Record-breaking temperatures known as heat waves are deadly and their human toll can be enormous. The heat waves that slammed the United States and Canada in recent weeks reportedly saw dozens of people dead. The death toll is likely to rise further, several reports said.
And now, a mountain of scientific research has attributed 37 per cent of deaths related to heat exposure around the world to human-induced climate change. Rancorous
The study was carried out by a team of about 70 researchers led by Ana Vicedo-Cabrera of the University of Bern, Switzerland, and Antonio Gasparrini of the London School of Hygiene and Tropical Medicine.
The researchers collected temperature and mortality data during the warm season from 732 sites across 43 countries on six continents over a 27-year period, between 1991 and 2018.
The scientists calculated the death risk from extreme heat in each location. They also ran two climate simulations–one that factored in warming caused by greenhouse-gas emissions and one that didn’t – and compared the deaths under each scenario.
In their study published in Nature Climate Change, the researchers reported that, on average, 37 per cent of all heat-related deaths can be pinned directly on climate change.
The study, obtained by Sunday PUNCH, showed that 37 per cent of the heat-related deaths could be attributed to rising temperatures induced by human activities.
The combined toll from all assessed sites is roughly 9,700 deaths per year of the study, the authors estimate. The most affected areas are Southern Asia, Southern Europe, and Central and South America.
“Climate change is not something in the future; it’s something in the present, and it is already affecting our health in very dramatic ways,” said Vicedo-Cabrera, the lead author of the study and a climate change epidemiologist at the University of Bern.
According to the study, the highest percentage of heat deaths during the period covered is in South America.
Some cities adapt to heat better than others because of air conditioning, cultural factors and environmental conditions, Vicedo-Cabrera said.
In many locations studied, the scientists found, “the attributable mortality is already on the order of dozens to hundreds of deaths each year” from heat attributed to climate change.
“Taken together, our findings demonstrate that a substantial proportion of total and heat-related deaths during our study period can be attributed to human-induced climate change,” the authors wrote.
The new paper comes amid a rush of recent research on heat stress and economic inequality across the world.
Some earlier studies had performed similar analyses for individual cities during particular heat waves, but the new study applies these ideas to hundreds of locations and across decades to draw broader conclusions.
“It is a thoughtful, insightful, clever approach to try to understand how climate change is altering heat-related mortality,” Prof Kristie Ebi of the Centre for Health and the Global Environment at the University of Washington told the New York Times.
Ebi, who was not involved in the study, said communities must adapt to heat through measures such as cooling centres and actions on tackling heat.
She emphasised that some actions to be taken were simple, like making sure people have access to fans, air conditioning, and shade.
She said, “Climate change is already affecting our health. Essentially, all heat-related deaths are preventable, but much depends on decisions. Communities must adapt to heat through measures like cooling centres and heat action plans to help those most vulnerable. In the long term, there are lots of choices that will affect our future vulnerability, including reducing our greenhouse gas emissions.”
The Director of the Global Health Institute at the University of Wisconsin, US, Dr Jonathan Patz, said the study was one of the first to detail climate change-related heat deaths.
“People continue to ask for proof that climate change is already affecting our health. This attribution study directly answers that question using state-of-the-science epidemiological methods,” he said.
Nigeria has also witnessed effects of climate change in recent times, with the Nigerian Meteorological Agency stating in a report that the trend was clear for all to see.
NiMET stated that the mean annual variability and trend of rainfall over Nigeria in the last six decades depicted several inter-annual fluctuations that had been responsible for dry and wet years or extreme climate events such as droughts and floods in many parts of the country.
The agency noted that the country would be subject to consistent changes in rainfall and temperatures in the not-so-distant future.
“Hotter and drier conditions would likely exacerbate floods, droughts and heat waves and hamper agricultural production, particularly rain-fed agriculture, which many Nigerians rely on for their livelihoods,” NiMET said.
Perhaps, one of the biggest devastations heat waves have had in Nigeria was the death of at least 60 people dying of heatstroke within one week in 2002 in Maiduguri, Borno State.
The Chief Medical Director, University of Maiduguri Teaching Hospital, in a report at the time, said intense heat waves, with temperatures of between 55-60 degrees Celsius, claimed lives in the areas nearest to the Sahara Desert.
“In the last one week, at least 60 people died of heatstroke caused by intense heat of between 55 degrees and 60 degrees Celsius,” Kida was quoted by Radio Kaduna as saying.
The situation was linked to the late arrival of rainfall, and apart from the death toll, the situation resulted in crop failure and food shortage in the region.
Speaking on climate change-induced heat waves in Nigeria, the Resident Representative for the United Nations Development Programme, Mohamed Yahya, said now was the time for the country to lead on climate change.
He said, “Unless we take action, these trends are likely to jeopardise hard-won progress. Already, climate-induced conflicts are exacerbating fragile security situations, with flashpoints mainly in the middle belt of the country. Climate change, therefore, poses a significant threat to Nigeria’s development ambitions of meeting the Sustainable Development Goals, and could stunt and even reverse the progress that’s already been made.”
Also, a cardiologist and Executive Secretary, Nigerian Heart Foundation, Dr Kingsley Akinroye, recently said hot temperatures could cause strokes and heart attacks.
The experts said heat waves could kill via the dehydration caused by heavy sweating, noting that the altered sodium and potassium concentrations in the blood confuse both heart and nerve cells, and so breathing or heartbeat may suddenly stop.
A professor of Environmental Sustainability, Environmental Education and Learning for Sustainable Development at the Faculty of Education, Osun State University, Anthony Kola-Olusanya said now was the time Nigerians should embark on massive afforestation, among other measures, to curb climate change-induced deadly heat waves.
He said, “Climate change is a phenomenon that occurs as a result of global warming, which is caused by human activities. For instance, if you lock your car in the morning, you can sit in it comfortably. But if you sit in it in the afternoon when it is hot, the heat inside the car becomes unbearable. You become exhausted and exhaustion can lead to death.
“Now is the time to embark on massive reforestation so we can create a natural carbon sink. The government must promulgate a law that makes every household have at least a tree. Also, we need alternative energy sources such as solar and wind to power and industries. We must also explore nuclear sources. People must also do away with burning waste.”
However, a professor and consultant paediatrician at the Bayero University Kano, Mustafa Asani, said the dearth of statistical data and non-collection of environmental data in a systematic manner was making it difficult to estimate in concrete terms the overall effect of climate change on temperature increase in Nigeria.
He said, “A comprehensive audit of the environment is needed to quantify the effects of global warming and the level of degradation and loss of biodiversity so that we can start to put in place some mechanism for responding to these challenges.’’ ,,
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