A Bayesian inversion technique to determine the location and strength of trace gas emissions from a point source in open air is presented. It was tested using atmospheric measurements of nitrous oxide (N2O) and carbon dioxide (CO2) released at known rates from a source located within an array of eight evenly spaced sampling points on a 20 m radius circle. The analysis requires knowledge of concentration enhancement downwind of the source and the normalized, three-dimensional distribution (shape) of concentration in the dispersion plume. The influence of varying background concentrations of ~1% for N2O and ~10% for CO2 was removed by subtracting upwind concentrations from those downwind of the source to yield only concentration enhancements. Continuous measurements of turbulent wind and temperature statistics were used to model the dispersion plume. The analysis localized the source to within 0.8 m of the true position and the emission rates were determined to better than 3% accuracy. This technique will be useful in assurance monitoring for geological storage of CO2 and for applications requiring knowledge of the location and rate of fugitive emissions.

Geological storage of greenhouse gases is one approach that the Australian Government is pursuing to assist Australia, and the world, to reduce greenhouse gas emissions into the atmosphere. Understanding the geology of Australia's sedimentary basins and their potential for greenhouse gas storage is an important component of Geoscience Australia's work in supporting emission reductions.

The first large-scale projects for geological storage of carbon dioxide on the Australian mainland are likely to occur within sedimentary sequences that underlie or are within the Triassic-Cretaceous, Great Artesian Basin (GAB) aquifer sequence. Recent national1 and state2 assessments have concluded that certain deep formations within the GAB show considerable geological suitability for the storage of greenhouse gases. These same formations contain trapped methane and naturally generated CO2 stored for millions of years. In July 2010, the Queensland government released exploration permits for Greenhouse Gas Storage in the Surat and Galilee basins.An important consideration in assessing the potential economic, environmental, health and safety risks of such projects is the potential impact CO2 migrating out of storage reservoirs could have on overlying groundwater resources. The risk and impact of CO2 migrating from a greenhouse gas storage reservoir into groundwater cannot be objectively assessed without knowledge of the natural baseline characteristics of the groundwater within these systems. Due to the phase behaviour of CO2, geological storage of carbon dioxide in the supercritical state requires depths greater than 800m, but there are few hydrogeochemical studies of these deeper aquifers in the prospective storage areas. Historical hydrogeochemical data are compiled from various State and Federal Government agencies. In addition, hydrogeochemical information is compiled from thousands of petroleum well completion reports in order to obtain more information on the deeper aquifers, not typically used for agriculture or human consumption. The data are passed through a QC procedure to check for mud contamination and to ascertain whether a representative sample had been collected. The large majority of the samples proved to be contaminated but a small selection passed the QC criteria. The full dataset is available for download from GA's Virtual Dataroom. Oral presentation at "Groundwater 2010" Conference, 31 October - 4 November 2010, Canberra

Australia has embarked on a process of potential commitment through the Kyoto Protocol to contain growth in greenhouse gas emissions to 8% between 1990 and the reporting period of 2008 - 2012. The target is well below the estimated growth of about 28% under the `business as usual' condition. Australia's greenhouse gas inventory estimates that 502 million tonnes of carbon dioxide equivalents were emitted in the base year of 1990. This report examines over 175 candidate options for reducing greenhouse gas emissions to identify their technical feasibility, cost per tonne of carbon dioxide avoided and capability to reduce emissions under Australian conditions. The candidate options were not intended to represent an exhaustive list but they encompass major and some lesser options being canvassed in Australia and overseas. Preferred options were selected on their performance towards the criteria of technical feasibility, cost and capability.

In July 2010 Geoscience Australia and CSIRO Marine & Atmospheric Research jointly commissioned a new atmospheric composition monitoring station (' Arcturus') in central Queensland. The facility is designed as a proto-type remotely operated `baseline monitoring station' such as could be deployed in areas that are likely targets for commercial scale carbon capture and geological storage (CCS). It is envisaged that such a station could act as a high quality reference point for later in-fill, site based, atmospheric monitoring associated with geological storage of CO2. The station uses two wavelength scanned cavity ringdown instruments to measure concentrations of carbon dioxide (CO2), methane (CH4), water vapour and the isotopic signature (?13C) of CO2. Meteorological parameters such as wind speed and wind direction are also measured. In combination with CSIRO's TAPM (The Air Pollution Model), data will be used to understand the local variations in CO2 and CH4 and the contributions of natural and anthropogenic sources in the area to this variability. The site is located in a region that supports cropping, grazing, cattle feedlotting, coal mining and gas production activities, which may be associated with fluxes of CO2 and CH4. We present in this paper some of the challenges found during the installation and operation of the station in a remote, sub-tropical environment and how these were resolved. We will also present the first results from the site coupled with preliminary modelling of the relative contribution of large point source anthropogenic emissions and their contribution to the background.

Monitoring is an important aspect in verifying the integrity of the geological storage of greenhouse gases. Geoscience Australia is working with CSIRO, the CO2CRC, the Australian National University, the University of Adelaide and the University of Wollongong to develop and evaluate new techniques to detect and quantify greenhouse gas emissions.

The decision at the 2011 United Nations climate change meeting in Durban to accept CCS as a CDM project activity was truly historic and long overdue. The United Nations Clean Development Mechanism (CDM) allows emission reduction projects in developing countries to earn certified emission reduction (CER) credits, each equivalent to one tonne of CO2. CERs can be traded and sold, and used by developed countries to meet part of their emission reduction targets under the Kyoto Protocol. The intention of the mechanism is to stimulate sustainable development and emission reductions, while providing developed countries with some flexibility in how they achieve their emission reduction targets. The CDM allows developed countries to invest in emission reductions at lowest cost. Since its inception, the CDM has been identified as a means to reduce the cost of CCS projects and so initiate more projects. After five years of negotiations to get CCS accepted as a CDM project activity, the Cancun Decision (2010) put in place a work program to address issues of general concern before CCS could be included in the CDM. The 2010 work program consisted of submissions, a synthesis report, a technical workshop, and concluded with the UNFCCC Secretariat producing draft 'modalities and procedures' describing comprehensive requirements for CCS projects within the CDM. This twenty page 'rulebook' provided the basis for negotiations in Durban. The challenging negotiations, lasting over 32 hours, concluded on 9th December, 2012, with Parties agreeing to the text specifying the modalities and procedures for CCS as CDM project activities. The provisions of the Durban Decision (2011) cover a range of technical issues including site selection and characterisation, risk and safety assessment, monitoring, liabilities, verification and certification, environmental and social impact assessments, responsibilities for non-permanence, and timing of the CDM-project end. etc

No abstract available

This animation has been developed by Geoscience Australia to illustrate the carbon dioxide capture, transportation and storage process. Carbon capture and storage (CCS) is one of the technologies that we can use to reduce greenhouse gas emissions to the atmosphere, particularly from sources such as coal or natural gas fired power stations and industrial plants. In this process carbon dioxide (CO2) is captured at the source (e.g. power station), transported via pipeline and injected deep underground into a porous rock, such as sandstone. There it is trapped by the overlying fine grained and impermeable mud rocks.

Eddy Covariance (EC) is considered a key atmospheric technique for quantifying CO2 leakage. However the complex and localised heterogeneity of a CO2 leak above the background environmental signal violates several of the critical assumptions made when implementing the EC technique, including: - That horizontal gradients in CO2 concentration are zero. - That horizontal and vertical gradients in the covariance of CO2 and orthogonal wind directions are zero. The ability of EC measurements of CO2 flux at the surface to provide information on the location and strength of CO2 leakage from below ground stores was tested during a 144 kg/day release event (27 March - 13 June 2012) at the Ginninderra controlled release facility. We show that the direction of the leak can be ascertained with some confidence although this depends on leak strength and distance from leak. Elevated CO2 levels are seen in the direction of the leakage area, however quantifying the emissions is confounded by the potential bias within each measurement through breaching of the assumptions underpinning the EC technique. The CO2 flux due to advection of the horizontal CO2 concentration gradients, thought to be the largest component of the error with the violation of the EC technique's assumptions, has been estimated using the modelling software Windtrax. The magnitude of the CO2 flux due to advection is then compared with the measured CO2 flux measured using the EC technique, to provide an initial assessment of the suitability of the EC technique to quantifying leakage source rates.