Warming Trends: Outdoor Heaters, More Drownings In Warmer Winters and Where to Put Leftover Turkey

A column highlighting climate-related studies, innovations, books, cultural events and other developments from the global warming frontier.

People sit outside a restaurant that uses umbrella heaters on October 15, 2020 in Berlin, Germany. Credit: Maja Hitij/Getty Images
People sit outside a restaurant that uses umbrella heaters on October 15, 2020 in Berlin, Germany. Credit: Maja Hitij/Getty Images

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Warming Trends



Outdoor Heaters: Bad for the Climate? 

Winter is coming and the coronavirus is surging across the country, sending restaurant owners searching for ways to keep diners warm, as sidewalk patios grow nippy.

A recent survey by the National Restaurant Association found that nearly half the nation’s full-service eateries “are taking actions to extend the outdoor dining season for their restaurants, including installing tents or patio heaters.”

AmeriGas, the largest retail propane distributor in the U.S., has sold 25 percent more portable propane tanks from March through September than over the same period last year, according to the Propane Education and Research Council. That raises a question: Is there a climate impact?


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Research is hard to come by, but climate concerns drove the French government to ban outdoor heaters at restaurants earlier this year, though the rule won’t go into effect this winter.

Still, outdoor heaters, even thousands upon thousands of them, don’t use that much propane in the grand scheme. The so-called “cylinder market”—which includes the 20-pound tanks that attach to grills and many outdoor heaters—is a tiny portion of the overall propane market, accounting for just 4 percent of 2018 sales, the most recent data available, according to the propane council. This may explain why national demand for propane is similar to what it was a year ago, even with more sales of portable tanks.

And while the pandemic is leading more restaurants to fire up outdoor heaters, consider the drop in travel that has come with the virus. In September, Americans drove 23.4 billion fewer miles than the previous year. Using EPA figures, that reduction works out to a drop in greenhouse gas emissions roughly equal to the output of burning 1.6 billion gallons of propane. In all of 2018, only 354 million gallons was sold in propane cylinders.

Put another way, the additional emissions from the extra heaters that may be warming outdoor diners are insignificant compared to the larger emissions reduction caused by lockdowns and depressed economic activity. So enjoy the heated patio. But maybe ride a bike to get there.




If You’re a Cold-Blooded Animal, Climate Change May Be a Health Risk 

Wildlife species living in cool environments are at a higher risk of parasitic infections, as local temperatures increase with climate change, according to a new study.

The study, published in the Nov. 19 issue of the journal Science, found that disease risk was highest for species that are adapted to living in cold environments, especially cold-blooded—or “ectothermic”—species, like some fish and amphibians, that do not migrate in winter. Such species cannot regulate their own body temperature, which affects their ability to mount an effective immune response to diseases. And an infection combined with abnormal temperatures can be harmful or even deadly. 

In the study, the researchers, from the University of South Tampa, the University of Wisconsin-Madison and the University of Notre Dame, examined the relationship between populations of thousands of wildlife species around the globe and local parasites and climate data. They found that cold-climate species may be exposed to more parasites during warm periods, increasing their risk of infection.

Conversely, species accustomed to warm environments may have a higher risk of contracting an infectious disease when the local climate is abnormally cool, and a lower risk when the climate is abnormally warm, the study found.

The findings are supported by the “thermal mismatch hypothesis,” which suggests that small parasites are more tolerant to temperature swings than their larger hosts, and therefore perform better, making hosts more susceptible to infections.





Don’t Throw That Leftover Turkey in the Trash 

The USDA estimates that 35 percent of turkey goes to waste—most of it around the holidays. 

With coronavirus cases surging around the nation, fewer people will be gathering around the Thanksgiving table this season, meaning Thanksgiving hosts will need to plan their meals for smaller groups.

Lauren Olson, a sustainability expert and zero waste manager of World Centric, said that to prevent food waste, she recommends using an online tool called Guestimator, which projects how much food to prepare for a given number of guests. 

“There’s always recipes and ways to utilize leftovers after Thanksgiving, but I think we all know that those get old after a while,” Olson said.

The best way to discard food waste after a Thanksgiving meal is to compost the leftovers, rather than throwing them out as trash that ends up in a landfill.

Composted food decomposes to form “a nutrient-rich material that revitalizes soil and prevents runoff in our gardens, farms, and backyards,” said Blake Rupe, a global health professor at the University of Iowa, who has researched waste proliferation. 

Many communities offer composting services curbside or at drop-off locations, but if those aren’t available, there are lots of ways to compost at home. 




Will Warmer Winters Mean More Drowning Deaths?

Skating, snowmobiling, ice fishing and other winter activities may be becoming more dangerous as the planet warms, a new study found. 

Published Thursday in the journal Plos One, researchers from York University in Toronto evaluated 4,000 winter drownings in 10 countries from 1991 to 2017, including the United States. They found that drownings were much more likely to occur when temperatures were warmer, between 23 degrees Fahrenheit (-5 Celsius) and 32 degrees Fahrenheit (0 degrees Celsius), the temperature at which water freezes. Drownings were most common at the end of the winter season, when the ice began to melt and more people were outside to enjoy warmer weather. 

As climate change leads to warmer winters, there will be more days within the 23 degrees to 32  degrees Fahrenheit range, and more risk of drownings, the researchers projected, as more people enjoy recreational activities on frozen lakes and rivers. 

This is the first time that research has shown the consequence of warmer winters on winter drownings, the study said.

“Excess winter deaths have been difficult to correlate to cold temperatures because of the influence of seasonal factors such as influenza, respiratory infections and cardiac risk,” the authors wrote.

However, if a country’s average temperatures exceed 32 degrees Fahrenheit, they noted,  winter drownings would decrease to zero, because there would no longer be ice forming on  inland water bodies. 

Nicholas Kusnetz contributed to this report