Geoscience Reference
In-Depth Information
Changing lifestyles
Livestock consumption
Kyoto
Globalisation and commoditisation
Transport costs
Biofuels Technology change
Energy usage
Water constraints
Demographic change
Competing land uses
Ocean
Desertification
chemistry
&
degradation
Sea levels
Biodiversity
loss
Cli mate
change
Ecosystem
function
Figure 6.4
Global drivers of change, their impacts on earth systems and sustainable
agriculture
Source: Adapted from Howden et al., 2010
emissions seem likely to emphasize these existing challenges, through impacts
on rainfall, temperatures and climate extremes (Easterling et al., 2007). The
resulting global changes in agricultural trade and prices will impact on Australian
agriculture, interacting with domestic changes and with climate variability.
For example, estimates by Childs (2008) suggest that the projected impact
of climate change-related food price increases will reduce the GDP of most
Asian and African countries between 0.6 and 1.6 per cent, impacting on food
trade. Importantly, climate change impacts will likely be co-occurring with a
large range of other changes (
Figure 6.4
)
, introducing considerable uncertainty
and complexity into longer-term decision-making. The impacts of climate
change, in conjunction with these other supply-and-demand forces operating on
agriculture, raise questions as to the sustainability of Australia's current grain and
livestock production rates and our capacity to be a consistent and large exporter
of some agricultural commodities. This chapter addresses briefly some of these
issues following a summary of anticipated climate changes.
Australia's future climate and its impact
Uncertainties
Projections of climate changes are made using a suite of Global Circulation
Models (GCMs). These model energy and mass transfers, biogeochemistry and
atmospheric chemistry and other processes in and on the oceans, land and
atmosphere. The GCMs are in turn driven by a range of scenarios of human
