Australia’s biodiversity as carbon: how we count the greenhouse emissions from Australia’s living environment, and why it matters

Dan Rosauer, Greenhouse Abatement Scientist, Environment, CSIRO 

Australia is a country with a small population and economy, when compared to its huge land area. This means that when we estimate and report Australia’s greenhouse gas emissions, the land sector (basically trees and soil) account for a larger part than in most developed countries.  In this talk I will outline the science and methods used to estimate greenhouse emissions due to trees, the contribution and limitations of the land sector in reducing emissions, and exciting ways in which new data sources are changing our understanding of greenhouse emissions and sinks from the living environment.

Dan Rosauer is a senior research scientist at CSIRO, working on models of Australia’s carbon cycle and vegetation. He has previously worked on Australia’s greenhouse gas inventory at the Department of Climate Change, Energy, the Environment and Water, and as a research fellow in macroecology at ANU and at Yale University.

Optimising biology and chemistry to drive soil-based carbon dioxide removal 

Wolfram Buss, Postdoctoral Fellow, Research School of Biology, ANU

Soil-based carbon dioxide removal include soil organic carbon, biochar and enhanced rock weathering. All processes are driven by both biology and chemistry. Here I show new research outlining why understanding both is important to optimise carbon dioxide removal.

Fixing the carbon cycle - the role of biological carbon sequestration

Denis J Murphy, Emeritus Professor of Biotechnology, University of South Wales, UK

In the Global Carbon Cycle, atmospheric carbon emissions, both ‘natural’ and anthropogenic, are balanced by carbon uptake (i.e. sequestration) that mostly occurs via photosynthesis. Relatively low atmospheric CO2 levels were the norm for the past 10 million years, and during the past million years they averaged about 220 ppm. More recently, immense quantities of sequestered fossil carbon have been used as energy sources, resulting in a particularly rapid increase in CO2emissions after 1950 CE to the current value of 424 ppm, with further rises to >800 ppm predicted by 2100. This is already perturbing the previously stable Holocene climate and is threatening future food production and social stability. Today, the global carbon cycle has been shifted to the extent that carbon sequestration is no longer keeping up with recent anthropogenic emissions. 

In order to address this imbalance, it is important to understand the roles of biological systems, such as natural forests and tropical croplands, in carbon sequestration and to devise strategies to facilitate net CO2 uptake. These include limitations on deforestation and the use of carbon-rich peatland, as well as auditing the carbon impact of major cropping systems to focus on those crops that deliver both high yields and carbon efficiency. As an initial step in this process a case study will be presented on the tropical tree crop, the African oil palm, Elaeis guineensis. This study demonstrates the unexpectedly high potential of oil palm plantations to sequester CO2 at higher rates than all other crops and even exceeding rates of some tropical forests. Ongoing yield improvements will further increase the efficiency of the land footprint of oil palm, while limitations of negative land-use conversions (such as deforestation) will facilitate progress towards overall carbon neutrality for the cropping system.