Loss of biodiversity through the destruction of the world’s forests will ‘unleash more pandemics’

Conservationists have warned that environmental destruction, such as deforestation and the exploitation of wild animals, could lead to increasing numbers of pandemics. 

A UN summit on biodiversity, being held in New York in September, will be told by biologists there is evidence of a strong link between loss of biodiversity and deadly new diseases, such as Covid-19.

Scientists will warn world leaders that the rapid rate of deforestation and the uncontrolled expansion of farming is providing a ‘perfect storm’ for diseases to pass from wildlife to humans, The Guardian reported.

Stuart Pimm, professor of conservation at Duke University, said: ‘There are now a whole raft of activities – illegal logging, clearing and mining – with associated international trades in bushmeat and exotic pets that have created this crisis.’

He added that ‘urgent action is needed’ as coronavirus has killed ‘almost a million people’ and cost ‘trillions of dollars’.

Conservationists said that as a result of land use change, such as deforestation, five or six new epidemics could soon affect the world each year.

They claimed that almost a third of all emerging diseases have originated through such land use change.

In the process, the destruction of wild animals, which are hosts to many unknown viruses and bacteria, can lead to humans or livestock being accidentally infected. 

These ‘spillovers’ can lead a new disease in humans if the viruses thrive and spread, or lead to transmission, to other individuals.

It has been estimated that an average rate of deforestation is around 10million hectares each year.

This decreased from an average of 16million hectares per year in the 1990s, as it is thought new forests, both naturally and man-made, are being established.

But before human civilisations, the Earth was originally covered by 60million sq km of forest.

But now, following deforestation accelerated due to human activity, there is said to be less than 40million sq km remaining.

It is used for farm cattle, to extract oil and provide access to mines and mineral deposits. 

In a paper published in Science last month, scientists and economists have proposed setting up a scheme to monitor wildlife and reduce deforestation.

The researchers added the programme, which could cost more than $20billion a year, would also be able to help the fight against climate change. 

The scientists said: ‘Postponing a global strategy to reduce pandemic risk would lead to continued soaring costs. Society must strive to avoid the impacts of future pandemics.’

The HIV virus originally spread from chimpanzees and gorillas, which were slaughtered for bushmeat in West Africa, to men and woman.

Other viruses which spread from wild animals to humans include the 2009 swine flu epidemic and Ebola fever, which is passed on by bats.

But zoologist David Redding, of University College London, stressed that not every emerging disease is caused by a single ‘spillover event’. 

He said: ‘Bats, rodents and other pests carrying strange new viruses come from surviving clumps of forests and infect farm animals – who then pass on these infections to humans.’

Lassa fever, which was first discovered in Nigeria in 1969, is spread by the rodent Mastomys natalensis.

The rodent was widespread in Africa’s forests but colonises in homes and farms, spreading the disease it carried to humans.

Andy Dobson, professor of ecology and evolutionary biology at Princeton University, said that during land use change, workers who chop down rainforest trees do not take food with them.

Instead, he said, the workers eat ‘what they can kill’ which can expose them to a number of infections.

He added that humans are outnumbered by infections, as there are probably ‘ten times more’ species of viruses than mammals.

This comes after physicists claimed that human civilisation stands a 90 per cent chance of an ‘irreversible collapse’ due to deforestation. 

Last month it was claimed that within the next two to four decades, Earth may no longer be able to sustain a large human population, according to a peer-reviewed paper published in Nature Scientific Reports.

The study, written by Dr Gerardo Aquino and Professor Mauro Bologna, states that if the rate of deforestation continues ‘all the forests would disappear approximately in 100–200 years’.

This trajectory would result in the loss of planetary life-support systems necessary for human survival including carbon storage, oxygen production, soil conservation and water cycle regulation. 

It is thought this would ultimately result in the collapse of human civilization as ‘it is highly unlikely to imagine the survival of many species, including ours, on Earth without [forests]’. 

The paper, which was published in May this year, states: ‘The progressive degradation of the environment due to deforestation would heavily affect human society and consequently the human collapse would start much earlier.’ 

‘Calculations show that, maintaining the actual rate of population growth and resource consumption, in particular forest consumption, we have a few decades left before an irreversible collapse of our civilization,’ the paper concludes.