Climate change could wipe out California’s Joshua trees by end of century

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LOS ANGELES, Aug 8, 2019 (BSS/AFP) – Joshua trees, an iconic species of
the arid southwestern United States, may totally disappear by the end of the
century because of climate change, according to a new study.

A team from the University of California at Riverside used data from the
Intergovernmental Panel on Climate Change to assess the impact of warming on
the distribution of Joshua trees (Yucca brevifolia) in their namesake Joshua
Tree National Park.

The park, which straddles the Colorado and Mojave deserts in southern
California, is home to the greatest concentration of the species, which are
in fact not trees at all but members of the agave family which can sometimes
appear tree-like.

According to the team’s modeling, in an optimistic scenario whereby
humanity is able to limit greenhouse emissions to a degree, the trees’ cover
would retreat by about 80 percent by end of the 21st century.

But under a “business as usual” scenario, the modeling indicates the
complete elimination of a species that dates to the Pleistocene era.

Lynn Sweet, the study’s lead author told the Los Angeles Times that under
their pessimistic scenario, the park could see average hot temperatures in
summer rise by about five to nine degrees Fahrenheit (2.8 to 5 degrees
Celsius) and three to seven inches (7.5 to 18 centimeters) less rainfall.

“If Joshua trees could survive those conditions, they would already be in
them,” said Sweet.

The Joshua tree, also the name of a seminal U2 album, is said to have been
named by a group of Mormon travelers who crossed the Mojave Desert in the
19th century.

They gave it its name because it reminded them of the Biblical figure
Joshua raising his hands skyward in prayer.