محیط‌زیست: علت‌ها و پیامدهاThe environment: causes and consequences

Long causal chains: participles, sentential which and the perfect passive

استدلال زیست‌محیطی به‌ندرت یک علت و یک معلول است؛ زنجیره است، و انگلیسی گرامری دارد که برای زنجیره‌کردن ساخته شده، بی‌آنکه پنج جملهٔ جدا بنویسی. عبارت وصفی (درس ۱۵) علت را درون یک جمله به پیامدش وصل می‌کند: «Drained for irrigation, the lake shrank by two-thirds.» «Having lost its inflow, the wetland dried within a decade.» whichِ جمله‌ای (درس ۱۷) پیامدی را به همهٔ آنچه پیش از آن آمده آویزان می‌کند: «The wells were never licensed, which made enforcement impossible.» دقت کن به کل جمله ارجاع می‌دهد نه به یک اسم — و دقیقاً همین الگو می‌گذارد زنجیره بسازی: A, which caused B, which in turn led to C. عبارت in turn را برای همین ارزش دارد از بر کنی. مجهولِ حال کامل وضعیتی انباشته و همچنان برقرار را بیان می‌کند: «The aquifer has been depleted» — نه was depleted، چون تحلیل‌رفتگی وضعیت کنونیِ جهان است. و برای تمایز کلیدیِ این درس، انگلیسی ماشه را از علت و از عامل کمکی جدا می‌کند: the drought triggered it؛ over-extraction caused it؛ poor enforcement contributed to it. مفید دیگر: X is largely / partly / primarily responsible for Y، و تعدیلِ صادقانهٔ X is one factor among several.

Environmental argument is rarely one cause and one effect; it is a chain, and English has grammar built for chaining without writing five separate sentences. THE PARTICIPLE CLAUSE (lesson 15) links a cause to its consequence inside one sentence: "Drained for irrigation, the lake shrank by two-thirds." "Having lost its inflow, the wetland dried within a decade." THE SENTENTIAL WHICH (lesson 17) hangs a consequence off everything that came before it: "The wells were never licensed, which made enforcement impossible." Note it refers to the whole clause, not to a noun — and this is exactly the pattern that lets you build a chain: A, which caused B, which in turn led to C. The phrase in turn is worth memorising for this. THE PRESENT PERFECT PASSIVE states an accumulated, still-standing situation: "The aquifer has been depleted" — not was depleted, because the depletion is the present state of the world. And for the crucial distinction in this lesson, English separates TRIGGER from CAUSE and from CONTRIBUTING FACTOR: the drought triggered it; over-extraction caused it; poor enforcement contributed to it. Also useful: X is largely / partly / primarily responsible for Y, and the honest hedge X is one factor among several.