In 2015, the Paris Agreement set a global goal to limit warming to well below 2 degrees C, while aiming for a limit of 1.5 degrees C. Achieving this goal and avoiding exceedingly dangerous levels of global warming requires slashing greenhouse gas emissions (GHG) in half by 2030 compared to today’s levels and reaching net-zero GHG emissions early in the second half of the century.
Even as countries confront the ongoing COVID-19 pandemic, efforts towards net zero show no sign of letting up. To date, 19 countries and the European Union have net-zero targets, and more than 100 others are considering adopting their own targets.
While setting a net-zero target can signal a serious commitment to long-term climate action, the devil is in the details. Several critical design factors determine the rigor of these targets and the extent to which they set a country on a plausible pathway to a net-zero future in accordance with the Paris Agreement.
Here are seven things countries need to do to design a robust net-zero target:
1. Develop Robust and Inclusive Processes
Achieving net-zero emissions will require fundamental shifts in how society operates. While there are significant opportunities associated with a zero-carbon future, there will be winners, losers and trade-offs along the way to achieving this vision.
Robust stakeholder processes play a critical role in surfacing and managing trade-offs, promoting societal buy-in and ensuring a just transition. Additionally, high-level political support and engagement with relevant ministries, parliaments, experts and the public can enhance a net-zero target’s prospects for withstanding future government changes. Independent expert bodies can also provide accountability and review design and implementation choices.
Governments should also consider the most effective legal status of the target. Depending on the national context, a law or other binding policy may be the best instrument to send long-term policy signals and drive changes in near-term decision-making.
Several countries — including Sweden, the United Kingdom, France, Scotland, Denmark and New Zealand — adopted formal legislation enshrining their net-zero targets. Legal commitment will help ensure that net-zero targets are transformative instruments that drive action towards realizing the goals of the Paris Agreement, rather than aspirational visions that fail to have any bearing on today’s decisions.
2. Cover All Greenhouse Gases and Sectors
The latest science shows that meeting the Paris Agreement’s temperature goals will require unprecedented changes across all sectors of the economy. It will also require significant reductions in all GHG emissions. Accordingly, a net-zero target should cover all GHGs and all sectors. With the exception of New Zealand, which excludes biogenic methane, all countries with adopted net-zero targets include all GHGs and domestic sectors in their targets.
Reducing emissions in some sectors may prove difficult based on current technologies, which provides an extra impetus to include all sectors in a net-zero target. Residual emissions can balance with removals in other sectors, such as carbon removal from the land sector.
Countries should also consider including emissions from international aviation and shipping, which occur outside of national boundaries, in their targets to reflect their highest possible ambition. The United Kingdom, for example, established a net-zero target that includes international aviation and shipping, but Norway and Sweden explicitly excluded these emissions from their net-zero targets.
3. Aim For Net Zero by Mid-century or Earlier
To limit warming below 1.5 degrees C, global CO2 emissions need to reach net zero by 2044, and global GHG emissions need to reach net zero by 2066. This does not mean that all countries will reach net-zero at the same time. For example, a small handful of countries already have net-negative emissions, while others aim to reach net-zero in 2050. For this to work, any net-positive emissions from one country in 2044 (CO2) and 2066 (GHGs) will need to balance out with net-negative emissions in another country.
Governments should therefore set net-zero targets for as early as feasible. Targets should also be consistent with global scenarios compatible with the Paris temperature goals. Countries with the highest emissions, greatest responsibility or capability — or a combination of the three — should adopt the most ambitious target time frames. Major emitters should adopt a time frame that is at least as early as the global time frame to achieve the Paris Agreement goals, and earlier still if they have high historical and per capita emissions and capacity to mitigate. Countries with a high capacity for reducing GHG emissions and removing carbon should supplement net-zero targets with plans to achieve net-negative emissions after achieving net-zero emissions.
Currently, countries with net-zero targets established a range of target time frames. Most countries reference specific years between 2030 and 2050, while others like Singapore and Japan use more general references to the second half of the century.
4. Include an Absolute Emissions Reduction Target
Countries should specify separate targets and pathways for reducing GHG emissions and achieving net-zero targets that reflect a balance of emissions and removals. If a net-zero target does not also specify the necessary GHG emissions reductions, meeting a net-zero target could rely on overly high rates of annual GHG removals to balance high rates of emissions. Uncertainty remains around the scale and availability of future carbon removals from land-based carbon sinks and emerging carbon-removal technologies. There are also ongoing risks of reversals and losses from carbon stored in land-based and geologic pools that could negate the climate benefit of carbon removals.
Distinct targets provide a clear road map for decarbonization, scaling carbon removals and achieving net-zero or net-negative emissions. For example, Sweden set a goal to achieve net-zero GHG emissions by 2045 and reach net-negative GHG emissions thereafter. Sweden also set a target for emissions from activities within the country in 2045 to be at least 85% below 1990 levels. This implies that CO2 removal within Sweden or investments in GHG mitigation in other countries can meet up to 15% of the 2045 target.
5.Avoid or Limit Offsets
Some countries adopted net-zero targets that reflect a balance of GHG emissions and carbon dioxide removals occurring within their national borders, without using offsets. France, for example, specified that it will not use international GHG mitigation to help reach its net-zero targets.
Other countries envision meeting net-zero targets in part through investing in or paying for emissions reductions or removal enhancements outside their territory. Sweden and Switzerland, for example, plan to use a limited amount of international GHG mitigation to reach their net-zero targets for 2045 and 2050, respectively.
Governments should prioritize reducing GHG emissions and enhancing GHG removals within their territory, rather than relying on international transfers of GHG mitigation to achieve net-zero targets. Doing so will maintain clear signals for domestic mitigation and investment and avoid locking in long-lived carbon-intensive infrastructure. If countries use international transfers of GHG mitigation to meet the target, they should establish limits to the amounts of transfers, ensure robust accounting and limit transfers to only surplus mitigation from other countries. To complement this approach, access to finance should be provided to developing countries to achieve their own GHG reduction, GHG removal and net-zero or net-negative goals.
6. Ensure the Target Informs Near- and Mid-term Climate Action
Countries should ensure that net-zero targets inform near- and mid-term climate action. This includes targets and policies, NDCs, development plans, investments and long-term low-emissions development strategies to support just transitions. For example, interim targets (e.g., to 2030 and 2040) set periodic milestones against which to measure GHG emissions and other indicators en route to achieving net-zero emissions.
Setting up short-term carbon budgets, which limit warming over a multi-year period, e.g., from 2030-2035, can also help ensure near- and mid-term action. France, New Zealand and the United Kingdom established short-term carbon budgets to facilitate coherence between shorter- and longer-term policymaking.
7. Be Transparent
Clearly communicating a net-zero target to domestic and international stakeholders is essential. Doing so will prevent genuine commitments to transform economic systems from appearing as political greenwashing. Net-zero targets should clearly provide information on the parameters of the net-zero target, including the GHG and sector coverage, time frame, decarbonization targets and, if applicable, use of international transfers and any limits.
Advancing Net-zero Targets
The COVID-19 pandemic presents a tremendous challenge as countries address an unprecedented health crisis, job losses, poverty and inequity. At the same time, the scale of investments dedicated to recovery presents and opportunity to create a net zero, equitable and just future while responding to the pandemic in an effective way. Despite current challenges, many countries are still embracing the goals of the Paris Agreement at the national level and seeking to adopt net-zero targets.
Decision-makers face several choices when designing net-zero targets. These choices should maximize the contribution of net-zero targets to drive decarbonization in a way that is commensurate with the scale of the climate crisis.
