The Ups & Downs of Ancient Rome’s Economy–All 1,900 Years of It–Get Documented by Pollution Traces Found in Greenland’s Ice

When we see sto­ries pop up involv­ing sci­en­tif­ic find­ings in glac­i­er ice, we might brace for unpleas­ant envi­ron­men­tal news about the future. But a paper pub­lished just recent­ly in Pro­ceed­ings of the Nation­al Acad­e­my of Sci­ences instead reveals fas­ci­nat­ing find­ings about the dis­tant past—the his­to­ry of ancient Rome between 1100 B.C.E. to 800 C.E. His­to­ri­ans know this 1,900-year peri­od through archae­o­log­i­cal and lit­er­ary evi­dence. Now cli­mate sci­en­tists have pro­vid­ed a trea­sury of new data to help sub­stan­ti­ate or revise schol­ar­ly under­stand­ings of Rome’s eco­nom­ic ris­es and falls, by mea­sur­ing the strat­i­fi­ca­tions of lead pol­lu­tion in a rough­ly 400-meter ice core from Green­land.

Why lead? “It’s a proxy for coin pro­duc­tion,” says Seth Bernard, pro­fes­sor of ancient his­to­ry at the Uni­ver­si­ty of Toron­to. Roman cur­ren­cy, the denar­ius, was made from sil­ver, mined pri­mar­i­ly on the Iber­ian Penin­su­la. “But these mines didn’t exca­vate pure sil­ver,” notes Robin­son Mey­er at The Atlantic. “Instead, they unearthed an ore of sil­ver, lead, and cop­per that had to be smelt­ed into sil­ver. This process filled the air with lead pol­lu­tion,” which even­tu­al­ly made its way on air cur­rents to Green­land, where “storms deposit­ed lead-taint­ed snow or sleet over the Arc­tic island.” New lay­ers formed upon the old, each one pre­served for pos­ter­i­ty.

In the mid-1990s, sci­en­tists began drilling Greenland’s ice sheet in the North Green­land Ice core Project (NGRIP). At the time, a team attempt­ed a sim­i­lar analy­sis on the lead lev­els and their cor­re­spon­dence to ancient coinage, “which used a sim­i­lar but rudi­men­ta­ry tech­nique,” Mey­er writes. But this study only drew from 18 data points. By con­trast, the new research “made 25,000 dif­fer­ent mea­sure­ments of the ice core.” Improved tech­nol­o­gy has refined the mea­sure­ment process, allow­ing researchers to detect “the pres­ence of 35 dif­fer­ent ele­ments and chem­i­cals at once,” and to tie their obser­va­tions to spe­cif­ic years, or fair­ly close to it, any­way. The chart above shows the fluc­tu­a­tions in lead emis­sions over the almost 2000-year span.

One of the study’s authors, Joseph McConnell, esti­mates the mar­gin of error as with­in one or two years. “That’s pret­ty good,” he says, “a lot bet­ter than what archae­ol­o­gists are used to, I can tell you that.” This allows the team of cli­mate sci­en­tists, archae­ol­o­gists, and his­to­ri­ans to match their obser­va­tions about lead lev­els to known his­tor­i­cal events. As The New York Times reports, “lead emis­sions rose in peri­ods of peace and pros­per­i­ty, such as the Pax Romana, which ran from 27 BC to 180 A.D. and dropped dur­ing the civ­il wars that pre­ced­ed the Pax and the rise of the emper­or Augus­tus. There were also dra­mat­ic drops that coin­cid­ed with the Anto­nine plague of 165–180 A.D., thought to have been small pox, and the Cypri­an plague, cause uncer­tain, of 250–270 A.D.”

The data, notes The Econ­o­mist, “pro­vide a new win­dow onto the work­ings of the ancient econ­o­my…. Not all of the lead trapped in the glac­i­er comes from sil­ver mind­ing, but much of it does,” and sci­en­tists can make informed guess­es about just how much. Many unan­swered ques­tions remain. “What we’d love to have is a doc­u­ment that says Rome had a state mon­e­tary pol­i­cy,” says Bernard. The empire’s spe­cif­ic eco­nom­ic poli­cies are large­ly a mys­tery, but the ice core sam­ples pro­vide a wealth of new evi­dence for the increase and decrease in cur­ren­cy pro­duc­tion, and ever-more refined tech­nolo­gies will allow for even more data to emerge from the pol­lu­tants trapped in glacial ice in the near future.

via The Atlantic

Relat­ed Con­tent:  

How Did the Romans Make Con­crete That Lasts Longer Than Mod­ern Con­crete? The Mys­tery Final­ly Solved

The Rise & Fall of the Romans: Every Year Shown in a Time­lapse Map Ani­ma­tion (753 BC ‑1479 AD)

A Huge Scale Mod­el of Ancient Rome at Its Archi­tec­tur­al Peak, Orig­i­nal­ly Com­mis­sioned by Mus­soli­ni

Josh Jones is a writer and musi­cian based in Durham, NC. Fol­low him at @jdmagness

by | Permalink | Comments (0) |

Sup­port Open Cul­ture

We’re hop­ing to rely on our loy­al read­ers rather than errat­ic ads. To sup­port Open Cul­ture’s edu­ca­tion­al mis­sion, please con­sid­er mak­ing a dona­tion. We accept Pay­Pal, Ven­mo (@openculture), Patre­on and Cryp­to! Please find all options here. We thank you!

Leave a Reply

Open Culture was founded by Dan Colman.