New study ranks countries on environmental impact

A new study  has ranked most of the world’s countries for their environmental impact.

The research uses seven indicators of environmental degradation to form two rankings – a proportional environmental impact index, where impact is measured against total resource availability, and an absolute environmental impact index measuring total environmental degradation at a global scale.

Led by the Environment Institute’s Director of Ecological Modelling Professor Corey Bradshaw, the study has been published in the on-line, peer-reviewed science journal PLoS ONE (found at

The world’s 10 worst environmental performers according to the proportional environmental impact index (relative to resource availability) are: Singapore, Korea, Qatar, Kuwait, Japan, Thailand, Bahrain, Malaysia, Philippines and Netherlands.

In absolute global terms, the 10 countries with the worst environmental impact are (in order, worst first): Brazil, USA, China, Indonesia, Japan, Mexico, India, Russia, Australia and Peru.

The indicators used were natural forest loss, habitat conversion, fisheries and other marine captures, fertiliser use, water pollution, carbon emissions from land use and species threat.

“The environmental crises currently gripping the planet are the corollary of excessive human consumption of natural resources,” said Professor Bradshaw. “There is considerable and mounting evidence that elevated degradation and loss of habitats and species are compromising ecosystems that sustain the quality of life for billions of people worldwide.”

Professor Bradshaw said these indices were robust and comprehensive and, unlike existing rankings, deliberately avoided including human health and economic data – measuring environmental impact only.

The study, in collaboration with the National University of Singapore and Princeton University, found that the total wealth of a country (measured by gross national income) was the most important driver of environmental impact.

“We correlated rankings against three socio-economic variables (human population size, gross national income and governance quality) and found that total wealth was the most important explanatory variable – the richer a country, the greater its average environmental impact,” Professor Bradshaw said.

There was no evidence to support the popular idea that environmental degradation plateaus or declines past a certain threshold of per capital wealth (known as the Kuznets curve hypothesis).

“There is a theory that as wealth increases, nations have more access to clean technology and become more environmentally aware so that the environmental impact starts to decline. This wasn’t supported,” he said.

Corey is the author the blog Conservation Bytes and earlier this year was named Scopus Young Researcher of the Year in the Life Sciences and Biological Sciences category.

Saving the Grey Nurse Shark.

The number of grey nurse sharks around the world has declined, in Australia they are now classified as Critically Endangered. Associate Professor Corey Bradshaw, from the University of Adelaide’s Environment Institute, was invited by the Department of the Environment, Water, Heritage and the Arts to attend a forum held at the Sydney Institute of Marine Science on the 27th of November to help develop a new five-year action plan to help ensure the future of the grey nurse shark.

A worldwide decline in shark populations has major consequences for the marine ecosystem. Large predators have a top-down control of other marine species, so their survival and abundance is vital to the health of the entire system. Although no shark species have been recorded to go extinct since human records began, the grey nurse shark population on the eastern coast of Australia is in a precarious position due to previous over-exploitation and now, accidental deaths.

Read Corey’s blog Conservation Bytes.