Anita Talberg, Science, Technology, Environment and Resources
Section
The science on climate change suggests further reductions in
greenhouse gas emissions from the energy sector are needed. Ideally
this would occur by transitioning to a renewable energy economy
(see the Brief Powering Australia from renewable sources).
However, it could form part of a broader portfolio of technologies
for acting on climate change. Following are some of the
technologies and concepts currently being developed.
Carbon capture and storage
The concept of carbon capture and storage (CCS) is to reduce
greenhouse gas emissions from fossil fuel-based electricity
production by preventing carbon gases from entering the atmosphere.
As long as coal remains the cheapest and most viable solution to
Australia’s electricity needs, there will be a place for CCS.
Given Australia’s reliance on coal exports, the development
of CCS technology is pivotal to the long-term direction of the
national economy. In 2009, Australia launched the Global CCS
Institute and committed $100 million to the initiative, which
now has 20 government and 80 non-government members. The Institute
facilitates the development, testing and deployment of CCS
technologies. The Rudd Government launched the CCS Flagships
Program to support the construction of up to four commercial scale
projects.
The carbon capture and storage process
There are three stages to CCS:
(1) capturing the carbon dioxide either before or after combustion
(can be applied to plants fuelled by biomass, gas and coal, or even
to steel, oil and aluminium refineries)
(2) compressing and transporting the carbon dioxide by road or
pipeline, and
(3) storing the carbon dioxide, generally in liquid form, about a
kilometre underground (some storage sites are depleted oil and gas
fields where the injected carbon dioxide can increase
production).
Biochar to trap carbon in soil
Biochar is a type of charcoal produced from the slow,
oxygen-free burning of plants and other organic material. Creating
biochar stores carbon for long periods, delaying its release into
the atmosphere. Biochar can also add nutrients to soil and improve
soil quality. The capacity of biochar to reduce emissions is
uncertain as the science is still new. Some estimate that more than
one per cent of global man-made carbon emissions can be
offset in soils (including through the use of biochar). However,
there are limits to the ‘biochar solution’: the first
is the need for suitable organic matter; the second is the need for
significantly more research. The Rudd Government announced
$1.4 million funding to CSIRO for biochar research in 2009.
Soil carbon, and biochar more specifically, was the key feature of
the Coalition’s Direct Action Plan on Climate Change and part
of the Coalition’s election policy, the Plan for Real Action
on Energy and Resources. The Labor Party’s approach to
biochar is more cautious. Within its Carbon Farming Initiative,
Labor seeks to support research and development into biochar and
soil carbon. This is broadly in line with the position of the
Greens who support biochar but also urge the use of sustainable
feedstock.
Algae to turn emissions into biofuels
Grown in water with adequate light and temperature, algae absorb
carbon dioxide (CO2) and use it to produce compounds that can be
converted into ethanol or biodiesel. The idea is similar to growing
biofuels from land plants, but algae are more compact and, in
theory, are able to transform more of the absorbed CO2 into usable
product. The concept remains to be proven outside the laboratory on
a large scale, but technologies are already being developed to
address issues such as harvesting and maximising carbon absorption.
The Government’s Second Generation Biofuels Research and
Development Program furthers ‘research, development and
demonstration of new biofuel technologies and feedstocks that
address the sustainable development of a biofuels industry in
Australia’. As part of this, the University of Melbourne is
undertaking a project examining the prospect of biofuel from algal
biomass.
Nuclear power
Because electricity production from nuclear fission produces no
greenhouse gas emissions, it is a genuine option for reducing
climate change. A proven technology, it currently provides more
than five per cent of total global primary energy.
Australia’s extensive supply of uranium adds a further
advantage. However, if Australia were to proceed down the road of
nuclear energy, at least 15 years would be required for new plants
to be constructed and begin operation. Also, nuclear plants would
utilise the existing energy infrastructure. However, that would not
be conducive to the development of renewable energy
technologies.
Geoengineering
Geoengineering is any large-scale interference in the climate
system to counteract global warming. In some interpretations of
this definition, concepts such as CCS and biochar, and even
large-scale afforestation projects, can be included. However, more
commonly, geoengineering is used to encompass some of the less
conventional ideas for combating global warming. Under this view,
geoengineering concepts fit into two categories:
- carbon dioxide reduction techniques aim to reduce existing
concentrations of atmospheric carbon. Examples include:
- chemically ‘extracting’ CO2 out of the air with
tree-mimicking devices, and
- adding iron to the ocean to stimulate biological growth that
absorbs CO2 from the air and eventually sinks to the seabed.
- solar radiation management aims to either reduce the amount of
incoming solar radiation, or increase the amount reflected. Some
proposed methods are:
- whitening clouds with tiny salt water droplets to make them
more reflective
- engineering whiter crops or covering deserts with reflective
material
- injecting sulphur dioxide into the stratosphere to reflect
sunlight, and
- propelling mirrors into space to reflect incoming
radiation.
These ideas are untested, and could have dangerous side-effects.
Some geoengineering methods could reduce average rainfall globally,
delay the recovery of the ozone hole by up to 70 years, suffocate
marine ecosystems, or even cause failure of the Asian and African
monsoons thus threatening the lives of millions. The very concept
of geoengineering also poses a series of complex ethical and legal
questions around the issues of global management and treatment of
global commons. And who is to blame if or when the side effects
prove disastrous?
Although these questions seem premature, they must be considered
throughout any discussions and be integral to the direction of any
research. It is likely that global politics, not science, will be
the major hurdle for geoengineering.
Conclusions
There is no ‘silver bullet’ to reduce climate
change. The problem requires a commitment to a portfolio of
solutions. Biochar, CCS, algal biofuel, nuclear power and
geoengineering are just a few of many options.
Library publications and key documents
A Talberg, The Basics of Biochar,
Background note, 2009–10, Parliamentary Library, Canberra,
2009, http://www.aph.gov.au/Library/pubs/BN/sci/Biochar.pdf
The Royal Society, Geoengineering the
climate: science, governance and uncertainty, The Royal
Society, London, 2009, http://royalsociety.org/geoengineering-the-climate/