The sooner we can reach net zero emissions the better it will be. Net zero means that the amount of greenhouse gases going into the atmosphere are no greater than the amount being absorbed out of the atmosphere. 

The term 'net zero' is important because it means we will no longer be contributing to increased global warming.

We have already seen a global temperature rise of over 1°C and we are experiencing the consequences of that increase already. The terrible bushfires of 2019-2020 and the three years of back to back coral bleaching on the Great Barrier Reef show us that our climate system is highly sensitive to even small changes in temperature. So, we cannot be sure that achieving net zero by 2050 will avoid exceeding the 2°C limit and 1.5°C target that we set ourselves in the Paris Agreement or that limiting warming to 1.5°C or 2°C will avoid serious harm.

The longer we wait, the higher the chance of failure. Most scenarios associated with the 2050 target only offer a 50 or 66 per cent chance of staying below the temperature limit. That isn’t very reassuring, and we should be doing all we can to increase our chances of success by bringing forward our decarbonisation commitments. Earlier action to arrest and reverse emissions trajectories will be much better than waiting until the last minute and possibly having a situation where temperatures overshoot the 2°C limit.

Finally, making the transition now will save us money in the long term. New energy and business opportunities will open up if we embrace decarbonisation now and we can avoid some (but not all) of the droughts, bushfires and heatwaves that cause so much economic loss, environmental damage and human suffering.

Let me answer this question across the three levels of government – local, state and national (federal).

While local governments can’t influence national climate policy, they do some important things at the local level, like promoting green building design, installing busways and bikeways and improving public transport to encourage a move away from private vehicle use. They are also responsible for approving new coal mines, although in some states their ability to reject proposed new mines is limited by state-level law.

State governments can provide incentives to industry to change their industrial processes and energy inputs, or make laws actually requiring them to do so. Some state governments offer incentives for people to instal solar panels or energy efficient appliances and could use the car registration system to encourage people to buy electric vehicles.

However, consistent and coherent climate policy really rests with the federal government.  The national government has laws requiring a mandatory amount of renewable energy as part of every electricity companies supply. There are also laws relating to energy efficiency. The main plank of the Federal government’s climate policy is the Carbon Solutions Fund. This involves paying individuals and businesses to undertake activities that will reduce emissions. The government initiates a reverse auction in which it invites people to indicate how many emissions reductions they could deliver, at what price. The government then buys those emissions reduction from the party offering to do so at the lowest price. This might achieve small level of emissions reduction, but it costs a lot of money and it will not deliver the kind of transformation that is desperately needed. It provides no incentive for large emitters to reduce their emissions because there are no legal obligations for them to do so and there are no costs associated with continuing with high emitting activities.

The national government could also stop new coal mines by using federal environmental laws. So far it has not done so. In fact, three new coal mines have been approved by the Commonwealth environment minister in the last two months. The Australian government has said that because this coal is intended for export and not domestic consumption, it is not Australia's responsibility to discontinue mining. The responsibility for the emissions coming from burning this coal, according to the government, should rest with the countries that buy the coal. While this may be true in a technical sense based on international carbon accounting rules, it is a missed opportunity in terms of Australia’s leadership on climate action.

Every country must design its own plan for mitigating and adapting to climate change because every country has different industries, energy profiles, and geography. For example, some countries have been able to commit to net-zero carbon emissions for their energy sector because they rely on nuclear power.

That said, there are examples from many countries of how Australia can transition away from high-emissions policies. The UK has committed to the largest emissions reductions. It is committing to a 68% reduction by 2030, 78% by 2035 and net-zero by 2050. This is significant because these commitments clearly require strong action now, not just a commitment to net-zero by 2050 all the action being put off until 2049! The EU has committed to emissions cuts of 55%, on 1990 levels and has made these targets legally binding. The United States has also significantly increased its climate ambition. These are the commitments that Australia will be pressured to strive for at the November COP.

There are so many potential examples of good practice. Many countries, including Belgium and the UK, have either ended or committed to ending coal-fired power. Denmark has some of the best renewable energy policies. Sweden is the largest per-capita contributor to the Green Climate Fund (to help developing countries with the costs of adaptation and mitigation). The United States offers significant tax incentives to encourage the uptake of electric vehicles and states like California have strong car emissions standards.

Finally, it’s worth pointing out that Australia has much that it can share with the world. Our researchers are world leaders on many aspects of climate change science and adaptation, and we have already started trialling carbon-negative agricultural techniques. We can also learn from our own past. Australia did have an excellent framework in place when Julia Gillard introduced the carbon price back in 2011. In the year that it operated it already started to bring down emissions because emitters realised it was going to be cheaper in the long term to transition than to keep paying to be able to emit. It was repealed by the Abbott Government and emissions have been rising ever since.