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Whatsapp The four seasons that we have imported from Europe don't seem to make much sense in Australia.

Spring starts on the first day of September, right? Not if Dr Tim Entwisle, director of the Royal Botanic Gardens in Melbourne and the author of 'Sprinter and Sprummer', has anything to do with it. Here he argues we should scrap the European approach and adopt a five season model.

The first, or the 21st, day of September is the start of spring in some countries. But not, I think, in Australia. Australia is different. It has different seasons. Yet most Australians don’t acknowledge or even notice these differences.

That’s partly because minutes, hours, days and months are the way we organise our lives—sowing crops, attending job interviews, picking up kids from child care, playing footy, getting our hair cut and so on. Seasons are for noting, celebrating and tracking the changes in the world around us. If we get them wrong we don’t lose our crop, job or children.

It’s a tweaking of the current system. The familiar anchors, summer and winter, are there, but the bits in between and the duration of the seasons are adjusted for the southern Australian climate.

No-one has responsibility for approving the seasons, and they are not anchored by Greenwich Mean or International Atomic Time. However, they are part of our inherited culture, part of the ritual of living on Planet Earth. Our responses to seasons—like the seasons themselves, vary from place to place.

The definition of a season seems simple enough but, as I argue in my new book Sprinter and Sprummer: Australia's Changing Seasons, the term is misunderstood, misinterpreted and misused.

Why should we have four seasons? Why must they each take up three months of the year? Indigenous communities have always known that Australia’s climate is more complex than a simple four-season arrangement suggests.

When I began the book in 2010, while director of Sydney’s Royal Botanic Gardens and Domain, I wanted to make two somewhat contradictory points. First, there is a peak flowering period in most Australian gardens and bushland, and it happens before what we normally call spring. Second, plants flower all year round, not just in ‘spring’.

Then, three years ago, I moved to England, the source of many of our cultural traditions including our idea of four neat seasons, each three months long. I gained first-hand experience of ‘true seasons’ and the plants that either define them or respond to them, depending on your perspective.

I found that even in England, the four seasons don’t always match the annual cycles of nature. So I expanded the scope of the book to address a more fundamental question about whether seasons are ever really ‘fit for purpose’. Perhaps it’s not only Australia that needs a thorough review of its seasons.

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I don’t want to overstate the case for having a set of good, robust seasons. Seasons, like most natural phenomena, have been part of pagan rituals for millennia. Each season has been given characteristics much like the signs of the zodiac, and with as much value. For example, the Greek elements of air, fire, earth and water have been correlated with the seasons spring, summer, autumn and winter respectively. As have the so-called humours—blood, yellow bile, black bile and phlegm. In a modern twist, I’ve even seen the Myers-Briggs personality types mapped against seasons. While climate may affect our mood and behaviour, any seasonal classification is unlikely to assist in clinical diagnosis, life planning or recruitment.

Still, why not have seasons that suit Australia? Since 1788, we have laboured and partied under a set of four European seasons that make no sense in most parts of the country. We may like them for historical or cultural reasons, or because they are the same throughout the world, but they tell us nothing about our natural environment. In time-honoured fashion, I decided from the safe distance of London that it was time for Australia to reject these seasons and adopt a system that brings Australians more in tune with their plants and animals; a system that can help us respond to climate change.

After two years abroad I returned to Australia to take up my current role as director of Melbourne’s Royal Botanic Gardens in March 2013 and experienced nine days in a row with temperatures over 30°C, a record for the city. This tallied nicely with my preference for a longer summer season in Australia.

Living in Sydney, London and now Melbourne, I’m convinced that the four traditional seasons don’t make sense in Australia. My proposal is that we instead have five seasons based on the climatic and biological cycles we observe around us.

I start with the origins and theory of the traditional seasonal system—which I’ve nicknamed the Vivaldi Option—then review the Aboriginal seasonal classifications used across Australia, followed by my five season proposal.

Seasons have been with us since early in recorded human history. In fact, we could argue that breeding and feeding seasons are part of the cycles of many animals and that our species, Homo sapiens, has merely extended this concept a little. The key element of human seasons is our division of the solar year into segments that start at predefined times each year.

In ancient Mesopotamia, the year was divided into two: one half beginning with the sowing of the barley (autumn), the other with its harvesting (spring). The early Egyptians, living beside the Nile, added an extra season and brought in the concept of cold and hot seasons. Their three seasons were more or less ‘flood’, winter and summer.

The Vivaldi Option of four neatly defined seasons appears to have originated in the Mediterranean region, though it may have also emerged independently in China and in places with less well documented histories. The Sumerians and Babylonians were the first in the region to use equinoxes and solstices to define four evenly timed seasons. The four season system was taken up by the Greeks then by the Romans. It spread through Europe and eventually to colonial countries such as Australia. The seasons start regularly on the first day of a month, or sometimes the 21st or thereabouts, depending on local habits and quirks.

Others before me have suggested a new set of seasons, but we seem reluctant to change, as with the Union Jack in our flag or the monarchy; perhaps we draw comfort from these anachronisms. In the 1990s, environmental educator Alan Reid encouraged members of the Gould League of Victoria to record their seasonal observations as part of his Timelines Project, leading to a six season proposal for Melbourne. Retired Sydney schoolteacher Rick Kemp contacted me when I first started talking about my seasonal discontent. Kemp has devised an eight season system based on the relative positions of the Earth and the Sun. Like me, he wants to move the first day of spring, Wattle Day, from the 1st of September back to the 1st of August.

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Our Indigenous communities have watched the world around them over tens of thousands of years, and have two to seven seasons to suit their local area. I can find only one example of Aboriginal Australians using four seasons; six is the most common number.

We could embrace one of the Aboriginal seasonal systems, but I fear this might be just too radical for most Australians (who, contrary to popular belief, are a rather conservative people).

Instead, I propose a modified Vivaldi Option for southern Australia, by which I mean south of about Brisbane. It’s a tweaking of the current system. The familiar anchors, summer and winter, are there, but the bits in between and the duration of the seasons are adjusted for the southern Australian climate.

Sprinter (August and September), the early Australian spring, starts my seasonal year. It’s when the bushland and our gardens burst into flower. It’s also when that quintessential Australian plant, the wattle, is in peak flowering across Australia.

Sprummer (October and November) is the changeable season, bringing a second wave of flowering.

Summer (December to March) should be four months long, extending beyond February, when there are still plenty of fine warm days.

Autumn (April and May) barely registers in Sydney, but further south we get good autumn colour on exotic trees, as well as peak fungal fruiting.

Winter (June and July) is a short burst of cold weather and a time when the plant world is preparing for the sprinter ahead.

The first season, sprinter, in my mind is a no-brainer. It is easy to recognise and backed up by good observational data. The other four are perhaps more aspirational: concepts to test and probe a little further.

Then there is climate change and the fact that the seasons are changing, whether we like it or not. Perhaps we need an evolving system of seasons. However, we should at least get it right in the first place and try to reflect, if not our specific region, then large sections of the country.

There are no perfect or correct seasons. I am happy for my system to be rigorously debated and tested, and I would be thrilled if, through more people observing and monitoring the natural world, I have to totally redesign it. I’m sceptical by nature but I’ve happily included conjecture and perception alongside peer-reviewed evidence and analysis. That’s mainly because we have so little data on how our Australian plants and animals respond to our climate.

That said, I’m pleased to see more research on this topic over recent years, mostly driven by the need to understand the impacts of accelerated climate change. I’m also a big supporter of ClimateWatch, a citizen-science program set up by Earthwatch and other partners to help track more accurately the seasonal and other changes around us.

Thomas Huxley said that science is nothing but trained and organised common sense. That common sense has me convinced that the September 1 is not the first day of spring. September is the second half of sprinter, the characteristically early flowering season of southern Australia.

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