Climate change to take health toll

Tree-eating beetles, malarial mosquitoes and deer ticks that spread Lyme disease are three signs that climate change is likely to exact a heavy toll on human health, Reuters reported. And as the global mean temperature rises, heat waves will increase, hitting the most vulnerable people hardest. “Climate change,” says the British medical journal The Lancet, “is the biggest global health threat of the 21st century.”


The United Nations Intergovernmental Panel on Climate Change projects 25% more heat waves in Chicago by the year 2100, for example, while Los Angeles likely will have a four-to-eightfold increase in the number of heat-wave days. People with heart problems and asthma, the elderly, the very young and the homeless will suffer most from these “direct temperature effects”, according to the United States Environmental Protection Agency (EPA).


Insect pests are expanding their ranges in a warming world. As the air becomes hotter, the EPA said, it can hold more moisture, helping certain disease-carriers to thrive. A changing climate could increase the risk of mosquito-borne diseases such as malaria, dengue fever, yellow fever and various viral causes of encephalitis. Algae blooms in water could be more frequent, increasing the risk of diseases such as cholera. Respiratory problems may be aggravated by increases in smog.


Dead timber left standing by tree-devouring pine bark beetles would provide ideal fuel for wildfires. People who live within 100 kilometres of a shoreline — about one-third of the world’s population — could be affected if sea levels rise as expected over the coming decades. Flooded homes and crops could make environmental refugees of one billion people.


As well as modifying climate, experts say, carbon-dioxide (CO2) emissions stimulate ragweed, some pollen-bearing trees and fungi, extending allergy and asthma seasons. Without cuts in CO2 emissions, some types of toxic air and water pollution will remain. Additionally, other unhealthy effects of climate change will continue, including more extreme weather events.


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