With giant tortoises, elephants, and other fruit-eating animals disappearing from many of the world’s tropical woodlands, forests are suffering from the loss of a key function performed by these creatures: the dispersal of tree seeds. But a new experiment shows that introduced species may be able to fulfill this vital ecological role.

The Ethiopian region of Gambella is home to Africa’s second-largest mammal migration, with more than a million endangered antelope and other animals moving through its grasslands. But the government has now leased vast tracts to foreign agribusinesses who are planning huge farms on land designated a national park.

For decades, deadly outbreaks of cholera were attributed to the spread of disease through poor sanitation. But recent research demonstrates how closely cholera is tied to environmental and hydrological factors and to weather patterns — all of which may lead to more frequent cholera outbreaks as the world warms.

The inland Niger delta of Mali is a unique wetland ecosystem that supports a million farmers, fishermen, and herders and a rich diversity of wildlife. But now, the country’s president and Libyan leader Moammar Gaddafi have begun a major agricultural project that will divert much of the river’s water and put the delta’s future at risk.

One of the more contentious issues facing climate scientists is whether rising ocean temperatures will cause more frequent and powerful hurricanes. In an interview with Yale Environment 360, Kerry Emanuel, of the Massachusetts Institute of Technology, says that amid the uncertainty, one thing seems likely: an increase in the most potent — and destructive — storms.

Coffee production has long been vulnerable to drought or excess rains. But recently, a tiny insect that thrives in warmer temperatures — the coffee berry borer — has been spreading steadily, devastating coffee plants in Africa, Latin America, and around the world.

A dispute between Egypt and upstream African nations has brought to the fore a long-standing controversy over who has rights to the waters of the Nile. The outcome could have profound consequences for the ecological health of the river and for one of the world’s largest tropical wetlands.

The tropical forest conservation plan, known as REDD, has the potential to significantly reduce deforestation and carbon dioxide emissions worldwide. But unless projects are carefully designed and monitored, the program could be undercut by shady dealings at all levels, from the forests to global carbon markets.

Insecticides such as DDT have long been used to combat the scourge of malaria in the developing world. But with the disease parasite becoming increasingly adept at resisting the chemical onslaught, some countries are achieving striking success by eliminating the environmental conditions that give rise to malarial mosquitoes.

In Africa and elsewhere, burgeoning population growth threatens to overwhelm already over-stretched food supply systems. But the next agricultural revolution needs to get local — and must start to see rising populations as potentially part of the solution.

As burgeoning human populations place greater pressure on wild areas, a strategy is emerging for preserving threatened lands and wildlife. Known as ‘rewilding,’ it involves expanding core wilderness areas, connecting them via corridors that allow humans and animals to co-exist, and protecting and reintroducing top predators.

The shrinking ice cap atop Mount Kilimanjaro is Africa’s most famous glacier. But the continent harbors other pockets of ice, most notably in the Rwenzori Mountains of western Uganda. And as temperatures rise, the Rwenzori’s tropical glaciers — located as high as 16,500 feet — are fast disappearing.

The traditional parks model of closing off areas and keeping people out simply may not work in Africa, where human demands on the land are great. Instead, what’s needed is an approach that finds ways to enable people and animals to co-exist.

Since the government's collapse after a coup last March, Madagascar's rainforests have been plundered for their precious wood and unique wildlife. But now there are a few encouraging signs, as officials promise a crackdown on illegal logging and ecotourists begin to return to the island.

Governments from the developed world will never come up with enough money to help poorer nations adapt to global warming and implement renewable energy technologies. The solution may lie in using a modest allocation of government funds to spur private sector investment in green energy projects in Africa, Asia, and Latin America.

As humans increasingly encroach on forested lands and as temperatures rise, the transmission of disease from animals and insects to people is growing. Now a new field, known as “conservation medicine,” is exploring how ecosystem disturbance and changing interactions between wildlife and humans can lead to the spread of new pathogens.

Recent studies show that wildlife in some African nations is declining even in national parks, as poaching increases and human settlements hem in habitat. With the continent expected to add more than a billion people by 2050, do these trends portend an Africa devoid of wild animals?

Two prominent — and iconoclastic — environmentalists argue that current efforts to tax or cap carbon emissions are doomed to failure and that the answer lies not in making dirty energy expensive but in making clean energy cheap.

Two decades after the Exxon Valdez spilled 11 million gallons of crude oil into Alaska’s waters, the Prince William Sound, its fishermen, and its wildlife have still not fully recovered.