We can fly halfway around the world — Newark to Beijing — in 12 hours. With the exception of a few far-flung villages, we can almost always find someone who understands English enough to translate our needs to the local shopkeeper. The Internet and global cellular telephone service have made communication almost instantaneous. But what are we losing?

SOUTH AMERICA: THERE’S OIL IN THE RAIN FOREST
The Rio Madre de Dios – the River of the Mother of God – takes you to one of the last remaining undisturbed tracts of Amazonian rain forest, Peru’s renowned Manu Biosphere Reserve. But corporate interests have staked claims inside the reserve, risking its precious biodiversity and the lifestyle of its indigenous people.

The reserve boasts the world’s highest level of biodiversity. Covering more than 7,263 square miles, it shelters a significant portion of untouched habitat in the Amazon basin — puna grasslands, elfin forests, cloud forests and lowland rain forests. The forest teems with life — jaguars, anteaters, giant armadillo, monkeys and sloths. At 1,000 and counting, it is home to more bird species than the entire United States.

“Even though the Manu Biosphere is supposed to be protected, it is being invaded by a Chinese oil exploration company,” said Marianne van Vlaardingen, a Dutch primatologist who runs Pantiacolla Tours with her Peruvian husband, Gustavo Moscoso.

She’s referring to China Petroleum Corp., which recently signed an $83 million contract with the Peruvian government allowing it to explore for oil amid the rain forest’s bounty — including inside the reserve’s multiple-use zone, set aside as indigenous tribal lands.

The reserve is divided into three zones: a national park, open only to scientists and natives who live inside with no modern contact; a reserved zone, used for ecotourism; and a multiple-use zone, where semi-modern indigenous tribes live in pocket communities that combine their primitive pasts and the modern world.

Pantiacolla Tours pioneered community-based tourism by initiating a partnership with the Yine Indians that provides an economic incentive for them to preserve the rain forest rather than harvest timber or hunt to excess.

“Ecotourism can benefit the rain forest and its people, as long as it is done small scale and in a very respectful and cautious way,” said van Vlaardingen.

Highlights of Pantiacolla tours include village visits during which participants make pottery, learn to paint tribal designs or ride in a traditional dugout canoe. The project encourages the Yine to appreciate that their culture — and the rain forest where they live and subsist — has value to the rest of the world. But more than that, it becomes a tool enabling the Yine to interact with modern society and gain an understanding of Peruvian contractual law — a fact of life they will increasingly encounter. As oil companies negotiate deals that directly impact their native lands, they may have to fight through legal means to preserve their culture, their rain forest and their way of life.

Only a few operators, including Pantiacolla Tours (www.pantiacolla.com) and InkaNatura Selva (www.inkanatura.com), have permits to take tourists into the reserved zone, the most pristine part of the rain forest.

AUSTRALIA: THE GREAT BARRIER REEF IS LOSING ITS LUSTER
Three waves of bleaching in the last eight years have turned the world’s biggest living — and decidedly technicolor — organism bone white. Australia’s Great Barrier Reef, an underwater paradise alive with jewel-toned tropical fish, sharks, sea turtles and manta rays, stretches some 1,200 miles along the northeast coast of Australia, covering 135,000 square miles within the Coral Sea. Up to 6 percent of the reef has been affected by coral bleaching, the result of excessively high water temperatures.

Environmental stressors — in this case, hot water —  cause tiny algae that live inside coral reefs to abandon ship. The algae — living in a symbiotic relationship with the reef — give the corals their color.

“Corals turn white when they are stressed by unusually warm water, and they can die if the warming persists for more than a few weeks,” said Terry Hughes, director of the Center for Coral Reef.

Bleaching incidences have increased since first noticed in 1979 and scientists are hard at work studying how warming oceans will affect the Great Barrier Reef. One study by World Wildlife Fund indicates up to 95 percent of the reef could die by 2050 if ocean temperatures increase by just 1.5 degrees. Coral bleaching affects reefs worldwide, and the Great Barrier Reef is faring comparatively well — in part due to its massive size and a team of scientists and government officials dedicated to preserving this World Heritage Site.

Dead reefs will recover over a period of years with a little help. Reducing other stressors such as pollution and overfishing will allow the coral polyp’s free-swimming juveniles to re-colonize the hard calcium structures left behind.

“Australia’s reefs are better managed to cope with climate change than anywhere else,” said Hughes. “Controls on pollution and overfishing can preserve the resilience of a reef in the face of inevitable bouts of bleaching that are occurring now and into the future.”

Pro Dive-Undersea (www.undersea.com.au) is an eco-certified livea-board dive boat that operates tours to the outer reef.

SOUTHERN AFRICA: ITS DELTA IN DANGER, THE REGION FACES AN UNCERTAIN FUTURE
As it faces the biggest drought in more than a century, reports indicate Southern Africa could be in store for a desertlike future. A study published in the scientific journal Science suggests Africa’s Okavango Delta — a watering hole for thousands of African animals — is at risk. South Africa’s Cape also may face a reduced rainfall. The Orange River that runs through South Africa and empties into the Atlantic Ocean, one of few permanent water sources in the arid western part of the continent, could completely evaporate.

Permanent water sources are a stable and necessary requirement for wildlife. A decline in wildlife populations could have a negative impact on tourism, an economic staple to the economies of many African nations. And because rivers form nearly 40 percent of African countries’ borders, water — or the lack of water — could lead to conflict. Encouraging water conservation is the first step in planning for the possibility of water shortages.

“In the past, water was treated as a renewable, non-exhaustible resource. This is clearly no longer the case,” said Maarten de Wit, the lead scientist on the study published in Science.

Combining existing environmental stresses, such as overgrazing, with decreasing rainfall puts more of the population and its wildlife at risk.

“[Many] areas sustain only marginal farming, yet there are important intergenerational cultural and social practices that are tied to them. Should we be farming there at all?” asked de Wit. “This, in fact, is the real tragedy of the commons: We don’t know how to deal with it yet within a social framework of equity, so instead, everyone continues to grab things, greedily, for themselves.”

Ecologically friendly tour options include the Mala Mala Private Game Reserve (www.malamala.com) in South Africa and Phinda Lodges (www.ccafrica.com/reserve-1-id-2-1). Wildland Adventures (www.wildlandadventures.com) offers a “Walking with Elephants Botswana Safari.”

EURASIA: WHERE THE HIMALAYAN GLACIERS ARE MELTING
The Himalayas — spanning India, Nepal and China — are known for drawing adventurous souls who climb to see the world from new heights, the indigenous Sherpa culture and unique wildlife. The glacier-filled area is also one of the most vulnerable to the immediate consequences of global warming. Sir Edmund Hillary, the first to reach the summit of the Himalayas’ Mount Everest, joined in petitioning UNESCO to put Nepal’s Sagarmatha National Park — which contains Mount Everest — on its danger list due to global warming.

World Wildlife Fund scientists who put a monitor on top of the world – on Mount Everest and several other peaks — found that Himalayan glaciers are receding at an alarming rate. In fact, 95 percent of Tibet’s glaciers are melting. Glacial melting threatens fragile alpine and sub-alpine habitats, home to endangered wildlife species, including the Himalayan black bear, the snow leopard, the red panda and several endangered ungulates — Himalayan tahr, blue sheep and musk deer.

The Himalayas are also a hot spot for research on medicinal plants. Herbs used for thousands of years in Ayurvedic culture, traditional Chinese medicine and Tibetan Amchi are found in the Himalayas. More recently, modern scientists have started to recognize the healing and potential medicinal benefits of the herbs, many of which — already rare due to poaching — could disappear as the alpine habitat changes. Additionally, global warming puts rural Nepali and Tibetan villagers at risk from bursting glacial lakes, the incidence of which has increased in recent years. It also compromises the Eastern Himalayan forests, home to the rare red panda.

The Red Panda Project (tel 650 279 1650, www.redpandaproject.org) involves local Nepali people in habitat conservation. Their eco-trip takes you from Kathmandu to Mount Everest and beyond, where you’ll see Himalayan habitat and tea plantations, and scout the red panda. Other ecologically responsible operators include World Expeditions (www.worldexpeditions.org) and Sita Nepal (www.sitanepal.com).

ANTARCTICA: PIRATE FISHING IS TAKING ITS TOLL
Still the most pristine wilderness in the world, Antarctica is nearly one and a half times the size of the United States (with Alaska included). Penguins, seals and seabirds touch down on land, but spend most of their lives in the encircling Southern Ocean.

Pirate fishermen, who don’t follow laws dictated by international treaty, are known to sneak into Antarctic waters and harvest Patagonian toothfish which is sold in the United States as Chilean sea bass. According to a U.S. Dept. of State advisory, Chilean sea bass is a deepwater species also known as toothfish, caught in southern ocean waters near and around Antarctica. The Chileans were the first to market toothfish commercially in the United States, earning it the name Chilean sea bass.

The advisory warns that although Chilean sea bass is not an endangered species, “large unreported catches from illegal fishing has made effective management difficult. In 2000, more than 16,000 tons of Chilean sea bass were legally harvested in the Antarctic management area. Estimates vary, but there may be up to twice that amount taken illegally.” Australia petitioned the Convention on International Trade in Endangered Species of Wild Fauna and Flora to list the fish, but so far the effort hasn’t succeeded.

To complicate matters, the miles-long, hooked lines used by pirate fishermen to catch toothfish can be lethal to fish-eating seabirds including the endangered giant albatross.

Changes in fishing techniques have reduced accidental seabird deaths within the legal fishery industry, but ultimately halting pirate fisheries will require better monitoring of the ocean and of fish imports. Many restaurants have joined citizens in boycotting Chilean sea bass until countries keep better tabs on the source of imported fish.

Choose a member of the International Association of Antarctic Tour Operators (www.iaato.org), which follows a code of environmentally conscious guidelines, to ensure your impact on the last wild continent will be minimal.

NORTH AMERICA: IT’S TIME TO REVERSE THE DAMAGE
It took a century for public perception of the Everglades to change from one of festering swamp to national treasure. When Europeans colonized America, the bountiful landscape included more than 221 million acres of wetlands, 20.3 million in Florida. Although we now reflect on the beauty, biodiversity, wildlife habitat and ecological functions these wetlands provide, they were not always so revered. Fears of “swamp monsters” and disease inspired a rush to suck wetlands dry, so much so that the Swamp Lands Acts of the 1800s dictated the drainage of wetlands.

The heyday of environmentalism in the 1970s saw the passage of the Clean Water Act, and helped bring about more positive views of wetlands, including the Everglades. But by the time public opinion shifted, every drop of water reaching south Florida — the base of the Everglades ecosystem — had been controlled by dikes, channels and levees.

“Our biggest problem is not enough water in the right places,” said Sue Perry, Everglades National Park ecologist. “We need sheet flow through the marshes, rather than having water introduced at just a few points.”

Engineering the ecosystem damaged the “river of grass,” but also allowed for runaway suburban expansion into the region. Development not only paved over wildlife habitat, it reduced water quality because runoff containing pesticides and fertilizers eventually washed into Lake Okeechobee and its tributary rivers and wetlands.

In 2000, Congress passed a $7.8 billion bipartisan bill to revive the Everglades. Among other things, legislation called for returning the harnessed Kissimmee to a natural winding river, restoring 69 endangered species and fixing dilemmas caused by human engineering. The world is keeping an eye on the progress of the Comprehensive Everglades Restoration Plan — even as developers build more homes in South Florida.

Everglades National Park (tel 305 242 7700, www.nps.gov/ever) lists several national wildlife refuges and state parks that showcase the ecosystem. The Seminole Tribe (tel 800 949 6101, www.seminoletours.com) runs airboat tours.