{"id":44507,"date":"2025-02-20t15:12:00","date_gmt":"2025-02-20t15:12:00","guid":{"rendered":"\/\/www.getitdoneaz.com\/?p=44507"},"modified":"2025-02-20t15:12:01","modified_gmt":"2025-02-20t15:12:01","slug":"ancient-rocks-climate-trends","status":"publish","type":"post","link":"\/\/www.getitdoneaz.com\/story\/ancient-rocks-climate-trends\/","title":{"rendered":"clues in ancient rocks show global atmospheric climate trends in sync"},"content":{"rendered":"
by frances mack<\/em><\/strong><\/p>\n\n\n\n global temperature has risen at an unprecedented rate since the mid-1800s<\/a>, and it\u2019s clear humans, not natural forces, are responsible for this change. <\/p>\n\n\n\n scientists are turning to clues found in ancient ice and rocks to understand how the planet\u2019s climate system has responded to rising temperatures in the past.<\/p>\n\n\n\n a team of researchers led by university of maine climate scientist aaron putnam has uncovered evidence in norway suggesting atmospheric climate trends are globally synchronous. this research gives scientists insight into how the earth could respond to human actions, like the burning of fossil fuels, and it can help society strategize next moves.<\/p>\n\n\n\n \u201cby studying the times when climate has done this before, naturally, without humans\u2019 help, we can start to get an idea of how the climate system responds when you crank up the temperature,\u201d said tricia hall collins, a member of putnam\u2019s team and ph.d. student at the school of earth and climate sciences at the university of maine.<\/p>\n\n\n\n putnam, collins and graduate student katie westbrook, spent a month in the field near forsand, norway, in summer 2023. they collected samples of rocks deposited on well-preserved moraines and have been calculating their ages to construct a timeline of climate system responses.<\/p>\n\n\n\n moraines are piles of rocks ripped off the sides of mountains by passing glaciers, that are then dumped into large piles when the glaciers recede during warming spells. <\/p>\n\n\n\n glaciers respond to changes in climate: they advance as the atmosphere cools and retreat tens of thousands of years later as it warms. this means the placement of a moraine and its age can indicate when and how fast the glaciers moved away as they melted. this gives researchers insights into climate history.<\/p>\n\n\n\n the team collected pieces of rock from the moraines they found. then, they extracted atoms of beryllium-10<\/a>, an isotope found in the quartz minerals of rocks exposed to cosmic rays from the sun, from the samples. the beryllium-10 collects at predictable rates after the rocks are free of ice.<\/p>\n\n\n\n the number of beryllium-10 atoms tells us how long ago the retreating glacier pushed the rock moraines aside. <\/p>\n\n\n\n using the data they collected, collins tracked climate trends in norway, and compared them to trends across the world.<\/p>\n\n\n she presented her findings at the annual comer climate conference<\/a> in southwestern wisconsin in october. collins\u2019 dates showed that cooling and warming events occurred at roughly the same time in the northern and southern hemispheres. <\/p>\n\n\n\n this suggests that climate changes were not isolated occurrences, which is a pattern reflected in modern climate trends.<\/p>\n\n\n\n