Irish team investigating potential link between climate and Covid-19

28 Apr 2020

Long Biên Bridge in Hanoi, Vietnam. Image: © Hanoi Photography/

A team from the ICHEC is hoping to kick-start further research into whether a region’s climate influences the spread of Covid-19.

As researchers across the world attempt to better understand how the coronavirus is spreading, a team based in Ireland is looking at a potential link between a region’s climate and the number of Covid-19 cases.

In a blog post, the Irish Centre for High-End Computing (ICHEC) team said it is continuing research presented in a number of studies that examined the influence that temperature and humidity may have on the spread of Covid-19. While one study reported that high temperature and high humidity appeared to significantly reduce transmission, another found evidence for “significant community spread” in cities and regions with consistent weather patterns.

Hoping to guide future strategies

In an attempt to examine the role of climate in the spread of the virus, the ICHEC team compared ECMWF ERA5 reanalysis climate data with national Covid-19 deaths. These results suggested that, to date, countries with high levels of mortality have mean temperatures in the approximate range of four to 12 degrees Celsius and mean relative humidity ranging from 67pc to 77pc.

Other findings suggested a weak signal between increasing surface shortwave and UV radiation, and decreasing Covid-19 mortality.

The team said that additional work is required to establish if these weak radiation links are simply a byproduct of the temperature and humidity results, or are directly related to factors such as “increased immunity due to enhanced vitamin D production”.

Dr Paul Nolan, climate science programme engineer at ICHEC, admitted that while he and his fellow researchers are “reluctant” to release preliminary results, he said on this occasion that it may “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 and winter”.

“We recommend further research of these trends nationally and internationally to validate these findings as more data becomes available,” Nolan said.

A graph showing the number of deaths per population in a country compared with the mean specific humidity.

A graph showing the number of deaths per population in a country compared with the mean specific humidity. Image: ICHEC

‘An important step’

The team pointed out some important caveats, including the fact that more reliable data may change these results as the virus progresses globally. Also, a high level of uncertainty remains due to the varied national healthcare standards and containment strategies.

However, the ICHEC said it will update these results as more data becomes available.

Ray McGrath, a meteorology and climate adjunct lecturer at University College Dublin, said the research is an important step towards finding a definitive answer on a potential link between climate and the spread of the virus.

“Humidity is known to affect the survival of influenza virus in aerosols expelled through coughing,” he said.

“Whether the same applies to the current virus, or indeed whether other meteorological factors play a significant role in transmission, remains to be seen. Analysing the weather conditions prevailing during the current crisis is an important step in addressing this issue.”

Colm Gorey was a senior journalist with Silicon Republic