1 full degree warmer, on average, than it was a little over a century ago. If, collectively, we can reverse emissions of carbon dioxide in the next decade or less, we stand a pretty good chance of keeping the globe from warming more than 2 degrees. Even that will stretch our capacity - personally and as a community - to cope, but we'll get to keep our way of life, more or less.

But fail to act and temperatures will soar beyond all recognition - 3 degrees by mid century, 4 degrees or more by 2100.