Lincoln University ecologist Prof Steve Wratten speaks at the Geographically Appropriate Integrated Agriculture Workshop at Lincoln University last month. Supplied photo
Just how many people can world agriculture sustain?That was
among the questions considered by leading ecological and
environmental scientists at a workshop at Lincoln
University's Bio-Protection Research Centre last month.
Known as the Geographically Appropriate Integrated
Agriculture Workshop (Gaia), its objective was to develop and
evaluate a range of scenarios for agricultural land use and
management from the perspective of ecosystems and the
fundamental services they provide.
The 23 participants in the workshop - from countries such as
Denmark, the United Kingdom, the United States, the
Netherlands, Kenya and Australia - built on developments in
agro-ecology to estimate how many people the world could
sustain without the current dependence on, and over-use of,
water resources and fossil fuel-based chemicals such as
fertilisers and pesticides.
Such questions were highly relevant next to the intensive use
of the planet's resources, which has been estimated to be at
a rate about 50% higher than the planet can maintain. Under
the workshop's proposed scenario, it was estimated the Earth
was suited to a population of about 4.2 billion - three
billion fewer than its current population.
Agriculture operates on about 40% of the Earth's surface,
making it the planet's most significant terrestrial
ecosystem, but also one that has developed through the
deliberate designs of humankind. While the contribution
agriculture has made to the life-supporting development of
our species is immense, it has also impacted negatively on
ecosystems and biodiversity - the fundamental systems that
keep people alive, the workshop suggested.
''It is widely acknowledged that agricultural lands show a
steady decline in ecological asset quality,'' Lincoln
University ecologist Prof Steve Wratten, one of the principal
organisers of the workshop, said.
''This jeopardises the production of other important
ecosystem services that are critical to sustainable, healthy
''Much research and investment in agro-ecological practices,
however, has shown that it is possible to substantially
reduce dependency on non-renewable resources.''
One key output from the workshop will be a series of papers
for a special issue of academic journal Ecosystem Services,
as well as a paper intended for a high-profile journal such
The week also included presentations by three of the workshop
delegates at a special forum held at Environment Canterbury
(ECan). There was a high level of interest in the forum,
which was aimed at stimulating discussion around the
consideration of ecosystem services in future policy.
Prof Robert Costanza, a leading ecological economist and
author of many books on public policy, environmental
management and sustainability, spoke on the importance of
resource economics, which values the natural capital that
delivers ecosystem services, and stresses the need to include
ecological considerations in the commercial realm.
He also advocated for the advantages of utilising the Genuine
Progress Indicator (GPI) as a more credible and ''full cost
accounting'' measure of wellbeing and equality than GDP.
The ECan forum also saw Prof Wratten speak on how crop
monocultures can be diversified to improve functional
biodiversity, reduce costly inputs and, crucially, increase
farm profits. He noted the giant grass miscanthus could
deliver about 14 beneficial ecosystem services on dairy farms
alone and, when planted around paddocks, could contribute to
a farm's overall financial and environmental stability.
Sasha Courville, a senior manager with the National Australia
Bank who specialises in commercial strategies around
sustainable investment with consideration for true natural
value, also spoke.
She is developing a link between improvements in
environmental management and farming financial packages.
In recent decades, there has been a greatly improved
understanding of ecosystems and, more specifically, the
vitally important goods and services they provide: goods and
services, that is, that have often been taken for granted or
overlooked in commercial and social decision-making.
Improved research in recent times has led to more
sophisticated skills in modelling and simulating the dynamic
complexity of ecosystems, leading to a better understanding
of where market and institutional failures may be causing the
unintentional depletion of natural and ecological assets.