Deadly links between environment, climate and contagion

Struggling to control one pandemic, we face a prospect of many more

An exchange in US Senate hearings last week spoke volumes about the state of that country. A highly agitated senator, Rand Paul, accused immunologist Anthony Fauci of dictating to political leaders. A measured Fauci responded that he was only there to advise.

As a physician, Paul knows you can’t control a pandemic without rules of behaviour; as a libertarian he despises such rules. That tension was almost palpable in his aggression toward Fauci.

Where politicians like Paul have felt free to ignore signals from nature, ignoring the pandemic is looking like a political death sentence. Now there is a new element in the mix: governments being called on to treat environment damage and contagion as a single package, where a warming, degraded world is a path to more pandemics.

People spotted the connection between infectious disease and climate a long time ago. Aristocrats in ancient Rome, for instance, moved to homes in the hills to avoid the summer’s malaria. Now, with general warming causing weather to become more extreme, what was a manageable seasonal threat is becoming something less predictable, and therefore more dangerous.

Science has now identified a possibility of ancient viruses being resurrected by a warming world. In 2015, when the US and China were still being polite to each other, a team of scientists from the two countries went to Tibet to obtain samples of glacial ice over 15,000 years old. Microscopic analysis of the ice cores revealed 33 ancient virus groups, 28 of which scientists had never seen before.

In a peer-reviewed paper published last January, the team warned that melting of these ancient glaciers could be releasing pathogens completely new to science.

Changing average temperatures, humidity levels, the condition of vegetation and large-scale animal migration all result in changed patterns of the distribution of insects and other life forms that spread and transmit disease. Study of how land clearing is linked to infectious disease has found numerous cases of displaced native species carrying deadly pathogens to domestic animals and humans.

Hendra virus has killed numerous horses and several people in Australia. It began after large numbers of fruit bats, which harbour the virus, moved to more settled areas when their native habitat was destroyed in land clearing in Queensland in the 1990s.

Outbreaks of the related nipah virus from 1998 in Malaysia, Bangladesh and India were traced back to forest clearing in Indonesia displacing flying foxes, which then infected pigs and, through them, people. The disease kills more than half of its human victims.

Clearing of the species-rich Amazon rainforest has massive public health implications. Recent studies have found that a steady rise in cases of malaria in the region since the 1960s corresponds closely with forest clearing, which provides ideal breeding conditions for malarial mosquitos.

The World Health Organisation has many times warned that climate change and environmental damage on top of other large-scale economic, demographic and social shifts, including overcrowding and pollution, will rapidly make us more susceptible to respiratory infections.

Ten years ago, responding to an Ebola viral epidemic in tropical Africa, Barak Obama set up a program to detect and study viruses passing from wild species to humans before they break out and infect millions. By late last year it had found nearly a thousand different viruses. But the Trump administration wanted its funding for something else, and terminated it.

Blaming China for the damage COVID-19 has done to his country, Donald Trump is missing the target by 180 degrees. The virus originated in China, but its spread in the US, especially since restrictions were lifted in May, is entirely a home-grown affair.

With the novel coronavirus proving a difficult adversary for all governments, multiple new pathogens attacking humanity on multiple fronts is beyond imagining. That is apart from all the other impacts of an overheating planet.

Now, voters whose eyes have been opened by the pandemic are seeing once-impregnable careers in freefall as the fantasyland of right-wing populism – sheltered, gated and fact-free – is destroyed by forces of nature. We can only hope that an informed and enlightened administration will emerge from the wreckage of the old.

But there will be no time to cheer. Rebuilding a pandemic early-warning system, getting global emissions down and restoring environmental health call for unprecedented cooperation between peoples and nations. Right now that looks farther away than ever.

All is not lost – stopping the clearing of forested lands would eliminate much of the disease threat. But above all we need to start behaving as if our planet is something truly precious. Because it really is.

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