IELTS Academic Reading Practice Test 32

For thousands of years, the narrow strip of land between the Mediterranean and the Red Sea, known as the Isthmus of Suez, forced an awkward choice upon anyone who wished to move goods between Europe and Asia. Cargo could be unloaded and carried overland to a port on the other side, or ships could make the long voyage around the southern tip of Africa.

The idea of a waterway linking the two seas was therefore an ancient one. Several rulers of ancient Egypt, and later the Persian king Darius I, are known to have built or restored canals connecting the Red Sea with the Nile, and so indirectly with the Mediterranean. These early channels were difficult to maintain, however, because wind-blown sand steadily filled them, and each was eventually abandoned.

Interest revived when French forces under Napoleon Bonaparte occupied Egypt in 1798. Napoleon asked his engineers to investigate whether a direct canal could be built, and a survey team led by Jacques-Marie Le Père spent many months measuring the land between the two seas. Their conclusion was discouraging. According to their calculations, the surface of the Red Sea lay several metres above that of the Mediterranean, which implied that an open channel would allow seawater to pour northwards and flood low-lying land. Later surveys showed that the two seas are at almost exactly the same level, but the mistake was not widely recognised for several decades, and it helped to postpone serious planning for about half a century.

The man who finally turned the idea into reality was Ferdinand de Lesseps, a former French diplomat with no engineering training. In 1854 he obtained a concession from Said Pasha, the ruler of Egypt, whom he had known since Said's youth, allowing him to form a company to build and operate a canal across the isthmus. The Suez Canal Company was established in 1858, and its shares were bought mainly by French investors, with the Egyptian ruler acquiring a large part of the remainder. Britain, which feared that a waterway under French influence might threaten its routes to India, opposed the project for years and did little to help it.

Construction began in April 1859 at the site on the Mediterranean coast that would become Port Said. From there the planned route ran south for more than 160 kilometres across a landscape of sand, marsh and shallow salt lakes, including Lake Timsah and the Great Bitter Lake. The greatest practical problem of the early years was not the sand itself but water. Thousands of labourers needed something to drink, and in the desert this had to be transported over long distances by camel, at considerable expense. To solve the problem, the company dug a freshwater channel from the Nile to the middle of the isthmus, where the new town of Ismailia was founded on the shore of Lake Timsah.

During the first years, most of the digging was done by hand. Large numbers of Egyptian peasants were conscripted under a system of compulsory labour and worked in rotation, often using simple tools and carrying earth away in baskets. Conditions were harsh, and outbreaks of disease, including cholera, caused many deaths. How many workers died during the construction remains uncertain. Figures as high as 120,000 have sometimes been quoted, but historians have pointed out that no reliable records exist to support such estimates. In 1864, after Said's successor Ismail Pasha had come to power and criticism of the practice had grown in Europe, forced labour on the canal was brought to an end.

The loss of this workforce might have halted the project, but instead it transformed the way the work was done. The company recruited labourers from southern Europe and elsewhere around the Mediterranean, and it invested heavily in machinery. Its contractors developed steam-driven dredgers and excavators, together with long inclined chutes that carried the excavated spoil away from the channel and dumped it on the banks. These machines could move earth far faster than men with baskets, and in the later stages of construction most of the material was being removed mechanically rather than by hand. In 1869 water from the Mediterranean was finally allowed to flow into the dry basin of the Bitter Lakes, which slowly filled to sea level.

The canal was formally opened in November 1869 with lavish celebrations attended by European royalty, including the French Empress Eugénie. Unlike many later canals, it had no locks, since the water level was the same along its whole length. For ships sailing between Britain and India, it removed the need for the voyage around Africa, shortening the journey by thousands of kilometres and greatly reducing its duration. The financial costs, however, fell heavily on Egypt. Ismail's government accumulated enormous debts, and in 1875 he was forced to sell Egypt's shares in the company to the British government, which thereby gained a major stake in a project it had once opposed.

The canal has remained at the centre of international politics ever since. In 1956 the Egyptian president Gamal Abdel Nasser nationalised the company, provoking an invasion by Britain, France and Israel that was abandoned under international pressure. After the war of June 1967 the waterway was closed for eight years, leaving fifteen merchant ships trapped in the Great Bitter Lake until it reopened in 1975. More recently, a parallel channel about 35 kilometres long was opened in 2015 to allow two-way traffic along part of the route. In March 2021 the grounding of the container ship Ever Given blocked the canal for six days, a reminder of how much of the world's trade still depends on this narrow channel.

Peat is an unusual kind of soil. It consists of the partly decomposed remains of plants that have accumulated in places where the ground is permanently waterlogged. In most environments, dead leaves and stems are broken down quickly by bacteria and fungi, which need oxygen to do their work. In saturated ground, however, oxygen is scarce, decomposition slows almost to a halt, and plant material builds up faster than it decays. The process is extremely slow: a peatland typically grows by around a millimetre a year, so a deposit several metres deep may represent many thousands of years of accumulation. Peatlands occur on every continent, from the frozen north of Canada and Siberia to the swamp forests of the tropics, and together they cover about three per cent of the Earth's land surface.

Their importance far exceeds their size. Because the carbon taken from the air by growing plants is locked away in the peat rather than returned to the atmosphere, peatlands have become one of the largest stores of carbon on land. They are estimated to contain roughly twice as much carbon as all the world's forests combined. The difference is that a forest stores most of its carbon in living trees, which can grow back within decades if they are cut down, whereas a peatland's carbon has been gathered over millennia. Once released, it cannot be replaced on any timescale that matters to human societies.

Ecologists distinguish two main kinds of peatland. Fens are fed by groundwater or streams that have passed through mineral soils, so their water carries dissolved nutrients, and they support a varied vegetation of sedges, reeds and flowering plants. Bogs, by contrast, have grown so high above the surrounding land that they receive water only from rain and snow. Their water is therefore poor in nutrients and strongly acidic, and they are dominated by Sphagnum mosses. These mosses are remarkable engineers of their environment. Their cells can hold many times their own dry weight in water, so they keep the bog wet even in dry spells, and they release acids that further slow the activity of decomposing microbes.

The same conditions that preserve plant material also preserve much else. Pollen grains that fell onto a bog thousands of years ago remain in the peat layer by layer, allowing scientists to reconstruct how vegetation and climate changed over time. Archaeologists have recovered wooden trackways, weapons and containers of butter from bogs in northern Europe. Most famous are the so-called bog bodies, such as Tollund Man in Denmark, whose skin and facial features survived for more than two thousand years. Peat cut for fuel has therefore been an accidental source of some of the most detailed evidence we have about prehistoric life.

Despite their significance, peatlands remain surprisingly poorly mapped. In 2017 a team of British and Congolese scientists reported in the journal Nature that the swamp forests of the central Congo Basin conceal the most extensive peatland complex in the tropics, covering about 145,000 square kilometres. Its existence had been suspected, but its scale was unknown. The researchers combined satellite data with weeks of fieldwork, wading through flooded forest to measure the depth of the peat and extract samples. They calculated that the area holds about 30 billion tonnes of carbon, a quantity similar to that stored above ground in all the forests of the Congo Basin.

The main threat to peatlands is drainage. Over the past two centuries, vast areas have been drained for agriculture, for timber plantations and for the extraction of peat itself, which has been burned as fuel and sold as compost for gardens. When the water table falls, oxygen penetrates the peat and microbes begin to consume it, releasing carbon dioxide. The surface of drained land gradually sinks as the peat disappears. Dry peat also burns easily, and fires can smoulder below ground for weeks, making them extremely hard to extinguish. According to the Global Peatlands Assessment, published by the United Nations Environment Programme in 2022, degraded peatlands release around two billion tonnes of carbon dioxide equivalent each year, about four per cent of all emissions caused by human activity.

Restoring a damaged peatland begins with raising the water table again. Drainage ditches are blocked with dams made of peat, timber or plastic, and in some areas commercial conifer plantations are removed. One of the largest such efforts is taking place in the Flow Country of northern Scotland, a vast expanse of blanket bog where nearly a fifth of the land was drained and planted with trees during the twentieth century. Thousands of hectares of plantation have since been cleared, and in 2024 the Flow Country became the first peatland to be inscribed as a UNESCO World Heritage Site.

Restoration is not a quick or simple solution. Rewetted peat can initially release more methane, a powerful greenhouse gas, and it may take decades for Sphagnum to re-establish itself and for the bog to begin accumulating carbon again. Rewetting farmland also affects the people who depend on it, which is why researchers are developing paludiculture, the cultivation of crops such as reeds that tolerate wet ground. Most specialists agree, however, that the most cost-effective measure of all is the simplest: protecting the peatlands that remain intact before they need restoring.

Few words in the vocabulary of town planning carry as much disapproval as 'sprawl'. The term is generally used to describe the low-density, car-dependent growth that has spread outwards from cities across much of the world since the middle of the twentieth century: detached houses on large plots, shopping centres surrounded by car parks, and business parks reached only by motorway. Critics hold sprawl responsible for traffic congestion, high carbon emissions, the loss of farmland and even social isolation. Its defenders reply that it simply reflects what millions of households want, namely more space at a price they can afford. Both positions contain some truth, but both, I would argue, misunderstand the nature of the problem and therefore the nature of the solution.

The rapid suburban growth of the post-war decades is often treated as a peculiarly American phenomenon, and the United States certainly provided the most striking examples. Government-backed mortgages made home ownership possible for millions of families, builders mass-produced entire suburbs on former farmland, and the interstate highway programme launched in 1956 made long-distance commuting practical. Yet research led by the urban planner Shlomo Angel, who has mapped the growth of a large global sample of cities using satellite images, has shown that the same tendency appears almost everywhere. In the 1990s, the land occupied by the cities in his sample grew roughly twice as fast as their populations, which means that average densities were falling in rich and poor countries alike.

The costs of very low density are nonetheless real, and they are perhaps best illustrated by a comparison that the urban economist Alain Bertaud has made famous. In the 1990s the metropolitan areas of Atlanta and Barcelona had broadly similar populations. Atlanta's built-up area, however, was roughly twenty-six times larger. In Barcelona, about sixty per cent of the population lived within walking distance of a metro station; in Atlanta, a network of similar length served only about four per cent. Unsurprisingly, residents of Atlanta depended almost entirely on cars, and the carbon emissions from transport per person were many times higher than in the Spanish city.

Other costs are less visible. Roads, water pipes and sewers must be extended over far greater distances to serve each household at low density, so the cost of providing infrastructure per home is higher, and these costs are frequently borne by the existing taxpayers of a city rather than by the residents of new developments. Scattered development also fragments the habitats of wildlife and consumes agricultural land, and long journeys to work take time away from families and communities.

None of this, however, means that the outward growth of cities is unnatural or necessarily harmful. Cities have been spreading for well over a century, ever since railways and then trams first allowed workers to live at a distance from their workplaces. As incomes rise and transport becomes cheaper, people have consistently chosen to consume more living space, and the outward movement of the middle classes is as much a sign of prosperity as of poor planning. For many lower-income families, a house on the edge of a city has been the only route into home ownership.

Governments that have tried simply to stop sprawl have discovered that the consequences can be painful. Britain's green belts, established in the decades after the Second World War, have successfully kept large areas of countryside around London and other cities free of building. Oregon introduced a law in 1973 requiring every city to draw an urban growth boundary, and Portland's boundary has become the best-known example of the approach. Such policies have protected farmland and forests, but by restricting the supply of land they can also raise the price of housing. Economists disagree about how large this effect has been in Portland, but in the south-east of England, where demand for homes is intense and building land is tightly restricted, the link between scarce land and high housing costs is difficult to dispute.

In my view, the real problem lies not in expansion itself but in two failures that usually accompany it. The first is that expansion often happens in a disorderly way, with each new estate connected to the city by a single congested road and no space reserved for public transport or parks. Angel has argued persuasively that rapidly growing cities in developing countries should plan ahead for their expansion, acquiring land for a grid of arterial roads and for public open space before development arrives, rather than attempting to prevent growth that will occur anyway. The second failure is that many existing cities make it difficult or illegal to build more homes where infrastructure already exists. Zoning rules that permit nothing but detached houses across large residential districts force growth outwards, and then the same authorities complain about sprawl.

A more sensible approach would treat density as something to be allowed rather than imposed. Cities should permit more homes near stations and along transport corridors, require the users of roads and parking to pay a fairer share of their costs, and prepare the land on their edges for orderly growth. A boundary that ignores rising demand merely displaces development to towns beyond it, lengthening the commutes it was meant to shorten. The question is not whether cities will grow but how well, and answering it requires planners to accept growth instead of pretending that it can be stopped.