{"id":3251032,"date":"2024-09-30T12:35:48","date_gmt":"2024-09-30T16:35:48","guid":{"rendered":"https:\/\/www.futurity.org\/?p=3251032"},"modified":"2024-09-30T12:35:48","modified_gmt":"2024-09-30T16:35:48","slug":"climate-change-temperature-carbon-dioxide-3251032-2","status":"publish","type":"post","link":"https:\/\/www.futurity.org\/climate-change-temperature-carbon-dioxide-3251032-2\/","title":{"rendered":"Humans can’t adapt fast enough for climate change"},"content":{"rendered":"
A new study offers the most detailed glimpse yet into how Earth’s surface temperature has changed over the past 485 million years.<\/p>\n
Published in the journal 糖心视频<\/em><\/a>, the study presents a curve of global mean surface temperature that reveals Earth’s temperature has varied more than previously thought over much of the Phanerozoic Eon, a period of geologic time when life diversified, populated land, and endured multiple mass extinctions<\/a>.<\/p>\n The curve also confirms Earth’s temperature is strongly correlated to the amount of carbon dioxide in the atmosphere.<\/p>\n The start of the Phanerozoic Eon 540 million years ago is marked by the Cambrian Explosion<\/a>, a point in time when complex, hard-shelled organisms first appeared in the fossil record. Although researchers can create simulations that look back 540 million years, the temperature curve in the study focuses on the last 485 million years, since there is limited geological data of temperature before then.<\/p>\n “It’s hard to find rocks that are that old and have temperature indicators preserved in them\u2014even at 485 million years ago we don’t have that many. We were limited with how far back we could go,” says study coauthor Jessica Tierney, a paleoclimatologist and professor of geosciences at the University of Arizona.<\/p>\n The researchers created the temperature curve using an approach called data assimilation. This allowed them to combine data from the geologic record and climate models to create a more cohesive understanding of ancient climates.<\/p>\n “This method was originally developed for weather forecasting,” says Emily Judd, lead author of the paper and a former postdoctoral researcher at the Smithsonian National Museum of Natural History and the University of Arizona. “Instead of using it to forecast future weather, here we’re using it to hindcast ancient climates.”<\/p>\n Refining scientists’ understanding of how Earth’s temperature has fluctuated over time provides crucial context for understanding modern climate change.<\/p>\n “If you’re studying the last couple of million years, you won’t find anything that looks like what we expect in 2100 or 2500,” says Scott Wing, a coauthor on the paper and a curator of paleobotany at the Smithsonian National Museum of Natural History.<\/p>\n “You need to go back even further to periods when the Earth was really warm, because that’s the only way we’re going to get a better understanding of how the climate might change in the future.”<\/p>\n The new curve reveals that temperature varied more greatly during the past 485 million years than previously thought. Over the eon, the global temperature spanned 52 to 97 degrees Fahrenheit. Periods of extreme heat were most often linked to elevated levels of the greenhouse gas carbon dioxide in the atmosphere.<\/p>\n “This research illustrates clearly that carbon dioxide is the dominant control on global temperatures across geological time,” Tierney says. “When CO2 is low, the temperature is cold; when CO2 is high, the temperature is warm.”<\/p>\n The findings also reveal that the Earth’s current global temperature of 59 degrees Fahrenheit is cooler than Earth has been over much of the Phanerozoic. But greenhouse gas emissions from human-caused climate change are currently warming the planet at a much faster rate than even the fastest warming events of the Phanerozoic, the researchers say.<\/p>\n