Page 28 - ARUBA TODAY

A28 SCIENCE
Friday 28 July 2017

Warming to worsen dead zones, algae blooms choking U.S. waters

By SETH BORENSTEIN year-in, year-out from these
AP Science Writer dead zones and algal
WASHINGTON (AP) — Pro- blooms,” said one of the re-
jected increases in rain searchers, Anna Michalak,
from global warming could an ecologist at the Carn-
further choke U.S. water- egie Institution for Science
ways with fertilizer runoff at Stanford University. “And
that trigger dead zones climate change will make it
and massive algae blooms, all worse.”
a new study said. When waterways are over-
If greenhouse gas emis- loaded with nutrients, al-
sions keep rising, more and gae growth can run amok,
heavier rain will increase creating dead zones. Al-
nitrogen flowing into lakes, gae can also choke wa-
rivers and bays by about terways with “green mats
19 percent by the end of of goop on top of the wa-
the century, according to ter” that are giant floating
a study in Thursday’s jour- blooms, Michalak said.
nal Science . The blooms often have tox-
While that may not sound ins that can pollute drinking
like much, many coastal water. In 2014, a bloom on
areas are already heavily Lake Erie fouled tap water
loaded with nitrogen. Re- for half a million people in
searchers calculated that Toledo, Ohio, for more than
an extra 860,000 tons of ni- two days. The study, which
trogen yearly will wash into In this image provided by NASA, taken Aug. 3, 2015, phytoplankton is seen off the coast of New is based on computer simu-
American waterways by York, top and New Jersey, lations, found the North-
century’s end. left.Associated Press east and Midwest will be hit
The nutrients create low- harmful blooms of algae in Lakes, Pacific Northwest “Many of these coastal ar- hardest by the increase in
oxygen dead zones and the Gulf of Mexico, Great and Atlantic coast. eas are already suffering nitrogen runoff. q

How loss of Arctic sea ice

further fuels global warming

of floes that gently dance es freezing point, usually
across the frigid waters. around the start of Octo-
The floating ice slowly ber. As temperatures con-
shrinks throughout summer tinue to fall, this first-year
until another winter season ice grows downward until
starts. it is several feet thick. If the
Because of global warm- ice survives the following
ing, more sea ice is being summer melt, it becomes
lost each summer than is second-year ice. Anoth-
being replenished in win- er cycle and it becomes
ters. Although sea ice is multi-year ice — which is
likely to continue forming the toughest kind.
each winter, it may be re- Sea ice plays an important
stricted to even higher lati- role in the global climate
tudes. system by cooling the sur-
Less sea ice coverage also rounding water and air. It
means that less sunlight will helps maintain ocean and
The Finnish icebreaker MSV Nordica sails through sea ice floating on the Beaufort Sea off the coast be reflected off the surface atmospheric currents that
of Alaska while traversing the Arctic’s Northwest Passage, Sunday, July 16, 2017. of the ocean. affect weather that is char-
Associated Press The water will absorb more acteristic for certain parts
heat, further fueling global of the world, such as the
By FRANK JORDANS For much of the year, the snow before great chunks warming. comparatively mild tem-
Associated Press Arctic appears as a crum- break off around the edg- Sea ice forms when the peratures found in western
THE ARCTIC CIRCLE (AP) — pled white sheet of ice and es in spring, forming a sea top layer of water reach- Europe.q