Month: May 2020

by Jack Board

BANGKOK: Preventing the further destruction of Southeast Asia’s forests will be a critical step to stopping the spread of future deadly viruses similar to COVID-19, according to leading experts studying the risk factors that have contributed to the current global pandemic.

Over the past four decades, swathes of the region’s pristine forests have been felled at astonishing rates. Agriculture and infrastructure have swallowed up land perennially owned by nature, in the vast pursuits of economic development. 

A third of the region’s forest cover has been lost in that time. Humans and wild animals have come into closer contact and conflict. 

Now, research shows more conclusively that the destruction and fragmentation of forest land is not only a leading cause of climate change. It is also linked to dangerous viruses jumping between animals and humans.  

While the exact source of COVID-19 is yet to be established, its zoonotic origins, which make up 58 per cent of all infectious diseases, are not in question. More than two-thirds of zoonotic diseases are known to come from wild animals. 

“Pandemic risk is linked to habitat loss and exploitation of wildlife. Spillover of zoonotic viruses is more common than we realise and is happening at a rate that is faster than ever, said Christine Johnson, a professor of epidemiology and ecosystem health at the University of California, Davis. 

“As natural habitat is diminished, wildlife often redistribute into marginal habitats in closer and more frequent contact with people,” she said. 

The professor has directed animal and human surveillance activities for PREDICT, part of USAID’s Emerging Pandemic Threats project, which recently uncovered previously undetected strains of coronavirus in bats in Myanmar. 

Climate change – exacerbated by deforestation – is increasing the risk of disease emergence by pushing animals and the vectors that can transmit viruses into new regions that have not encountered those pathogens previously, she explained.

She said it has never been more important to recognise the connection between the health of the environment and global public health.

“Protection of natural habitats for wildlife and restriction of the live animal wildlife trade are going to be essential for mitigating disease emergence, which is the establishment of new viruses from animals into susceptible human populations, and, if viruses are human-to-human transmissible, can cause pandemics,” she said.

A recent Stanford University study looked at how landscape changes brought about by deforestation and the intensification of agriculture brought humans into closer contact with animals in Uganda. The research mapped a complex range of different behaviours and interactions to better understand where and how disease transmission could occur.

It is the type of information that could be helpful in an Asian context, the study’s lead researcher and doctoral candidate, Laura Bloomfield said.

“It represents the complex environmental, social and economic forces that are at play in many tropical forested areas across the world that have an increasing density of people and pressure on wild animal habitats,” she said.

While much of the blame for the inception of COVID-19 has fallen onto a single individual action at a wet market in Wuhan, China, Bloomfield said that simplistic explanation undermines the root cause of the spread of such viruses.

“It takes the focus away from the complex set of circumstances that lead to forest fragmentation, local dependence on forest resources, development, destruction of wild animal habitat, and human-animal contact.  It is important to think about these events in a global context,” she said.

Ebola, Malaria and Lyme diseases are examples of damaging outbreaks that have origins with disrupted forest landscapes. 

Research by the IDEAAL project – Infectious Disease Emergence and Economics of Altered Landscapes – conducted between 2013 and 2019 and mainly in Southeast Asia, estimates land-use change is the biggest driving factor of such diseases, in about one-third of all new cases.

That project aimed to put an economic cost on deforestation when linked with the spread of infectious diseases, notably Malaria, in Sabah, Peninsular Malaysia, Sarawak, and Thailand. In a final report, it concluded that net present value loss between 2015 and 2030 would exceed US$4.35 trillion if deforestation continues at business-as-usual rates.

CHANGE NEEDED IN HOW FORESTS ARE VALUED

Environmental campaigners in the region say there needs to be a fundamental change in the way forests are valued, in the face of ongoing rapid rates of deforestation. The benefits would be economic, environmental and health-related.

“You have competition for food security in the same landscapes. The economics of palm oil, you can’t compete with any other product right now. Everyone will continue to profit on palm oil and its expansion,” said David Ganz, the executive director of The Center for People and Forests (RECOFTC).

“I talk about bundling ecosystem services; we need to value not just the carbon but the water, the pollination values, the recreation values. You have to have full natural capital accounting so forests are really seen for their full value,” he added.

The challenges are steep in Indonesia, where it is estimated that more than one million hectares of rainforest are lost every year, mostly to palm oil, which is also being enthusiastically promoted by Malaysia. 

President Joko Widodo’s proposed Omnibus law is expected to further slash environmental protections, such as permits and impact assessments, and further promote foreign direct investment in the palm oil sector. 

On top of zoonotic disease spread, Arie Rompas, the Forest Campaign Team Leader for Greenpeace Indonesia, is also worried about the health impacts from plantation fires and the cascading impact on an already suffering economy.

“Potentially more land will be needed to be converted into palm oil plantation to meet the demand and this increases the risk of more fires and haze. Last year, the fires that broke across Indonesia released at least 708 million tonnes of carbon dioxide equivalent – nearly twice the amount of greenhouse gases as the Amazon fires,” he said. 

“In 2019 the United Nations warned the Indonesian forest fires were putting nearly 10 million children at risk due to air pollution. Today, we are facing a global health crisis with a virus that affects people’s lungs.”

Rompas of Greenpeace said a lack of transparency is hiding crucial information from the public, which would otherwise “help fight deforestation and reduce emissions”.

“We need systemic change in how we run and fuel our society. We cannot continue to exploit nature at this global scale for short-sighted economic returns. Forest protection is now more important than ever for securing the health of people and the planet,” he added.

LOCAL COMMUNITIES REQUIRE PROTECTION

For Ganz of RECOFTC, empowering and protecting local communities – those at the literal front line of forest protection – should be front of mind once the pandemic is brought under control and investments start to flow once more in the region. 

“These are marginalised people; they’re either indigenous groups or vulnerable people, particularly susceptible during the pandemic. They are the best stewards of our global forest estate. If we give them the keys to the car they’ll do a much better job than what governments are doing,” he said.

While these governments have made “pronounced” commitments to address the problems of forest management, land use and climate change, he is awaiting the willpower to back up those pledges with real action. 

The widespread impacts of this pandemic are good enough reasons for why it must happen, Ganz believes.

“The health of the forest is tied to the health of human civilisation and the health of the planet. “The more large tracts of healthy forest that we keep as is, the better off we are. The more we displace animals by fragmenting the forest, the worse off it is,” he said.

“ If we start conveying that message and people get a newfound awakening, who knows?”

View the original article here.

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by Jonathan Watts, Global environment editor

Habitat destruction forces wildlife into human environments, where new diseases flourish

Humanity’s “promiscuous treatment of nature” needs to change or there will be more deadly pandemics such as Covid-19, warn scientists who have analysed the link between viruses, wildlife and habitat destruction.

Deforestation and other forms of land conversion are driving exotic species out of their evolutionary niches and into manmade environments, where they interact and breed new strains of disease, the experts say.

Three-quarters of new or emerging diseases that infect humans originate in animals, according to the US Centers for Disease Control and Prevention, but it is human activity that multiplies the risks of contagion.

A growing body of research confirms that bats – the origin of Covid 19 – naturally host many viruses which they are more likely transfer to humans or animals if they live in or near human-disturbed ecosystems, such as recently cleared forests or swamps drained for farmland, mining projects or residential projects.

In the wild, bats are less likely to transfer the viruses they host to other animals or come into contact with new pathogens because species tend to specialise within distinct and well-established habitats. But once land is converted to human use, the probability increases of contact and viruses jumping zoonotically from one species to another.

As natural habitats shrink, wild animals concentrate in ever smaller territories or migrate to anthropogenic areas, such as homes, sheds and barns. This is particularly true of bats, which feed on the large number of insects drawn to lamplight or fruit in orchards.

Two years ago, scientists predicted a new coronavirus would emerge from bats in Asia, partly because this was the area most affected by deforestation and other environmental pressures.

One of the authors, Roger Frutos, a specialist in infectious diseases at the University of Montpellier, said multiple studies have confirmed the density and variety of bat-borne viruses is higher near human habitation.

“Humans destroy the bats’ natural environment and then we offer them alternatives. Some adapt to an anthropomorphised environment, in which different species cross that would not cross in the wild,” he said.

Habitat destruction is an essential condition for the proliferation of a new virus, he added, but it is only one of several factors. Bats also need to pass the disease on to humans. There is no evidence of this being done directly for coronaviruses. Until now there has been an intermediary – either a domesticated animal or a wild animal which humans came into contact with for food, trade, pets or medicine. In the 2003 Sars outbreak in China, it was a civet cat. In the Mers outbreak in the Middle East in 2012, it was a camel. Scientists are not yet certain of the animal for Covid-19, though Frutos said initial theories that a pangolin was the intermediary now seem less likely.

In a soon-to-be-published paper in Frontiers in Medicine, Frutos and his co-authors argue the key to containing future epidemics is not to fear the wild, but to recognise that human activities are responsible for the emergence and propagation of the zoonosis. “The focus must be on these human activities because they can be properly organised,” notes the paper titled, the Conjunction of Events Leading to the Pandemic and Lessons to Learn for Future Threats.

Scientists have detected about 3,200 different strains of coronavirus in bats. Most are harmless to humans, but two very closely related sarbecoviruses found in east Asia were responsible for Sars and Covid-19. The paper says future sarbecovirus emergence will certainly take place in east Asia, but epidemics of other new diseases could be triggered elsewhere.

South America is a key area of concern due to the rapid clearance of the Amazon and other forests. Scientists in Brazil have found viral prevalence was 9.3% among bats near deforested sites, compared to 3.7% in pristine woodland. “With deforestation and land-use change, you open a door,” said Alessandra Nava, of the Manaus-based Biobank research centre.

She said diseases were naturally diluted in the wild, but this broke down when humans rapidly disrupted the ecological balance. As a local example, she pointed to Lyme disease, which has spread to humans through capybaras. Some municipalities are culling the giant rodents to prevent contagion, but Nava said this was not necessary in pristine forests that still had jaguars. “You don’t find Lyme disease in areas with jaguars because they keep the capybara numbers in check,” she said.

“The problem is when you put different species that aren’t naturally close to one another in the same environment. That allows virus mutations to jump to other species,” she said. “We have to think about how we treat wild animals and nature. Right now we deal with them far too promiscuously.”

Her conclusions were echoed by Tierra Smiley Evans, an epidemiologist at the University of California who studies virus distributions in the rapidly degrading forests of Myanmar. She has found that endangered or threatened species are more likely to have viruses than animals at lower risk of habitat loss and hunting. She said the connection between environmental stress and human health had been made more apparent by Covid-19 pandemic.

“I’m hopeful that one of the most positive things to come out of horrible tragedy will be the realisation that there is a link between how we treat the forest and our wellbeing,” she said. “It really impacts our health. It is not just a wildlife issue or an environmental issue.”

To prevent future pandemics, the academics said international cooperation was needed to encourage monitoring and education at a local level so that virus outbreaks could be detected and contained at an early stage. Although this would be expensive, they said it would more economically efficient than waiting for an outbreak to become a pandemic, which forces the world into lockdown.

They also emphasised that bat culls and bans on wet markets were likely to be ineffective and could prove counterproductive because bats play an important role in insect control and plant pollination. “Living safely with bats is what we should be focusing on, not eliminating them,” Evans said.

Conservation groups have also urged greater protection of existing habitats. A recent Greenpeace report warned the Amazon could see the next spillover of zoonotic viruses because the Brazilian president, Jair Bolsonaro, is putting a higher priority on opening up the forest than protecting people’s health.

“It’s unforgivable. His appetite for destruction is fuelling the current health crisis and will make future crises we face even worse,” Daniela Montalto, Greenpeace forests campaigner, said. “He must be stopped and forest protection prioritised. Without it, we will all pay the price.”

Read the original article here.