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(Dr. Mark Lonsdale) Cities are amongst the great inventions of
civilisation, and for the first time in 2007 more than half
of the global population was living in cities.
That's the first time in our history that that's been true.
Eighty-seven percent of Australians live in cities.
Globally cities occupy 2% of the landscape, but use about 75%
of the resources. So cities are wonderful crucibles of invention
and cultural change, but there's also an argument that they
pose a threat to the environment because of that resource use.
Cities of course occupy land, and often it's the best land,
the land where biodiversity is richest, the land
with rich soil and permanent water
supplies tends to be occupied by cities.
So there's a direct impact on ecosystems
from the presence of cities. City populations demand
novelty, and so city people will be looking for ornamental plants,
often from overseas. Or pets, exotic pets to entertain them.
Those kind of organisms tend to enter our country through our
cities, and then migrate across the landscape where, as we've
seen over the last hundred years and more, they have a major negative
impact on our biodiversity. So there's no doubt that cities can
be a negative for our biodiversity.
There's another way of looking at cities though,
and that is that by concentrating people we
actually take pressure off the land by having people in cities.
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Biodiversity is our life support system.
Through ecosystem services such as water filtration through our forests
clean water is provided into our cities.
There are apparently measurable benefits to people's
psychological health and wellbeing from
the presence of parkland in cities.
And people generally want to live in cities that look and
feel beautiful and well vegetated, and with birdlife around them.
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Within cities we can get better biodiversity outcomes by the way
we lay those cities out, so green spaces are obviously important,
but the right kind of green spaces with some diversity of tree
canopy and so on to encourage birds. Also encouraging remnant vegetation
in cities is a very positive way of getting good biodiversity
outcomes, even within a city boundary.
In Australia we can expect another ten to 20 million
people to be living in our cities by 2050,
so we've got a big opportunity there to get things right,
or get things wrong, as our city populations expand.
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One of the issues with people living in cities
is that they become divorced from nature.
We talk about an extinction of experience.
People no longer experience biodiversity.
So if we can get our cities and the interaction between
people and biodiversity in our cities right we can
potentially reconnect the urban population to biodiversity and see
cities as centres for cultural change, which they have been throughout
history, but a cultural change that brings people back into
connection with nature, and potentially see them
not only as reducing their environmental footprint,
but also connecting them back into nature in such a way that they become
advocates for our nature and our biodiversity.
One thing that people can do in cities is to look at
a wonderful information tool that they've got at their disposal.
The Atlas of Living Australia is an online resource available to
everyone that will tell you what species you can expect to find in
your area, so you can click on a map and look at all the species that
you can expect to find near you. You can also enter data.
You can become a citizen scientist.
You can enter data that we as scientists
can then use in terms of the changing and
evolving distribution of our species.
Australian cities are going to expand over the next
few decades quite markedly in population.
In doing so our cities are going to have to grow
in area and in environmental footprint,
but we can still minimise the impact on biodiversity,
and indeed potentially benefit biodiversity
in the way we manage that growth.
It's going to need some research to help us
to shape how our cities grow and develop.
It's going to need the urban population to really get
involved in determining how their cities grow and develop and evolve.
But potentially there's an awful lot of good that we can do as
these cities expand. It's a great opportunity for Australia.
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