Addressing a crowd of more than 350 people gathered in Trenton, Nobel laureate Dr. Eric Chivian asked a question: How many people have had Lyme disease or know someone who had it?
Almost every hand shot up. This should not surprise most folks who live in New Jersey.
But why? Chivian, a Harvard University professor and New Jersey native, offered a theory: Reduced vertebrate diversity, caused at least in part by climate change, promotes the disease’s spread.
He explained that the bacteria causing Lyme disease spread only when a deer tick bites an infected mammal capable of passing the bacteria into the tick. Many mammal species are not capable of passing the Lyme bacteria between generations of ticks, but white-footed mice are extremely capable.
In places lacking vertebrate diversity, noted Chivian, there are fewer “incapable hosts” for ticks to feed on; thus more whitefooted mice are bitten.
Less diversity also means fewer rodents competing with white-footed mice … and fewer large predators like gray foxes, bobcats, short-tailed weasels, black rat snakes, barred owls and sharpshinned hawks available to prey on mice. In that way, places like the East Coast end up with high concentrations of mice and ticks carrying Lyme bacteria – and, eventually, more Lyme disease in humans.
Chivian was the keynote speaker on March 6 at the annual New Jersey Land Conservation Conference, an educational event for professionals and volunteers in the field of preserving land. His talk centered on how to make global warming more understandable and compelling by focusing on human health impacts.
In 1985, Chivian and three other Harvard faculty members won the Nobel Peace Prize for establishing the International Physicians for the Prevention of Nuclear War.
The group succeeded, he said, because it described nuclear explosions in terms of human health impacts – third degree burns, skull fractures and radiation sickness.
He suggests using the same “medical model” in talking about climate change.
Here are two other examples:
Polar bears are greatly affected by global warming, because the melting of the Arctic ice sheet harms their ability to capture seals, their main food source.
Polar bears are fascinating to medical researchers. They are immobile five to seven months a year during hibernation, yet they do not get osteoporosis, the loss of bone mass that affects humans and nearly every other mammal during prolonged inactivity.
They do not eat, drink, urinate or defecate during hibernation, yet they do not starve, become dehydrated or have kidney failure. They become massively obese from eating seal blubber, yet they do not develop Type II diabetes.
“With the loss of polar bears, which must be studied in the wild as bears do not hibernate in zoos, we may lose with them the secrets they hold that could allow us to treat and perhaps even prevent three largely untreatable diseases — osteoporosis, kidney failure and obesity-related Type II diabetes,” Chivian said.
Together, these diseases kill some 400,000 Americans each year.
“This is what global warming and the melting of Arctic ice and the loss of polar bears in the wild really means for us,” he said.
Climate change is also causing the loss of tropical coral reefs, mainly from warming ocean temperatures, but also because waters are becoming more acidic.
Among the animals that live in coral reefs are cone snails, which paralyze their prey by firing poison-coated “harpoons.” Some 700 cone snail species each make many distinct toxins.
Only a small number have been studied, said Chivian, but one has been shown to be a powerful painkiller in humans — 1,000 times more potent than morphine, without causing addiction or tolerance.
“Some believe cone snails may provide more leads to important medications for people than any other group of organisms in nature,” said Chivian. But can they survive global warming and ocean acidification? “This is what losing coral reefs really means.”
Chivian’s message provides serious food for thought. While many of us may be able to imagine life without snorkeling in coral reefs or watching polar bear cubs, it is far less tolerable to contemplate forever losing pieces of nature that hold the promise of enormous medical advances.
Chivian will be leaving the Harvard School of Public Health this summer to run his own nonprofit, the Program for Preserving the Natural World. His message is one that deserves to be heard and we hope the world takes heed.
Michele S. Byers is the executive director of the New Jersey Conservation Foundation, Far Hills.