This long read is part of Unearthed’s Life Support project, in which we explore why the global nature crisis matters for our lives. Watch the 4-part film series here.


At London Zoo one week ago, frog experts from around the world gathered to discuss an emergency plan.

The crisis largely concerns chytridiomycosis, a fungal disease that is eating away the skin of amphibians – mostly frogs, but also toads and salamanders – at speed. In the last 50 years, from Europe to Africa to South America, mass mortality events have sent at least 90 species to global extinction, with 500 more experiencing dramatic declines.

But it’s not only ecologists that need to be worried about global amphibian declines, which are down not only to chytridiomycosis, but to chemical contamination, the exploitation of habitats, UVB radiation and climate change.

Amphibians are integral to their ecosystems. They are herbivores and carnivores, predator and prey. They link habitats on land with those in water. They provide food for birds, animals and snakes. They eat flies and mosquitoes that spread human diseases, from dengue fever to malaria. Their skin can have medical uses, and they have been useful to those studying the regeneration of limbs and organs.

They could even have a role to play in climate change: one study on salamanders showed that because they eat creatures like beetles, flies and ants, their presence in an ecosystem can lead to significantly more leaves on and in the soil, which means it can capture more carbon.

Fewer frogs also means fewer tadpoles, which means more algae (because they feed on it). Without tadpoles, dead algae can build up, creating layers of muck on the rocks, which can break loose, float downstream and contaminate water supplies.

Everything is connected in the natural world – and that includes us.

A critically endangered corroboree frog walks across the gloved palm of a reptile keeper at Sydney’s Taronga Zoo in 2007. Corroboree populations have been decimated by chytridiomycosis. Photo: Getty

Shortly before the frog experts arrived in London, Sir David Attenborough opened a much heralded BBC documentary on climate change, calling it “our greatest threat in thousands of years”.

But could we be facing another threat, that is equally as urgent, with the potential to be just as dangerous to humanity, but about which we are talking – and doing – far less?

The former chair of the IPCC, the UN’s intergovernmental panel on climate change, now believes that is the case.

Sir Bob Watson told Unearthed: “Loss of biodiversity and the degradation of nature is equally important as human-induced climate change. We all know human-induced climate change will affect food security, water security, human health  – so will loss of biodiversity.”

Watson now chairs the UN’s equivalent global scientific body on biodiversity: the pithily named Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).

IPBES chair, and former IPCC chair, Sir Bob Watson in London, 2019. Photo: Isabelle Povery / Unearthed

On Monday, IPBES published their first inter-governmental assessment of the global state of the natural world. It’s been written by 150 world leading scientists and has taken three years to produce.

It estimates that a million plant and animal species are now threatened with global extinction – many within decades – if swift action is not taken.

“The rate of global change in nature during the past 50 years is unprecedented in human history,” it says.  

“Nature is essential for human existence and good quality of life. Most of nature’s contributions to people are not fully replaceable, and some are irreplaceable.”

The effects of biological evolution are now being observed over the course of years, with animal and plants species going extinct tens to hundreds of times faster than in the last 10 million years.

The biggest driver is our changing relationship to land. More than a third of the Earth’s land has been transformed into agriculture. The oceans have suffered too: industrial fishing now covers over half the ocean, a third of which is illegal, unreported or unregulated.

A hammerhead shark is found with other bycatch in the hold of a Chinese fishing vessel in Guinea, 2017. Photo: Pierre Gleizes / Greenpeace

Many scientists are now referring to this human-induced exponential decline as a “sixth mass extinction”.

The implications for human society and wellbeing are manifold.

There are implications for food production, with global crops dependent on insects and other animals for pollination, pest control and soil health. There are implications for global health, with half the world’s population chiefly reliant on natural medicines and around 70% of cancer drugs based on natural products or synthetic products inspired by nature. There are implications for extreme weather events, with the impact on coastal communities around the world lessened by coral reefs, mangroves, wetlands and seagrasses.

There are implications for the quality and quantity of the water we drink, the air we breathe, for the homes we live in, the clothes we wear and for our own mental wellbeing, culture and identity.

These implications have implications for peace and violence, for the movement of people around the planet and for the global economy.

Everything is connected.