Lalo de Almeida for The New York Times
The torrid growth is visible in places like Parauapebas. On the outskirts, slums stretch to the horizon and houses continue to go up. More Photos »
PARAUAPEBAS, Brazil — The Amazon has been viewed for ages as a vast quilt of rain forest interspersed by remote river outposts. But the surging population growth of cities in the jungle is turning that rural vision on its head and alarming scientists, as an array of new industrial projects transforms the Amazon into Brazil’s fastest-growing region.
The torrid expansion of rain forest cities is visible in places like Parauapebas, which has changed in a generation from an obscure frontier settlement with gold miners and gunfights to a sprawling urban area with an air-conditioned shopping mall, gated communities and a dealership selling Chevy pickup trucks.
Scientists are studying such developments and focusing on the demands on the resources of the Amazon, the world’s largest remaining area of tropical forest. Though Brazilian officials have historically viewed the colonization of the Amazon as a matter of national security — military rulers built roads to the forest under the slogan “Occupy it to avoid surrendering it” — deforestation in the region already ranks among the largest contributors to global greenhouse-gas emissions.
Brazil has shifted away from colonization, but policies that regularize land claims by squatters still lure migrants to the Amazon. And while the country has recently made progress in curbing deforestation, largely by enforcing logging laws and carving out protected forest areas, biologists and other climate researchers fear that the sharp increase in migration to cities in the Amazon, which now has a population approaching 25 million, could erode those gains.
“More population leads to more deforestation,” said Philip M. Fearnside, a researcher at the National Institute for Amazon Research in Manaus, an Amazonian city that registered by far the fastest growth of Brazil’s 10 largest cities from 2000 to 2010. The number of residents grew 22 percent to 1.7 million, according to government statistics.
Of the 19 Brazilian cities that the latest census indicates have doubled in population over the past decade, 10 are in the Amazon. Altogether, the region’s population climbed 23 percent from 2000 to 2010, while Brazil as a whole grew just 12 percent.
Various factors are fueling this growth, among them larger family sizes and the Amazon’s high levels of poverty in comparison with other regions that draw people to the cities for work. While Brazil’s birthrate has fallen to 1.86 children per woman, one of the lowest in Latin America, the Amazon has Brazil’s highest rate, at 2.42.
Then there is the region’s economic allure.
Sinop, a city of 111,000 people in Mato Grosso State, grew about 50 percent in the past decade as soybean farmers expanded operations there. Fiscal incentives for manufacturing promote growth in Manaus and satellite towns like Manacapuru and Rio Preto da Eva. Logging still provides the lifeblood for growing towns along BR-163, an important Amazon highway now being paved.
Elsewhere in the Amazon, the biggest linchpins for the fast-growing cities are major energy and industrial projects. The construction of dozens of hydroelectric projects, including sprawling dams that have drawn protests, are luring manual laborers from around Brazil to cities like Pôrto Velho, in Rondônia State, and Altamira, in Pará.
Here in Parauapebas, also in Pará, an open-pit iron ore mine provides thousands of jobs. Plans for additional mines here, supported largely by forecasts of robust demand in China, have lured many to this corner of the Amazon in search of work. Just since the 2010 census, the city’s population has swelled to an estimated 220,000 from 154,000.
“This entire area was thick, almost impenetrable, jungle,” said Oriovaldo Mateus, an engineer who arrived here in 1981 to work for Vale, the Brazilian mining giant. That was about the time that the authorities cut a road through the forest, making the settlement of Parauapebas feasible. By the early 1990s, he said, it had muddy roads, brothels and more than 25,000 people.
“Now, Brazil’s future is in Parauapebas and other cities of the Amazon,” said Mr. Mateus, 62, who heads the city’s business association and owns a company that leases mining equipment. He boasted that on some frenetic days, as many as two homes are built each hour to meet surging demand in the city’s settlements.
Indeed, the streets of Parauapebas pulse with vitality. People shout to be heard along Rua 24 de Março, a traffic-clogged thoroughfare reverberating with the buzzing of motorcycle taxis, Pentecostal preachers bellowing warnings of sin and car stereos blaring eletromelody, the thumping electronic music style popular in this part of the Amazon.
Venture to the outskirts of Parauapebas, and slums of wooden shacks stretch to the horizon. One area where squatters have put down stakes is called Nova Vitória. With about 1,200 such homes, it is a magnet for strivers.
