Academic Reading Articles Practice 14 Test 03

A
Cities are frequently warmer than their surrounding countryside, a pattern known as the urban heat island effect. One reason is albedo: dark roof membranes and asphalt surfaces reflect little sunlight and instead absorb solar radiation, converting it into heat that is released back into the air. Another reason is urban form. Dense building clusters restrict airflow, store heat in concrete and brick, and reduce nighttime cooling. In this context, green roofs—engineered layers of growing medium and vegetation installed on rooftops—have moved from architectural curiosity to a practical policy tool. By turning previously “unused” roof area into living surface, they can cool buildings, slow stormwater runoff, and provide small pockets of habitat. The approach is not a single solution to urban warming, but it offers a way to modify the physics of rooftops at scale, especially in districts where ground-level space for new parks is limited.

B
Not all green roofs are built for the same purpose, and the design differences have consequences. Extensive roofs typically use a shallow substrate, often only a few centimetres deep, and support hardy, drought-tolerant plants such as sedum, mosses, and certain grasses. Because they are relatively light and need minimal maintenance, they can be installed on many existing buildings with limited structural reinforcement. Intensive roofs, by contrast, use deeper soil layers that can sustain shrubs and sometimes small trees, creating spaces that resemble elevated gardens. These systems are heavier and require stronger structural support, as well as more irrigation and regular upkeep. Designers also consider local climate, wind exposure, drainage layers, and intended use. A roof meant mainly for insulation and runoff control may prioritise resilient plants and low weight, while a roof intended for recreation may prioritise aesthetics, accessibility, and biodiversity.

C
The best-documented benefit of green roofs is thermal regulation. Vegetation shades the roof surface, lowering the temperature of materials that would otherwise heat rapidly in direct sun. More importantly, plants cool the surrounding air through evapotranspiration, a process in which water is transported from the substrate through plant tissues and released as vapour. This phase change requires energy, so heat is absorbed as latent heat flux rather than remaining as sensible heat that warms the roof and indoor spaces. In summer, this can reduce heat entering the building, lowering demand for air conditioning. If adoption is widespread, it can also reduce the overall heat island intensity by decreasing the amount of heat stored and re-radiated by roofs. However, performance depends on moisture and plant health. In prolonged drought, a dry roof provides less evaporative cooling, and stressed vegetation can reduce coverage, limiting the benefits that planners often assume in ideal conditions.

D
Stormwater management is another major motivation, particularly in cities where drainage systems are strained by intense rainfall. Conventional roofs shed water quickly into gutters and pipes, contributing to flash flooding and, in some older systems, sewage overflows. Green roofs can alter this pattern by storing rainwater temporarily in their substrate and vegetation. Some of the water is retained and later returned to the atmosphere through evaporation and plant transpiration, while some is detained—released more slowly as delayed drainage. This reduction in peak flow can relieve pressure on urban infrastructure, a benefit sometimes described as “peak shaving.” Yet the limits are important. During saturated conditions, when the substrate has already absorbed as much water as it can hold, additional rainfall produces more runoff. Extreme storms can therefore overwhelm the storage capacity, meaning that green roofs reduce—but do not eliminate—flood risk.

E
Biodiversity gains are possible, but they are not automatic. Many green roofs use a narrow palette of drought-tolerant species and create relatively simple habitats that support fewer insects and birds. More diverse plantings, combined with microhabitats such as varied soil depths, stones, or small logs, can provide resources for pollinators and offer nesting or shelter opportunities. In well-planned networks, roofs can act as “stepping stones” that help species move between parks and other green spaces, partially offsetting habitat fragmentation at street level. Even so, ecological success depends on roof height, isolation, and local air pollution, as well as on long-term maintenance. Some roofs become ecological “islands,” supporting limited communities that cannot easily connect to other habitats. As a result, biodiversity benefits tend to be highest where roof design is deliberately tailored to local species and where green roofs are treated as part of an urban ecological system rather than decorative landscaping.

F
Economic and policy considerations largely determine whether green roofs spread beyond pilot projects. Installation costs can be substantial, particularly for intensive roofs that require reinforced structures, irrigation systems, and public access measures. Maintenance is also commonly underestimated, since living systems need monitoring, replanting, and drainage checks. On the other hand, green roofs can protect roof membranes by shielding them from ultraviolet radiation and large temperature swings, potentially extending the roof’s service life and reducing replacement costs. Energy savings may offset expenses in some building types and climates, but outcomes depend on local energy prices and the quality of design. Policy has accelerated adoption in several cities through mandates for new developments or through incentives such as tax rebates, density bonuses, and grants. However, critics argue that rigid requirements can encourage minimal “tick-box” installations that meet the letter of the rule while delivering limited performance. Supporters respond that well-written standards and inspection regimes can improve quality over time by pushing the market toward skilled design and reliable installation.

G
Practical constraints mean that green roofs are rarely a universal solution. Water use is a sensitive issue in dry climates: irrigation may conflict with conservation goals unless drought-tolerant planting and recycled water are used. Added weight can be a barrier for older buildings, and poor drainage design can increase leak risk or create maintenance problems if water pools where it should not. Safety and access requirements can raise costs, particularly if roofs are intended for public use, and building owners may be reluctant to accept new liabilities. For these reasons, the “revolution” in green roofs is less about a single technology than about integrated planning and long-term stewardship. Cities that treat roofs as living infrastructure—monitored, upgraded, and connected to broader heat, water, and biodiversity strategies—are more likely to achieve durable benefits than those that treat green roofs as cosmetic additions. In that sense, green roofs are most effective when targeted to suitable buildings and when supported by design expertise, maintenance capacity, and realistic policy goals.

A
Deep-sea mining refers to the extraction of mineral resources from the seabed, commonly at depths of several kilometres where pressure is extreme and ecosystems function under chronic scarcity. Interest has surged because metals such as nickel, cobalt, copper, and manganese are central to batteries, wind turbines, and other low-carbon technologies. Governments and firms also worry about geopolitical leverage: some high-grade terrestrial deposits are concentrated in a small number of regions, exposing supply chains to instability, export controls, or conflict. Proponents argue that seabed resources could diversify supply and reduce dependence on politically sensitive sources. Critics respond that shifting extraction offshore does not eliminate risk; it relocates it to an environment that is poorly understood and potentially difficult to remediate once disturbed.

B
Among the most frequently discussed targets are polymetallic nodules, potato-sized concretions scattered across vast abyssal plains. These nodules contain concentrated metals, typically bound within layered mineral structures that form around a nucleus over millions of years. On human timescales, this makes them effectively non-renewable. Industrial collection would require vehicles that crawl across the seabed, vacuuming nodules and disturbing the upper sediment layer that has accumulated slowly in the absence of strong currents. Unlike many shallow coastal habitats, the abyss is characterised by low temperatures, low food availability, and slow biological turnover. Many organisms are long-lived and reproduce infrequently, so even a physically “thin” disturbance can translate into long recovery horizons. Because nodules also provide hard substrate in an otherwise soft-sediment environment, removing them can eliminate attachment points that certain specialised species depend on.

C
Ecological concern is not limited to the area directly scraped by machinery. Mining activity can generate turbidity and sediment plume clouds as fine particles are resuspended and transported by currents. These plumes may drift well beyond the mined track, settling on organisms and potentially smothering animals or clogging the feeding structures of filter feeders. Noise and vibration add additional stressors in an environment where some species rely on pressure cues and low-frequency sound to navigate or communicate. Artificial light from vehicles and sensors may also disrupt organisms adapted to near-total darkness, altering behaviour and predation dynamics. Moreover, processing ships at the surface can create secondary plumes if wastewater or sediment-laden discharge is released back into the ocean. Because deep-sea impacts can be spatially diffuse, defining the true footprint of a project is complex and may depend on local hydrodynamics that are not fully mapped.

D
The economic argument for seabed extraction tends to emphasise urgency. Rapid electrification is expected to expand demand for critical minerals, and expanding terrestrial mining can bring its own environmental and social harms, including deforestation, toxic tailings, and community displacement. Proponents therefore claim deep-sea mining might offer a smaller land footprint and possibly reduce some onshore impacts. However, the business case is constrained by costs and operational uncertainty. Working at extreme depth requires specialised robotics, durable riser systems to lift material, and continuous maintenance in harsh conditions. Energy use is significant, logistics are complex, and the financial model must account for volatile commodity prices. Firms also face reputational and regulatory risk: if projects become associated with irreversible ecological harm, they may lose customers, investors, or permits. In this sense, the economic calculus is inseparable from societal tolerance for ecological uncertainty.

E
Governance is central because many proposed mining areas lie beyond national jurisdiction. In those regions, the International Seabed Authority (ISA), established under the UN Convention on the Law of the Sea, issues exploration contracts and is developing rules for potential commercial extraction. Supporters argue that a formal regulatory body provides a pathway for oversight, standards, and benefit-sharing. Critics counter that the framework remains incomplete and that enforcement capacity is uncertain at the scale implied by industrial operations. They also point to a potential conflict in mandate: encouraging resource development while also protecting the marine environment. As a result, some governments, scientists, and civil society organisations argue for applying the precautionary principle, calling for a moratorium or precautionary pause until stronger safeguards, baseline knowledge, and monitoring systems are in place.

F
Scientific uncertainty is not a peripheral issue but the core of the dilemma. Deep-sea biodiversity is still being catalogued, and many species are known from only a handful of samples, making it difficult to predict how disturbance will propagate through food webs. Baseline studies must capture natural variability—seasonal patterns, episodic food falls, and multi-year shifts—yet such datasets can require years to assemble. Monitoring recovery is also difficult: sensors must function reliably under high pressure, and ecological change may unfold over decades. These challenges intersect with the debate about need. Alternatives to seabed mining include improved recycling of batteries and electronics, redesigns that reduce reliance on scarce metals, and new battery chemistries that substitute more abundant materials. Yet each alternative has limits. Recycling depends on collection systems and a time lag as products reach end-of-life, while new chemistries must meet stringent safety and performance requirements. As a result, the pace of innovation influences how “urgent” seabed extraction appears, and uncertainty remains on both the ecological and technological sides of the ledger.

G
Public debate increasingly turns on values as well as facts. One view is that mining the deep ocean repeats a familiar historical pattern: exploiting an ecosystem before understanding it, then struggling to restore damage that proves effectively permanent. Another view is that the climate transition requires materials at scale, and that refusing seabed resources may shift extraction pressure onto communities near terrestrial mines, where harms are visible and immediate. Comparing these harms across places and times is inherently difficult under uncertainty, especially when costs and benefits are distributed unevenly between consumers, producers, and distant ecosystems. Consequently, the dilemma is not simply “resources versus ecology,” but how to make decisions when knowledge is incomplete. Many commentators argue that if mining proceeds at all, it should be under robust governance with transparent science, credible monitoring, and cautious thresholds that aim to keep choices reversible. At the same time, investment in demand reduction and circular-economy strategies is presented as a way to ensure the deep sea is not treated as a default solution to resource pressure.

Fast fashion is often described as a triumph of responsiveness: designs move from catwalk or screen to storefront in weeks, prices appear unusually low, and consumers are offered a steady stream of novelty. Yet the system is better understood as an economic arrangement in which much of the cost is treated as an externality—borne not by the brand at the checkout but by workers, ecosystems, and public waste systems. The business model depends on rapid inventory turnover and “scarcity tactics” such as frequent drops that create urgency and fear of missing out. Social media accelerates this cycle by converting clothing into fast-moving content, shortening what counts as “current” and rewarding constant reinvention. Over time, consumers can be pulled into a hedonic treadmill: satisfaction is temporary, and the next purchase is framed as the quickest path back to feeling updated. The result is a market in which garments are valued less as durable goods and more as disposable signals.

Overproduction is the engine that keeps this system running. Retailers place large orders to avoid stock-outs and to ensure that a wide range of sizes and styles are always available, but the arithmetic makes waste unavoidable: when output is designed to exceed likely demand, surplus becomes structural rather than accidental. Unsold items may be discounted repeatedly, returned to warehouses, or in some cases destroyed to protect brand positioning and avoid secondary-market competition. A substantial share is exported as second-hand bales, often to countries with limited capacity to absorb the volume. While donation and resale can extend the life of individual items, these channels are frequently overwhelmed by the scale of production and by the low quality of many garments, which limits their resale value. In receiving markets, imported clothing can undercut local textile industries and flood informal systems that lack robust waste collection, shifting the disposal problem across borders.

Material choices compound these pressures. Many low-cost garments rely on synthetic fibres such as polyester, which are derived from fossil-fuel inputs and engineered for durability in ways that can become an environmental liability. During washing, polyester and other synthetics can shed microfibres that enter wastewater streams and contribute to microplastic pollution. Such particles may persist in rivers and coastal waters and, through bioaccumulation, can move through food webs. Cotton presents different trade-offs: it may require heavy water use and pesticide inputs depending on how it is grown and processed, and its impacts vary widely by region and farming practice. Blended fabrics—common examples include poly-cotton mixes—are attractive to brands because they can hit a desired price point and texture, but they complicate circularity. Separating mixed fibres is chemically and mechanically difficult, and many blends cannot be efficiently recycled into high-quality new textiles, leaving downcycling or disposal as the default outcome.

Chemical use is another hidden cost, particularly during dyeing and finishing. Achieving colour fastness, softness, wrinkle resistance, or water repellency can involve large volumes of water and a complex suite of treatments. In regions where regulation or enforcement is weak, wastewater may be discharged without adequate treatment, releasing dyes and other contaminants into local rivers. Even when brands publish “restricted substance lists,” supply chains are often opaque and fragmented, with multiple tiers of subcontractors performing specialised steps. Monitoring every subcontractor consistently is difficult, especially when production timelines are compressed. As a result, compliance on paper can coexist with high environmental risk on the ground, and the harms are frequently concentrated in communities that have limited political leverage to demand remediation.

Labour conditions sit at the centre of the “true cost” debate because the speed-and-price model creates a race to the bottom. Garment work can provide crucial income and entry into formal employment, yet low unit prices and sudden design changes push factories to deliver more for less. During peak seasons, workers may face long hours, unstable contracts, and wage theft through unpaid overtime. The fragmentation of production can hide violations: unauthorised subcontracting may shift orders to unapproved sites that lack proper safeguards, allowing brands to claim ignorance while still benefiting from the output. Brands often point to audits and codes of conduct, but audits are snapshots in time. Factories can coach staff, tidy conditions temporarily, or move the most demanding work to locations that auditors do not visit. Moreover, purchasing practices can undermine ethical commitments: if a brand demands last-minute changes, short lead times, and lower prices, factories may meet the deadline by extending hours, cutting corners on safety, or outsourcing tasks beyond the approved chain.

Waste is where the system becomes most visible to the public, but it is also where easy solutions are most elusive. Clothing worn only a few times has a high footprint per wear, even if each item is cheap. Recycling is frequently promoted as a remedy, yet textile-to-textile recycling remains technically complex and relatively rare at scale. Garments contain mixed fibres, elastane content, zips, buttons, labels, and dye residues that complicate processing and reduce the quality of recycled output. Downcycling into insulation or cleaning rags can postpone disposal, but it does not produce an equivalent new garment, meaning it does not close the loop. In effect, the volume of waste generated by fast fashion often exceeds the capacity of current recycling infrastructure, leaving landfilling and incineration as persistent endpoints.

Policy and business reforms are therefore gaining attention, especially mechanisms designed to realign incentives. Extended Producer Responsibility (EPR) is one approach that attempts to shift some waste costs back onto brands by making them financially or operationally responsible for collection, sorting, and end-of-life processing. In theory, EPR encourages eco-design—greater durability, fewer mixed materials, and easier disassembly—because brands that create hard-to-manage waste would face higher compliance costs. Some companies also explore repair services, resale, rental, and take-back schemes, but their impact depends on logistics, consumer participation, and whether the economics work beyond niche markets. Critics argue that efficiency improvements alone will not solve the problem if total consumption keeps rising; without demand-side change, gains can be absorbed by continued growth in volume. The “true cost” question is therefore about trade-offs: cheaper clothing can help households with limited budgets, but it can also normalise disposability and externalise harm to workers and communities with little voice. A more sustainable system likely requires a combination of material innovation, stronger labour protections, transparent purchasing practices, and slower consumption so that value is measured across the full lifecycle of what is worn, repaired, and ultimately discarded.