October 17, 2011
Climate Change Could Be Causing Plants, Animals To Shrink
Warmer temperatures and a lack of water are causing some types of plants and animals to become smaller, claims a new study published Monday in the journal Nature Climate Change.
According to Marlowe Hood of the AFP, authors Jennifer Sheridan and David Bickford of the National University of Singapore discovered that nearly 45% of the species they studied had decreased in size over the past few generations, and they say climate change is at fault."The impact of rapidly climbing temperatures and shifts in rainfall patterns on body size could have unpredictable and possible severe consequences, they warned," Hood wrote on Sunday, adding that Sheridan and Bickford "looked at scientific literature on climate-change episodes in the distant past and at experiments and observations in recent history."
"Fossil records, they found, were unambiguous: past periods of rising temperatures had led both marine and land organisms to become progressively smaller," the AFP reporter added.
Reuters reports that the duo discovered that for each degree of Celsius the temperature of various plants increases, shoots and fruit are shrinking by between 3% and 17%. Likewise, each degree of warming caused mammal invertebrates to decrease in size by between 0.5% and 4%, and fish to shrink from 6% to 22% in total size.
Additionally, the AFP reports that a warming event that occurred 55 million years ago and is believed to be comparable to modern global warming, caused ants, bees, beetles, spiders, and wasps to shrink a total of 50% to 75% over a span of several thousand years, while mammals such as the squirrel decreased by approximately 40% during what is known as the Palaeocene-Eocene Thermal Maximum (PETM).
"The consequences of shrinkage are not yet fully understood, but could be far-reaching for biodiversity and humans alike," Bickford and Sheridan wrote in their paper, which was quoted by Telegraph Science Correspondent Nick Collins in a Sunday piece. "Because recent climate change may be faster than past historical changes in climate, many organisms may not respond or adapt quickly enough. This implies that species may go extinct because of climate change."
"The worst-case scenarios ... are that food crops and animals will shrink enough to have real implications for food security," Bickford told Reuters. "Impacts could range from food resources becoming more limited“¦ to wholesale biodiversity loss and eventual catastrophic cascades of ecosystem services“¦ We have not seen large-scale effects yet, but as temperatures change even more, these changes in body size might become much more pronounced -- even having impacts for food security."
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