Bali, Indonesia ? More than 3,000 flying foxes dropped dead, falling from trees in Australia. Giant squid migrated north to commercial fishing grounds off California, gobbling anchovy and hake. Butterflies have gone extinct in the Alps.

While humans debate at U.N. climate change talks in Bali, global warming is already wreaking havoc with nature. Most plants and animals are affected, and the change is occurring too quickly for them to evolve.

“A hell of a lot of species are in big trouble,” said Stephen E. Williams, the director of the Centre for Tropical Biodiversity & Climate Change at James Cook University in Australia.

“I don’t think there is any doubt we will see a lot of (extinctions),” he said. “But even before a species goes extinct, there are a lot of impacts. Most of the species here in the wet tropics would be reduced to … 15 percent of their current habitat.”

Globally, 30 percent of the Earth’s species could disappear if temperatures rise 4.5 degrees Fahrenheit – and up to 70 percent if they rise 6.3 degrees Fahrenheit, a U.N. network of scientists reported last month.

It wouldn’t be the first time. There have been five major extinctions in the last 520 million years, and four of them have been linked to warmer tropical seas, according to a study published last month in the Proceedings of the Royal Society B, a British scientific journal.

The hardest hit will include plants and animals in colder climates or at higher elevations and those with limited ranges or little tolerance for temperature change, said Wendy Foden, a conservation biologist with the World Conservation Union, which catalogs threatened species.

Butterflies that lived at high altitudes in North America and southern France have vanished, and polar bears and penguins are watching their habitat melt away.

The carbon dioxide emissions that are a leading cause of global warming also turn oceans more acidic, killing coral reefs and the microscopic plankton that blue whales and other marine mammals depend on for food.

“In the long run, every species will be affected,” Foden said.

A few will benefit, chiefly those that breed quickly, already exist in varied climates and are able to adapt swiftly to changing conditions, scientists said. Think cockroaches, pigeons and weeds.

The spread of a deadly fungus that thrives in warmer conditions has decimated some frog populations in South America, Africa and Europe.

Then there are Australia’s flying foxes.

More than 3,500 gray-headed and black flying foxes – huge bats – died in 2002 after temperatures rose above 107 degrees Fahrenheit in New South Wales, according to a report published last week in the Royal Society B journal.

The rising temperatures are related to global warming, said the author, Justin Welbergen of the University of Cambridge.

“It got really hot and suddenly started raining foxes from the trees,” said Welbergen, who witnessed the die-off. “It was quite gruesome. This colony had between 20,000 and 30,000 animals and about 10 percent of those individuals died.”

In Australia’s Queensland state, temperatures are projected to rise 5.4 degrees Fahrenheit, an outcome that could drive half the species to extinction in a mountainous stretch of tropical rain forest, Williams said.