2011 Science News of the Year: Environment

Courtesy of Christopher Arp/USGS

Arctic warming signs

Climatologists pointing to the Arctic as the leading baro­meter of global change have plenty of new evidence that wholesale warming is under way. Observational data indicate that the region’s air, soils and water have warmed substantially since 2006, suggesting that the climate has established a “new normal” (SN Online: 12/2/11). Among the symptoms: An anomalous pool of freshwater (27 meters deep in places) fed by inland meltwater has been found floating atop Arctic Ocean seawater (SN Online: 4/5/11). Erosion is also up across the Arctic, with area coastlines retreating on average by a half-meter per year (SN: 5/21/11, p. 13).

This year’s summer sea ice extent, a common marker for how bad things are getting, either approached or matched 2007’s record low, depending on which data scientists use (SN Online: 9/14/11; SN Online: 10/6/11). And computer projections by 19 different global climate programs indicate that relatively deep waters around Greenland will probably warm over the next 90 years at double the rate of deep water globally. The projected impact: Coastal glaciers will melt faster than had been anticipated — largely from below (SN Online: 7/6/11). — Janet Raloff

Supercyclones  A cloud of air pollution over northern India and surrounding regions has doubled — and occasionally tripled — the intensity of late spring cyclones in the Arabian Sea during the last three decades (SN: 12/17/11, p. 13).

Up and up  Cores taken from North Carolina sediment reveal that sea levels began rising precipitously in the late 19th century and have since tripled the rate of climb seen at any time in the last two millennia (SN: 7/16/11, p. 13).

IQ dropper  Children exposed in the womb to substantial levels of neurotoxic pesticides have lower IQs by the time they enter school than do kids with virtually no exposure, three studies find (SN: 5/21/11, p. 15).

Clothing dangers  Plastic fibers from polyester or synthetic fabrics foul coastal environments worldwide (SN Online: 9/14/11).

BPA revisited  Two new studies link feminized behaviors in adult male mice with exposure during development to the plastics chemical bisphenol A (SN: 7/30/11, p. 16). Another study shows that BPA can trigger hormone-responsive gene changes in people (SN Online: 8/27/11).

Germy skies  Microbes aloft in the atmosphere can catalyze ice nucleation, leading to cloud formation and bad weather conditions (SN: 6/18/11, p. 12).

Immune weeds  Research uncovers a rapid rise in herbicide-resistant weeds and increasing numbers of weeds immune to multiple herbicides (SN: 7/2/11, p. 5).

Polar ozone  Record ozone depletion over the Arctic rivals what was observed in the Antarctic when holes in the protective atmospheric layer first appeared there (SN: 11/19/11, p. 11). To the south, scientists see signs of recovery in the Antarctic ozone hole more than a decade earlier than expected (SN: 6/4/11, p. 15).

Missing fish  New studies suggest that ecologically valuable predatory fish are rapidly disappearing (SN: 4/9/11, p. 28).

Noise woes  Sonar exercises at an under­water test range led beaked whales to flee the area. Tagged whales exposed to sounds at about 140 decibels stopped hunting and swam toward the surface (SN: 4/23/11, p. 16).

Fishy return  Within 14 years of a Mexican marine park in the Gulf of California prohibiting fishing, the total mass of its denizens more than quintupled, a sign of habitat protection’s potential (SN: 9/24/11, p. 14).

Acid ignorance  Juvenile clown fish raised in water mimicking the predicted acidifying chemistry of future oceans appear willing to swim toward a predator-packed reef (SN: 7/2/11, p. 12).