More than 100 countries recognised the need to reverse species decline by 2030 and acknowledged the consequences of harmful environmental practices and climate change for biodiversity.

Exactly how one leads to the other is not yet fully understood, as the struggle to establish the origin of covid-19 shows (the virus may have leaked from a lab, or “spilled over” from bats into humans, via an intermediary species)?

And although many factors are involved in disease transmission, including population growth, migration and climate change, scientists are increasingly turning their attention to how altering land interferes with a pathogen’s journey from animals to humans.

One probable reason for the increase in pathogens is that felling trees increases contact between humans and disease-carrying animals.

The Ebola virus is thought to be transmitted by infected bats and primates, although exactly how is not yet fully understood.

These harbour potentially zoonotic pathogens and tend to cluster in places where they will be more frequently exposed to humans and livestock.

Mango trees planted on pig farms in Malaysia probably attracted fruit bats carrying nipah, a virus that infected local pig farmers in 1999 and still breaks out yearly in Bangladesh.

The UN’s climate summit promises new targets, big bills and plenty of hot air

The UN’s climate summit promises new targets, big bills and plenty of hot air