世界气象组织：二氧化碳、甲烷和氧化亚氮的大气水平在2021年均创下了新高

地球再传坏消息：温室气体水平创新高

WMO记录到了自开始测量以来甲烷浓度的最大增幅

10月26日，日内瓦/纽约（WMO）— 根据世界气象组织（WMO）一份新报告，在另一个充满不祥之气的气候变化警报中，三种主要温室气体：二氧化碳、甲烷和氧化亚氮的大气水平在2021年均创下了新高。

WMO《温室气体公报》报告道：自近40年前开始系统测量以来，2021年的甲烷浓度出现了最大的同比增幅。这一异常增长的原因尚不清楚，但似乎是生物和人类引发的过程的结果。

从2020年到2021年，二氧化碳水平的增幅大于过去十年的平均年增长率。WMO全球大气监视网内台站的测量结果显示，2022年全球的上述水平均在继续上升。

在1990至2021年间，长寿命温室气体对气候的增温效应（称为辐射强迫）增加了近50%，其中二氧化碳约占80%。

2021年的二氧化碳浓度为百万分之415.7（ppm），甲烷为十亿分之1908（ppb），氧化亚氮为334.5ppb。这些数值分别占工业化前（人类活动开始破坏大气中这些气体的自然平衡之前）水平的149%、262%和124%。

“WMO《温室气体公报》再次强调了采取紧急行动、减少温室气体排放并防止未来全球温度进一步上升面临的巨大挑战，及其极端必要性，”WMO秘书长佩特里·塔拉斯说。

“主要吸热气体的浓度持续上升，包括甲烷水平的创纪录加速，表明我们正朝着错误的方向发展，”他说。 

“有一些具成本效益的战略可用于应对甲烷排放问题，特别是应对化石燃料部门的排放，我们应该立即实施这些战略。然而，甲烷的寿命相对较短，不到10年，因此它对气候的影响是可逆转的。作为首要和最紧迫的优先事项，我们必须削减二氧化碳的排放，因为它是气候变化和相关极端天气的主要驱动因素，而且将通过极地冰层损失、海洋增温和海平面上升等方式影响气候数千年，”塔拉斯教授说。

“我们需要改变工业、能源和运输系统以及整体生活方式。所需的变革在经济上是可以承受的，在技术上也是可能的。但时间已经不多了，”塔拉斯教授说。

联合国气候变化大会（COP27）将于11月7日至18日在埃及举行。在沙姆沙伊赫会议前夕，WMO将提交其《2022年全球气候状况》临时报告，该报告将说明温室气体如何继续推动气候变化和极端天气。2015年至2021年是有记录以来最暖的七年。

WMO的报告旨在激励COP27的谈判代表采取更具雄心的行动，以实现《巴黎协定》将全球升温限制在远低于工业化前水平的2摄氏度，最好是1.5摄氏度以下的目标。目前，全球平均温度比1850-1900年工业化前的平均温度高出1.1℃以上。

鉴于需要加强温室气体的信息基础，为气候减缓工作的决定提供依据，WMO正在与更广泛的温室气体界合作，以开发一个推进持续的、国际协调的全球温室气体监测框架，包括观测网络的设计和国际交换及所产生的观测结果的使用等。WMO将与更广泛的科学界和国际社会合作，特别是在陆面和海洋观测与模拟方面。

WMO测量大气温室气体浓度，也就是测量在温室气体被海洋和生物圈等汇吸收后，留在大气中的部分。这部分与排放是不同的。

联合国环境署将于10月27日单独发布一份补充性《排放差距报告》。该《排放差距报告》评估了关于当前和估计未来温室气体排放的最新科学研究。“可能达到的水平与需要达到的水平”之间的差异被称为排放差距。

只要继续排放，全球温度就会继续上升。鉴于二氧化碳的寿命很长，即使排放量迅速减少到净零，已经观测到的温度水平仍将持续数十年。

公报的要点

二氧化碳（CO2）

2021年，大气二氧化碳达到了工业化前水平的149%，主要是因为来自化石燃料燃烧和水泥生产的排放。自2020年因新冠疫情采取隔离措施以来，全球排放量有所反弹。在2011-2020年期间人类活动的总排放量中，约48%累积在大气中，26%在海洋中，29%在陆地上。

陆地生态系统和海洋作为“汇”的能力在未来可能会变得不那么有效，从而降低其吸收二氧化碳和减缓温度上升的能力。在有些地方，已经出现了土地汇变成二氧化碳源的情况。

甲烷（CH4）

大气甲烷是气候变化的第二大贡献者，它由多种重叠的源和汇组成，因此很难按来源类型来量化排放。

自2007年以来，全球平均大气甲烷浓度一直在加速增加。2020年和2021年的年度增长率（分别为15和18 ppb）是自1983年开始系统记录以来的最大增幅。

全球温室气体科学界仍在调查其原因。分析表明，自2007年以来，造成甲烷再次增加的最主要原因是生物源，如湿地或稻田。目前尚不能确定2020年和2021年的极端增长是否是气候反馈，即如果天气变暖，有机物会分解得更快。如果有机物在水中（无氧）分解，这将导致甲烷排放。因此，如果热带湿地变得更湿润和更温暖，就有可能产生更多排放。

急剧增加也可能是由于自然年际变化。2020年和2021年出现了拉尼娜事件，这与热带地区的降水增加相关。

氧化亚氮（N2O）

氧化亚氮是第三种最重要的温室气体。它即可通过自然源（约57%）也可通过人为源（约43%）排放到大气中，包括海洋、土壤、生物质燃烧、化肥使用和各种工业过程等。2020年至2021年的增幅略高于2019年至2020年观测到的增幅，也高于过去10年的平均年增长率。

编者按

WMO全球大气监视网计划负责协调对温室气体（GHG）的系统观测和分析。公报中纳入了来自55个WMO会员的测量数据。这些数据由设在日本气象厅的世界温室气体数据中心（WDCGG）负责归档和分发。

世界气象组织是联合国系统关于天气、气候和水的权威声音

欲了解更多信息，请联系：WMO媒体官员Clare Nullis。电子邮件：cnullis@wmo.int. 手机：+41 79 709 13 97

More bad news for the planet: greenhouse gas levels hit new highs

WMO records biggest increase in methane concentrations since start of measurements

Geneva/New York, 26 October (WMO) - In yet another ominous climate change warning, atmospheric levels of the three main greenhouse gases - carbon dioxide, methane and nitrous oxide all reached new record highs in 2021, according to a new report from the World Meteorological Organization (WMO).

WMO’s Greenhouse Gas Bulletin reported the biggest year-on-year jump in methane concentrations in 2021 since systematic measurements began nearly 40 years ago. The reason for this exceptional increase is not clear, but seems to be a result of both biological and human-induced processes.

The increase in carbon dioxide levels from 2020 to 2021 was larger than the average annual growth rate over the last decade. Measurements from WMO’s Global Atmosphere Watch network stations show that these levels continues to rise in 2022 over the whole globe.

Between 1990 and 2021, the warming effect on our climate (known as radiative forcing) by long-lived greenhouse gases rose by nearly 50%, with carbon dioxide accounting for about 80% of this increase.

Carbon dioxide concentrations in 2021 were 415.7 parts per million (ppm), methane at 1908 parts per billion (ppb) and nitrous oxide at 334.5 ppb. These values constitute, respectively, 149%, 262% and 124% of pre-industrial levels before human activities started disrupting natural equilibrium of these gases in the atmosphere.

“WMO’s Greenhouse Gas Bulletin has underlined, once again, the enormous challenge – and the vital necessity – of urgent action to cut greenhouse gas emissions and prevent global temperatures rising even further in the future,” said WMO Secretary-General Prof. Petteri Taalas.

“The continuing rise in concentrations of the main heat-trapping gases, including the record acceleration in methane levels, shows that we are heading in the wrong direction,” he said. 

“There are cost-effective strategies available to tackle methane emissions, especially from the fossil fuel sector, and we should implement these without delay. However, methane has a relatively short lifetime of less than 10 years and so its impact on climate is reversible. As the top and most urgent priority, we have to slash carbon dioxide emissions which are the main driver of climate change and associated extreme weather, and which will affect climate for thousands of years through polar ice loss, ocean warming and sea level rise,” said Prof. Taalas.

“We need to transform our industrial, energy and transport systems and whole way of life.  The needed changes are economically affordable and technically possible. Time is running out,” said Prof. Taalas.

WMO UN Climate Change conference, COP27, in Egypt from 7-18 November. On the eve of the conference in Sharm-el-Sheikh it will present its provisional State of the Global Climate 2022 report, which will show how greenhouse gases continue to drive climate change and extreme weather.  The years from 2015 to 2021 were the seven warmest on record.

The WMO reports seek to galvanize COP27 negotiators into more ambitious action decision makers to achieve the Paris Agreement goal to limit global warming to well below 2, preferably to 1.5 degrees Celsius, compared to pre-industrial levels. The average global temperature is now more than 1.1°C above the 1850–1900 pre-industrial average.

Given the need to strengthen the greenhouse gas information basis for decisions on climate mitigation efforts, WMO is working with the broader greenhouse gas community to develop a framework for sustained, internationally coordinated global greenhouse gas monitoring, including observing network design and international exchange and use of the resulting observations. It will engage with the broader scientific and international community, in particular regarding land surface and ocean observation and modelling.

WMO measures atmospheric concentrations of greenhouse gases – what remains in the atmosphere after gases are absorbed by sinks like the ocean and biosphere. This is not the same as emissions.

A separate and complementary Emissions Gap Report by UN Environment will be released on 27 October. The Emissions Gap report assesses the latest scientific studies on current and estimated future greenhouse gas emissions. This difference between “where we are likely to be and where we need to be” is known as the emissions gap.

As long as emissions continue, global temperature will continue to rise.  Given the long life of CO2, the temperature level already observed will persist for decades even if emissions are rapidly reduced to net zero.

Highlights of the Bulletin

Carbon dioxide (CO2)

Atmospheric carbon dioxide reached 149% of the pre-industrial level in 2021, primarily because of emissions from the combustion of fossil fuels and cement production. Global emissions have rebounded since the COVID-related lockdowns in 2020. Of the total emissions from human activities during the 2011–2020 period, about 48% accumulated in the atmosphere, 26% in the ocean and 29% on land.

There is concern that the ability of land ecosystems and oceans to act as “sinks” may become less effective in future, thus reducing their ability to absorb carbon dioxide and act as a buffer against larger temperature increase. In some parts of the world the transition of the land sink into CO2 source is already happening.

Methane (CH4)

Atmospheric methane is the second largest contributor to climate change and consists of a diverse mix of overlapping sources and sinks, so it is difficult to quantify emissions by source type.

Since 2007, globally-averaged atmospheric methane concentration has been increasing at an accelerating rate. The annual increases in 2020 and 2021 (15 and 18 ppb respectively) are the largest since systematic record began in 1983.

Causes are still being investigated by the global greenhouse gas science community. Analysis indicates that the largest contribution to the renewed increase in methane since 2007 comes from biogenic sources, such as wetlands or rice paddies. It is not yet possible to say if the extreme increases in 2020 an 2021 represent a climate feedback – if it gets warmer, the organic material decomposes faster. If it decomposes in the water (without oxygen) this leads to methane emissions. Thus, if tropical wetlands become wetter and warmer, more emissions are possible.

The dramatic increase might also be because of natural interannual variability. The years 2020 and 2021 saw La Niña events which are associated with increased precipitation in tropics.

Nitrous oxide (N2O)

Nitrous oxide is the third most important greenhouse gas. It is emitted into the atmosphere from both natural sources (approximately 57%) and anthropogenic sources (approximately 43%), including oceans, soils, biomass burning, fertilizer use, and various industrial processes. The increase from 2020 to 2021 was slightly higher than that observed from 2019 to 2020 and higher than the average annual growth rate over the past 10 years

Notes for Editors

The WMO Global Atmosphere Watch Programme coordinates systematic observations and analyses of greenhouse gases (GHG). The Bulletin includes measurement data from 55 WMO Members. This data is archived and distributed by the World Data Centre for Greenhouse Gases (WDCGG) at the Japan Meteorological Agency.

The World Meteorological Organization is the United Nations System’s authoritative voice
on Weather, Climate and Water

For further information contact: Clare Nullis, WMO media officer, cnullis@wmo.int. Tel 41-79-7091397

文章来源：中外能源经济观察