Editor"s Note: This article was updated in May 2021 khổng lồ include mongkiemthe.com’s lachạy thử research & information about new national net-zero targets.
The lathử nghiệm research is clear: To avoid the worst climate impacts, global greenhouse gas (GHG) emissions will need to lớn drop by half by 2030 và reach net-zero around mid-century.
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Recognizing this urgency, a rapidly growing number of national government, local government và business leaders are making commitments to lớn reach net-zero emissions within their jurisdictions or businesses. To date, over fifty countries have sầu communicated such “net-zero targets,” including the world’s largest emitters (Đài Loan Trung Quốc & the United States). On top of that, hundreds more regions, cities và businesses have sầu phối targets of their own.
These numbers are climbing quickly, particularly because the U.N. Secretary General asked countries to lớn come forward with net-zero targets. The U.N. High Level Climate Champions’ Race to lớn Zero chiến dịch also calls on regions, cities, businesses, investors and civil society to lớn submit plans to lớn reach net-zero emissions by 2050 in advance of the United Nations climate negotiations (COPhường 26) in Glasgow in November 2021.
But what does a net-zero target mean, what’s the science behind net-zero & which countries have already made such commitments? Here are nine comtháng questions & answers about net zero:
1. What Does It Mean to lớn Reach Net-Zero Emissions?
Net-zero emissions will be achieved when all GHG emissions released by humans are counterbalanced by removing GHGs from the atmosphere in a process known as carbon removal.
First & foremost, human-caused emissions (such as those from fossil-fueled vehicles and factories) should be reduced as close lớn zero as possible. Any remaining GHGs should then be balanced with an equivalent amount of carbon removal, which can happen through things lượt thích restoring forests or using direct air capture và storage (DACS) giải pháp công nghệ. Reaching net-zero emissions is akin lớn achieving "climate neutrality."
The Special Report on Global Warming of 1.5˚C, from the Intergovernmental Panel on Climate Change (IPCC), finds that if the world reaches net-zero emissions by 2040, the chance of limiting warming to lớn 1.5 degrees C is considerably higher. The sooner emissions peak, & 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 lớn reach net-zero emissions at the same time. The chances of limiting warming to 1.5 degrees C, however, depend significantly on how soon the highest emitters reach net-zero emissions. Equity-related considerations — including responsibility for past emissions, eunique in per-capita emissions và capathành phố khổng lồ 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 GHGs lượt thích methane, nitrous oxide and fluorinated gases. For non-CO2 emissions, the net zero date is later because models suggest that some of these emissions — such as methane from agricultural sources — are more difficult lớn phase out. However, these potent but short-lived gases will drive sầu 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 lớn 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.
3. What Needs to lớn Happen to lớn Achieve sầu Net-Zero Emissions?
Policy, technology and behavior need to lớn shift across the board. For example, in pathways to lớn 1.5 degrees C, renewables are projected to supply 70-85% of electricity by 2050. Energy efficiency và fuel-switching measures are critical for transportation. Improving the efficiency of food production, changing dietary choices, halting deforestation, restoring degraded lands and reducing food loss & waste also have sầu significant potential lớn reduce emissions.
In some cases, emissions are actually getting worse. Despite tremendous acceleration in renewable energy, adoption will need lớn increase by a factor of five sầu lớn reach 2030 & 2050 goals. Current rates of renovation for both residential & commercial buildings, for instance, fall between 1% và 2% per year on average, whereas they need lớn reach 2.5-3.5% per year by 2030. And the world needs khổng lồ drastically slow deforestation và increase tree cover gain five sầu times faster by 2030.
5. How Many Countries Have sầu Net-Zero Targets?
Global momentum for setting net-zero targets is growing quickly, with key economies lượt thích China, the United States & the European Union articulating such commitments. Bhutan was the first country to mix a net-zero target in năm ngoái. Now over 50 countries, representing more than half of global emissions, have mix 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 (LTS), domestic laws,policies or high-màn chơi political pledges from heads of state or other cabinet members.
6. Why & How Should Countries Align Their 2030 Emissions-Reduction Targets with a Net-Zero Emissions Goal?
When beginning a journey khổng lồ reach net-zero emissions by mid-century, countries must pursue near-term action with their long-term objectives in mind. This will help avoid locking in carbon-intensive, non-resilient infrastructure & technologies. Countries can also cut near- và long-term costs by investing in green infrastructure that will not need lớn be phased out later, designing consistent policies và sending strong signals lớn the private sector khổng lồ invest in climate action.
Under the Paris Agreement, countries agreed lớn submit climate plans every five years, known as nationally determined contributions, or NDCs. NDCs are an important tool to lớn align near- & long-term goals. When informed by a country’s long-term vision, these documents can help governments implement the types of policies, signals, targets và other enhancement strategies necessary in the nearer term lớn realize an ambitious mid-century objective.
Many countries with net-zero targets are beginning to lớn incorporate them directly inkhổng lồ their near-term NDCs. These targets are also being expressed in many countries across other law and policy documents. The most advantageous action, ultimately, will be for countries to express their net-zero commitments in as many source documents as possible, including NDCs. This will make the target as durable và binding as possible, allowing for synergistic planning.
7. Does the Paris Agreement Commit Countries khổng lồ Achieving Net-Zero Emissions?
In short, yes. However, while the Paris Agreement establishes a global goal that implies reaching net-zero emissions, it was left unresolved when individual countries should reach that goal.
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, & in the context of sustainable development and efforts lớn eradicate poverty." This concept of balancing emissions & removals is akin lớn reaching net-zero emissions.
The Paris Agreement also commits governments to putting forward plans to sharply reduce emissions and ramp up efforts lớn reach net-zero emissions. The Paris Agreement’s invitation to countries to lớn submit long-term, low-emissions development strategies by COPhường. 26 is one opportunity for countries khổng lồ phối net-zero targets & chart how they ayên ổn khổng lồ make such transitions.
Ultimately, commitments to create bold short- và long-term targets that align with a net-zero emissions future send important signals to lớn all levels of government, the private sector and the public that leaders are betting on a safe & prosperous future.
8. Are Net-Zero Targets a Form of Greenwashing?
No, but they can be if used as an excuse lớn not take bold climate action in the near-term.
Although net-zero targets continue to gain traction with governments và companies, skeptical voices have emerged, from academic journals khổng lồ chiến dịch groups to Greta Thunberg’s speech in Davos. Critiques of net-zero targets include:a. The “net” aspect of net-zero targets could dampen efforts lớn rapidly cut emissions.
Critics are concerned that this could foster an overreliance on carbon dioxide removal, allowing decision-makers to use net-zero targets to lớn avoid emission reductions in the near-term. Decision-makers can address this concern by setting absolute reduction targets (targets that vì chưng not rely on removals) alongside their longer-term net reduction targets.b. 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 investing in or paying for emissions reductions from other countries khổng lồ use toward their own targets. There’s concern that government leaders might use this strategy to lớn 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 khổng lồ achieve their goals.c. The time horizon for net-zero targets — typically 2050 — feels distant.
Today’s infrastructure can last for decades và have a major impact on mid-century targets. Decision-makers must take this into lớn account by establishing near- and mid-term milestones for their path lớn net-zero emissions, including by setting ambitious 2030 emission reduction targets as part of their NDCs. NDCs are subject lớn transparency & 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 lớn be effective và advance climate action. Countries must take concrete steps khổng lồ set robust targets.