Tackle climate change and biodiversity loss together: UN panel

The world must tackle the dual crises of climate change and biodiversity loss together, two UN expert groups meeting together said Thursday, warning against measures to combat global warming that harm nature.

In the first ever collaboration between the United Nations' intergovernmental panels on climate and nature loss, the scientists said that while the twin threats were mutually reinforcing, they had historically been treated as if they were independent of each other. 

A peer-reviewed workshop report, based on virtual discussions between experts from the IPBES biodiversity and IPCC climate panels, warned that a number of planned interventions against global heating would adversely impact nature.

These include planting bioenergy crops over large land areas, which are detrimental to ecosystems. 

They also cautioned against planting trees to suck up carbon pollution in ecosystems that have not historically been forested, which often damages biodiversity and food production.

The panel called for an end to the loss and degradation of carbon- and species-rich ecosystems on land and oceans.

Subsidies supporting activities harmful to nature -- such as deforestation, over-fertilisation and over-fishing -- must halt, the experts concluded.

At the same time, they underlined the need for changes in individual consumption habits.

Restoring ecosystems was among the cheapest and quickest climate interventions available, and could also offer much-needed additional habitat for plants and animals, the researchers said.

Improved management of cropland and grazing systems alone could save three-six billion tonnes of carbon dioxide equivalent emissions a year.

"Climate change and biodiversity loss combine to threaten society -- often magnifying and accelerating each other," said Hoesung Lee, chair of the IPCC.

Lee said that Thursday's report was an "important step" in the collaboration between scientific fields focusing on climate and those focused on biodiversity.

Long overdue

Alexandre Antonelli, director of science at Britain's Royal Botanic Gardens, said the IPCC and IPBES collaboration was "long overdue".

"Although climate change and biodiversity loss pose unseen threats to our future, the good news is that we can tackle both through the right measures -– those that are based on solid science," said Antonelli, who was not involved in the report.

Several IPCC and IPBES members took the opportunity to stress the need for a total transformation in the way humans interact with nature.

Ana Maria Hernández Salgar, chair of IPBES, said that nothing short of a "complimentary" approach to both crises would avert the worst. 

"Transformative change in all parts of society and our economy is needed to stabilise our climate, stop biodiversity loss and chart a path to the sustainable future we want," she said.

Environmental groups welcomed Thursday's collaboration, as well as the joint assessment's conclusion that nature alone cannot be relied upon to offset humanity's vast carbon emissions.

"The report unequivocally concludes that land- and ocean-based actions that capture carbon must be in addition to, and not in lieu of, ambitious reductions of emissions from fossil fuels," said Doreen Stabinsky, professor of global environmental politics at the College of the Atlantic.