We already know that contact with trees improves our health, and obviously stopping deforestation could help slow climate change — which, among other things, is a major human health risk. But it turns out that there's also another, more immediate, link between the health of our forests and the health of our communities.

Deforestation can lead to the spread of dangerous infectious diseases like Ebola. 

As reported by Al Jazeera and The Guardian, researchers suggest that large-scale deforestation, coupled with the movement of increasing numbers of humans into areas previously dominated by forests, has lead to a growing risk of viral epidemics as diseases cross from animal hosts into humans. Here's how it works.

Increased human-wildlife interaction
As forested areas become fewer and more dispersed, and as they become increasingly intertwined with farms, mines, logging roads and outposts and other signs of human habitation, it stands to reason that humans and wildlife will come into closer contact. Because there is also a tradition in West Africa of eating bush meat — including species like fruit bats and primates — some of this contact will involve the direct ingestion of a potential virus host by humans. There is also an increased risk of infection as wildlife come into closer contact with livestock too. 

Robert Garry, professor of microbiology and immunology at Tulane University, described the problem to Al Jazeera.

"As people go further and further into these rain-forest-type areas, they seem to come more in contact with the reservoirs of the virus. In this case, it looks like [people in Guinea] just cut far enough into the forest to find a reservoir."
A vicious cycle
As if this confluence of challenges was not bad enough, the problem may only get worse unless we tackle the root causes. Not only do diseases like Ebola threaten food security, leading to increased pressure on forests and further incentive to hunt wild animals, but as climate change — exacerbated by deforestation — kicks in, in earnest, researchers also predict disruption to crop cycles. That disruption further drives people into the forests to support themselves and their families, and may also lead fruit bats and other species to come out of their remaining habitats in search of food. 

An urgent need to rethink priorities
There are, however, reasons to be hopeful. As the world wakes up to the threat of climate change, there is a renewed emphasis on conservation, agro-forestry and reforestation, not just as an environmental effort, but as a means to ensure food security and development goals. On the other side of the continent, for example, Ethiopia has "regreened" vast areas of land and has pledged to restore 15,000,000 hectares by 2030. That pledge at the U.N. climate summit came as part of a major international commitment to curb deforestation and begin work on restoration. Other signatories to the initiative included the Democratic Republic of Congo and Uganda, nations that have been struck by the recent Ebola outbreak. Non-profit groups like Tree Aid are also working on reconnecting environmental action with community resilience and economic development, working with local non-profit groups and communities to develop strategies for meeting human needs, and caring for the environment at the same time. 

Here's hoping that the ongoing Ebola epidemic serves as a turning point in how we think about the natural world. Our environment and our health may depend on it. 

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