The conventional regulatory approach to climate change mitigation, as discussed in Chapter 9, has focused attention on reducing emissions of greenhouse gases from electricity generation and energy use. However, both the international climate change regime and many national schemes recognise the scope for mitigation through biosequestration activities: actions in the land use and natural resources sector that reduce emissions (principally but not exclusively CO2). There are a number of activities that sequester carbon from the atmosphere in sinks such as forests, which make an important contribution to mitigation. Biosequestration, or carbon sequestration, is the term often given to these activities. On a broad definition, biosequestration extends well beyond simply planting more trees to sequester carbon. It may also include activities that reduce forest loss and the associated carbon emissions, as well as those that increase carbon sequestration rates through agricultural and other land management practices. In addition to the broad spectrum of sequestration activities, other land sector activities may reduce emissions of GHGs such as methane. Another widely used term is ‘carbon offsets’. As explained in Chapter 6, this typically refers to reductions in carbon emissions through sequestration or emission avoidance activities that are used to compensate for emissions generated by carbon-producing activities.
In recent years, climate policy at international and national levels has placed increasing emphasis on the contribution of biosequestration activities and land use changes to reducing emissions. Biosequestration and associated activities may lower the cost of achieving overall emission reductions, and some proponents also argue that abatement in the land sector may be achieved more rapidly than transformations in other sectors. In addition, biosequestration could allow for improvements in other aspects of the environment, such as water quality, soil protection or biodiversity conservation. These improvements are termed ‘co-benefits’. Internationally, this renewed interest in the mitigation potential of biosequestration is reflected in the pace of investment and enthusiasm for schemes such as REDD. Nationally, Australia now has a federal legislative regime focused on biosequestration, as well as emission reductions from land-use change activities (the Carbon Farming Initiative or CFI), along with an array of state-based schemes.