What Does "Net-Zero Emissions" Mean? 8 Common Questions, Answered
Editor's Note: This article was updated in March 2023 to include WRI’s latest research and information about new national net-zero targets.
The latest climate science is clear: Limiting global warming to 1.5 degrees C (2.7 degrees F) is still possible. But to avoid the worst climate impacts, global greenhouse gas (GHG) emissions will need to drop by nearly half by 2030 and ultimately reach net zero.
Recognizing this urgency, a rapidly growing number of national governments, local governments and business leaders are making commitments to reach net-zero emissions within their jurisdictions or businesses. To date, over 90 countries have communicated such “net-zero targets,” including the world’s largest emitters (China, the United States and India). On top of that, hundreds more regions, cities and companies have set targets of their own.
But what does a net-zero target mean, what’s the science behind net zero and which countries have already made such commitments? Here are answers to eight common questions:
1. What Does Net-Zero Emissions Mean?
Net-zero emissions, or “net zero,” will be achieved when all emissions released by human activities are counterbalanced by removing carbon from the atmosphere in a process known as carbon removal.
Achieving net zero will require a two-part approach: First and foremost, human-caused emissions (such as those from fossil-fueled vehicles and factories) should be reduced as close to zero as possible. Any remaining emissions should then be balanced with an equivalent amount of carbon removal, which can happen through natural approaches like restoring forests or through technologies like direct air capture and storage (DACS), which scrubs carbon directly from the atmosphere.
2. When Does the World Need to Reach Net-Zero Emissions?
Under the Paris Agreement, countries agreed to limit warming to well below 2 degrees C (3.6 degrees F), ideally to 1.5 degrees C (2.7 degrees F). Global climate impacts that are already unfolding under the current 1.1 degrees C (1.98 degrees F) of warming — from melting ice to devastating heat waves and more intense storms — show the urgency of minimizing temperature increase.
The latest science suggests that limiting warming to 1.5 degrees C depends on CO2 emissions reaching net zero between 2050 and 2060. Reaching net zero earlier in that range (closer to 2050) avoids a risk of temporarily "overshooting," or exceeding 1.5 degrees C. Reaching net zero later (nearer to 2060) almost guarantees surpassing 1.5 degrees C for some time before global temperature can be reduced back to safer limits through carbon removal.
Critically, the sooner emissions peak, and the lower they are at that point, the more realistic achieving net zero becomes. This would also create less reliance on carbon removal in the second half of the century.
This does not suggest that all countries need to reach net-zero emissions at the same time. However, the chances of limiting warming to 1.5 degrees C depend significantly on how soon the highest emitters reach net zero. Equity-related considerations — including responsibility for past emissions, equality in per-capita emissions and capacity to act — also suggest earlier dates for wealthier, higher-emitting countries.
Importantly, the time frame for reaching net-zero emissions is different for CO2 alone versus for CO2 plus other greenhouse gases like methane, nitrous oxide and fluorinated gases. For non-CO2 emissions, the net zero date is later, in part because models assume that some of these emissions — such as methane from agricultural sources — are more difficult to phase out. However, these potent but short-lived gases will drive temperatures higher in the near term, potentially pushing temperature change past the 1.5 degrees C threshold much earlier.
Because of this, it's important for countries to specify whether their net-zero targets cover CO2 only or all GHGs. A comprehensive net-zero emissions target would include all GHGs, ensuring that non-CO2 gases are also reduced with urgency.
3. Is the World on Track to Reach Net-Zero Emissions on Time?
No — despite the enormous benefits of climate action to date, progress is happening far too slowly for the world to hold temperature rise to 1.5 degrees C (2.7 degrees F). The UN finds that climate policies currently in place point to a 2.8 degrees C temperature rise by the end of the century.
4. What Needs to Happen to Achieve Net-Zero Emissions?
To achieve net-zero emissions, rapid transformation will be required across all global systems — from how we power our economies, to how we transport people and goods and feed a growing population.
For example, in pathways to 1.5 degrees C, zero-carbon sources will need to supply 98%-100% of electricity by 2050. Energy efficiency and fuel-switching measures are critical for reducing emissions from transportation. Improving the efficiency of food production, changing dietary choices, restoring degraded lands and reducing food loss and waste also have significant potential to reduce emissions.
Additionally, action must be taken to reverse course in cases where change is at a standstill or headed in the wrong direction entirely. For instance, efforts to phase out unabated coal remain well off-track and must decline six times faster by 2030. The world also needs to halt deforestation and increase tree cover gain two times faster by 2030.
It is critical that the structural and economic transition toward net zero is approached in a just manner, especially for workers tied to high-carbon industries. Indeed, the costs and benefits of transitioning to a net-zero emissions economy must be distributed equitably.
The good news is that most of the technologies needed to unlock net zero are already available and increasingly cost-competitive with high-carbon alternatives. Solar and wind now provide the cheapest power available for most of the world. Markets are waking up to these opportunities and to the risks of a high-carbon economy, and they are shifting accordingly.
Investments in carbon removal techniques are also necessary. The different pathways assessed by the IPCC to achieve 1.5 degrees C all rely on carbon removal to some extent. Removing CO2 from the atmosphere will compensate for emissions from sectors in which reaching net-zero emissions is more difficult, such as aviation.
5. How Many Countries Have Set Net-Zero Targets?
Global momentum for setting net-zero targets is growing quickly, with key economies like China, the United States, India and the European Union articulating such commitments. Bhutan was the first country to set a net-zero target in 2015. Now over 90 countries, representing nearly 80% of global emissions, are covered by a net-zero target.
Climate Watch’s Net-Zero Tracker shows how these targets were set, such as through nationally determined contributions (NDCs), long-term low GHG emissions development strategies (long-term strategies), domestic laws, policies, or high-level political pledges from heads of state or other cabinet members. The tracker also includes information on the scope of national net-zero targets, providing details about the GHGs and sectors covered by each, the extent to which the target relies on international offsets and more.
6. Does the Paris Agreement Commit Countries to Achieving Net-Zero Emissions?
In short, yes. Specifically, the Paris Agreement sets a long-term goal of achieving "a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century, on the basis of equity, and in the context of sustainable development and efforts to eradicate poverty." This concept of balancing emissions and removals is akin to reaching net-zero emissions.
The Glasgow Climate Pact, signed at COP26 and marking the five-year anniversary of the Paris Agreement, also emphasized the importance of setting ambitious net zero goals. The pact urges countries to move “towards just transitions to net zero emissions by or around midcentury, taking into account different national circumstances.” To this end, it encourages parties “that have not yet done so to communicate…long-term low greenhouse gas emission development strategies” that set the country on a pathway toward net zero. The shift from “in the second half of this century” to “by or around mid-century” reflects a notable increase in perceived urgency.
7. Why and How Should Countries Align Their Near-term Emissions Reduction Targets with Longer-term Net-Zero Goals?
Countries typically set net-zero targets for around 2050 — nearly three decades from now. However, to ensure that the world gets on the right track toward reaching net zero, those long-term objectives must guide and inform near-term action today. This will help avoid locking in carbon-intensive, non-resilient infrastructure and technologies. Countries can also cut near- and long-term costs by investing in green infrastructure that will not need to be phased out later, designing consistent policies and sending strong signals to the private sector to invest in climate action.
Under the Paris Agreement, countries agreed to submit climate plans every five years, known as nationally determined contributions (NDCs). NDCs, which currently target 2030, are an important tool to align near- and long-term emissions reduction goals. When informed by a country’s long-term vision, these documents can help governments implement the policies necessary today to realize an ambitious mid-century objective.
Many countries with net-zero targets are beginning to incorporate them directly into their NDCs, particularly now that the Glasgow Climate Pact “notes the importance of aligning nationally determined contributions with long-term low greenhouse gas emission development strategies.”
8. Are Net-Zero Targets a Form of Greenwashing?
Not necessarily, but they can be if used as an excuse to not take bold climate action in the near term.
Although net-zero targets continue to gain traction with governments and companies, skeptical voices have emerged, from academic journals to Greta Thunberg’s speech in Davos. Critiques of net-zero targets include:
The “net” aspect of net-zero targets could dampen efforts to rapidly cut emissions.
Critics are concerned that this could foster an overreliance on carbon removal, allowing decision-makers to use net-zero targets to avoid emission reductions in the near term. Decision-makers can address this concern by setting ambitious gross reduction targets (targets that do not rely on removals) alongside their longer-term net reduction targets.
Some countries’ net-zero targets rely on purchasing emissions reductions, delaying reductions within their own boundaries.
Some countries are setting net-zero targets that rely on carbon offsetting, which involves investing in or paying for emissions reductions from other countries to use toward their own targets. There’s concern that government leaders might use this strategy to avoid reducing their own emissions in the long term. Decision-makers can address this concern by setting deep emission reduction targets that explicitly avoid or limit using offsets to achieve their goals.
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The time horizon for net-zero targets — typically 2050 — feels distant.
Today’s infrastructure can last for decades and have a major impact on mid-century targets. Decision-makers must take this into account by establishing near- and mid-term milestones for their path to net-zero emissions, including by setting ambitious 2030 emission reduction targets as part of their NDCs. NDCs are subject to transparency and accountability mechanisms under the Paris Agreement that can foster implementation in the near term, which is critical for a long-term net-zero goal to be credible.
In short, net-zero commitments must be robust to be effective and advance climate action. Countries must take concrete steps to ensure this if they are to effectively address the challenge at hand.