Irish Centre for High-End Computing Investigates possible link between Climate and Covid-19 25 April 2020
Recent research has suggested that climate, and in particular temperature and humidity, may influence the spread of COVID-19. For example, Wang et al. (2020) [1] reported that “high temperature and high humidity significantly reduce the transmission of COVID-19”. Similarly, Sajadi et al. (2020) [2] found that COVID-19 “has established significant community spread in cities and regions along a narrow east west distribution roughly along the 30-50°N corridor at consistently similar weather patterns consisting of average temperatures of 5-11°C, combined with low specific humidity (3-6 g/kg)”. The EU Copernicus Climate Change Service has used these results to map regions where climate conditions are considered to be more conducive to the spread of COVID-19, alongside regional mortality data [3]. Other studies have indicated that regions with higher levels of ultraviolet light are associated with lower COVID-19 growth rates [4,5]. To date, the transmission of COVID-19 continues to be pronounced in regions with moderate temperature and humidity (e.g. Europe and US). Conversely, hot and/or humid regions with large populations (e.g. Thailand, Philippines, Malaysia, Vietnam, India, Africa, Australia, etc.) have, to date, reported relatively low numbers of COVID-19 cases per population. It is worth noting that a number of these countries have close trading, cultural, tourism and migration ties with China, and yet the virus has not spread to the same extent as in Europe and the US. It is very clear that the transmission of the virus is multi-faceted, underpinned by strong social, economic and geographic drivers. Linkage with local climate may be tenuous and difficult to establish to robust standards, particularly now with the introduction of social-distancing measures, but nevertheless the weather/climate may have some role in the spread of the virus. This study looks at the evidence. To attempt to quantify links between COVID-19 and climate, researchers at ICHEC have compared ECMWF ERA5 reanalysis climate data with national COVID-19 deaths (the methods are outlined below). We compared COVID-19 data [6] with ECMWF ERA5 reanalysis [7] 2m temperature (surface), humidity (lowest pressure level) and downward radiation (surface) data. The following criteria were used: For each country, the mean climate fields are calculated from the date of the first confirmed case to six days ago (due to a delay with ERA5 availability). Only countries with population greater than one million are considered Only countries with cases present for at least 30 days are considered Only countries with at least 50 cases are considered The y-axis shows #deaths/ population/ (# days since first case) Commenting on the preliminary investigations, Dr Paul Nolan, Climate Science Programme Manager at ICHEC(opens in new window) said: “As scientists we are always reluctant to release results which are preliminary, on this occasion, however, the results may assist in the understanding of the effects of local climate on the spread of COVID-19 and play a small part in informing authorities tasked with implementing national strategies to combat COVID-19, particularly in the event of a second wave of infection during autumn/winter. We recommend further research of these trends nationally and internationally to validate these findings as more data become available.” The full article is available at: https://www.ichec.ie/news/irish-centre-high-end-computing-investigates-possible-link-between-climate-and-covid-19(opens in new window) Some recent media coverage is available here: https://www.thetimes.co.uk/article/virus-thrives-in-cooler-climates-v9kz0mg3r(opens in new window) and https://www.businesspost.ie/health/moderate-weather-is-linked-to-high-covid-19-death-rates-663c6919(opens in new window)
