EigoPro 1級 読解 — The Calculus of Adaptation

For decades, climate policy was framed almost exclusively around mitigation—the project of curbing emissions to forestall catastrophe. Adaptation, by contrast, was treated as a tacit admission of defeat, a concession that prevention had failed. Yet as the physical signatures of warming have become irreversible on any politically meaningful timescale, economists have begun to rehabilitate adaptation not as capitulation but as prudent hedging. The shift is less a repudiation of mitigation than an acknowledgement that the two are temporally decoupled: emissions reductions yield benefits diffused across centuries and continents, whereas a sea wall or a drought-resistant cultivar pays dividends locally and within a generation. This immediacy is precisely what complicates the economics. Adaptation investments are notoriously difficult to appraise because their returns are contingent, asymmetric, and frequently invisible. A levee that holds confers no measurable benefit in a year without floods; its value materialises only in the counterfactual disaster it averts. Conventional cost-benefit analysis, predicated on discounting future cash flows, tends to undervalue such defensive expenditures, particularly when the relevant hazards are characterised by fat-tailed distributions—rare but ruinous events whose probabilities defy confident estimation. Some theorists therefore contend that adaptation should be evaluated through the lens of insurance rather than investment, with society paying a premium not for an expected return but for the curtailment of catastrophic variance. The distributional dimension is thornier still. Mitigation is a global public good; adaptation is stubbornly parochial. The wealthy can fortify their coastlines and air-condition their cities, while the poor, who have contributed least to the problem, possess neither the fiscal capacity nor the institutional machinery to insulate themselves. Left to markets, adaptation thus threatens to entrench existing inequities, transforming a shared atmospheric predicament into a ledger of differential survival. Whether the international community can engineer transfers commensurate with this asymmetry—or whether adaptation will simply ratify the privileges of the affluent—remains the unresolved moral arithmetic at the heart of the discipline.

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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 of the following best expresses the main argument of the passage?

  • Adaptation has been reconceived from a sign of failure into a defensible economic strategy, even as it raises difficult valuation and equity problems.
  • The chief obstacle to adaptation is the technical difficulty of building sea walls and developing drought-resistant crops.
  • Cost-benefit analysis offers a reliable framework for appraising adaptation once future cash flows are properly discounted.
  • Adaptation should now replace mitigation as the central focus of climate policy because emissions reductions have proven futile.
Phrase

全体の論旨：適応の位置づけの転換と残された難問

1級読解主旨把握論旨展開
⚡ひとことで

適応は「敗北」から慎重なヘッジへと再評価されつつあるが、評価と公平性の難問が残る。

選択肢の解説Choice Analysis

「Adaptation has been reconceived from a sign of failure into a defensible economic strategy, even as it raises difficult valuation and equity problems.」

正解

第1段落で適応が「敗北の告白」から「prudent hedging（慎重なヘッジ）」へ rehabilitate されたと述べ、第2段落で評価（valuation）の困難、第3段落で分配・公平性（equity）の問題を提起する。この再評価＋二つの未解決問題という三部構成全体を要約しているため正解。本文は適応を擁護しつつも難点を強調する両義的な論調で、その均衡を捉えている。

  • 「Adaptation should now replace mitigation as the central focus of climate policy because emissions reductions have proven futile.」

    = 適応が緩和を完全に置換すべきだとする主張 ━ 本文は冒頭で『less a repudiation of mitigation』と明言し、両者の置換ではなく時間的分離だと述べるため矛盾。

  • 「The chief obstacle to adaptation is the technical difficulty of building sea walls and developing drought-resistant crops.」

    = 海岸堤防や耐乾性作物の建設技術が最大の障害だとする見方 ━ 本文の主眼は技術ではなく valuation と distribution の経済・倫理問題であり、論点を取り違えている。

  • 「Cost-benefit analysis offers a reliable framework for appraising adaptation once future cash flows are properly discounted.」

    = 割引を正しく行えば費用便益分析で適応を評価できるとする見解 ━ 第2段落は CBA が defensive expenditures を『undervalue』すると批判しており、本文と正反対。

▦Collocation
パターン意味例
a tacit admission of ~~の暗黙の認めAdaptation was a tacit admission of defeat.
forestall + 名詞~を未然に防ぐmeasures to forestall catastrophe
rehabilitate A as BAをBとして再評価・復権させるeconomists rehabilitate adaptation as hedging
a concession that ~~という譲歩・認容a concession that prevention had failed
temporally decoupled時間的に切り離されたthe two goals are temporally decoupled
❝例文

  • The report reframes adaptation as prudent hedging rather than capitulation.

    その報告書は適応を降伏ではなく慎重なヘッジとして捉え直している。

  • Critics dismissed the plan as a tacit admission that mitigation had failed.

    批判者はその計画を緩和の失敗を暗に認めるものだと退けた。

  • The benefits of the two policies are temporally decoupled.

    二つの政策の便益は時間的に切り離されている。

  • Aggressive intervention may forestall the worst outcomes.

    積極的な介入が最悪の結果を未然に防ぐかもしれない。

💡Tip · 覚えるコツ

C2 の主旨設問では、賛否どちらかに振り切った選択肢は罠であることが多い。本文が『擁護しつつ留保する』両義的トーンを取るとき、正解も同じ均衡（再評価＋問題提起）を保つ。冒頭と各段落の topic sentence だけを連結し、論の骨格を再構成してから選択肢を照合せよ。

問 2

According to the passage, why does conventional cost-benefit analysis tend to undervalue adaptation measures such as levees?

  • Their benefits accrue across centuries and continents rather than within a single generation.
  • Their returns are contingent and become visible only in disasters they prevent, while discounting and fat-tailed hazards further depress their apparent value.
  • Markets systematically overstate the probability of rare but ruinous flood events.
  • Levees are too expensive to construct relative to the floods they are designed to prevent.
Phrase

levee / counterfactual / discounting / fat-tailed

1級読解詳細評価の困難
⚡ひとことで

防御支出の便益は回避された災害という反実仮想でしか現れず、割引とファットテールが価値を過小評価させる。

選択肢の解説Choice Analysis

「Their returns are contingent and become visible only in disasters they prevent, while discounting and fat-tailed hazards further depress their apparent value.」

正解

第2段落は『A levee that holds confers no measurable benefit in a year without floods; its value materialises only in the counterfactual disaster it averts』と述べ、便益が contingent で不可視だと指摘する。さらに discounting が defensive expenditures を undervalue し、fat-tailed distributions が確率推定を困難にすると続く。これらの複合要因を正確に統合した選択肢が正解。

  • 「Levees are too expensive to construct relative to the floods they are designed to prevent.」

    = 堤防が予防する洪水に比して建設費が過大だとする説明 ━ 本文はコスト過大ではなく便益の不可視性・割引・確率分布を問題にしており、論点が異なる。

  • 「Their benefits accrue across whole centuries and across continents rather than within the span of any single generation, which makes them difficult to price.」

    = 便益が世代を超え大陸規模に拡散するため過小評価される ━ それは第1段落で『緩和（mitigation）』の特徴として述べられたもの。適応はむしろ local と明言され、混同している。

  • 「Markets systematically overstate the probability of rare but ruinous flood events.」

    = 稀で破滅的な洪水の確率を市場が過大に見積もる ━ 本文は確率が『defy confident estimation』＝推定困難とするだけで、過大評価とは述べておらず捏造。

▦Collocation
パターン意味例
confer a benefit on ~~に便益を与えるThe levee confers no benefit in a calm year.
materialise in ~~の形で現実化するIts value materialises in averted disaster.
predicated on ~~を前提としたanalysis predicated on discounting
fat-tailed distribution裾の重い分布（稀で甚大）hazards with fat-tailed distributions
defy estimation推定を寄せつけないprobabilities that defy confident estimation
❝例文

  • The policy's value materialises only in the crisis it averts.

    その政策の価値は回避した危機においてのみ現れる。

  • Their model is predicated on a low discount rate.

    彼らのモデルは低い割引率を前提としている。

  • Tail risks defy confident estimation.

    テールリスクは確信をもった推定を拒む。

  • A successful defence confers no visible benefit.

    成功した防御は目に見える便益を与えない。

💡Tip · 覚えるコツ

複数要因を列挙する詳細設問では、正解は本文中の根拠を漏れなく束ねる。誤答は『一要因だけ抜き出す』か『別段落の特徴を流用する』のいずれか。段落をまたいで属性が入れ替わっていないか（適応 vs 緩和）を必ず確認せよ。

問 3

What does the passage identify as the distributional problem posed by relying on markets to deliver adaptation?

  • Adaptation, like mitigation, is a global public good that markets reliably underprovide for everyone equally.
  • Markets allocate adaptation efficiently, so the burden falls fairly on those who emitted the most.
  • Because adaptation is local and resource-dependent, market provision tends to entrench inequities, leaving the poorest least able to protect themselves.
  • International transfers have already corrected the asymmetry between rich and poor nations.
Phrase

parochial / public good / entrench inequities

1級読解詳細分配の問題
⚡ひとことで

適応はparochial（局所的）ゆえ、市場任せでは富者が身を守り既存の不平等を固定化する。

選択肢の解説Choice Analysis

「Because adaptation is local and resource-dependent, market provision tends to entrench inequities, leaving the poorest least able to protect themselves.」

正解

第3段落は『Mitigation is a global public good; adaptation is stubbornly parochial』と対比し、富者は海岸を補強・冷房できるが貧者は財政力も制度も持たないと述べる。そして市場任せでは『entrench existing inequities』に至ると明言する。この局所性→資源格差→不平等固定化の連鎖を捉えた選択肢が正解。

  • 「Markets allocate adaptation efficiently, so the burden falls fairly on those who emitted the most.」

    = 市場が効率的で、排出の多い者に負担が公正に落ちる ━ 本文は逆に、排出責任が最も小さい貧者が最も脆弱（contributed least）と述べ矛盾。

  • 「Adaptation, much like mitigation itself, is a global public good that markets reliably underprovide for every population equally, irrespective of wealth.」

    = 適応も緩和同様グローバル公共財で皆に等しく過少供給される ━ 本文は適応を public good ではなく『parochial』と明確に区別しており誤り。

  • 「International transfers have already corrected the asymmetry between rich and poor nations.」

    = 国際移転が既に貧富の非対称を是正した ━ 本文は是正可能かを『remains unresolved』＝未解決とし、達成済みとは述べていない。

▦Collocation
パターン意味例
stubbornly parochial頑固なまでに局所的adaptation is stubbornly parochial
entrench inequities不平等を固定化するmarkets entrench existing inequities
fiscal capacity財政的余力the poor lack fiscal capacity
institutional machinery制度的仕組みthe institutional machinery to insulate
commensurate with ~~に見合ったtransfers commensurate with the asymmetry
❝例文

  • Unregulated provision tends to entrench existing inequities.

    規制なき供給は既存の不平等を固定化しがちだ。

  • Poorer regions lack the fiscal capacity to adapt.

    貧しい地域は適応のための財政的余力を欠く。

  • The response must be commensurate with the threat.

    対応は脅威に見合ったものでなければならない。

  • Adaptation remains stubbornly parochial in its benefits.

    適応はその便益において頑固なまでに局所的なままだ。

💡Tip · 覚えるコツ

対比構造（A is X; B is Y）を含む段落では、設問はしばしば一方の属性を他方に貼り替えて誤答を作る。『mitigation=公共財／adaptation=parochial』の対比を固定し、選択肢で属性が交差していないか機械的に照合するとよい。

残り2問は、解いて確かめられます

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