As the 21st Century begins, environmentalists warn rapidly growing populations, combined with rising living standards in parts of the developing world, are placing unsustainable pressures on natural resources. All agree on the need to eradicate poverty, but the challenge is how to do so without destroying the environment.
Rush hour and traffic in Bangkok is at a standstill. The vehicles idling on the streets waste millions of dollars worth of fuel and spew tons of pollution into the air each day.
Their exhaust fumes add to the discharge from massive air conditioners cooling the skyscrapers along the streets and the fuel-burning power plants outside the city.
Environmentalists say this is one of the negatives as people in developing nations begin to emerge from poverty and join the consumer culture. There are other problems too: rising health threats, degradation of waterways, farmland, forests, coastal areas, and, in the longer term, climate change and loss of biodiversity.
The United Nations Environmental Program released its Global Environment Outlook last month (Feb. 7) stating that nearly two-thirds of the world's ecosystems are in decline. The UN report says climate change caused by burning fossil fuels is spawning drought, more hurricanes and floods, which last year cost the insurance industry an estimated $200 billion.
U.N. Spokesman Nick Nuttall says this has become the price of development on a crowded planet.
"The economic and environmental issues have come really together over the past 12 months. The message is now crystal clear that the environment is the actual basis of [for] overcoming poverty, the basis of economic growth and stability in this world of six billion people," he said.
Nowhere is the effect of population on the environment more evident than in Asia -home to nearly two-thirds of the world's people and some of the most vibrant economies.
Chulalongkorn University population expert, Professor Vipan Prachuabmoh, says Asia also has some of the world's fastest growing cities. But the rush to greater economic opportunity in urban centers has big drawbacks.
"Rapid urban growth and unplanned, or poorly managed urbanization, may lead to urban poverty, unemployment, inadequate housing and infrastructure, as well as environmental deterioration and health hazards," she added.
Vipan says rising standards of living in Asia are also creating a voracious appetite for consumer goods, which means more oil, coal and water are used by industry to provide the goods at market.
But U.N. spokesman Nuttall says emerging economic powers like China, India and Brazil cannot be blamed for pursuing the same prosperity seen in the industrialized world. And he says they deserve credit for understanding the link between growth and pressures on the environment.
"There are very encouraging signs that the developing countries of Asia are taking environmental sustainability very seriously, and taking it more seriously and at an earlier stage than we did in the West," said Nuttall.
He notes Chinese plans to lessen dependence on fossil fuels like coal while hoping to get 20 percent of its energy from renewable resources, such as hydroelectric dams, by 2015. India is working to clean up a half million rivers and lakes - noting a healthy environment is crucial to better development.
But that only goes so far when the number of people living on less than $2 a day has grown to three billion or half the world's population.
The poor present their own pressures on the environment. Those living at subsistence levels often are forced to resort to desperate measures. This can include cutting down or burning forestland indiscriminately - either to sell the lumber or cultivate the soil for food.
So while development can cause pressure on the environment, so can lack of development. Population expert Vipan says governmental action is key.
"Especially in the developing country, the government needs to invest in people, education and skills," noted Professor Vipan. "The government should stress investment in human resources and care more about harmony with nature than about unnecessary consumption."
The U.N. Environmental Program's Nick Nuttall suggests a step further: that rich countries pay poor countries for maintaining their natural reserves - like vital forestland.
"It is estimated that the tropical forests of the world are soaking up $60 billion worth of carbon. But the people in those countries, like the Congo, get paid nothing for their standing trees. Maybe there should be some kind of recompense for that," he continued.
Nuttall notes that many of the forests, wetlands and coral reefs in developing nations are also being explored to develop new crops, vital medicines and industrial products.
"We are moving from the old industries of the past into a biological century. And they [least developed nations] are the havens in many cases of these new genetic products," he said. "The question is how do [can] we come up with some kind of global regime that will recompense these people for the wealth they have."
Throughout the world, Nuttall says, there is a growing awareness not only of the value of preserving the environment, but that the environment is also a huge source of monetary value if developed correctly. He calls it a new horizon for global environmental health.
But for people in the exhaust-choked streets of cities like Bangkok, that horizon at times may be difficult to see.