Connect with us

Published

on

漫步在有着中国“新能源汽车第一城”之称的深圳街头,你不会错过停放在路边的大量新能源汽车,以及宣传“绿色低碳”生活方式的标语。

深圳是一座紧邻香港的城市,有着1800万人口。这座城市因40多年前成为中国的改革开放试验田而闻名。

如今,它在碳减排方面也走在前列,是中国“低碳城市”建设的“试点”地区之一。

深圳是中国首个将公交车、出租车和网约车全部实现电气化的城市。2024年,深圳新车销量中有约77%为新能源汽车,远高于48%的全国平均水平。

深圳还率先设立了碳排放总量控制机制,推动“能耗双控”向“碳排放双控”转型——这比全国层面出台碳排放总量控制政策更早。

上微信关注《碳简报》

此外,深圳的地方性碳排放权交易市场(ETS)和“绿色债券”也都早于国家层面推出。

尽管深圳在碳减排领域很早就采取了措施,但一些专家对Carbon Brief表示,深圳的政策——这被当地政府称为“深圳模式”——很难在中国其他进行低碳转型的城市复制。

Carbon Brief回顾了深圳在低碳转型方面迄今为止所做的努力,并评估了其减排成效。

电动交通

官方智库中国(深圳)综合开发研究院财税贸易与产业发展研究中心主任韦福雷对Carbon Brief表示,深圳的低碳转型并非一蹴而就,而是建立在早期规划、政府支持和市场驱动相结合的基础上。

深圳的低碳转型始于21世纪初,当时该市的空气重污染天数达到峰值。

BBC新闻2017年的一篇报道称,经过十年的污染治理,深圳的空气污染程度“下降了近一半”。

报道称,这一成果很大程度上源于其“产业基础”的改变,也使深圳成为全国首批“低碳城市”之一。

这一时期,当地官员们制定了“低碳发展”战略,其中包括培育一批“战略性新兴产业”,如“信息通信技术”。这些产业后来为深圳包括新能源汽车行业在内的低碳行业提供了核心技术支持。

例如,目前全球领先的电动汽车巨头比亚迪,正是在这样的背景下诞生于深圳的。

韦福雷指出:“有了这种‘产业基因’,深圳只需把产业链重新梳理一遍,,就能快速满足新能源汽车行业(在2020年代)的新需求。”

尽管人口仅占全国约1%,但2025年深圳地方“两会”上的政府工作报告显示,该市在2024年的新能源汽车产量占到全国的22%。

报告同时称,深圳将在未来一年启动大约100个“气候投融资项目”,计划新增“绿色贷款”约1800亿元人民币(约合240亿美元)。

能源与清洁空气研究中心(CREA)分析师和中国团队负责人沈昕一对Carbon Brief说,深圳地方政府在扶持新兴产业方面经验丰富。

她说:“20年前,风电、太阳能发电,以及电动汽车,都还是需要大量投资和技术研发的新兴行业……当时的失败风险很高,但深圳市政府敢于推出很多创新政策加以扶持。”

新能源汽车企业的迅猛发展带动本地市场中新能源汽车占比持续上升。除了国家层面的补贴,地方政府也在生产和消费两端给予有力支持。

2024年,深圳销售的新车中约77%为新能源汽车,远高于48%的全国平均水平。

此外,深圳还率先实现了本市公交车、出租车和网约车全部电气化,是中国首个做到这一点的城市。

伦敦大学学院(UCL)可持续基建、经济与金融学讲师郑赫然向Carbon Brief指出,“更环保的交通车队”加快了深圳的低碳转型步伐,因为一座城市的低碳转型主要依赖两个关键方面——“交通转型”和“产业脱碳”。

他说:“一个城市在碳减排上的政策工具其实有限,但它可以推动更绿色的交通。比如,伦敦设立了超低排放区,鼓励人们使用公共交通和更清洁的车辆。城市也可以推动产业升级和减排,但这更难做到,因为很少有城市愿意放慢经济增长的步伐。”

郑赫然表示,深圳“与中国一些煤矿城市不同”,在产业转型方面具有“优势”,这使其可以设定“更具雄心”的排放目标。

New energy vehicles being charged at a charging area in China's Guizhou Province.
New energy vehicles being charged at a charging area in China’s Guizhou Province. Credit: Xinhua / Alamy Stock Photo

碳控机制

中国将能源强度和碳强度(即单位国内生产总值GDP的能源使用量和排放量)作为其气候政策的关键指标。

此外,自2016年以来,中国一直实行“能耗双控”机制,即同时控制能源消费强度和能源消费总量。但中国政府已经宣布将在2024年起转向“碳排放双控”机制。

新机制将对二氧化碳排放总量设定约束性上限,并将成为2030年后的主要目标,而2030年前的主要指标——碳强度——将逐渐成为次要目标。

在这一领域,深圳依然是先行者。据“对话地球”(Dialogue Earth)报道,早在2023年,深圳就已成为中国首个明确承诺实行“(碳排放)双控机制”的城市。

为此,深圳市在2023年发布了两份《实施方案》,同时设定了市级碳排放总量控制目标。

与国家层面的方案相比,深圳在进程上更具雄心,其目标是在2025年建立起市级“碳排放双控”机制,并计划于2026年至2030年“全面实施”。

其中一份方案提出:“力争到2028年实现深圳碳市场制造业基本采用碳排放双控方式开展配额分配工作……力争到2030年实现市场调节能力显著提升。”

深圳还计划到2025年底,将能源强度在2020年的基础上降低14.5%,高于同期全国13.5%的目标。

郑赫然表示,深圳的这些目标是“量力而行的”。他解释道:“(就中国整体而言)碳减排主要集中在三个领域——钢铁、水泥和电力。深圳没有大型钢铁或水泥产业,因此只需将重心放在电力领域……而且它也不属于化石燃料城市,不位于供应链上游,无需担心煤炭开采等业务。深圳的产业结构主要以‘高附加值’行业为主,比如科技和新能源汽车,这些行业的碳排放更容易削减。”

“此外,深圳是科技中心,很多高碳排企业已搬到周边城市,比如汕尾。这就是所谓的‘排放外包’,受益于此,深圳的绿色转型面临的障碍更少。”

去年,郑赫然和同事在《自然》杂志上发表了一篇有关中国城市间碳排放外​​包的研究,指出“一些城市从其他城市的碳减排成果中获得大于其自身的收益”,并建议政策制定者正视其影响。

他还指出,深圳与其他城市相比还有一个“巨大差异”:“深圳拥有自己的核电站”,而这对深圳实现电力转型具有“重要”意义。电力行业是深圳在当前低碳转型中需要着力的最后一环。

低碳能源

根据2021年的一份报告,大亚湾核电站是深圳“最大的本地电力来源”,总装机容量达6.1吉瓦(GW)。

2021年,核电在深圳总发电量中的占比达到35%。

这也拉高了深圳的低碳能源使用水平。2024年,深圳一次能源消费中约47%来自清洁能源。

对深圳而言,核能发电量远超其他并入城市电网的清洁能源来源。市政府在2025年工作报告中提到,当前本地太阳能发电装机容量约为1吉瓦,风电装机并未被提及。

《深圳市应对气候变化“十四五”规划》写道,由于本地能源资源匮乏,加之风电、光伏“受土地和资源限制”,可再生能源的增长空间“有限”。

与此同时,深圳对外来电力的依赖程度也非常高——约七成的用电从外部进口。

这种依赖限制了深圳对电力行业碳排放的掌控,也给本地电网在用电高峰期的调度带来压力。

2024年,中国批准在毗邻深圳的惠州建设更多核电机组。

根据2022年一份研究报告,深圳市政府计划“到2025年将天然气、核能和可再生能源在能源结构中的总占比从当前的77%提升至90%,远高于全国52%的平均水平”。

郑赫然表示,“深圳与邻近的香港非常相似,香港的能源转型也不依赖太阳能和风能的建设”。

他补充说,深圳和香港应充分发挥自身作为“金融城市”的优势,以实现可持续的能源转型。

Daya Bay (Dayawan) Nuclear Power Plant in Shenzhen city.
Daya Bay (Dayawan) Nuclear Power Plant in Shenzhen city. Credit: Imaginechina Limited / Alamy Stock Photo

“绿色金融”

韦福雷表示,深圳一直善于利用“市场机制”,“在政府支持与市场驱动之间”成功找到平衡。其中,企业“担任主力角色,承担了90%的工作”,政府只在必要时出手干预。

在政府干预较少的情况下,深圳早在2013年就成为全国首批建立碳排放权交易市场“试点”的七个省市之一,远早于2021年全国碳市场的上线。

和全国层面的碳市场类似,深圳的本地碳市场并不以绝对排放量为基准,而是根据企业的排放强度(即单位产值的碳排放量),为企业分配可交易的排放配额。

深圳本地的碳排放权交易市场启动时覆盖了全市约38%的碳排放量。国际碳行动伙伴组织(ICPA)在一份报告中指出,这一比例到2020年已经提升至50%,并将进一步扩大。深圳还宣布将从2027年起为碳排放设置“绝对上限”。

(目前,国家层面的碳市场也未设置排放总量上限,但这也将在未来有所改变。)

不过,咨询公司ClearBlue Markets分析师秦炎对Carbon Brief说,虽然深圳碳排放权交易市场的覆盖范围还在扩大,但许多试点地区的碳排放权交易市场正在“收缩”,因为越来越多企业选择退出地方市场,转而加入国家碳市场。

国际碳行动伙伴组织的研究也发现,自2019年深圳碳排放权交易市场“向国家市场过渡”以来,发电已不再被纳入深圳碳排放权交易市场。

尽管如此,秦炎强调,这些地方试点“仍是一个重要的试验田,为国家碳排放权交易市场的成功落地铺平道路。(它们)会继续存在,覆盖中小企业以及国家市场尚未涉及的行业”。

国际碳行动伙伴组织称,截至2022年,深圳的地方碳排放权交易市场涵盖了水利、燃气、供热、制造业和交通等多个行业。

根据《深圳商报》报道,截至2024年,深圳已拥有全国最大的地方碳排放权交易市场,年交易量连续多年居全国首位。

与此同时,深圳也在“绿色金融”领域积极布局,将私人投资引入市场。

2021年,深圳在香港发行了中国首支面向海外市场的“绿色政府债券”,并出台了中国首部地方性“绿色金融法规”。国际绿色金融研究所(International Institute of Green Finance)在一份对该立法的评估中指出,其为规范“绿色市场”提供了“坚实的制度保障”。

相比之下,中国的首支主权绿色债券自2025年4月起才向国际买家发行。

深圳还推出了多种“绿色金融”产品。据官媒《经济日报》报道,2024年上半年,沪深两地交易所内新能源、新能源汽车及其他环保相关行业公司的市值达约4.6万亿元人民币(约合6,330亿美元)。

不过,郑赫然表示,“绿色债券”的效果“很难评估”。他说:“有很多项目,比如污水处理,也可以被归入‘绿色债券’的范畴。”

据官媒中央电视台报道,深圳2021年发行的“绿色债券”涵盖了“普通公办高中建设、城市轨道交通和水治理”等项目。

郑赫然表示,这些项目虽然在一定程度上与提高能效有关,但它们对碳减排的直接影响仍“有限”。

他补充说,市场引导在一座城市的低碳转型中“不可或缺”,但“目前尚无关于绿色金融产品在减排方面能发挥多大作用的研究”。

沈昕一则指出,“金融工具”在支持低碳转型方面仍发挥着重要作用。

她说:“低碳产业的成本往往高于化石燃料相关行业……通过政策支持和金融工具,才能够规模化,成本才能够降下来。”

“深圳模式”

深圳地方政府和媒体将深圳在气候领域取得的成就誉为“深圳模式”,意在其可以被推广到其他地区。

深圳市生态环境局党组成员许化表示,在去年的联合国气候变化大会(COP29)上,这一模式“向世界展示了成果”:“一是持续完善顶层设计,坚持立法先行,构建政策体系……二是聚焦重点领域转型升级……将新能源、安全节能环保等战略性新兴产业纳入重点产业集群,培育赋能……三是坚持开放共享,探索绿色低碳发展新路径。”

许化补充说,深圳的“绿色发展水平走在全国前列”,截至2023年底,深圳的“万元GDP能耗、水耗、碳排放分别降到了全国平均水平的1/3、1/8和1/5”。

不过,沈昕一指出,深圳的发展路径并非完全“可复制”,因为“深圳抓住了时代的机遇”。

她对Carbon Brief说:“比如,深圳的产业链优势和技术工人的聚集,给其高端制造业提供了很好的基础。”

郑赫然也认同这一观点。他认为,深圳只能代表中国一种特定类型的城市。

“深圳就像中国的硅谷,在高端科技领域投入巨大。它只能代表一线城市这一(特定)类别的中国城市,比如北京、上海、广州。中国有三百多个城市,每个城市都面临着独特的转型形势。依赖煤炭的工业城市照搬深圳的做法并不现实。”

与此同时,中国的其他城市也开始探索各自的可持续发展之路。

苏州建成了中国首批低碳工业园区试点之一的苏州工业园区。当地还建立了“市场化碳普惠交易体系”,鼓励居民和中小企业“自愿”参与碳排放交易。

据新华社报道,天津也与新加坡开展合作,“探索城市绿色低碳发展路径”。

沈昕一表示,其他城市必须“因地制宜地制定策略”。这种理念也体现在国务院于2023年发布的《新时代的中国绿色发展》白皮书中。

该文件指出,地方政府要“依托资源环境禀赋和产业发展基础……充分发挥各地区比较优势。”

The post 解读:何为中国城市低碳转型的“深圳模式”? appeared first on Carbon Brief.

解读:何为中国城市低碳转型的“深圳模式”?

Continue Reading

Climate Change

‘Bloody dangerous territory’: UN report an indictment of govt climate inaction

Published

on

KOROR, PALAU, Wednesday 2 September 2026 — The new global heating projection by the United Nations Environment Programme (UNEP) has laid bare the dire realities of inevitable climate disaster, loss and damage for the Pacific and Australia in a 1.8°C world, with Greenpeace warning ‘we are now in bloody dangerous territory’, and must do everything possible to return warming to 1.5°C.

The report, Limiting Overshoot – Navigating exceedance of 1.5°C and pathways towards return, released as world leaders meet at this year’s Pacific Islands Forum in Palau, highlights the urgency of the climate crisis, the greatest security threat facing the Pacific. It comes as fracked gas from the Beetaloo Basin, one of Australia’s biggest climate bombs, began flowing for the first time.

Australia is the biggest polluter of all Pacific Islands Forum member states, far exceeding all other forum members combined. Greenpeace is calling on Prime Minister Anthony Albanese to centre Pacific priorities at the Forum, and walk the talk on climate solutions as a genuine family member of the Pacific.

Speaking from Palau, Shiva Gounden, Head of Pacific at Greenpeace Australia Pacific, said: “The latest UNEP report has printed in black and white that fossil fuel-hungry nations have overstepped, overshot and overindulged at the expense of Pacific lives, livelihoods, cultures and communities. This year’s Pacific Islands Forum has made it more apparent than ever that climate change is the region’s greatest security threat, and we cannot waste time on geopolitical power games when our world is sinking beneath our feet.

“As a person from the Pacific, I know our communities will not quietly accept these dire warnings of climate overshoot as our fate; we are already living and fiercely resisting this reality every single day. With every increment of warming, our lands, our livelihoods, and our island homes are threatened, but the Pacific’s resolve only grows stronger. We draw strength from our ocean and those who walked before us; our people are the protectors of the frontlines of climate change and the beacons of climate justice.

“By harnessing the natural power of our sun, winds, and seas through a rapid transition to renewable energy, and uniting in true global collaboration, we can steer back to 1.5°C – this is our moral, legal, and scientific imperative. A Fossil Fuel Free Pacific can breathe life back into the lungs of our islands.”

Also in Palau, Dr Simon Bradshaw, COP31 Lead and climate expert at Greenpeace Australia Pacific, said: “The UN report is warning that we are now in bloody dangerous territory. It lays bare the deadly consequences of reckless fossil fuel expansion, and a failure to listen to Pacific voices and to the decades of emphatic scientific warnings.

“It is a damning indictment of government climate inaction and negligence, coming just days after fracked gas from the Beetaloo Basin started flowing and Woodside’s disastrous Browse gas mega project undergoes Federal decision — two carbon bombs that would lock in decades of dangerous climate pollution and push us past the point of no return.

“Every new fossil fuel project pushes us closer to dangerous and irreversible tipping points in the climate system, with almost unimaginable consequences for the safety and security of communities in the Pacific, Australia and around the world.

“The task now is to minimise the magnitude, duration and consequences of any temperature overshoot. A pathway back to 1.5°C is possible but this pathway cannot be paved by fossil fuels.

“Accelerating the shift from fossil fuels to renewable energy, and working with our big energy partners across Asia to decarbonise together, is not only the path back from the climate brink, but also the key to our energy security and our future prosperity.”

Also in Palau, Vishal Prasad, Director of Pacific Islands Students Fighting Climate Change, said: “This report is terrifying for the young people of the Pacific. We know what 1.5, and what anything beyond it, means for our future, our families, our culture and our environment. 1.5 to stay alive has never been just slogan. It is our reality.

“The International Court of Justice has made it clear: keeping to 1.5 is not a choice, it is a legal obligation. Every new fossil fuel project drives us further from it. So we are not asking for your goodwill. We are not begging you. We are telling you what international law requires of you: end fossil fuel expansion. No new coal, no new oil, no new gas. Your corporate profits cannot be allowed to extinguish our future.”

—ENDS—

Greenpeace Australia Pacific has delegates from the Pacific and Australia at the PIFLM in Palau available for interview

Headshots can be found here

Media contact: Kimberley Bernard in Palau on +61407 581 404 or kbernard@greenpeace.org

‘Bloody dangerous territory’: UN report an indictment of govt climate inaction

Continue Reading

Climate Change

UN sets out narrow path back to 1.5C warming after inevitable overshoot

Published

on

Governments must slash emissions further and faster, and keep every climate promise they have made for the planet to be able to return to 1.5C of warming by the end of the century after an inevitable overshoot, a group of prominent climate scientists has said.

In a flagship new report sketching out a way not to lose the most ambitious Paris Agreement goal, the scientists said that global temperatures need to peak at no higher than 1.8C above pre-industrial levels to give the world “a fighting chance” to reverse course. They added that plans to suck carbon dioxide out of the atmosphere can only play a limited role in this effort and cannot substitute for emissions cuts.

A return to the 1.5C warming limit will only be reached in an optimistic scenario that sees governments turn their full national climate plans – known as NDCs – into reality and meet their additional, more ambitious targets to reach net zero emissions, said the report published by the UN Environment Programme (UNEP).

Actual government policy is far off that track. Current measures to cut emissions that are funded and in force put the world on course for around 2.8C of warming by 2100, UNEP has previously found.

Joeri Rogelj, professor of climate science and policy at Imperial College London and one of the report’s authors, said it is necessary to keep the temperature peak as low as possible as there are limits to how fast the world can reverse global warming.

That is because the scale of carbon dioxide removal (CDR) interventions that can be implemented sustainably and in a just way will otherwise not be sufficient and some measures, such as tree-planting or forest management, will be less effective at higher temperatures, he added. 

Commenting on the report, UN Secretary-General António Guterres called for the 1.5C overshoot to be “as small and short as possible”. This, he added, “demands an overshoot of ambition”, involving accelerating the phaseout of fossil fuels and pursuing the renewables revolution, slashing methane pollution, and protecting land, forest and oceans.

“Governments must over-deliver on national climate plans, net-zero commitments, and beyond,” he urged in a video message. “The fight for 1.5 degrees is the fight for humanity.”

Overshoot, peak and decline

The report comes out nearly a year after the UN conceded for the first time that it is inevitable that global warming will exceed 1.5C temporarily and the world should focus on making that overshoot as small and short as possible.

UNEP’s Executive Director Inger Andersen told journalists that 1.5C remains the key goal, but “we now need a different approach from above”, while stepping up efforts to adapt to a warming world.

“A return to 1.5C is not assured,” she added. “But limiting the magnitude, duration and consequences of overshoot, while preserving the possibility of bringing temperatures back down, is the best remaining option to protect vulnerable people, reduce losses and secure a livable future for all.”

Battle over cleaning up shipping set to resume at London talks

Scientists warn in the report that warming above 1.5C should not be seen as safe or acceptable. Climate risks above that threshold intensify with every additional fraction of a degree of warming, they said. The report paints a grim picture of expected climate impacts: glaciers could lose more than a quarter of their remaining mass by 2100 and global food production could fall by as much as 14% by 2050 without effective adaptation.

Some small island developing states and low-lying coastal cities could be partially or completely submerged, while damaged ecosystems could further accelerate climate change.

“This report is a ‘fork in the road’ moment for the planet,” said Surangel Whipps, Jr., president of the Pacific island nation of Palau. “It is a further glimpse into a perilous future that has already arrived. To continue to have a fighting chance, calls for greater ambition are no longer enough – we need to see an urgent and unprecedented increase in political will and investment in a climate-safe future.”

Cut emissions first, remove carbon after

The authors call for a three-phase approach to bringing temperatures back down: an “immediate response” of deep and rapid emissions cuts and urgent protection for the most vulnerable as warming approaches and passes 1.5C; a “coping and containment” phase focused on reaching net-zero emissions and building resilience as temperatures peak; and a “long-term resilience” phase of net-negative emissions through carbon dioxide removal (CDR) and lasting adaptation as temperatures eventually decline.

Richard Betts, who leads climate impact research at the UK Met Office, said CDR is not a “get-out-of-jail-free card” and should only be additional to emission reductions that need to be achieved with “even more urgency than before”.

    Critics of CDR have long pointed to the technology’s record of overpromising and underdelivering, and warn it has been exploited by the fossil fuel industry and some oil-producing states to try to delay the clean energy transition.

    Not everyone was fully convinced by the UNEP overshoot report. Veteran climate scientist Bill Hare from Climate Analytics said it “does a good job of describing the hole we’ve dug ourselves into” but “a poor job of showing us that there is a way out”. He argued that its thin treatment of the need for a fossil fuel phase-out and ambitious mitigation pathways to cut emissions risk “turning it into a call to apathy rather than a call to arms”.

    “Host of challenges” with CDR

    Debra Roberts, honorary professor at the University of KwaZulu-Natal in South Africa, told journalists that limiting global warming to around 1.8C is needed to give the world “a realistic and fighting chance” of returning to the 1.5C limit because of the “questionable” feasibility of interventions above that threshold.

    CDR comes with “a whole host of challenges”, she added, including the impacts on food and water security of rolling out large-scale programmes and the unanswered questions of whether newer technologies will work at scale and who will foot the bill.

    “It’s going to happen in a very, very complex decision-making space where the risks and impacts are dramatically becoming more complex and interrelated,” she said. “That’s why the pressure there is keep those emissions as low as possible because they give us the greatest fighting chance of the return to 1.5C in a more equitable and just way.”

    The post UN sets out narrow path back to 1.5C warming after inevitable overshoot appeared first on Climate Home News.

    UN sets out narrow path back to 1.5C warming after inevitable overshoot

    Continue Reading

    Climate Change

    Keeping to 1.5C of warming is no longer possible – but we must still limit the overshoot

    Published

    on

    Laurence Tubiana is CEO of the European Climate Foundation and was formerly France’s Climate Change Ambassador and Special Representative for COP21 in Paris.

    The UN has released a report this week confirming what many people have feared: the world is going to pass 1.5C of warming.

    At current emissions, the remaining carbon budget will be exhausted within roughly three years. We are heading into “exceedance” of the 1.5C threshold: a sustained breach of the Paris Agreement’s primary temperature goal before any possible return below it.

    1.5C is the line we should not have crossed – and, once we cross it, the line we must quickly get back below, on what the UN Environment Programme calls an “overshoot, peak and decline pathway”.

      Of course, climate risk is a spectrum: 1.4C is not safe, and 1.5C is not a sudden cliff edge. But the further the world moves beyond that level, the harder it becomes for communities and economies to adapt, and the greater the risk of more abrupt or systemic changes.

      The importance of 1.5C

      Some will argue that exceeding 1.5C means the Paris Agreement has failed, and that it is no longer a useful threshold. I disagree.

      Before Paris, the world was heading for roughly 3.5C to 4C of warming. The UN now estimates that warming will reach a lower level of around 2.6C by 2100, due to policies implemented since Paris. That is still far too dangerous, but it is not the same world we were facing in 2015.

      When we negotiated the Paris Agreement, 1.5C was not an arbitrary number. It was fought for by small island states and other climate-vulnerable countries because it represented a red line for their survival. Since then, we have witnessed the stark impacts of global temperature rises even in countries that did not consider themselves vulnerable, as seen with the devastating heatwaves in Europe this summer.

      WHO issues new guidance on heat-health action plans, as El Niño sets in

      The International Court of Justice underlined this in an advisory opinion, endorsed overwhelmingly by the UN General Assembly earlier this year, recognising 1.5C as the primary temperature threshold under the Paris Agreement and affirming that states must align their commitments with it. Overshoot does not move the goalposts. 1.5C remains the benchmark we must work to return to.

      Lasting consequences of overshoot

      But even as we fight to get back below 1.5C as quickly as possible, we now have to reckon honestly with what overshoot means. We are entering a period for which our societies, economies and institutions are not prepared. Even if overshoot itself is temporary, many of its consequences will not be. The longer it lasts, and the higher temperatures rise, the greater the lasting damage. We therefore need to limit its duration and magnitude.

      The longer warming remains above 1.5C, the greater the risk of crossing tipping points in major Earth systems such as ice sheets, the Atlantic Meridional Overturning Circulation, permafrost and tropical forests. Crossing them can trigger self-reinforcing changes that may prove irreversible even if temperatures later fall. We need to understand and monitor these systems more than ever. That requires sustained investment in climate science – just as funding is being cut in many places.

      An overshoot pathway will also strain human systems. When a flood destroys a home, the damage is not undone because global temperatures later fall. Crop failures, missed schooling, debt and displacement can have lasting effects. Farms, cities, healthcare systems and insurance markets will all have to cope with risks they were not designed for, and risk facing “tipping points” of their own, such as financial panic when markets suddenly reprice risks they had underestimated. Infrastructure built today will stand for decades, so we need to design and plan for the climate risks it will actually face.

      From firefighting to future-proofing: Preventing wildfires must be the priority

      Our priority must be to transition away from fossil fuels and rapidly cut emissions, including short-lived climate pollutants like methane. It traps around 80 times more heat than carbon dioxide over a 20-year period, and cutting it sharply can act as an emergency brake on near-term warming. Much of the methane from fossil fuel operations can be cut with existing technologies.

      We will also need sustainable carbon dioxide removal, although its role will be limited: trying to use it as a substitute for emissions cuts would be prohibitively expensive at scale.

      The radical options

      The major risks of overshoot have led to proposals to explore active intervention in the climate system itself. Solar radiation modification (SRM) is the best-known example: reflecting a small share of sunlight back into space to reduce warming. Other proposals would target different parts of the climate and Earth systems, such as trying to stabilise glaciers.

      These responses would bring us into further uncharted territory across Earth systems and nature, diplomacy and governance, technology and societies.

      Such ideas are born of genuine concern about the major risks facing vulnerable countries and communities as temperatures rise. But even under the most favourable assumptions, these are tactics for managing some of the symptoms of overshoot, not a strategy for addressing its causes. Greenhouse gases would keep accumulating, oceans would keep acidifying, and many of the social and economic impacts of overshoot would remain.

      EU warns on solar geoengineering but research debate grinds on

      The more we learn about the complexity of the climate and Earth systems we are disrupting and how much uncertainty there already is, the clearer it becomes that full control is likely an illusion, and new interventions bring new complex risks. SRM, for example, could change regional climates, such as rainfall patterns or agricultural production, in ways that benefit some regions and harm others, with knock-on geopolitical risks.

      Governance and research needed

      None of this is an argument against research into these technologies. On the contrary, the risks they’re responding to are so extreme that we must explore all the options we might have. But we need to understand the potential effects and capabilities much better and from many more angles, including the political and social implications. Serious global governance is particularly urgent, alongside transparent research that is open to scrutiny.

      But the fundamental elements of a strategy to navigate overshoot are already understood. The priority is still to rapidly cut greenhouse gas emissions to limit peak warming, protect people against the warming already locked in, and ensure technological innovation aligns with the public interest.

      Overshoot is not just an engineering challenge. We need a full-scale response across societies, economies and political systems to prepare to navigate a more uncertain climate.

      The post Keeping to 1.5C of warming is no longer possible – but we must still limit the overshoot appeared first on Climate Home News.

      Keeping to 1.5C of warming is no longer possible – but we must still limit the overshoot

      Continue Reading

      Trending

      Copyright © 2022 BreakingClimateChange.com