Climate Change and Global Health
If you’ve ever been on vacation somewhere warm and tropical, chances are you know what it’s like to be a mosquito snack (or if you’re sweet-blooded like me, you may have had the privilege of being a mosquito feast). We all know mosquitoes thrive in warm temperatures, so it should come as no surprise that rising global temperatures are bringing these vectors—and the diseases they carry (malaria, dengue, etc.)—to people who have never owned a bed net. So why not give everyone a lifetime supply of “OFF!” insect repellent and call it a day? Because climate’s grip on health doesn’t end here.
For starters, mosquitoes aren’t the only vectors celebrating global warming. Enter Vibrio: a bacterium that causes cholera, wound infections, and diarrhea and kills children in least-developed countries (LDCs). What does this bug have to do with climate change? Rising ocean surface temperatures have altered salinity patterns, causing algal blooms, which in turn produce Vibrio that enters the water supply and is ingested by humans. A recent study led by Dr. Nick Watts of University College London suggests that the number of days suitable, around the world, for the transmission of Vibrio has doubled—from 53 days to 107 days—since ocean surface temperatures started climbing.
But vectors aren’t the only thing we have to worry about. Dr. Watts and his team show that the yield potential of the world’s staple crops—maize, rice, soybeans, and wheat—has recently plummeted by 6% due to unfavorable climatic conditions. When fewer crops are produced, prices increase, and fewer people can afford to eat; it’s a domino effect. Malnutrition does irreversible damage on the human body. For example, malnourished women are more vulnerable to osteopenia, osteoporosis, and premature births. Micronutrient deficiencies are coupled with a host of symptoms: iron deficiency can lead to anemia, while vitamin A deficiency (VAD) can cause blindness. Furthermore, malnutrition weakens the immune system, rendering the human body more susceptible to infectious diseases such as malaria and TB.
The list goes on. If you’ve ever stood too close to a smoker, your lungs may have been screaming at you to move away. Now multiply that feeling by the thousands. Carbon dioxide emissions make us all—even those of us in the Global North—fair game for non-communicable respiratory diseases such as lung cancer.
Given the facts, it’s no wonder that, in 2018, the Lancet identified climate change as “the biggest global health threat of the 21st century.” It’s time to take action: any climate policy we devise must also address health.
Ella Nudell (SFS ‘22) is an undergraduate studying global health. She is a student fellow with the Global Health Initiative.