Climate mitigation: Science-backed solutions to reduce emissions
The latest national State of the Climate report stated that global greenhouse gas emissions continue to rise, and increasing emissions from fossil fuels are the dominant contributors to growth in atmospheric carbon dioxide. To avoid continued and increased consequences, the world must reduce, stabilise and extract greenhouse gases – a concept known as ‘climate change mitigation’.
Greenhouse gas emissions can be traced to a broad spectrum of activities, including electricity, industrial activity, agriculture, and waste. Mitigation efforts can include the use of new and renewable solutions in place of fossil-based technologies, increasing efficiencies in energy use or power generation, or changing the way we behave and consume.
The mitigation movement has ramifications for all, from households, businesses, to major industrial emitters. While Australia’s emissions are low on a whole-of-country basis compared with some of our neighbours, when we look at emissions per capita, Australia ranks within the top five in the world. We are also the world’s third largest fossil fuel exporter, (measured by CO2 emissions potential), behind Russia and Saudi Arabia, although under international rules only fuel burnt within a country counts towards national emissions.
With the evidence before us, and the impetus to act, there are plenty of ways to limit emissions across all sectors and do all that we can to mitigate the effects of climate change.
Unpacking Australia’s emissions profile
The energy sector is the main contributor to Australia’s emissions, responsible for over 80% of our total. This includes emissions from electricity that powers buildings and industry, emissions from direct combustion (where fuels are combusted to generate heat, steam or pressure), all transportation, and fugitive emissions (mostly from releases of underground CO2 and methane that occur during coal and gas mining).
Australia’s booming energy sector has been a key driver of our economy for many years, given that we’re well endowed with energy-rich resources. With the strong global drive towards decarbonisation, our traditional fossil fuel export industry must evolve. Thankfully, Australia’s energy resources are not limited to coal and gas, and renewable sources may one day take their place to prolong our energy exports.
Our remaining emissions – just under one fifth of the total – can be attributed to ‘non-energy’ sources including industrial processes, agriculture, waste and ‘land use, land use change, and forestry’ (LULUCF). Agriculture emissions are predominantly a result of enteric fermentation processes associated with livestock for which there are a number of solutions being developed.
Moving to a solution focus
While it’s clear that we have some work to do to limit further emissions, these measures needn’t limit our economic prosperity nor way of life. There are a range of new or existing technology options for each sector which can make substantial cuts. These activities, such as adopting low-emissions and renewable energy technologies and changing our land use and food production systems, can limit further greenhouse gas emissions and mitigate the effects of climate change.
CSIRO’s Chief Energy Economist Paul Graham said: “National and global efforts to develop cost effective abatement options for each sector are really starting to deliver. While there is no ‘silver bullet’, we’re more confident than ever that each sector has a range of options available to mitigate emissions”.
Electricity: The electricity sector is likely to decarbonise the fastest of all sectors, based on ongoing reductions in the cost of renewables. Although we’ve relied on coal-fired power and gas for many years, solar and wind are now the cheapest new-build electricity generation options for Australia. Wind and solar photovoltaics are expected to become our dominant energy generation technologies, and energy storage (in the form of batteries and pumped hydro) will handle daily requirements for supporting these renewable sources. Natural gas will play a role to support the transition to increased renewables. We have also already seen major progress in energy efficiency of electrical appliances in homes and commercial buildings.
Direct combustion: Natural gas is used for process heat and chemical production in many industrial processes. It is also a source of heating and cooking energy in commercial and residential buildings. Solutions such as renewable hydrogen may play a role in direct combustion of natural gas. Hydrogen may also replace coal use in steel production. This sector can also benefit from energy efficiency improvements, electrification, carbon capture and storage (CCS) and other types of low emissions fuel switching (such as solar thermal and bioenergy).
Transport: Emissions for the transport sector have risen over recent years, but can be lowered through broad adoption of electric and hydrogen-powered vehicles in the road sector, while low emission versions of diesel and jet fuel can be synthesised from hydrogen and biomass for use in rail, shipping and aviation.
Fugitive emissions: As our use of fossil fuels decreases, so too may the level of fugitive emissions from gas and coal mining. In the meantime, technologies to either limit emissions or utilise methane in underground coal mining are well advanced, while improved operational practices, carbon capture and storage (CCS) and efficiencies may make an impact for fugitive emissions from the gas industry.
Non-energy: Many technologies can be adopted in the non-energy sector, such as improved waste management, circular economy practices, land regeneration, savanna fire management and carbon forestry. In the agricultural sector, an innovative livestock feed ‘FutureFeed’ uses a specific type of seaweed which can increase production and reduce methane emissions simultaneously.
While all these solutions have merit, each carries different levels of financial, commercial, technical, social and stakeholder risk which must be overcome. As innovation continues, we will also see the benefits of exporting our R&D and ‘know how’ to benefit other nations and contribute to global decarbonisation.
How can we achieve ‘net zero emissions’?
2019’s Australian National Outlook report showed scenarios under which net zero emissions was possible by 2050. After examining the breakdown of Australia’s emissions and available mitigation technologies, it’s clear that we can deliver significant cuts.
CSIRO’s Paul Graham added: “The deepest cuts in emissions by 2050 were delivered from the electricity and transport sectors which have some of the lowest cost mitigation opportunities available”
But reducing our total emissions to zero in all sectors would be nigh-on impossible in the timeframe required. This is where negative emissions technologies can star. These technologies remove carbon dioxide directly from the atmosphere, subtracting it from the greenhouse equation. When used in combination with low emission technologies across sectors, net zero emissions can be within reach.
Keep doing what we’re doing, plus more
In the wake of hotter summers and increased extreme weather events, the public is motivated to both learn and do more at a local and global level, industry wants to invest in emissions reduction solutions, and international governments want sound advice. This provides an opportunity for innovation across sectors, where R&D can support continued international efforts.