You may have been hearing a lot of talk about ‘net zero emissions’ around the place. But what exactly does that mean, why do we want to achieve it and how do we get there?
What does net zero emissions mean?
‘Net zero emissions’ refers to achieving an overall balance between greenhouse gas emissions produced and greenhouse gas emissions taken out of the atmosphere. Think of it like a set of scales: producing greenhouse gas emissions tips the scales, and we want to get those scales back into balance with no new greenhouse gas being added to the atmosphere in any given year. Eventually, we will probably need to tip them the other way to repair past harm. Once we stop emitting greenhouse gases from fossil fuels, we still need to deal with all the emissions we’ve already pumped into the atmosphere over the years. That’s the difference between zero and net zero.
Getting to net zero means we can still produce some emissions, as long as they are offset by processes that reduce greenhouse gases already in the atmosphere. For example, these could be things like planting new forests, or or drawdown technologies like direct air capture. The more emissions that are produced, the more carbon dioxide we will eventually need to remove from the atmosphere (this is called sequestration) to reach net zero.
However, to meet the goal of net zero, new emissions of greenhouse gas must be as low as possible. This means that we need to rapidly phase out fossil fuels – coal, oil and gas – and transition to renewable energy.
Why is net zero emissions important?
Climate change isn’t a tap we can turn off once we stop using fossil fuels. Carbon dioxide, the main contributor to climate change, will stay in the atmosphere and keep heating the planet for years and years.
So reducing greenhouse gas emissions is hugely important, but we can’t stop there. The end goal is to balance the scales again, and restore the global climate to pre-climate change levels. To get there, we need to reduce greenhouse gas emissions to zero AND then get cracking on repairing past harm by drawing down past emissions.
Why is everyone talking about net zero emissions targets all of a sudden?
This explosion of interest in net zero was driven by the Intergovernmental Panel on Climate Change’s Special Report Global Warming of 1.5°C, released late 2018. This report made it clear to the world’s governments the vital importance of net zero as an interim goal in the response to climate change. This has seen many governments — local, state and national — around the world set their own net zero goals.
Basically, we know that the impacts of climate change can’t stop worsening until the overall quantity of greenhouse gases in the atmosphere stops increasing. Among other things, that means that fossil fuel consumption-that is, the burning of coal, oil and gas–must rapidly drop toward zero.
Net zero describes the point in time where humans stop adding to the burden of climate-heating gases in the atmosphere.
How can Australia achieve net zero emissions?
We already have the technology we need to power Australia and accelerate towards net zero emissions, including replacing coal- and gas-fired power stations with cheap, clean and reliable renewable energy backed by storage technologies.
To reach net zero, it is vital that we replace all fossil fuels use, meet all of our energy needs with renewables and take concrete action to restore damaged landscapes, promote resilience of those living on the land and repair past harm to the atmosphere. Doing this will reduce the new emissions of greenhouse gas to as close to zero as possible, and remove the greenhouse gases we put there in the past.
However, Australia lacks credible climate and renewable energy policy to drive us towards that future and its emission reduction targets are inadequate to meet its Paris climate target. What’s more, our exported emissions (in the form of coal and gas) are about 2.5 times higher than our domestic emissions – but these are not counted on Australia’s ledger. However, they still contribute to climate change.
When does Australia need to reach net zero emissions?
Every new tonne of greenhouse gas is heating the planet further. The sooner the world stops adding greenhouse gas to the atmosphere, the better.
In order to honour the Paris Agreement and limit global warming to well below 2 degrees higher than it was when we first started burning fossil fuels at massive scale (and pursue efforts to limit that increase to only 1.5 degrees!), global carbon emissions should reach net zero by 2050. Seventy-three countries have already pledged to do this.
But on its own, just reaching net zero in 2050 is nowhere near enough. To meet the goal of limiting global warming to 1.5 degrees, the whole world will need to reduce emissions by 7% per year every single year between 2020 and 2030. Even limiting global warming to well below 2 degrees would require annual global reductions of greenhouse gas emissions of 2.6% per cent per year.
But Australia is lagging behind the rest of the world. We are nowhere near on track to meeting our 2030 target, plus we already chose a 2030 target that is completely insufficient to meet the internationally agreed temperature goals. On top of this, Australia lacks a credible climate policy. Australia is a big emitter, but we have some of the best renewable resources in the world. Net zero by 2050 is a starting point, but we should be aiming to hit net zero as soon as possible.
Fortunately, as of July 9 2020, Australia has a net zero target of a kind: the Northern Territory has announced that it is formalising its draft net zero target and this means that, despite Federal Government inaction, every single Australian state and territory has a formal target to reach net zero by 2050.
To meet globally agreed temperature goals, our state and territory governments must do more than this: They must put in place policies and plans to not only meet, but exceed, these targets. That said, eight formal state and territory net zero targets is a great place to start in our collective effort to protect lives, livelihoods property and the places we love in a country as acutely vulnerable to climate impacts as Australia.
Have any other countries/states reached net zero emissions already?
Five countries have a net-zero target in place by law: Sweden, the United Kingdom, France, Denmark and New Zealand.
Closer to home, we have an entire state that has been net zero in some individual years. In 2014 and 2018, Tasmania’s emissions dropped below net zero. Two things allowed this to happen: Tasmania’s massive hydroelectric dams, and Tasmania’s massive carbon-dense forests. With the state’s electricity supply already nearing 100% renewable, the remaining emissions from the state – across transport, manufacturing, agriculture and forestry – were offset by the greenhouse gases sucked out of the atmosphere by the state’s forests. Tasmania has work to do to make this permanent, and could easily move beyond net zero to provide an overall benefit to the world by doing more to reduce its fossil fuel consumption, but it starts from an excellent position.
Is having a net zero emissions target an effective way of tackling climate change?
A target is only as good as the policies underpinning it. Australia’s states and territories all have net zero targets, but most governments have not outlined how these targets will be met. Several governments with a net zero goal, such as Western Australia, Northern Territory and Queensland, are still increasing their emissions each year. Even governments that are leading the pack when it comes to climate action – like South Australia and the ACT – still have more work to do to outline how they will meet their net zero goals. On top of this, no matter what our emissions are at home, it is not possible to be a government that is taking climate change seriously while continuing to export fossil fuels, especially if that government is growing its fossil fuel exports.