從 IPCC AR6 報告中學到的五件事
從格陵蘭冰架融化到珊瑚礁遭受破壞，與氣候變化相關的影響已經達到模型推演中最高值的一端，也比 IPCC 之前評估的速度快。最新報告指出，當前全球約 40% 人口在氣候變化所帶來的影響中是「受害風險最高」，但要承擔這惡果的他們卻是最不製造麻煩的一群。
全球適應中心（Global Center on Adaptation）是從事協助政府與私營機構作出大規模適應計劃的工作。首席執行官帕特里克·韋爾庫伊詹（Patrick Verkooijen）說：「在非洲，按照目前的溫室氣體排放軌跡，約 30% 的玉米產區將面臨絕收，大豆則是約 50%。也就是說，世界部分地區，尤其是在非洲，將變得不宜人類生存。」正如 IPCC 報告所言，要阻止推動這種氣候種族隔離的勢力，時間不多。
此前在蘇格蘭格拉斯哥舉行的第 26 屆聯合國氣候變化大會（COP26）上，美國與歐盟阻止建立一個損失與損害專項基金的政治努力，使應對此問題的政治努力受挫。
IPCC 的這次背書有望提升損失與損害在氣候談判中的分量，英方 COP 26 主席阿洛克·夏爾馬（Alok Sharma）也同意這一點。他說：「報告強調了一項緊迫性：我們必須為氣候變化做凖備，認識損失與損害這一新現實，尤其是世上最容易受氣候變化衝擊的群體身上所發生的事情，並給予解決問題。」
據 IPCC 所言，採用某些為限制氣候變暖或減少二氧化碳排放的科技，只會弄巧成拙。例如：人們擔心抽吸空氣中二氧化碳的機器是否反而導致更大規模的溫室氣體排放。
海因裏希·伯爾基金會（Heinrich Böll Foundation）氣候政策專家琳達·施耐德（Linda Schneider）是 IPCC 觀察員。她說：「當你從大氣中去除二氧化碳，碳循環中的其他環節會發生反彈效應。這會導致海洋與陸地中的碳儲備出現氣體釋出效應，補回大氣中被移除的那部分二氧化碳。」
IPCC 第二工作組聯席主席黛布拉·羅伯茨（Debra Roberts）說：「我們明確指出，世上各大城市均是關鍵的動員對象。」
IPCC 還稱，自然保育上投資同樣能成為抵擋最壞情況的堡壘，委員會呼籲把全球 30% 至 50% 地方劃為保育區域。
聯合國環境規劃署（UN Environment Programme, UNEP）執行主任英格·安德森（Inger Andersen）說：「自然能成為我們的救世主，但首先我們得拯救自然。」
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Climate change： Five things we’ve learned from the IPCC report
Author：Matt McGrath（2022 , March , 1 ）
A new report released this week by the UN’s Intergovernmental Panel on Climate Change （IPCC） looks at the causes, impacts and solutions to climate change.
The report gives the clearest indication to date of how a warmer world is affecting all living things on Earth.
Here are five things we learnt from it.
（1）Things are way worse than we thought.
From the melting of the Greenland ice sheet to the destruction of coral reefs, climate related impacts are hitting the world at the high end of what modellers once expected. And much more quickly than previously assessed by the IPCC.
Right now, as the new report makes clear, around 40% of the world’s population is “highly vulnerable” to the impacts of climate change.
But the burden is falling mainly on those who did the least to cause the problem.
“For Africa around 30% of all the maize growing areas will go out of production, for beans it’s around 50% on the current emissions trajectory,” said Patrick Verkooijen, CEO of the Global Center on Adaptation, which assists governments and the private sector in pushing for large scale adaptation solutions.
“So there are certain parts of the world, particularly in Africa, which will become uninhabitable.”
“And time is running out, as the IPCC report clearly says, to stop the forces driving this new climate apartheid,” he told BBC News.
（2）Loss and damage gets scientific backing.
For several years, developing countries have been trying to get richer nations to take the idea of loss and damage seriously.
It’s defined as those impacts of climate change that can’t be adapted to, or slow onset events like sea level rise.
It has been very controversial because it is bound up with the long-term historical responsibility for carbon emissions — and richer nations fear being dragged through the courts and forced to pay indefinitely for current and future losses and damages that they have contributed to.
At COP26 in Glasgow, political progress on the issue stalled when the US and EU blocked a dedicated funding facility for loss and damage.
Now the IPCC clearly states that the observed impacts of climate change include “widespread adverse impacts and related losses and damages to nature and people.”
The endorsement by the IPCC is likely to give loss and damage a major boost in climate talks, a fact recognised by the UK’s COP President, Alok Sharma, who is in charge of UN negotiations until COP27 begins in Egypt later this year.
“Today’s report underscores the urgency with which we must prepare for climate change and address a new reality of loss and damage, especially in the world’s most climate-vulnerable communities,” he said. “The next decade is crucial.”
（3）Technology is not a silver bullet.
According to the IPCC, the use of some technologies designed to limit warming or reduce CO2 could make matters worse rather than better.
There are also worries that machines that suck CO2 from the air could simply trigger the release of more warming gas.
“If you remove CO2 from the atmosphere, you’ll get a rebound effect from the others in the carbon cycle,” said Linda Schneider from the Heinrich Böll Foundation, who was an observer at the IPCC discussions.
“The oceans, the land reservoirs, will have an outgassing effect. And so some of the CO2 that that you removed from the atmosphere will be returned to the atmosphere.”
（4）Cities offer hope.
While large cities are hotspots for climate impacts, they also offer a real opportunity to avoid the worst impacts of warming.
As cities continue to grow they can push for renewable energy, greener transport, and buildings. This could limit destructive climate impacts for millions.
“We point very clearly to the cities of the world as a key place for mobilisation,” said IPCC co-chair Debra Roberts.
“This is where some of our most vulnerable people are located in coastal cities so that’s already an entry point, you can change your options by beginning to mobilise around coastal urban development.”
（5） The small window is closing fast.
While this is a bleak assessment of the impacts now and in the future, the authors remain convinced that the worst impacts can be averted — if we act in time.
The IPCC says this opportunity for action will only last for the rest of this decade, as the final sentence in the new report underlines.
“Any further delay in concerted global action will miss a brief and rapidly closing window to secure a liveable future.”
If the world can cut emissions drastically and significantly boost spending on adaptation, that could avoid locking in certain disaster.
And it’s not just about spending on green energy and electric cars. The authors say that investing in education, health systems and social justice could help people to cope with the impacts of rising temperatures.
Investing in nature will also be a bulwark against the worst, says the IPCC, which calls for 30–50% of the world to be conserved.
“Nature can be our saviour,” said Inger Anderson, the head of the UN Environment Programme.
“But only if we save it first.”