More than 15,000 scientists from 184 countries worldwide offer a ‘warning to humanity’

In 1992, 1,700 of the world’s leading scientists issued an appeal declaring ‘the environment is suffering critical stress’.

25 years on, more than 15,000 scientists have signed the letter due to the lack of fundamental changes.

Of the 9 areas highlighted as in serious need of a dramatic transformation, only one area has been improved, which is the ozone.

The scientists say urgent action must be taken to avoid ‘substantial and irreversible harm to the Earth‘, and ‘irretrievable mutilation and human misery’.

William Ripple of Oregon State University’s College of Forestry started the campaign when he realised this year would mark the 25th anniversary of the appeal.

Together with his graduate student, Christopher Wolf, he decided to revisit the concerns raised then, and find global data to show the trends since the letter was originally created.

Ripple and Wolf found an assortment of concerns, including:

  • A decline in freshwater availability
  • Unsustainable marine fisheries
  • Ocean dead zones
  • Forest losses
  • Dwindling biodiversity
  • Climate change
  • Population growth

Co-author, Dr Thomas Newsome, a research fellow at Deakin University and The University of Sydney, said in Australia, habitat loss was the number one threat, and in 2017 we ranked number two in the world for global biodiversity loss, behind Indonesia.

“There’s been recent reports on an alarming rise in tree clearance in Queensland – about 400,000 hectares per year; the equivalent of 400,000 football fields – which puts us in line with Brazil,” Dr Newsome said.

“All the while we have very low public spending for example on threatened species – around $70 million each year, or less than one hundredth of a percent of the federal government’s annual revenue of $416.9 billion – we spend more rehabilitating mine sites each year,” he said.

“In this paper we look back on these trends and evaluate the subsequent human response by exploring the available data,” Dr Newsome said.


Among the negative 25-year global trends noted were:

  • A 26% reduction in the amount of fresh water available per capita
  • A loss of nearly 300 million acres of forestland
  • A collective 29% reduction in the numbers of mammals, reptiles, amphibians, birds and fish
  • A 75% increase in the number of ocean dead zones.

The research suggests there is still time to make fundamental changes, but dramatic improvements need to be made.

To make these changes, the authors propose the promotion of vegetarian diets/reduced meat consumption, encourage the use of renewable energy, and suggest limiting human population growth.

For more, or to have your say, follow the #ScientistsWarningtoHumanity hashtag on Twitter.