<img class="styles__noscript__2rw2y" src="https://dsx.weather.com/util/image/w/gettyimages-925703976.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com/util/image/w/gettyimages-925703976.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com/util/image/w/gettyimages-925703976.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > A car drives through heavy snowfall along the palm tree-lined Promenade des Anglais on Feb. 28, 2018, in Nice, France. A recent study suggests the warming climate may push palm trees further north to areas in which they previously couldn't survive. (VALERY HACHE/AFP/Getty Images) (VALERY HACHE/AFP/Getty Images) 
 
 At a Glance A recent study suggests palm trees could be moving north as the climate changes. 
 
 Parts of the region are nearing winter climates that could allow the trees to survive. 
 
 Palm trees may be headed north to plant their roots in areas that have long been too cold for them, a recent study suggests. 
 
 An international team of researchers analyzed the relationship between temperature and the spread of palm trees across the globe. They wanted to determine how shifting climate zones will redistribute the plants, which is key for understanding how our ecosystems and landscapes will change over time. 
 
 They chose palm trees in particular because of their inability to survive in frigid temperatures. 
 
 “Palms are therefore sensitive indicators of changing climates, both in the remote geological past and in the present day ,” study co-author and Brandon University researcher David Greenwood said in a release. 
 
 Though palm trees typically aren’t built for cold weather, a 2007 study conducted in the Swiss Alps found palm trees in the foothills of the mountains . It determined that the trees spread because frost isn’t as common as it once was. 
 
 (MORE: Swiss Glacier Gets Covered in White Blankets ) 
 
 “Our results strongly suggest that the expansion of palms into (semi‐)natural forests is driven by changes in winter temperature and growing season length and not by delayed population expansion,” wrote the scientists. “This implies that this rapid expansion is likely to continue in the future under a warming climate.” 
 
 According to the current study, palm trees’ distribution relies on the average temperature of a region’s coldest month. In order for the trees to survive, temperatures have to be above 36 degrees Fahrenheit. 
 
 As climate zones begin to move north, plant habitats might migrate with them. 
 
 “As an example, this means that at present, Washington D.C. is just a little too cold (34 degrees in January) for palms to successfully propagate in the wild, but that you can expect range expansion in the coming decades as average winter temperatures warm up,” study co-author and Lamont-Doherty Earth Observatory researcher Tammo Reichgelt said in the release. 
 
 The scientists also discovered that the palms’ evolutionary heritage also plays a role in their ability to tolerate different temperatures. 
 
 “If you find a palm fossil and can determine its affinity to a modern subgroup of the palm family, you can, using our data, determine the temperature of the climate of when that palm was growing,” explained Reichgelt. 
 
 When reconstructing previous climates, the presence of palm trees usually indicated warmer conditions. However, Reichgelt said fossils of the trees dating back more than 50 million years were found in the Antarctic, which suggests the region’s climate at that time was “near-tropical.” 
 
 Palms’ ability to withstand certain cold temperatures also differs across their organs and life stages, according to the study. 
 
 “Seedlings, in particular, (are) less tolerant of subzero temperatures than adult plants, limiting successful establishment of populations while permitting adult palms to survive in cultivation outside their natural ranges,” wrote the scientists. 
 
 Greenwood told Earther that parts of the north and areas close to Canada are nearing winter climates that could allow cold-tolerant plants to survive . 
 
 “In all of these areas, palms in people’s gardens are flowering and setting fruit, which means the temperatures are now warm enough for that step in their reproduction,” he said. “A little bit more warming will see their seedlings survive winters.” ||||| Palms flourish in tropical zones, but as the world warms, they’ll show up in new places. Hitchster/CC By 2.0 
 
 Fifty-three million years ago, Antarctica wasn’t an unpleasant place for a midwinter sojourn. Back then, its shores and hills were ruffled with palm trees, beeches, and conifers. Winter temperatures hovered near 50 degrees Fahrenheit, so the region wasn’t frost-nipped, even if it was blanketed by near-constant darkness. 
 
 Today, of course, the landscape is harsher and notably empty of palms. The trees’ notorious intolerance to chilly conditions makes them useful proxies for estimating historical temperatures. The places fanned by fronds have varied over time. When they turn up in the fossil record, researchers can infer that the region’s temperatures probably once fluctuated within a fairly specific range. 
 
 In a new paper published in Nature Scientific Reports, researchers from Columbia University’s Lamont-Doherty Earth Observatory, Brandon University, and the University of Saskatchewan sifted through thousands of data points to untangle the relationship between temperature and distribution of palm trees, and offer hints about where the trees could put down roots in a warming world. 
 
 Unsurprisingly, the researchers found that most types of palms are clustered in tropical zones. Most palms flourish in areas with mean annual temperatures between 64 and 82 degrees Fahrenheit, but a few hardy varieties don’t mind damp, cold feet. The Trachycarpus fortunei, or windmill palm, for instance, grows at high altitudes in China. It can withstand temperatures below 35 degrees Fahrenheit, and won’t buckle under the occasional dusting of snow. 
 
 Windmill palms can tolerate nippy high altitudes and a dusting of snow. Wendy Cutler/CC By-SA 2.0 
 
 The windmill palm is a bit of an outlier, though: In order for most palm trees to flourish, the scientists concluded, the mean temperature of a region’s coldest month can’t dip below 41.36 degrees Fahrenheit. At present, “Washington, D.C. is just a little too cold for palms to successfully propagate in the wild, but … you can expect range expansion in the coming decades as average winter temperatures warm up,” said lead author Tammo Reichgelt in a statement. 
 
 In the coming years, more places will cross that temperature threshold: The Intergovernmental Panel on Climate Change, comprised of 1,300 scientists from around the world, estimates that temperatures will climb somewhere between 2.5 and 10 degrees Fahrenheit over the next 100 years. That will probably mean, in turn, that palms will show up in unexpected places. ||||| Image: pixabay 
 
 Washington, D.C. is famous for its cherry blossoms, but someday it could also be renowned for its palm trees. That’s according to a new study looking at how palm trees are expanding into northern parts of the world that have long been too cold for the iconic tropical trees. 
 
 There are over 2,500 species of living palm trees, and while the vast majority of them survive only in tropical climates, some are more hardy and can grow in places that regularly get snow. As climate change warms the planet, countless plants and animals are migrating into new habitats made more suitable for their survival. Palm trees are no different. 
 
 The study, published in Nature’s Scientific Reports, found that a palm tree’s latitudinal limit is determined by the average temperature of a region’s coldest month. If that average is above 2 degrees Celsius, or 36 degrees Fahrenheit, the palm may be able to successfully propagate in the wild. According to Tammo Reichgelt, a Lamont-Doherty Earth Observatory researcher who led the study, this means that at an average of 34 degrees Fahrenheit in January, Washington, D.C. is just a little too cold to host palm trees, “but that you can expect range expansion in the coming decades as average winter temperatures warm up.” 
 
 Looks like the National Arboretum might need to make room for some new species. 
 
 Average January temperatures in slightly farther south Norfolk, Virginia, and Greenville, North Carolina, have not dropped below 36 degrees Fahrenheit in January since the 80s, according to the study—long enough for a palm to grow to maturity. 
 
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 “But if that is actually the case also depends on other factors, such as the presence of cultivars and the amount of competition with the natural vegetation,” Reichgelt said. “I would love to see the data that shows how the range of palmettos has changed in eastern North America, or fan palms in California, but unfortunately I do not have that data.” 
 
 
 
 Image: AP Photo/Bruce Smith 
 
 Reichgelt told Earther that for many palm lineages, the average temperature of a place didn’t matter as much as the yearly temperature range. This could also impact the ability of palm trees to thrive in certain tropical locales as they face increased heat driven by climate change, which “could be detrimental to palms in those places.” 
 
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 Palm trees grow very quickly and thus their cells cannot go dormant in winter. They are also very aesthetically appealing, and when people plant them in non-native areas it allows the palms to potentially establish new strongholds in the wild. Reichgelt said that in Florida alone there are seven “category 2” invasive palm species that were introduced as ornamental plants but have since established healthy wild populations. For now they are co-existing with native flora, but eventually they could become “category 1” invasives if they begin to harm or displace local vegetation. 
 
 
 
 Graphic: Scientific Reports ISSN 2045-2322 
 
 David Greenwood, a paleobotanist from Brandon University who also worked on the study, said the authors wanted to see how cold some palms could go. Greenwood told Earther that the Chinese windmill palm (Trachycarpus fortunei) is especially cold hardy, and is commonly cultivated for this reason. Windmill palms have recently been found in the forests of southern Switzerland—the foothills of the Alps—after one such decorative palm escaped and spread “simply because frost is not as prevalent as it used to be,” according to the study. 
 
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 “A little bit more warming will see their seedlings survive winters.” 
 
 Greenwood said for a palm to colonize a new region, its seedlings must be able to survive their first winter. 
 
 
 
 “So just because you can grow a windmill palm or another cold-tolerant palm in your yard in Utah, British Columbia, or Ohio, doesn’t mean that species can colonize the nearby woods,” he said. “But this is of course changing as the climate gets warmer.” 
 
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 Greenwood said parts of the Northeast, Northwest, and neighboring areas of Canada are close to a winter climate that could allow cold-tolerant palms to become established. 
 
 “In all of these areas palms in people’s gardens are flowering and setting fruit, which means the temperatures are now warm enough for that step in their reproduction,” he said. “A little bit more warming will see their seedlings survive winters.”
– Utah, Ohio, and Canada might soon be dotted with palm trees—because welcome to climate change. Following a 2007 study that found palm trees in the foothills of the Swiss Alps, an international team of researchers set out to learn how cold is too cold for palm trees. Upon surveying global data, they determined most palm species (there are 2,500) grow successfully in the wild if a region's coldest month is above 41.36 degrees Fahrenheit on average, per Atlas Obscura. A handful of cold-tolerant palms, like the windmill palm, however, can grow in areas with a coldest month temperature above 36 degrees on average. With an average temp of 34 degrees in January, Washington, DC, isn't quite there, researchers say, but they note it could warm enough "in the coming decades" to allow palms to flourish, reports Weather.com. The same goes for the Northeast, Northwest, parts of Canada, and other parts of the world that have long been too cold for palms. "In all of these areas palms in people's gardens are flowering and setting fruit," study co-author David Greenwood says, per Earther. But "just because you can grow a windmill palm or another cold-tolerant palm in your yard in Utah, British Columbia, or Ohio, doesn't mean that species can colonize the nearby woods." For that to happen, seedlings—which are less tolerant of the cold than adult plants—must be able to survive their first winter, and that will take "a little bit more warming," Greenwood says. The study in Scientific Reports also looked at palms in the fossil record, noting their presence suggests a minimum temperature of roughly 36 degrees. (Los Angeles is losing its palm trees.)