Has Earth Warmed More Than We Thought?
2024-02-09
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1Old sponges from deep in the Caribbean Sea are causing some researchers to think human-caused climate change began sooner than scientists have thought.
2But, if a recent study is correct, world temperatures are increasing faster than United Nations' estimates suggest.
3The researchers from American and Australian universities published their sponge findings recently in Nature Climate Change.
4They said, if their findings are correct, the world has already gone past a temperature limit set by international negotiators.
5Negotiators of the Paris Agreement on climate change set 1.5 degrees Celsius as a limit for the increase of the world's temperature from pre-industrial times.
6Pre-industrial times are from about 1850 to 1900.
7But the American and Australian researchers said that the world hit a 1.7-degree Celsius increase in 2020.
8The scientists looked at six special sponges that are known to live hundreds of years.
9They examined the sponges' growth records to find very small levels of the elements calcium and strontium.
10The scientists said that the amount of calcium and strontium changes, depending on the water temperature.
11Malcolm McCulloch is an ocean scientist at the University of Western Australia.
12He was the lead writer of the study.
13McCulloch noted that the currently accepted temperature estimates for the 1850-1900 period were too high.
14That means that present-day temperature increases are larger and the Earth's temperature is warming faster than scientists have believed.
15He said, "We have a decade less than we thought."
16In the past several years, many scientists have noted that there seems to be more extreme weather than they had expected.
17One explanation would be that the Earth is warming faster than scientists had first believed, said Amos Winter.
18Winter helped write the study.
19He is an ocean scientist at Indiana State University.
20He said the study supports the theory that climate change is quickening.
21Former top NASA scientist James Hansen also has proposed that theory.
22Sponges get water flowing from all over them so they can record a larger area of environmental change, Winter and McCulloch said.
23The research team examined sponges that lived in a special "mixed" area of the ocean that is 33 to 91 meters deep.
24The researchers were able to estimate nearly the exact atmospheric temperature of the Earth from the amount of calcium and strontium in the deep-sea sponges.
25Their results were different from the scientifically accepted temperature estimates used by the United Nations' Intergovernmental Panel on Climate Change (IPCC).
26The IPCC temperature estimates are the basis for the U.N. temperature goals.
27The Nature Climate Change study finds that the mid-1800s were about half a degree Celsius cooler than believed.
28It also found that warming from heat-trapping gases started about 80 years earlier than the measurements the IPCC uses.
29IPCC numbers show warming started just after 1900.
30McCulloch and Winter said it makes sense that the warming started earlier than the IPCC stated because by the mid-1800s industries had begun polluting the air with carbon dioxide.
31For pre-industrial temperatures, the IPCC and most scientists use data that came from ships whose crews would take the temperature of water near the surface.
32Some of the measurements could change based on how the collection was done.
33The researchers said sponges provide better information because of the way they store chemical elements in their skeletons.
34When waters are warmer, there is more of the element strontium and less of the mineral calcium, Winter said.
35University of Pennsylvania climate scientist Michael Mann, who was not part of the study, has thought warming started before the IPCC said it did. But he doubted the study's findings.
36"In my view it begs credulity to claim that the instrumental record is wrong based on paleo-sponges from one region of the world," Mann said.
37But Winter and McCulloch have defended their use of sponges to identify world temperature change.
38They said, except for the 1800s, their temperature findings based on sponges follow global records from other devices.
39These include scientific instruments and measurements from things like coral, ice, and tree rings.
40Princeton University climate scientist Michael Oppenheimer was not part of the sponge study either.
41He said, even if the McCulloch team is right, it should not change warnings from scientists.
42He said that the danger level is not tied to the exact "value of preindustrial temperatures."
43McCulloch added that "...the only way to stop this is to reduce emissions. Urgently. Most Urgently.
44I'm Gena Bennett. And I'm Gregory Stachel.
1Old sponges from deep in the Caribbean Sea are causing some researchers to think human-caused climate change began sooner than scientists have thought. But, if a recent study is correct, world temperatures are increasing faster than United Nations' estimates suggest. 2The researchers from American and Australian universities published their sponge findings recently in Nature Climate Change. They said, if their findings are correct, the world has already gone past a temperature limit set by international negotiators. Negotiators of the Paris Agreement on climate change set 1.5 degrees Celsius as a limit for the increase of the world's temperature from pre-industrial times. Pre-industrial times are from about 1850 to 1900. But the American and Australian researchers said that the world hit a 1.7-degree Celsius increase in 2020. 3The scientists looked at six special sponges that are known to live hundreds of years. They examined the sponges' growth records to find very small levels of the elements calcium and strontium. The scientists said that the amount of calcium and strontium changes, depending on the water temperature. 4Malcolm McCulloch is an ocean scientist at the University of Western Australia. He was the lead writer of the study. McCulloch noted that the currently accepted temperature estimates for the 1850-1900 period were too high. That means that present-day temperature increases are larger and the Earth's temperature is warming faster than scientists have believed. He said, "We have a decade less than we thought." 5In the past several years, many scientists have noted that there seems to be more extreme weather than they had expected. One explanation would be that the Earth is warming faster than scientists had first believed, said Amos Winter. 6Winter helped write the study. He is an ocean scientist at Indiana State University. He said the study supports the theory that climate change is quickening. Former top NASA scientist James Hansen also has proposed that theory. 7Sponges get water flowing from all over them so they can record a larger area of environmental change, Winter and McCulloch said. The research team examined sponges that lived in a special "mixed" area of the ocean that is 33 to 91 meters deep. The researchers were able to estimate nearly the exact atmospheric temperature of the Earth from the amount of calcium and strontium in the deep-sea sponges. 8Their results were different from the scientifically accepted temperature estimates used by the United Nations' Intergovernmental Panel on Climate Change (IPCC). The IPCC temperature estimates are the basis for the U.N. temperature goals. 9The Nature Climate Change study finds that the mid-1800s were about half a degree Celsius cooler than believed. It also found that warming from heat-trapping gases started about 80 years earlier than the measurements the IPCC uses. IPCC numbers show warming started just after 1900. 10McCulloch and Winter said it makes sense that the warming started earlier than the IPCC stated because by the mid-1800s industries had begun polluting the air with carbon dioxide. 11For pre-industrial temperatures, the IPCC and most scientists use data that came from ships whose crews would take the temperature of water near the surface. Some of the measurements could change based on how the collection was done. 12The researchers said sponges provide better information because of the way they store chemical elements in their skeletons. When waters are warmer, there is more of the element strontium and less of the mineral calcium, Winter said. 13University of Pennsylvania climate scientist Michael Mann, who was not part of the study, has thought warming started before the IPCC said it did. But he doubted the study's findings. 14"In my view it begs credulity to claim that the instrumental record is wrong based on paleo-sponges from one region of the world," Mann said. 15But Winter and McCulloch have defended their use of sponges to identify world temperature change. They said, except for the 1800s, their temperature findings based on sponges follow global records from other devices. These include scientific instruments and measurements from things like coral, ice, and tree rings. 16Princeton University climate scientist Michael Oppenheimer was not part of the sponge study either. He said, even if the McCulloch team is right, it should not change warnings from scientists. He said that the danger level is not tied to the exact "value of preindustrial temperatures." 17McCulloch added that "...the only way to stop this is to reduce emissions. Urgently. Most Urgently. 18I'm Gena Bennett. And I'm Gregory Stachel. 19Gregory Stachel adapted this Associated Press story by Seth Borenstein for VOA Learning English. 20_______________________________________________ 21Words in This Story 22sponge - n. a type of sea animal from which natural sponges are made 23decade - n. a period of 10 years 24beg - v. to cause someone to ask a specified question as a reaction or response 25credulity - n. ability or willingness to believe something 26paleo- - prefix connected with ancient times 27region - n. a part of a country or of the world that is different or separate from other parts in some way 28emission - n. a gas, such as carbon dioxide, that is sent out or produced by a process like burning