Đề thi thử số 14 — Reading 40 câu (có bài đọc)

The concept of a circular economy has gained significant traction in recent years as a sustainable alternative to the traditional linear economic model. In a linear economy, raw materials are extracted, manufactured into products, used briefly, and then discarded as waste—a "take-make-dispose" approach that is fundamentally unsustainable. The circular economy, by contrast, is designed to eliminate waste and keep products, components, and materials in use for as long as possible through reuse, repair, refurbishment, remanufacturing, and recycling.

The European Union has been at the forefront of circular economy policies, with its Circular Economy Action Plan adopted in 2020 setting ambitious targets for sustainability. The plan includes measures to make products more durable, improve reparability, increase recycled content, and reduce single-use packaging. Other countries, including China, Japan, and Canada, have also implemented national circular economy strategies, recognizing the economic and environmental benefits of moving away from a purely linear model.

Businesses are increasingly recognizing the opportunities in circular models. Major companies like Patagonia, IKEA, and Rolls-Royce have built successful business models around circular principles. Patagonia's "Worn Wear" program encourages customers to repair and resell used clothing, while IKEA has pledged to become "climate positive" by 2030, in part through using only renewable or recycled materials. Rolls-Royce's "Power by the Hour" program sells jet engine availability rather than the engines themselves, incentivizing durability and continuous maintenance. These examples demonstrate that circularity can be both environmentally responsible and economically profitable.

However, transitioning to a circular economy is not without challenges. Many existing products were not designed with circularity in mind, making them difficult or impossible to repair or recycle. Consumer habits, built around convenience and disposability, can be slow to change. Infrastructure for collection, sorting, and processing of used products is often inadequate. Perhaps most fundamentally, transitioning to circularity requires rethinking business models, supply chains, and even the relationship between producers and consumers. Despite these challenges, the circular economy represents a promising path toward a more sustainable future, and momentum is building across governments, businesses, and civil society.

Globally, approximately one-third of all food produced for human consumption is lost or wasted—a staggering figure that translates to about 1.3 billion tons per year according to the United Nations. This waste occurs at every stage of the food supply chain, from harvesting and storage to processing, distribution, and consumption. In developed countries, the majority of food waste occurs at the consumer level, with households throwing away food that is still perfectly edible. In developing countries, by contrast, most food loss happens earlier in the supply chain due to inadequate storage, poor infrastructure, and limited market access for small farmers.

The environmental impact of food waste is profound. When food is discarded in landfills, it decomposes and produces methane, a greenhouse gas roughly 25 times more potent than carbon dioxide in trapping heat in the atmosphere. The resources used to produce food that is never eaten—land, water, energy, fertilizers—are also wasted. The carbon footprint of food waste, if it were a country, would rank as the third-largest emitter of greenhouse gases globally, behind only the United States and China. Additionally, food waste represents a massive waste of the freshwater resources used in agriculture.

The economic costs of food waste are equally significant. In the United States alone, an estimated $408 billion is spent on food that is never eaten. For an average family of four, this translates to roughly $1,500 per year thrown in the trash. Globally, the economic value of food waste exceeds $1 trillion annually, a figure that includes both the cost of the wasted food and the resources used to produce it. These numbers are particularly troubling given that an estimated 828 million people worldwide go hungry, suggesting that solving food waste could significantly alleviate global hunger.

Addressing food waste requires action at multiple levels. Individual consumers can reduce waste by planning meals, storing food properly, using leftovers creatively, and composting organic waste. Businesses can improve inventory management, donate surplus food to charities, and redesign packaging to extend shelf life. Governments can implement policies that standardize date labels, provide tax incentives for food donations, and invest in cold chain infrastructure to reduce losses in developing countries. Some innovative solutions are also emerging, including apps that connect consumers with surplus food from restaurants and grocery stores at reduced prices, turning what would be waste into affordable meals while reducing environmental impact.

The transition from fossil-fuel-based materials to renewable alternatives represents one of the most important sustainability challenges of our time. For over a century, industrial production has relied heavily on materials derived from petroleum—plastics, synthetic fibers, chemical fertilizers, and many others. While these materials have enabled extraordinary technological progress, their environmental costs—from carbon emissions to plastic pollution—are increasingly unsustainable. Renewable materials, derived from plants, algae, fungi, bacteria, or waste streams, offer a promising path toward a more sustainable materials economy.

Bio-based plastics, made from sources like corn starch, sugarcane, or cellulose, are among the most well-known renewable materials. Unlike conventional plastics, which can take hundreds of years to break down, many bio-based plastics are biodegradable or compostable under the right conditions. They also have a smaller carbon footprint during production, as the plants used to make them absorb CO2 from the atmosphere as they grow. However, bio-based plastics are not without controversy—their production can compete with food crops for agricultural land, and not all bio-based plastics are actually biodegradable in real-world conditions.

Beyond plastics, scientists and engineers are developing renewable alternatives across many industries. Mycelium—the root structure of mushrooms—can be grown into packaging materials, building insulation, and even leather-like textiles. Algae is being used to produce everything from biofuels to food supplements to bioplastics. Agricultural waste, such as rice husks, sugarcane bagasse, and corn stover, is being converted into building materials, paper, and bioplastics. These innovations demonstrate that waste streams can be transformed into valuable resources, embodying the principles of a circular economy.

Despite significant progress, the widespread adoption of renewable materials faces barriers. Production costs are often higher than for conventional materials, although this gap is narrowing as technology improves and economies of scale are achieved. Performance characteristics can differ—some renewable materials may not yet match the durability or versatility of their fossil-fuel counterparts. Consumer awareness and acceptance vary, and infrastructure for processing and recycling renewable materials is still developing in many places. Government policies, including incentives for renewable material production and regulations limiting single-use plastics, are helping to level the playing field. As research continues and markets mature, renewable materials are likely to play an increasingly important role in building a sustainable future.

Sustainable architecture, also known as green building or eco-architecture, refers to the design, construction, and operation of buildings in ways that reduce their environmental impact. As buildings account for approximately 40 percent of global energy consumption and 33 percent of greenhouse gas emissions, the way we design and construct our built environment has profound implications for climate change and resource use. Sustainable architecture seeks to minimize this impact through energy efficiency, use of renewable materials, water conservation, and creation of healthy indoor environments.

Several key strategies define sustainable architecture. Passive design strategies take advantage of the local climate and site conditions to reduce the need for mechanical heating, cooling, and lighting—for example, orienting a building to maximize natural daylight, using thermal mass to regulate indoor temperatures, and designing natural ventilation pathways. Active systems like solar panels, geothermal heat pumps, and high-efficiency HVAC systems further reduce energy use. Water-saving fixtures, rainwater harvesting, and greywater recycling help conserve water. Using locally sourced, recycled, or rapidly renewable materials reduces the embodied carbon of a building—the emissions associated with manufacturing and transporting construction materials.

The benefits of sustainable buildings extend beyond environmental impact. Occupants of green buildings often report better health, comfort, and productivity. Improved indoor air quality, abundant natural light, and thermal comfort contribute to well-being and can reduce absenteeism and increase cognitive performance. While green buildings can have higher upfront costs—typically 1 to 5 percent more than conventional construction—these costs are often recouped through lower operating expenses, with many green buildings achieving energy savings of 30 to 50 percent or more over their lifetimes. As energy prices rise and the cost of sustainable technologies continues to fall, the financial case for green buildings is becoming increasingly compelling.

Certification systems like LEED (Leadership in Energy and Environmental Design) and BREEAM (Building Research Establishment Environmental Assessment Method) have helped standardize and promote sustainable building practices worldwide. These systems award points for various sustainability features, with buildings receiving ratings from certified to platinum based on the total points achieved. Many countries now have their own green building certification programs adapted to local conditions. As awareness of climate change grows and the urgency of reducing carbon emissions intensifies, sustainable architecture is moving from a niche concern to a mainstream expectation. The buildings of the future will not only shelter us—they will actively contribute to a healthier planet.