DAVID GREENE, HOST:
So if we just think about global health, over the last two decades, the world has made so many strides - vaccinating kids, lifting millions out of poverty. Childhood deaths have been slashed in half. Adults are living an average of 5 1/2 years longer. But now scientists are warning this progress is under threat from climate change. The researchers, from more than two dozen universities and the World Health Organization, have published their findings in a sweeping new study in the journal The Lancet. NPR's Nurith Aizenman has more.
NURITH AIZENMAN, BYLINE: All this time the world has been doing so much to improve health, climate change has also been underway, slowly pushing up the average temperatures experienced around the planet. Today, it's about 1.8 degrees Fahrenheit hotter than preindustrial times. One consequence? The conditions for growing all sorts of crops around the world have become less favorable.
NICK WATTS: Each of the major crops. So we - so typically, we track maize. We track rice, soybean, and spring and winter wheat.
AIZENMAN: Dr. Nick Watts of University College London led this study. He says the research team found that the yield potential for these staple crops is now down as much as 6%, which might not sound like much, but...
WATTS: Who here is going to be the most vulnerable? Children.
AIZENMAN: Particularly in poor countries. Fewer crops drive up prices. People get less food, which leads to malnutrition. That's devastating for kids because their bodies are still growing.
WATTS: They end up with these health impacts that stick with them through the rest of their life - gastrointestinal disease, cardiovascular disease, cognitive defects, lifelong impact that is irreversible.
AIZENMAN: Another effect of climate change - it's improving conditions for the spread of a bacteria called Vibrio.
WATTS: It's a nasty bug. It causes all sorts of problems.
AIZENMAN: Cholera, wound infections and diarrhea - in poor countries, an especially big killer for kids. As the surface temperature of the ocean rises, the salinity patterns in the water shift.
WATTS: And then what you start to see is, over a period of time, those ideal conditions develop into algal bloom.
AIZENMAN: Algal blooms that then produce critical levels of Vibrio bacteria, which make it into the water supply and humans can end up ingesting.
WATTS: And we have seen the number of days suitable around the world for the transmission of Vibrio double.
AIZENMAN: As much as these impacts are disproportionately hitting poor countries, every nation is affected. Dr. Renee Salas is an emergency room doctor and Harvard professor who authored the report's section on the United States.
RENEE SALAS: People living in the United States are experiencing the health harms of climate change today.
AIZENMAN: Last year in the U.S., there were 3.1 million incidents in which elderly people were exposed to heat waves because of climate change. Salas saw the impact in her own ER at Massachusetts General Hospital last July. During a massive heat wave in Boston, an elderly man was brought in in a terrible state of disorientation.
SALAS: And, you know, I'll always remember - the ambulance crew, they said that when they opened the door, I mean, the amount of heat that hit them...
AIZENMAN: Salas' research on climate change has sprung directly from these experiences.
SALAS: As an emergency medicine doctor, I'm trained to respond to emergencies.
AIZENMAN: And she says, I can think of no greater emergency facing the health of our country than climate change. Nurith Aizenman, NPR News.
(SOUNDBITE OF AARON PARKS' "NEMESIS")
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.