Why a cooler, greener Hong Kong has a better chance of keeping a future pandemic at bay
2020-05-17
| South China Morning Post
| Mei Ng, Chairperson, Friends of the Earth (HK)
Wearing a face mask outdoors is becoming unbearable for many in Hong Kong, as urban temperatures have soared to over 30 degrees Celsius in recent days. Trying to seek refuge in the shade of a mature tree in the busy streets of a city of 7 million people can be a challenge.
Thanks to the Country Parks Ordinance, Hong Kong can pride itself on having a wealth of green space; around 40 per cent of our land area has been designated as country park and special areas for nature conservation. But when we consider the urban districts of Hong Kong, the available average green space drops to just a couple of square metres per person.
Scientists believe almost half of the new zoonotic diseases since 1940 stem from changes in land use, like deforestation. Mounting evidence indicates that biodiversity loss frequently boosts disease transmission. Climate change, which triggers extreme heat, droughts, hill fires and unavoidable biodiversity loss, is posing serious threats to eco-health as well as human health. All these should give an urgency to Hong Kong’s climate preparedness. It is about enhancing Hong Kong’s liveability through climate adaptation.
Extremely hot days can induce heatstroke, heat exhaustion, asthma and other respiratory illness. According to a 2016 study by Chinese University’s School of Public Health, the local hospital admission rate rose by 4.5 per cent for every 1 degree increase above 29, and 1.4 per cent for every decrease of 1 degree within the 8.2-26.9 degree range, with children and the elderly being especially vulnerable.
An average 1 degree increase in the daily mean temperature above 28.2 degrees was associated with an estimated 1.8 per cent increase in mortality, and cardiovascular and respiratory infection-related deaths were more sensitive to high temperatures.
It is a worrying prospect that Hong Kong’s health system might be overwhelmed by a surge of hospitalisation and mortality under the double blow of a future epidemic and climate change. Who can say for sure that this won’t happen?
May 22 is World Biodiversity Day. Hong Kong policymakers would be well advised to revalue country parks and urban forestry, boost biodiversity and enhance eco-health and public health by pledging priority policy and funding support. "Forest therapy” or "forest bathing” has a positive effect on physiological and psychological health, according to a 2017 study published in the International Journal of Environmental Research and Public Health. Biodiversity and urban forestry could give people stronger immunity against future viral outbreaks.
Biodiversity boosts biosafety and climate adaptability. Who knows, the cure for future infectious diseases could be found in the biodiverse treasure trove of Nature.