Since the 1980s, Almería in southern Spain has developed the largest concentration of greenhouses in the world, covering 26,000 hectares. The greenhouses reflect so much sunlight back into the atmosphere that they are actually cooling the province. While temperatures in the rest of Spain have climbed faster than the world average, meteorological observatories located in the so-called 'sea of plastic' have shown a decline of 0.3 degrees per decade. It turns out that the plastic’s white colour acts like a mirror, reflecting sunlight back into the atmosphere before it can reach and heat up the ground. This means that at a local level, the greenhouses offset global warming.
The main sources of deforestation in the Amazon rainforest are human settlement and clearance for farming. Between 1991 and 2000, the total area that had been cut down rose from 415,000 to 587,000km² – 64% larger than Germany, or 84% the size of Texas. Most of this lost forest is now cattle pasture.
In 2008, the Brazilian government announced that the rate of destruction had picked up over the time of the year when it normally slows. In just the last five months of 2007, more than 3,200km², an area equivalent to the US state of Rhode Island, was cleared. The rainforest is still shrinking, but this has been slowing down more recently; 2011 figures show the least deforestation since records began.
The Batu Hijau mine is an open pit copper-gold mine on the island of Sumbawa, 1,530km east of the Indonesian capital Jakarta. It is Asia’s second-largest copper mine, and along with its processing and support facilities, worker accommodation and dedicated port, it occupies 1,320 hectares. Production began in 2000; environmentalists have expressed concern at the disposal of waste rock in the surrounding rainforest and mine tailings in the deep ocean off the island’s coast.
In 1800, Beijing was the world’s only city with a population of more than a million. By 1900, 16 cities had reached this milestone; by 2000, that figure stood at 378. By 2025, it’s predicted to be 600.
China has the fastest urban growth of any nation. Its cities are growing annually at between 13.1% in coastal areas to 3.9% in the west.
The Biological Dynamics of Forest Fragments Project is a large-scale ecological experiment looking at the effects of habitat fragmentation on tropical rainforests; it is one of the most expensive biology experiments ever. It was set up in 1979 near Manaus, in the Brazilian Amazon. It is jointly managed by the Smithsonian Institution and INPA, the Brazilian Institute for Research in the Amazon.
The project divided an area of forest into fragments ranging in size between one and a hundred hectares. Beforehand, scientists collected data on the plants and animals living there and the ecological relationships between them; they’ve now spent more than 25 years monitoring the changes that fragmenting these habitats has caused.
Gold, copper, diamonds, and other precious metals and gemstones are important resources that are found in rainforests around the world. Extracting them is often a destructive activity that damages the rainforest ecosystem and causes problems for people living nearby and downstream from mining operations. In the Amazon rainforest, most mining today revolves around alluvial gold deposits – those left behind in layers of soil deposited by long-ago watercourses. Due to the meandering course of Amazon rivers, gold is found both in river channels and on the floodplains where rivers once ran.
Fossil water or paleowater is groundwater that has remained sealed underground in an aquifer for a long time. Water can stay in these deep stores for thousands or even millions of years. When changes in the surrounding geology seal the aquifer off so that they can’t be topped up anymore by rainfall, the water becomes trapped within. Now in many areas this ancient water is being tapped to grow crops in desert environments that could otherwise never support agriculture. But it is a finite resource, and it’s being used up quickly; once these aquifers have been drained they will never refill. Crops grown in the desert are often watered using hoses that turn around a central pivot, creating the characteristic round fields seen here.
Between January and March 2002, the Larsen B sector of Antarctic ice collapsed and broke up. In a single season, 3,250km² 220m-thick ice disintegrated. Until this sudden collapse, Larsen B had been stable for up to 12,000 years – essentially since the last ice age.
Glaciologists have long been fascinated with the complex terrain of ice sheets, massive bodies of land-based ice in Greenland and Antarctica. In the past decade, they have increasingly focused on the likelihood that climate change could melt ice sheets and raise sea levels, eventually driving millions of people living in coastal areas from their homes. To understand ice sheets, glaciologists venture both below the surface with ice cores, and into the sky with satellites.
But melting is not the only way a massive ice sheet slims down. Falling snow adds its weight on top of it, and the ice sheet slowly flattens, pushing its outer edges out until they crumble into the Atlantic as icebergs. This process is visible in the upper left of the image where the ice flow is converging into an outlet glacier. White flecks in the water are icebergs that have been shed from the outlet glacier.
The two processes — melting and iceberg-calving — are closely connected. Melting, it turns out, accelerates calving. As the ice sheet melts, water collects in large pools on the surface. Streams drain the pools, disappearing into crevasses. These cracks in the ice take it deep into the ice sheet, sometimes even to the rock beneath, where it lubricates the lowest layers of the ice so that it flows more quickly toward the ocean, and this means icebergs break into the sea more quickly. So the streams mean the ice sheet loses ice more quickly than it otherwise would.
Mount Tambora is an active volcano on the island of Sumbawa in Indonesia. It used to be 4,300m high, and was one of the tallest peaks in the Indonesian archipelago. But after a large magma chamber inside the mountain filled over the course of several decades, Mount Tambora exploded in a colossal explosion in April 1815. The blast measured 7 on the Volcanic Explosivity Index – the only eruption of that size since the Lake Taupo eruption in New Zealand in about 180 AD.
The eruption had a profound effect on the global climate, creating the phenomenon known as ‘volcanic winter’. 1816 became known as the ‘Year without a Summer’ because of the effect on North American and European weather. Crops failed and livestock died in much of the Northern Hemisphere, leading to the worst famine of the 19th century.
By 1950, the New York City metropolitan area had become the first urban area to reach a population of 10 million.
Global urbanization is following the blueprint of North American cities, but faster and at larger scales. These trends are most evident in developing countries.
We are beach bums at heart: 61% of the Earth’s human population lives close to the coast and 500 million people live on the world’s river deltas.
But damming, mining, irrigation and other human activities are causing many of the world’s largest deltas to sink.
Urban areas in low-lying coastal areas are growing faster than elsewhere. If we don’t adequately protect coastal cities from climate change, this will put the economies, roads and houses of 13% of the world's urban population at risk.
The Panama Canal is an 82-kilometre ship canal that connects the Atlantic Ocean to the Pacific. It is a key conduit for international maritime trade.
Work on the canal began in 1880 and was completed in 1914, eliminating the need for ships to sail all the way around the tip of South America and to navigate the dangerous waters of the Strait of Magellan. One of the largest and most difficult engineering projects ever undertaken, the canal shortcut halved the time needed for ships to travel between the Atlantic and Pacific. The shorter, faster, safer route to the US West Coast and to nations around the Pacific allowed those places to be integrated more closely with the world economy.
Humans began to cultivate food crops about 10,000 years ago. Before that, hunter-gatherers lived on what they could find as they travelled from place to place. When they saw some of the grains left behind at their campsites sprouting and growing to harvest, they began to cultivate these grains. From these humble beginnings, agriculture began.
Over time, human labour in agriculture has decreased, first because of the use of farm animals and finally with machinery powered by fossil fuels. Currently, plentiful and cheap energy supports an era of machinery and agricultural chemicals. We use the equivalent of about 1,000 litres of oil to grow a hectare of corn, yielding 9,000kg.
Worldwide, more than 99.7% of the calories people eat come from the land. Fossil-fuel intensive agriculture causes serious environmental problems including soil erosion, water runoff and pesticide pollution. We urgently need to assess fossil energy limits, the sustainability of agriculture and the food needs of a fast-growing world population.
Borneo, the world’s third-largest island, is divided between Indonesia, Malaysia and Brunei. It was once covered with dense rainforests, but along with its tropical lowland and highland forests, these have suffered widespread clearance since the mid-twentieth century. In the 1980s and 1990s, Borneo’s forests underwent a dramatic transition. They were levelled at a rate unparalleled in human history – burned, logged and cleared, often to be replaced with farmland or oil palm plantations. Half of the world’s annual tropical timber currently comes from Borneo. Oil palm plantations are now quickly encroaching on the last remnants of rainforest. Much of this forest clearance is illegal.
The global urban population is now 3.5 billion. In 2008, our civilization reached a landmark – half the world’s people lived in cities. Fifty years ago it was just a third of the population. A century ago it was 10%.
By 2030, city-dwellers are expected to number five billion. By 2100, this could be as high as 8.4 billion people. To meet this demand, we would need to create the equivalent of one new million-person city every week for the next few decades.
In 1962, Tokyo became the first megacity with more than 10 million people. Today, there are 19 megacities.
Tokyo is the world's biggest city and accounts for almost 2% of the world’s GDP. The Tokyo-Yokohama wider urban area is home to 36.7 million people and covers 13,500km². This is an area bigger than Jamaica.