OSLO (Reuters) - World leaders will next week consider a target for halting extinctions of animals and plants by 2020 that many experts rate impossibly ambitious given mounting threats such as climate change and loss of habitats.
"Biodiversity losses are accelerating," said Anne Larigauderie, executive director of the Paris-based Diversitas Secretariat, which groups international scientists and reckons the goal laid out in a draft U.N. plan is out of reach for 2020.
At the United Nations headquarters in New York on September 22, nations will discuss how to protect the diversity of plants and animals -- vital to everything from food to fresh water -- after failing to reach a goal set in 2002 of a "significant reduction" in losses by 2010.
The world has made some progress since 2002, such as in expanding protected areas for wildlife. But U.N. studies say extinction rates are running up to 1,000 times higher than those inferred from fossil records in the worst crisis since the dinosaurs were wiped out 65 million years ago.
Larigauderie said scientists had been largely left out of defining new goals. "Until we have an organised process we will continue to have these sort of feel-good objectives that we are going to miss again," she said of halting losses by 2020.
A draft U.N. strategic plan for 2020, to be formally adopted at U.N. talks in Japan in October, calls for "effective and urgent action" either "to halt the loss of biodiversity by 2020" or "towards halting the loss of biodiversity" with no deadline.
"Our goal has to be to halt the loss of biodiversity," said Achim Steiner, head of the U.N. Environment Programme.
"Can we already agree on targets and timelines that lead us to that over the course of a decade? It will be an immense struggle," he told Reuters, urging tough goals.
Apart from the overall target for 2020, some targets in a draft strategic plan are more measurable -- such as an option of "ending overfishing" or "halving" deforestation by 2020.
A rising human population, spread of cities, pollution and global warming are adding to problems that are damaging nature and vital free services ranging from insect pollination of crops to coral reefs that are nurseries for fish stocks.
Environmental group Greenpeace said the world should set the strictest possible goals for 2020.
"We favour halting the loss of biodiversity by 2020," said Nathalie Rey of Greenpeace. "We are at a crossroads where we are at a point of no return. You have to stay ambitious."
A U.N. study this year said the world risked "tipping points" of no return such as a drying out of the Amazon rainforest, a build-up of fertilisers that bring dead zones in the oceans or ocean acidification linked to climate change.
The International Union for Conservation of Nature, which groups governments, scientists and environmentalists, believes it is too ambitious to set a goal of halting losses by 2020.
It has argued for a vaguer target of "putting in place by 2020 all the necessary policies and actions to prevent further biodiversity loss". Beyond that, it wants a 2050 deadline for conserving and restoring biodiversity.