Many reports from northern and southern latitudes reflect the fact that temperature and precipitation extremes have been occurring there more often, and with more intensity, than in middle latitudes and the tropics.
Although climate change involves more than a few hot July and August afternoons, the clearest indication that the Earth is warmer than it used to be is a series of record hot days of about 100 degrees Fahrenheit in Siberia, north of the Arctic Circle. This relatively recent occurrence is documented in Chris Mooney and Jason Samenow’s 2016 Washington Post article “The North Pole Is an Insane 36 degrees Warmer than Normal as Winter Descends.” Arctic issues have been of particular interest in the countries that surround the North Pole, including the US, Canada, Denmark (by means of Greenland), Norway, Sweden, and Russia, as covered in Seth Borenstein’s “Report: Arctic Loses Snow, Ice; Absorbs More Heat.” Focusing on Russia, Julie Brigham-Grette et al. also study these environmental implications in “Pliocene Warmth, Polar Amplification, and Stepped Pleistocene Cooling Recorded in NE Arctic Russia.” Ecologically, polar bears have been an especially hard-hit population in this region, as the Washington Post reported in “Bears Face Days-Long Swims,” published in the Omaha World-Herald during 2016. Jeffrey F. Bromaghin et al. also look at the effect on bears in “Polar Bear Population Dynamics in the Southern Beaufort Sea during a Period of Sea Ice Decline,” as does Seth Borenstein’s “Study: Polar Bears Disappearing from Key Region.” Many scientific minds also are watching the movement of ice masses that comprise the West Antarctic Ice Sheet (WAIS). There is enough ice in the WAIS to raise world sea levels at least several inches and it is already cracking at its edges, as detailed by Thomas Sumner in “No Stopping the Collapse of West Antarctic Ice Sheet.” Other important sources that record this phenomenon include “Widespread, Rapid Grounding Line Retreat of Pine Island, Thwaites, Smith and Kohler Glaciers, West Antarctica from 1992 to 2011,” by E. Rignot et al.; Alexander Robel’s “The Long Future of Antarctic Melting”; Chris Mooney and Jody Warrick’s “Research Casts Alarming Light on Decline of West Antarctic Glaciers”; and “Sustained Increase in Ice Discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013,” by J. Mouginot et al. Another phenomenon to watch is the Arctic Oscillation, which, at roughly 30,000 to 40,000 feet above the Earth’s surface, steers air masses and storms above the Earth’s surface. The Arctic Oscillation seemed unpredictably screwy at first, until it was associated with wild changes in the jet stream. Jennifer A. Francis is an important scientist who established these relationships. The wild swings in the jet stream account for the wild variations of warm spells in Alaska and hard freezes and heavy snow in Texas and nearby states in February 2021. This sort of pattern has become more frequent in recent years and may be linked to persistent drought, heat, and wildfires in western North America. It is explored in depth in Francis’s article with Stephen J. Vavrus, “Evidence Linking Arctic Amplification to Extreme Weather in Mid-latitudes”; NASA Earth Observatory’s 2011 report, “Arctic Oscillation Chills North America, Warms Arctic”; and the Nature article “Human Contribution to More-Intense Precipitation Extremes,” by Seung-Ki Min et al. Additional articles that similarly treat this topic include Quirin Schiermeier’s “Global Warming Brews Weird Weather,” Martin P. Tingley and Peter Huybers’s “Recent Temperature Extremes at High Northern Latitudes Unprecedented in the Past 600 Years,” Carolyn Gramling’s “Arctic Impact: Is the Melting Arctic Really Bringing Frigid Winters to North America and Eurasia?” and Chelsea Harvey’s “Dominoes Fall: Vanishing Arctic Ice Shifts Jet Stream, Which Melts Greenland Glacier.” Another consequence of this oscillation is the decades-long decline of Arctic sea ice, as described in NASA Earth Observatory’s report from January 2021, “The Long Decline of Arctic Sea Ice.” Polar scientists Julienne Stroeve and Dirk Notz cover some of the resulting weather changes in their literature review of this topic, “Changing State of Arctic Sea Ice across All Seasons.” As detailed in “The Long Decline of Arctic Sea Ice,” Stroeve and Notz note that, “in addition to shrinking ice cover, melting seasons are getting longer and sea ice is losing its longevity.” They further contend that “the longer melting seasons are a result of increasingly earlier starts to spring melting and ever-later starts to freeze-up in autumn.” This partly results from a cycle called the “ice-albedo feedback,” in which diminishing sea ice, which would usually reflect the sun’s light, causes more solar heat to be absorbed by open ocean water, which in turn hastens the melting of more sea ice. This is weakening the Arctic sea ice pack, evidenced by how easily ships navigated the Northern Sea Route (free of ice) in summer 2020, even reaching the North Pole, which is also discussed in “The Long Decline of Arctic Sea Ice.”