For most of us, the word probably conjures up images of mayhem, serious injury and harried emergency personnel working frantically to save the lives of scores of injured people.

But this week, the word has been given a different context.

Sydney has declared a "climate emergency" after the city's councillors voted that climate change poses a serious risk to the people of Sydney and the rest of Australia.

Lord Mayor Clover Moore on Monday asked the council to call on the federal government to respond urgently to the emergency, by reintroducing a price on carbon to meet the Paris Agreement emissions reduction targets.

The response to this action has been predictable, with the usual suspects trotting out the usual lines as they use "climate change" as some kind of weapon to politically and philosophically knock each other around the head.

How did it all come to this? How did looking after the planet become an issue that politicians could use for point scoring?

We hear the "science is settled" argument a lot, and I wouldn't have a clue if it is definitively settled or not.

But I do know this: We only have one planet, a growing human population and a finite amount of stuff we can dig up and use.

In the 21^st Century, surely we should be able to do better than basically continuing to burn stuff to generate power?

There is something almost distasteful about the way political parties have clamped on to some of the descriptions that have become insults to fling at those with an opposing political viewpoint.

Currently, there are more than 7.3 billion humans on the planet and the United Nations believes we will reach nine billion by 2050.

Depending on who you listen to, the projections for the years after 2050 vary.

Some scientists actually believe that populations will decrease as gradual increases in living standards in under-developed parts of the planet will result in similar patterns to those in Western Europe where birth rates are declining rapidly.

But others believe that the current world population is unsustainable, and predict that humanity will simply not be able to produce enough food and oil to feed itself and sustain our industrial economy.

UNESCO - the United Nations' Educational, Scientific and Cultural Organisation - says water security is the most important resource issue, "cross-cutting all social, economic and environmental activities".

"It is a condition for all life on our planet, an enabling or limiting factor for any social and technological development, a possible source of welfare or misery, cooperation or conflict," according to the organisation.

After water, we can probably continue the list with food, shelter and health and then start to look at issues like education and personal freedom.

All of these are so fundamental, so important, you have to ask how we could have allowed them to become politicised and yet, despite knowing how basic and important they are, we are still getting bogged down in endless arguments over conflicting ideologies and petty political point-scoring.

By 2050, if the human population reaches the estimated figure of nine billion, the World Economic Forum predicts the world's demand for food will be 60 per cent higher than it is today.

And that's just to feed the humans. We also have to factor in how to protect the other animal and plant species on the planet.

We just have to get better at this, yet our differences continue to divide us.

Do we want to have yet another partisan squabble about whether "climate change" is real or do we want to acknowledge the reality of having only one planet and finite resources and just get on with it?

Our world is changing. It is foolish to assume we can continue the rampant materialism of recent decades. We no longer have any excuses. We all know the cost.

But one thing should be abundantly clear to each of us: We cannot allow our political groups to dictate our thinking and our actions because there are agendas at play and caring for the planet isn't always at the top of the priority list.

With apologies to Virgil, but in 2019 we need to beware politicians bearing their personal hobby horses.