国际能源署(IEA)在一份报告中称,热泵的普及可以加快中国高碳排的建筑和轻工业在用暖过程中的脱碳。

这份与清华大学合作发布的报告认为,由于使用热泵可以提高电气化程度并改善能效,因此如果把使用热泵作为中国实现2060年碳中和战略的一部分,为建筑供暖而产生的直接碳排放量到2025年将下降75%,降至7000万吨二氧化碳(MtCO2)。
同样,使用热泵也有助于减少为轻工业生产提供热量而产生二氧化碳排放。这可以将直接排放量从目前的1.1亿吨二氧化碳,减少到2050年的1000万吨二氧化碳以下。
2023年,中国是少数几个热泵总销量上升的国家之一。然而,报告指出,热泵的普及和建筑、轻工业向使用更多低碳能源的转型仍需要更多政策支持。
中国在供热方面消耗了多少能源?
2022年,中国的终端能源消费量为107艾焦(EJ)。国际能源署报告称,这其中热力消费量约为50艾焦。中国热力消费量相当于全球热力消费总量的“约三分之一”。
中国约四分之一的热力用于建筑业,其余用于工业。
在建筑领域,过去十年中国的热力消费增长速度超过任何其他国家,在2022年达到12艾焦。这主要是由于空间和水的用热需求不断增长,自2000年以来,直接和间接排放量增加了“近三倍”。
自2010年以来,用于供热的煤炭消费量总体下降了15%。国际能源署的报告将此归功于2010年代中期开始的政策推动。这些政策最初是“为了改善空气质量,后来是为了扩大清洁低碳能源的供暖”。
然而,区域供热——即集中供热机制——是一个例外。它是中国北方城市地区的主要热源。热泵和其他分散式解决方案在中国南方和北方农村地区更为常见。
中国北方的区域供热网络80%以上的热量生产来自煤炭。据国际能源署称,这是全国建筑供热中煤炭消耗的主要驱动因素。
2019年的一项研究发现,中国仅区域供热的碳排放量就超过了英国的二氧化碳排放总量。
该报告的主要作者基亚拉·德尔马斯特罗(Chiara Delmastro)博士和拉斐尔·马丁内斯·戈登(Rafael Martinez Gordon)博士告诉Carbon Brief:“(这)主要是由于中国北方城市(供热)网络扩张的推动,特别是……自2010年以来,区域供热网络的长度增加了250%,其中绝大部分在北方。”
不过,德尔马斯特罗和马丁内斯·戈登也指出,“中国近年来已经采取行动,朝着更清洁、更高效的供暖方向发展”——例如,从使用燃煤锅炉向更高效的热电联产电厂转型。

同时,2022年的工业用热总量为38艾焦。其中部分需求为中低温热力(低于200°C),这通常是轻工业、纸浆和造纸行业,以及一些化工行业工序所需的。
报告称,2022年这些中低温热力的需求量为4.7艾焦,直接碳排放量超过1.1亿吨二氧化碳,它可以通过现有最先进的热泵技术轻松满足。
然而,超过80%的工业供热需求需要200°C以上温度,这样的高温主要用于钢铁制造。其他需要如此高温的行业包括非金属矿物和有色金属,以及化工和石化、纸浆和造纸行业的一些流程。这些行业是工业供热需求的大用户,在2022年的消费量为33艾焦。
热泵如何帮助中国实现“双碳”目标?
中国建筑业和工业的供热需求主要由煤炭驱动,占中国煤炭消费量和二氧化碳排放量的40%。
不过,国际能源署也指出,煤炭供热量已略有减少,这主要归功于“改善空气质量、减少二氧化碳排放和最大限度提高能效的政策”。
2022年,在中国建筑的直接排放中,空间和水用热产生的碳排放量占绝大多数,约为2.9亿吨二氧化碳,而轻工业用热产生的直接排放总量为1.1亿吨二氧化碳。据国际能源署预计,中国2022年碳排放总量达到121.35亿吨二氧化碳。
该报告提供了在已宣布承诺情景(APS)下中国热泵使用量的估算。在该情景下,政府被假定会按时、全面地实现其所有气候目标。
报告还考察了既定政策情景(STEPS)下的热泵使用量情况,其反映了国际能源署自己对政府政策当前走向的判断。
如果中国坚持其“双碳”承诺、与已宣布承诺情景保持一致,那么国际能源署预计到2050年,建筑业热泵的装机容量将增至1400吉瓦(GW),可满足中国在该行业四分之一的用热需求。
根据已宣布承诺情景,到2050年,中国建筑行业每年将安装100吉瓦的热泵,相当于“美国、中国和欧盟在2022年部署的总容量”。
到2050年,建筑供热的排放量将从2.9亿吨二氧化碳降至8000万吨,减少2.1亿吨,其中热泵的贡献占到了30%。建筑业脱碳的其他驱动力还包括更多地采用电气化、能效措施和行为改变。
在轻工业方面,根据已宣布承诺情景,在2025至2050年间,中国每年将新增热泵装机容量约1.5吉瓦,可以在2050年满足五分之一的用热需求。
这将有助于“大幅”减少碳排放,其总量将从逾1.1亿吨二氧化碳锐减95%至1000万吨。电气化(包括通过采用热泵)将贡献减排量的70%。

报告还指出,有两个高耗能行业非常适合使用热泵:其一是纸浆和造纸行业,其目前约55%的用热需求可由工业热泵提供;其二是化工行业,该行业约18%的需求可由工业热泵提供。
然而,热泵不太可能满足其他高耗能行业的需求,因为“目前只有少数能满足200摄氏度以上温度的早期原型机,所有这些都远未为大众市场做好准备”。
即使在既定政策情景下,中国建筑行业中的热泵存量也将翻一番,到2050年将超过1100吉瓦,并推动建筑业排放量减少25%以上,煤改气等燃料转换措施也将发挥作用。
对于轻工业而言,在既定政策情景下,由热泵推动的碳减排 “仍然有限”,因为在当前的政策背景下,热泵的“部署可能比较缓慢”。总体而言,到2050年,与热力相关的排放量只会减少15%。
报告称,重要的是,在已宣布承诺情景下,中国和世界其他国家为实现气候目标所需的政策将“极大地调动”某些行业的积极性。采矿和机械等行业需要扩张,提高清洁能源技术产量,以满足国内和全球需求。
虽然与既定政策情景相比,这些新增工业活动将使已宣布承诺情景下中国的用热需求增加5%,但更广泛地应用电气化和清洁供热技术所节省的能源将足以抵消相关排放量。
此外,报告还指出,热泵的部署将使到2050年供热的能源强度(即单位热量的能源需求)比现在下降20%。
报告还补充称,随着更多可再生能源和核能发电并网,到2030年,热泵使用的扩张与电力系统去碳化之间的配合将使供热用电的间接排放量下降40%以上。到2050年,电力在供热中的份额可能超过75%。
例如,国际能源署指出,如果中国的气候目标得以实现,纸浆和造纸行业“到2050年将几乎完全淘汰”煤炭使用。由于电气化和煤改气,该行业已将煤炭在其能源需求中所占比例从2010年的43%减少到2022年的10%。
根据已宣布承诺情景,到2030年,中国用于空间和水供热的直接煤炭使用量将下降75%,到2040年将“几乎完全淘汰”,到2050年,热泵将成为城乡供热的关键技术。
然而,在这种情景下,需要大量投资才能部署足够的热泵来满足需求。
热泵在中国的应用效果如何?
报告称,在2023年,中国建筑业热泵装机容量超过250吉瓦,该国热泵销量占全球的25%以上,是2023年唯一热泵销量出现增长的主要市场。2022年,热泵占中国建筑业供热设备销售总量的8%。
在华中和华南部分地区,在没有集中区域供暖的情况下,热泵已成为建筑空间供暖和制冷的“常态”。报告补充说,由于当局通过政策支持鼓励农村地区限制煤炭消费,农村地区正在越来越多地采用热泵。
区域供热的情况也是如此,集中供暖管网运营商们正在越来越多地安装热泵。虽然大多数是在相对较低温度下运行的“空气源”热泵,但一些运营商也开始安装大型热泵,以回收钢铁厂、污水处理设施和煤化工工厂的废热。
报告称,这些热泵“为区域供热网络、建筑和工业提供了热力脱碳最有效的选择之一”。
目前中国单个热泵每年的碳排放量——无论是直接排放还是间接排放——都比燃气锅炉低30%以上。报告称:“从化石燃料锅炉转向热泵将减少几乎所有安装场所的二氧化碳排放”。
国际能源机构称,尽管热泵的前期安装成本较高,但它能帮助用户在使用期内节省能源开支。
下图显示了中国不同的气候带。在一些气候寒冷以及夏热冬冷的地区,空气能热泵比燃气锅炉和电加热器更具成本效益。

空气-水热泵比电取暖器更省钱,尽管在电价比天然气更有竞争力的地区,它们只比燃气锅炉便宜。
在高耗能行业中使用热泵的可行性较低,因为目前产生200°C以上高温的技术基本上仍在开发阶段。
但报告指出,对轻工业而言,工业热泵比燃气锅炉和电锅炉“便宜得多”,并且由于高能效,在其使用寿命内成本几乎可以与燃煤锅炉相媲美。
尽管如此,由于前期安装成本高昂以及公众对热泵的有效性缺乏认识,热泵的使用并不普遍。
德尔马斯特罗和马丁内斯·戈登告诉Carbon Brief:“在某些流程中,(热泵)的替代技术可能成本更低且更合适,而且不同的政策决定可能会刺激热泵应用的广泛性。但为了实现中国的碳中和目标,我们估计到2050年,热泵需至少满足轻工业20%的热力需求。”
该报告补充说,最先进的热泵——新发布或即将发布的热泵技术——能够很好地满足建筑领域和轻工业领域的用热需求,理论上可满足约40%的需求。
此外,中国目前浪费的热能资源可以通过热泵进行再利用。报告称,2021年,中国的核电站、其他发电厂、工业活动、数据中心和废水等来源产生了45艾焦的废热资源,几乎相当于建筑和工业用热需求总和。
政策如何支持热泵的应用?
作为能源转型的一个方面,热泵在中国国家级能源和气候政策中出现的频率“日益增加”。例如,《“十四五”现代能源体系规划》(2021-2025)要求提升终端用能低碳化电气化水平。
然而,德尔马斯特罗和马丁内斯·戈登解释说,国际能源署报告中更有针对性和实用的政策建议“应该(被纳入)一个明确的供热脱碳国家行动计划中,而这正是中国目前所缺乏的”。
该计划将使中国能够为热泵的使用设定量化目标,向市场发出明确信号,并促进对研发、制造和部署的更广泛投资。

与此同时,报告还建议:对新建建筑提出更严格的性能要求、制定更严格的能效基准、在建筑规范中纳入热泵安装要求,以及将国家碳排放权交易体系范围扩大到工业领域,这些都可以推动热泵的应用。
报告补充称,贷款、税收抵免和其他财政支持机制可以解决消费者不愿支付高昂的前期安装费用的问题。
北方城市天津为购买空气源热泵的用户提供了2.5万元(3700美元)的补贴,但这种做法(尤其在城市地区)并不普遍。
报告说,提高人们对工业热泵益处的认识并降低工业用电成本,可加快轻工业对热泵的采用。
电价激励措施已促使农村居民区从煤炭供暖转变为天然气供暖。根据国际能源署的计算,在北京的农村地区,类似的电价激励措施以及对安装热泵的补贴意味着热泵已成为当地家庭最便宜的取暖选择。
报告指出,在全国范围内推广这一政策可以“进一步提高热泵在目前电价明显高于天然气的地区的竞争力”。
其他可使热泵对消费者更具吸引力的措施包括,将热泵与太阳能电池板或太阳能光热解决方案相结合,以及调整电力系统以提供阶梯电价和分时电力市场措施。
最后,报告称,更多地回收废弃能源并结合热能储存技术,可以“通过将多余电力……转化为热能并储存起来供冬季供暖使用,从而优化供热”。
报告补充说,“以河北北部为例,到2050年,热泵从可再生能源和废热中回收的热力可占到冬季区域供热量的80%”。
The post 国际能源署:热泵可帮助中国减少75%为建筑供暖而产生的碳排放 appeared first on Carbon Brief.
Climate Change
Pawa in Palau
This week our powerful Pacific team is in Palau for the Pacific Islands Forum Leaders Meeting. This is a major moment in our campaigns for Pacific climate justice and to stop deep sea mining. So what’s it all about, what can we expect over the coming days, and why is this year’s meeting in particular so important? Read on to find out!
*Pawa is Melanesian word meaning collective power.
Meet Moemoana Schwenke, our Pacific Climate Campaigner
“When you love something deeply, you do everything you can to protect it.”
What is the Pacific Islands Forum (PIF)?
The Pacific Islands Forum, or ‘PIF’, is our region’s most important political organisation. It is where countries of the Pacific — including Australia and New Zealand — come together to collaborate on shared challenges and to set collective goals.
The PIF Leaders Meeting is an annual weeklong event that includes a dedicated meeting of the Pacific’s small island developing states (PSIDS), many special side events organised by Pacific civil society, the leaders’ meeting itself, and more. At the end of the week, leaders issue a Forum Communiqué, capturing what they have agreed on, their shared priorities and the actions they will take together.
This year’s meeting is being held in the beautiful northern Pacific nation of Palau, the same place our Pacific team gathered back in January to plan for the year.

What’s at stake this year?
Climate change has dominated the PIF for decades. Pacific leaders have been crystal clear it is their number one priority, and the annual gathering is the moment they can exert maximum pressure on Australia over its fossil fuel record.
The voyage to COP31
This year’s meeting comes less than three months before COP31, where Australia will take on the role of President of Negotiations — a role it has committed to undertaking in partnership with the Pacific — and less than a month before the ‘Pacific Pre-COP’, to be held in Fiji and Tuvalu.
Following a fraught round of mid-year negotiations in Bonn, PIF leaders will need to set out a clear vision and priorities for COP31. These include accelerating a just global transition away from fossil fuels, defending science as the foundation of international climate cooperation, and increasing the availability and accessibility of finance for renewable energy and climate adaptation.

Accountability for Australian fossil fuel exports
Since the last PIF Leaders Meeting, Australia has signed the Belém Declaration on the Transition Away from Fossil Fuels. The declaration reaffirmed the legally binding commitment to help limit global warming to 1.5°C and recognised that this is incompatible with new fossil fuel production. Yet, Australia has continued to approve new coal and gas projects, including at least five since the last PIF Leaders Meeting.

What is Greenpeace doing?
We’re going big this year, taking six members of our team to Palau to support Pacific leaders to hold the line, hold Australia accountable, and show the world what’s at stake. We’ll lobby leaders, hold press conferences, share our messages with the world, and support our incredible local partners in Palau.

How can you get involved?
PIF is the first in a drumbeat of major moments where we’ll be carrying the voices of the Pacific to the world. Come October we’ll be voyaging to Fiji on our ship Oceania for the Pacific Pre-COP, and in November we’ll be off to Antalya for the world’s climate negotiations (COP31).
Learn more about the Pacific way to a fossil fuel free future by checking out our report and exhibition.
Follow our journey, and check back here for more ways to join the movement for climate justice. Together we have the pawa!
Climate Change
From firefighting to future-proofing: Preventing wildfires must be the priority
Gill Einhorn is head of the Forest Future Alliance and Natalie Çilem is community lead of the Global Wildfire Leadership Network.
Wildfires have devastated communities across the world this summer, claiming lives, displacing thousands of people and leaving billions in economic damage in their wake. In Europe alone, wildfires have already caused an estimated €19 billion in losses this year.
They are an economic, financial and public health challenge that is growing faster than many governments and markets are prepared for – and exposing the real costs of poor land management.
A system built for recovery, not resilience
Far more money is currently spent responding to the disastrous effects of wildfires than preventing them in the first place. The United Nations Environment Programme estimates that more than half of wildfire-related spending goes towards response, while planning receives only around 0.2 percent. This problem is not limited to wildfires; over 95 percent of disaster aid between 2005 and 2017 was allocated to response, and less than 4 percent was directed towards prevention or preparedness.
Forests are critical, but without investment in how land is managed and protected, their value is neither stable nor guaranteed. Protecting forests requires investing not only in conservation, but in the conditions that keep forests standing.
Each dollar invested in wildfire-resistant construction could save around $210 in avoided future economic losses, according to a report by the World Economic Forum and Forest Future Alliance. Despite this evidence that prevention can significantly reduce future costs, wildfire resilience remains chronically underfunded.
This spending discrepancy is creating significant challenges for insurers, asset owners and financial institutions. Global insured losses from natural catastrophes reached $107 billion in 2025, with wildfires, floods and storms accounting for 92 percent of claims.
In this context, insurers are reassessing where and how they are willing to underwrite risk. Around 56 percent of global wildfire losses between 2000 and 2023 were uninsured. In some high-risk areas, insurers are scaling back coverage altogether, leaving homeowners, businesses and governments to shoulder a growing share of the costs – making it increasingly difficult to break even.
Proven solutions are already paying off
In many regions, wildfires are driven not by natural causes but by the deliberate clearing of land for agriculture. Degraded landscapes are becoming drier, more flammable and increasingly vulnerable to catastrophic loss, creating a vicious cycle of deforestation, economic damage and rising emissions.
The answer is not simply stronger firefighting capacity. Governments, investors and businesses must work together to shift capital upstream into prevention, resilience and long-term landscape stewardship of healthy forests. That means planting appropriately, investing in heat-resistant species, exploring approaches that minimise fire footprints through active management, and exploring the AI and technology solutions that are burgeoning.


Solutions to this already exist and are proven to have an impact. Following devastating wildfires year-on-year, Portugal shifted its approach to wildfire management, increasing prevention spending within its national rural fire management system from around 20 percent in 2017 to approximately 60 percent in 2022. While many countries remain locked in a reactive cycle of disaster response, public policy can shift investment upstream and make resilience a priority before fires occur.
Indigenous communities have long used proactive land stewardship to reduce wildfire risk while supporting healthy and productive landscapes. For example, the Cheslatta Carrier Nation in British Columbia traditionally managed fuels through cultural fire practices but now implements mechanised fuel removal methods under commercial agreements. By combining Indigenous stewardship with sustainable forest management, Cheslatta is generating community benefits while also boosting wildfire prevention.
Resilience can also be strengthened through finance and technology. FireSat, a partnership led by Earth Fire Alliance with Google.org, the Gordon and Betty Moore Foundation and Muon, is a satellite constellation designed for rapid wildfire detection. Scanning every 20 minutes, it can detect fires 400 times smaller than current systems and track them through smoke and darkness in almost real time. In California alone, FireSat could prevent up to 350,000 acres from burning each year. It has recently received significant new investments allowing it to expand towards a constellation of more than 50 satellites that will monitor every point on Earth every 20 minutes or less.
In Brazil’s Pantanal, the Embrace the Forest initiative uses AI-powered detection towers across 2.5 million hectares to support earlier intervention and faster response. During the severe 2024 fire season, the initiative contributed to a 40 percent reduction in burned area compared to 2020.


These examples illustrate what is possible when resilience is treated as an investment priority rather than a recovery cost. But we must ensure funding for these measures is scaled before disaster strikes. Initiatives like the Global Wildfire Leadership Network (GWLN) are key, bringing together corporate decision-makers, investors, insurers, governments and Indigenous leaders to direct investment towards prevention and align finance, technology and stewardship to protect nature, safeguard communities and strengthen future economic stability. With a goal of doing more together than the sum of our parts, the network focuses on Forest Future Alliance GWLN Solutions Labs – where partners sign up with the intent to collaborate.
Rewarding prevention
Financial incentives must be created that reward prevention. This can be done by scaling public-private partnerships, supporting long-term landscape stewardship, investing in community capacity including Indigenous wisdom and technology. Ultimately, our terrestrial natural reserves are critical infrastructure that support resilient economies and thriving communities.
One in three people are dependent on forest services, goods and economic opportunities for survival, so it’s in all our interests to protect what we have. Forests support cooling, water and food security – and are a very cost-effective way of removing carbon dioxide from the atmosphere, where done appropriately.
UN chief warns climate crisis “in overdrive” as El Niño threatens to fuel the fire
No sector can solve this challenge alone. The benefits of wildfire resilience are shared across communities, governments, insurers, investors, utilities and businesses. A single intervention can protect homes and livelihoods, reduce insurance claims, secure water supplies and lower future public costs. Because the benefits are shared, the solutions must be too. Coalitions of actors can take proven approaches further than any one individual or organisation could alone.
As wildfires continue to burn at an unprecedented scale, the opportunity now is to roll out solutions, shift investment upstream and build a future where resilience, rather than recovery, becomes the foundation of thriving economies.
The post From firefighting to future-proofing: Preventing wildfires must be the priority appeared first on Climate Home News.
From firefighting to future-proofing: Preventing wildfires must be the priority
Climate Change
Guest post: Why tough methane cuts are crucial for keeping warming ‘well-below’ 2C
Methane is a powerful greenhouse gas and the second-largest contributor to global warming after carbon dioxide (CO2).
Methane traps heat in the atmosphere more efficiently than CO2, but has a significantly shorter lifespan, fading after just a few decades.
Therefore, reducing emissions of methane – a gas primarily produced by agriculture, fossil fuels and waste management – is a powerful option for limiting global warming in the near-term.
Yet climate strategies and models often only focus on CO2, or combine all greenhouse gases into one metric known as “CO2 equivalent”.
The latter approach makes reducing methane emissions dependent on modelling choices and assumptions about the “equivalence” of methane and CO2.
It hides the opportunities and challenges linked to methane’s high warming and short lifetime.
In a new study, published in Communications Earth & Environment, we offer a different perspective that “decouples” CO2 and methane reduction and takes global warming limits as a starting point for determining the required level of methane cuts.
We show that, even under the most ambitious existing national net-zero targets, an absence of methane reduction leads to peak warming that exceeds 1.85C above pre-industrial levels.
The study highlights that, to limit peak warming to well-below 2C, net-zero CO2 targets must be complemented by stringent methane emissions cuts.
CO2 equivalent
How much methane corresponds to one tonne of CO2?
The question is as difficult to answer as: ‘how much spaghetti equals a chicken?’ You could compare the two meals according to their calories, protein content or cost. Each metric can be convenient, but is only valid for that specific comparison – no amount of spaghetti is the same as a chicken.
The same is true for the conversion of emissions of methane and other gases to CO2-equivalent emissions. It can be convenient, as it allows different gases to be compared or combined into a single number. This is why the metric is used in climate targets or evaluating the effectiveness of different mitigation options.
But, because methane and CO2 have different atmospheric lifetimes and warming properties, any conversion is only valid for a chosen time horizon and a chosen baseline.
Depending on the assumptions baked into calculations, methane mitigation can either appear as an immediate priority or framed as almost unnecessary.
There are a number of metrics that scientists use to convert greenhouse gases – whether methane, hydrofluorocarbons or nitrous oxide – into CO2-equivalent emissions:
- “GWP20” measures how much heat a greenhouse gas traps in the atmosphere over a 20-year period, relative to CO2. It emphasises urgent methane mitigation but has been criticised for its implicit discounting of future damages.
- “GWP100” looks at a 100-year timeline. It gives more weight to long-term warming and is used in “integrated assessment models” (IAMs) used by scientists, national emission reporting to the UN and by the GHG Protocol used by companies.
- “GWP*” considers the rate of emissions, rather than warming over a fixed time horizon. Under GWP*, very limited methane reductions bring CO2-equivalent emissions to zero, meaning remaining methane emissions can be designated as causing “no additional warming”. (This interpretation remains controversial as it assumes the continuation of historical levels of warming.)
IAMs are the tools used to generate future emissions scenarios. Because they combine CO2 and methane emissions, the impact of methane emission cuts alone is difficult to isolate in existing emission scenarios.
IAM-generated scenarios also assume mitigation decisions driven by costs. Combinations of CO2 and methane emission pathways that are not purely cost-effective are, therefore, not represented, even though climate policy is messy and emission pathways are rarely cost-effective in the real world.
Only a few countries – including Japan, Mexico and South Korea – specify methane mitigation targets.
A different approach
In our study, we separate CO2 and methane emissions and treat them as independent.
Instead of choosing a conversion method, we suggest that states and organisations set a limit on peak global warming first, then, based on their existing net-zero targets, determine the minimum compatible methane reduction target.
Companies and countries around the world have set net-zero targets focused on CO2, as well as those that include all greenhouse gases. As a result, our research looks at the necessary methane reductions for both types of goal. We consider scenarios where companies or countries deliver linear – in other words, steady – emissions reductions to reach net-zero.
Using a simple climate model, we systematically combined methane and CO2 (or greenhouse gas) mitigation pathways starting in 2025 and calculated peak warming.
The figure below shows how peak warming depends on both the year of reaching net-zero CO2 and the level of methane cuts.
The blue arrows in the figure show that to limit warming to 1.7C under a 2050 net-zero CO2 scenario, methane emissions would need to fall by at least 69% by 2050, relative to 2020.
Our research also finds that, if an organisation or country’s 2050 net zero-target covers all greenhouse gases, its methane emissions would need to fall by 63% instead.
However, under current policies, methane emissions are expected to increase by around 20% by 2050, relative to 2020. We find that this pathway would result in peak warming above 2C by 2050 – even if global CO2 emissions were to reach net-zero by that date (see purple bar on the right-hand side of the figure above).
The figure also shows how, if methane emissions remained at 2020 levels and net-zero CO2 was delivered by 2040 or later, warming would exceed 1.85C. This level of warming is above what has been argued as consistent with the Paris Agreement’s “well-below” 2C limit.
Conversely, cutting methane emissions by around one-third – in line with the Global Methane Pledge target for 2030 – could reduce peak warming by 0.15C, of which 0.05C could be delivered by interventions that come at no net cost. These are shown by the orange and red bars, respectively, on the figure above.
The table below highlights the minimum compatible methane cuts for three different peak warming levels and net-zero CO2 or greenhouse-gas emission targets.
| Peak warming | Year of net-zero CO2 emissions | Year of net-zero greenhouse-gas emissions | ||||
| 2050 | 2060 | 2100 | 2050 | 2060 | 2100 | |
| 1.7C | -69% | – | – | -63% | – | – |
| 1.8C | -32% | -56% | – | -11% | -47% | – |
| 2C | +8% | -8% | -83% | >50% | +33% | -78% |
Minimum methane emission reductions between 2020 and the year of net-zero emissions, consistent with peak warming of 1.7C, 1.8C, and 2.0C at 50% likelihood, assuming linear emission trajectories. For some net-zero targets and peak warming levels, there are no compatible methane mitigation targets (indicated by “–”).
Remaining carbon budget
The global carbon budget refers to the amount of cumulative CO2 emissions allowable while still meeting a particular global warming threshold.
The 2021 climate science report from the Intergovernmental Panel on Climate Change (IPCC) and a 2023 Nature study estimated that, by 2025, the remaining carbon budget for holding warming to 2C would be around 1,000-1,150bn tonnes of CO2 (GtCO2).
We find that these estimates are founded on the assumption of methane reductions of 27-35% by 2050, relative to a 2020 baseline. (A 2024 Communications Earth & Environment study reached similar conclusions.)
Under the GWP* metric, where methane emissions are only cut to maintain “no additional warming”, the remaining carbon budget would be constrained. The best estimate of a 2C budget shrinks by around 30% to approximately 750GtCO2.
Finally, if methane emissions are not cut at all in the future, our findings suggest that the remaining carbon budget for 1.7C of global warming has, in effect, already been exhausted.
Our analysis shows how peak warming depends on both CO2 and methane reduction – and how methane-specific targets can help refine existing net-zero targets.
Crucially, we show that complementing net-zero CO2 targets with stringent methane cuts is necessary to limit peak warming to well-below 2C.
Weber, K. et al. (2026) Limiting warming by CO2 and methane mitigation in an expanded scenario space, Communications Earth & Environment, doi:10.1038/s43247-026-03832-1
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The post Guest post: Why tough methane cuts are crucial for keeping warming ‘well-below’ 2C appeared first on Carbon Brief.
Guest post: Why tough methane cuts are crucial for keeping warming ‘well-below’ 2C
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