Though providing economic opportunities to Brazilians struggling to emerge from poverty, the intensifying urbanization of the Amazon is alarming scientists, as "deforestation in the region already ranks among the largest contributors to global greenhouse-gas emissions." The country has enforced logging laws and protected forest areas to curb deforestation, but the increase of migration to rain forest cities is threatening the process. The latest census indicates that 10 of 19 Brazilian cities that have doubled in population over the last decade are in the Amazon, and the region's population grew by 23 percent compared to the country's overall 12 percent. "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 the fastest growth of Brazil's largest cities.
"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," says Romero. The urbanization of the Brazilian Amazon can be attributed to "policies that regularize land claims by squatters" and "larger family sizes and the Amazon's high levels of poverty in comparison with other regions that draw people to the cities for works." In Parauapebas, an open-pit iron ore mine provides thousands of jobs, and there are plans for additional mines due to high demand. "Elsewhere in the Amazon, the biggest linchpins for the fast-growing cities are major energy and industrial projects." Oriovaldo Mateus, an engineer who arrived in 1981 to work for Brazilian mining giant Vale, said, "This entire area was thick, almost impenetrable, jungle. Now, Brazil's future is in Parauapebas and the other cities of the Amazon."
The surging population growth in the Amazonian cities, termed the "world's last great settlement frontier" by Brian J. Godfrey, is "intensifying an urbanization that has been advancing for decades." Some researchers have argued that migration to cities may reduce deforestation by depopulating some rural areas and allowing rain forests there to regrow, adds Romero, but others believe that current trends show migration is increasing deforestation. Mitchell Aide, a University of Puerto Rico biology professor whose research has shown that deforestation has occured on a larger scale than reforestation in Brazil's Amazon over the past decade, said, "It's great that people are moving out of poverty, but one of the things we need to understand when people move out of poverty is there is a larger demand on resources."