Climate change action: a multi-faceted approach

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/

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