By: LiveScience Staff
The few plants that live in Antarctica today are hardy hangers-on, growing just a few weeks out of the year and surviving poor soil, lack of rain and very little sunlight. But long ago, some parts of Antarctica were almost lush.
New research finds that between about 15 million and 20 million years ago, plant life thrived on the coasts of the southernmost continent. Ancient pollen samples suggest that the landscape was a bit like today's Chilean Andes: grassy tundra dotted with small trees.
This vegetated period peaked during the middle Miocene, when atmospheric carbon dioxide levels were around 400 to 600 parts per million. (Today, driven by fossil fuel use, atmospheric carbon dioxide has climbed to 393 parts per million.)
As a result, global temperatures warmed.
Antarctica followed suit. During this period, summer temperatures on the continent were 20 degrees Fahrenheit (11 degrees Celsius) warmer than today, researchers reported June 17 in the journal Nature Geoscience.
"When the planet heats up, the biggest changes are seen toward the poles," study researcher Jung-Eun Lee, a scientist at NASA's Jet Propulsion Laboratory, said in a statement. "The southward movement of rain bands made the margins of Antarctica less like a polar desert and more like present-day Iceland." [Ice World: Amazing Glaciers]
NASA researchers, along with scientists from the University of Southern California and Louisiana State University, collected long cores of sediment from below Antarctica's Ross Ice Shelf. Within the sediment, they found plant-leaf wax, an indication of ancient vegetation. The cores also contained pollen and algae.
A pollen grain from modern-day southern beech trees that grow in New Zealand. Ancient Antarctica would have hosted similar trees.
An analysis of the leaf wax provided a record of the water taken up by the plants when they lived. Researchers could then track variations in the hydrogen molecules in the water, called isotopes. Because isotopes vary over time and over certain environmental conditions, these variations allowed the researchers to reconstruct what the climate would have looked like when this water fell as rain.
If current carbon emissions continue as they are, atmospheric carbon is set to reach middle Miocene levels by the end of the century. The northern Antarctic Peninsula has already warmed by 4.5 degrees F (2.5 degrees C) over the last 50 years, and satellite views reveal melting ice shelves.
The ancient Antarctic sediment could provide a vision of what is to come, said study leader Sarah Feakins, an earth scientist at the University of Southern California.
"Just as history has a lot to teach us about the future, so does past climate," Feakins said in a statement. "What this record shows us is how much warmer and wetter it can get around the Antarctic ice sheet as the climate system heats up."
- North vs. South Poles: 10 Wild Differences
- Image Gallery: One-of-a-Kind Places on Earth
- Top 10 Surprising Results of Global Warming
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<a href="http://www.ciatnews.cgiar.org/wp-content/uploads/2011/09/Ghana_ivory_coast_climate_change_and_cocoa.pdf" target="_hplink">A report released by the International Center For Tropical Agriculture </a>warns chocolate could become a luxury item if farmers don't adapt to rising temperatures in Ghana and the Ivory Coast, where a majority of the world's cocoa is grown.
Coffee lovers may want to get that caffeine fix before the treasured drink becomes an extinct export. Starbucks raised the issue last year when the company's director of sustainability told <em>The Guardian</em> <a href="http://www.huffingtonpost.com/2011/10/16/starbucks-climate-change_n_1011222.html" target="_hplink">climate change is shortening the supply chain of Arabica coffee bean</a>.
Famed for producing some of the world's best beer, <a href="http://www.nature.com/news/2008/080502/full/news.2008.799.html" target="_hplink">Germany could suffer from a drop in production due to climate change induced water shortages</a>. Barley and hops can only be grown with water and using cheaper alternatives like corn isn't possible in Germany because of strict regulations about what you can make beer with.
Thanks to a failing peanut crop due to last summer's scorching hot weather, <a href="http://www.huffingtonpost.com/2011/10/10/peanut-butter-price-jump_n_1003732.html" target="_hplink">there's a shortage of peanuts in supply</a>. If temperatures continue to rise, a jump in peanut butter prices is just the prelude to what's in store for the beloved American spread.
Scientists at the British Meteorological Office warn that Italy may soon be forced to<a href="http://www.theaustralian.com.au/news/world/climate-threat-to-italys-pasta/story-e6frg6so-1225797946930" target="_hplink"> import the basic ingredients to make pasta because climate change will make it impossible to grow durum wheat domestically</a>. The crop could almost disappear from the country later this century, say scientists.
<a href="http://www.treehugger.com/green-food/goodbye-maple-syrup-climate-change-pushing-sugar-maple-out-of-northeast-us.html" target="_hplink">A warming climate could make maple syrup history.</a> Shorter cycles of below freezing weather mean sugar maples aren't producing enough sap, which is later boiled down to make maple syrup.
<a href="http://usda01.library.cornell.edu/usda/current/Hone/Hone-03-30-2012.pdf" target="_hplink">It's no secret that bee populations are dropping nationwide</a>. Wetter winters and rainy summers make it harder for bees to get out and about to collect, leaving them to starve or become malnourished and more prone to other diseases. This doesn't just mean a decline in honey. We rely on bees to pollinate crops. When bees disappear many food crops could also die off.
<a href="http://www.spiegel.de/international/europe/best-served-chilled-top-french-wines-at-risk-from-climate-change-a-748139.html" target="_hplink">France is losing its enviable climate for grape growing</a> thanks to a shifting climate. Because a wine's taste is a result of the balance of sugar and acidity in the grapes it is made from, the right growing temperature is essential. Grapes grown in cold are unlikely to develop fruity flavors, giving an acidic taste. Warm weather produces too much sugar, leaving a "jammy" and heavy taste.
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