The world's native languages are dying out at an unprecedented rate, taking with them irreplaceable knowledge about the natural world, according to a National Geographic study.
The study identified five global "hot spots" where languages are vanishing faster than anywhere else, eastern Siberia, northern Australia, central South America, the US state of Oklahoma and the US Pacific Northwest.
"Languages are undergoing a global extinction crisis that greatly exceeds the pace of species extinction," linguistics professor David Harrison told the National Geographic website. Harrison said half of the world's 7,000 languages were expected to disappear before the end of the century.
He said indigenous people had an intimate knowledge of their environment that was lost when their language disappeared, along with concepts dealing with mathematics and the nature of time often unfamiliar to western thinking.
"Most of what we know about species and ecosystems is not written down anywhere, it's only in people's heads," he said.
"We are seeing in front of our eyes the erosion of the human knowledge base," he added. Harrison was one of a team of linguists who carried out the study released yesterday. The researchers travelled to Australia this year to study Aboriginal languages, some of the most endangered.
"Australia is amazing because humans have been there for 50,000 years and they represent an unbroken link to the past in a way that other places on Earth don't," Harrison said.