EigoPro 1級読解 — The Hidden Costs of Biodiversity Loss

When conservationists lament the disappearance of a species, the public tends to picture a charismatic casualty—a tiger, a coral reef, a songbird stilled. Yet the most consequential losses are rarely so legible. Biodiversity functions less as a roster of organisms than as an intricate web of interdependencies, and it is the severing of these connections, rather than the demise of any single creature, that exacts the steepest toll. The collapse of a pollinator population, for instance, reverberates through agricultural yields, food prices, and ultimately the nutritional security of communities that never set eyes on a bee. Economists have lately attempted to render these stakes in monetary terms, cataloguing the so-called ecosystem services that intact habitats provide gratis: water purification, flood mitigation, carbon sequestration, the suppression of disease vectors. The exercise is instructive but treacherous. By translating the living world into a ledger of dollars, it risks implying that nature's worth is exhausted by its instrumental utility—that a wetland is valuable only insofar as it spares a city the expense of a treatment plant. Critics warn that such accounting, however well-intentioned, may legitimize a logic of substitution: if the service can be priced, it can in principle be replaced by an engineered alternative, and the organism rendered expendable. The deeper hazard is epistemic. Many of the functions performed by a given species remain wholly uncharted until that species is gone, at which point the accounting arrives too late to inform any decision. This opacity is precisely what makes biodiversity loss so insidious. Unlike a depleted oil field, whose exhaustion announces itself in falling output, an eroding ecosystem can appear robust until it crosses an invisible threshold and reorganizes abruptly into a degraded state from which recovery is slow or impossible. The grasslands that suddenly cede to scrub, the fishery that does not rebound despite a moratorium—these are not gradual declines but regime shifts, and their abruptness mocks our intuition that environmental damage is reversible if only we relent in time. The hidden cost, then, is not merely the species we knowingly forfeit but the latitude for error we unknowingly surrender. Each extinction narrows the margin within which a complex system can absorb shocks, until a perturbation that a richer ecosystem would have shrugged off becomes the one that tips it over. We are, in effect, dismantling our insurance while assuring ourselves the weather looks fine.

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この単元の問題を3問、解説つきで公開しています

1級 · 読解 · 全5問

問 1

Which statement best captures the central argument of the passage?

Biodiversity loss resembles the depletion of an oil field, in that its progress is steady, measurable, and ultimately reversible with timely intervention.
The gravest consequences of biodiversity loss lie in the disruption of ecological interdependencies and the erosion of a system's capacity to withstand shocks, both of which are easily overlooked.
Assigning monetary values to ecosystem services is the most effective way to persuade governments to halt the destruction of natural habitats.
Conservation campaigns should prioritise charismatic species because public sympathy for them is the most reliable engine of environmental protection.

Phrase

全体の論旨

1級読解主旨把握論旨

⚡ひとことで

最も重い代償は個々の種の消滅ではなく、相互依存の崩壊と回復力の喪失だと論じる。

選択肢の解説Choice Analysis

「The gravest consequences of biodiversity loss lie in the disruption of ecological interdependencies and the erosion of a system's capacity to withstand shocks, both of which are easily overlooked.」

正解

第1段落で「最も重大な損失は個々の生物の死ではなく、つながりの切断にある」と述べ、第3段落では各絶滅が「複雑系が衝撃を吸収できる余地を狭める」と結論づけている。筆者の主眼は終始、見落とされやすい相互依存とレジリエンスの喪失にある。よってこれが論旨を最もよく捉えている。

「Conservation campaigns should prioritise charismatic species because public sympathy for them is the most reliable engine of environmental protection.」
= 魅力的な種を保護の中心に据えるべきだという主張 ━ 第1段落はカリスマ種に注目する一般大衆の見方を、むしろ問題の本質を見えなくするものとして退けており、優先せよとは述べていない。
「Assigning monetary values to ecosystem services is the most effective way to persuade governments to halt the destruction of natural habitats.」
= 生態系サービスの貨幣換算が最も有効な説得手段だという主張 ━ 第2段落は貨幣換算を『有益だが危険 (instructive but treacherous)』と評し、代替可能性の論理を正当化しうると警告している。最善策とは正反対。
「Biodiversity loss closely resembles the depletion of an oil field, in that its progress is steady, readily measurable, and ultimately reversible provided that intervention arrives in good time.」
= 油田枯渇のように緩やかで可逆だという主張 ━ 第3段落は生態系崩壊を油田と対比し『突然のレジームシフト』で回復困難になると明言。可逆という記述と真っ向から矛盾する。

▦Collocation

パターン	意味	例
exact a toll	代償を強いる	The severing of connections exacts the steepest toll.
reverberate through ~	~に波及する	A pollinator collapse reverberates through food prices.
absorb shocks	衝撃を吸収する	A richer ecosystem can absorb shocks more readily.
tip ~ over	~を臨界に追いやる	A small perturbation can tip the system over.
narrow the margin	余地を狭める	Each extinction narrows the margin for error.

❝例文

The loss is not legible to the untrained eye.
その損失は素人目には判読しがたい。
Interdependencies, once severed, rarely heal on their own.
相互依存はいったん断たれると自然には回復しにくい。
The steepest toll is paid long after the species vanishes.
最も重い代償は種の消滅のずっと後に支払われる。
Resilience is what we forfeit without noticing.
我々が気づかぬまま手放すのが回復力である。

💡Tip · 覚えるコツ

C2 の主旨設問では、本文が繰り返し戻ってくる『軸』を探す。ここでは第1・第3段落がともに『つながり/回復力』に収斂しており、第2段落の貨幣換算批判はその軸を支える挿話にすぎない。最も劇的な細部 (カリスマ種・金銭) に飛びつかず、段落をまたいで反復される抽象概念を選ぶこと。

問 2

According to the passage, why do economists describe natural habitats as providing 'ecosystem services'?

Because intact habitats perform functions such as purifying water, mitigating floods, and storing carbon at no monetary charge.
Because these functions can be measured with greater precision than the output of a depleting oil field.
Because the term allows conservationists to focus public attention on charismatic species like tigers and reefs.
Because such services have already been successfully replaced by engineered alternatives in most developed economies.

Phrase

ecosystem services の内容

1級読解詳細生態系サービス

⚡ひとことで

無傷の生息地が無償で提供する水浄化・洪水緩和・炭素隔離などの機能を指す。

選択肢の解説Choice Analysis

「Because intact habitats perform functions such as purifying water, mitigating floods, and storing carbon at no monetary charge.」

正解

第2段落に『無傷の生息地が無償で (gratis) 提供する生態系サービス——水の浄化、洪水の緩和、炭素隔離、病害媒介者の抑制』と列挙されている。よって正解はこれらの無償機能を指すという説明である。

「Because such services have already been successfully replaced by engineered alternatives in most developed economies.」
= 工学的代替で大半が置き換え済みだという内容 ━ 本文は代替を『原理的に可能と示唆しかねない危険な論理』として警告するにとどまり、既に置換されたとは述べていない。
「Because the term allows conservationists to focus public attention on charismatic species like tigers and reefs.」
= 用語がカリスマ種への注目を促すという内容 ━ ecosystem services の説明は経済学者による貨幣換算の文脈であり、カリスマ種とは無関係。第1段落の話題を誤って接続している。
「Because these functions can be measured with greater precision than the output of a depleting oil field.」
= 油田の産出より精密に測れるという内容 ━ 油田との対比は第3段落の『可視性』の議論で、ecosystem services を測定精度で定義してはいない。部分的語句の流用。

▦Collocation

パターン	意味	例
provide ~ gratis	~を無償で提供する	Wetlands provide flood mitigation gratis.
render ~ in monetary terms	~を金銭で表す	Economists render these stakes in monetary terms.
a ledger of dollars	金額の帳簿	Nature is reduced to a ledger of dollars.
instrumental utility	道具的有用性	Worth is mistaken for instrumental utility.
suppress disease vectors	病害媒介者を抑える	Healthy habitats suppress disease vectors.

❝例文

A wetland spares the city a treatment plant.
湿地は都市に処理場の出費を免れさせる。
These benefits accrue without invoice.
これらの恩恵は請求書なしに生じる。
Carbon sequestration is one such uncosted service.
炭素隔離はそうした無償サービスの一つだ。
Pricing the service invites the logic of substitution.
サービスに値を付けると代替の論理を招く。

💡Tip · 覚えるコツ

詳細設問は本文の列挙箇所をピンポイントで照合する。gratis (無償で) という一語が定義の核心であり、選択肢にこの『無償性』が反映されているかを確認する。他段落 (油田・カリスマ種) の語彙を巧妙に混ぜた誤答に注意。

問 3

What does the passage identify as the 'deeper hazard' of pricing ecosystem services?

That engineered substitutes for natural services are invariably more expensive than the habitats they replace.
That governments will refuse to fund conservation unless every benefit is expressed as a precise dollar figure.
That a species' functions often remain unknown until it is already extinct, leaving the valuation too late to guide any decision.
That the public will lose all sympathy for charismatic species once their worth is reduced to numbers.

Phrase

deeper hazard / epistemic

1級読解詳細認識論的危険

⚡ひとことで

種の機能は消滅して初めて判明するため、評価が手遅れになる認識論的危険。

選択肢の解説Choice Analysis

「That a species' functions often remain unknown until it is already extinct, leaving the valuation too late to guide any decision.」

正解

第2段落末尾に『より深い危険は認識論的 (epistemic) である。多くの機能は種が消えるまで未解明のままで、その時点では会計は判断材料として手遅れに届く』とある。正解はこの『機能が事後にしか判明しない』点を正確に言い換えている。

「That governments will refuse to fund conservation unless every benefit is expressed as a precise dollar figure.」
= 金額化しないと政府が資金を出さないという内容 ━ 本文は政府の資金態度に言及していない。貨幣換算の害を論じる文脈に資金調達の話を持ち込んだ無関係な誤答。
「That engineered substitutes for natural services are invariably more expensive than the habitats they replace.」
= 工学的代替が必ず割高だという内容 ━ 本文は代替が割高とも安価とも述べず、『代替可能と示唆する論理』そのものを問題視している。コスト比較は本文外。
「That the public will lose all sympathy for charismatic species once their worth is reduced to numbers.」
= 数値化で大衆の共感が失われるという内容 ━ もっともらしいが本文は『共感の喪失』を deeper hazard として挙げていない。第1段落のカリスマ種話と混同させる誘導。

▦Collocation

パターン	意味	例
remain uncharted	未解明のままである	Many functions remain uncharted until too late.
arrive too late	手遅れで届く	The accounting arrives too late to inform a decision.
an epistemic hazard	認識論的危険	The deeper hazard is epistemic.
inform a decision	判断材料となる	Data should inform a decision in time.
a logic of substitution	代替の論理	Pricing may legitimize a logic of substitution.

❝例文

We learn a species' role only by its absence.
種の役割はその不在によってしか学べない。
By then, no valuation can avert the loss.
その頃には、いかなる評価も損失を防げない。
Knowledge that comes too late is no knowledge at all for the decider.
手遅れに来る知識は意思決定者にとって無知に等しい。
The ledger closes after the asset is gone.
資産が消えてから帳簿は締められる。

💡Tip · 覚えるコツ

『deeper / deepest』のような序列を示す形容詞は、筆者が複数の論点に重みづけしている合図。直後の epistemic という抽象語を見落とさず、その定義文 (until that species is gone) を根拠に選ぶ。資金や共感など本文未言及の常識論にすり替える誤答を排除する。

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EigoPro 1級 読解 — The Hidden Costs of Biodiversity Loss

この単元の問題を3問、解説つきで公開しています

全体の論旨

ecosystem services の内容

deeper hazard / epistemic

EigoPro 1級読解 — The Hidden Costs of Biodiversity Loss