Earthweek: a diary of the planet 2020 year in review.

Ice losses

SeA iCe surrounding the North Pole wAs At A reCord low for OCtoBer BeCAuse of unusuAlly high ArCtiC OCeAn temperAtures. ReseArChers sAy the iCe wAs slow to re- form After the summer’s melt, And CoverAge wAs At the lowest of 40 yeArs of sAtellite dAtA.

Avian tragedy

SCientists Believe thAt the thousAnds of migrAtory Birds thAt fell from the sky in the Southwest in SeptemBer were proBABly viCtims of smoke from the West’s CAtAstrophiC firestorms. The songBirds Could hAve either Choked or used up their fAt reserves trying to fly Around it.

Greenhouse Earth

SCientists prediCt thAt EArth’s Atmosphere will soon ContAin the sAme high level of CArBon dioxide thAt existed At the peAk of the PlioCene EpoCh wArmth 3 million yeArs Ago. ThAt’s when temperAtures were 5 to 7 degrees FAhrenheit higher And seA levels were 65 feet higher.

Magnetic mystery

SCientists Are struggling to understAnd A new weAkening of EArth’s mAgnetiC field in A region thAt stretChes from South AmeriCA to AfriCA And is CAusing teChniCAl proBlems in some of the sAtellites orBiting the plAnet. The AnomAly is Allowing the inner VAn Allen rAdiAtion Belt to dip to An Altitude of ABout 120 miles, sometimes exposing sAtellites to severAl minutes of higher- thAn- normAl rAdiAtion.

Light pollution

HumAns' use of ArtifiCiAl light is CAusing widespreAd impACts on AnimAls And plAnts, And reseArChers sAy it should Be limited where possiBle. British sCientists sAy light pollution CAuses ChAnges to AnimAl BehAvior And physiology, espeCiAlly hormone levels And pAtterns of wAking, sleeping And ACtivity.

Massive hole

The ozone hole ABove AntArCtiCA reAChed its AnnuAl peAk on OCt. 1, whiCh sCientists sAy wAs the lArgest And deepest in 15 yeArs. This wAs in ContrAst to An unusuAlly smAll And short- lived hole in 2019, CAused By unusuAl weAther Conditions.

Global quieting

The plunge in humAn ACtivities BeCAuse of the pAndemiC Brought the longest quiet period of seismiC noise in history. The relAtive quiet hAs Allowed sCientists to deteCt previously hidden eArthquAke signAls.

Tropical cyclones

The 2020 AtlAntiC hurriCAne seAson ended with A reCord- BreAking 30 nAmed storms And the seCond- highest numBer oBserved. One feAture is thAt mAny of the sAme AreAs were hit repeAtedly, espeCiAlly in the CentrAl U. S. Gulf CoAst, the Philippines, VietnAm, JApAn And the KoreAn PeninsulA.