Click here to sign in with or
Forget Password?
Learn more
share this!
1
Twit
Share
Email
June 10, 2024
This article has been reviewed according to Science X’s editorial process and policies. Editors have highlighted the following attributes while ensuring the content’s credibility:
fact-checked
peer-reviewed publication
trusted source
proofread
by Anne M. Stark, Lawrence Livermore National Laboratory
When comparing model simulations of Earth’s recent warming to real-world observations, differences can arise from several factors, including model errors in the simulated response to increased greenhouse gases and natural fluctuations within the climate system.
Natural climate variability, also called internal variability, can change regional and global atmospheric temperature by moving heat within the climate system. Diagnosing the role of natural climate variability over recent decades is critically important for both model validation and projections of future warming.
In an effort to quantify the role of natural fluctuations in model-observation differences, Lawrence Livermore National Laboratory scientist Stephen Po-Chedley and collaborators found the unique temperature trend patterns associated with natural climate variability for 1980–2022. The research appears in Geophysical Research Letters.
“The relative role of different drivers of model-observational discrepancies in the pattern of warming has important implications for our understanding of climate sensitivity, as well as regional climate changes,” said Po-Chedley, a co-author of the research. “This work shows that natural variations in Earth’s climate likely contribute to key differences in the simulated-versus-observed pattern of surface-air temperature changes.”
Previous studies by this research team have shown that natural climate variability has decreased global warming and enhanced Arctic warming. The team analyzed the multi-decadal trend patterns from hundreds of CMIP6 (the sixth phase of the Coupled Model Intercomparison Project, a global collaboration of climate modelers) simulations in which natural variability warms the Arctic but has a global cooling effect. They found that the majority of these model simulations also produce enhanced warming in the Barents Sea (near Norway) and Kara Sea (just north of Siberia) and cooling in the tropical eastern Pacific and Southern Ocean due to natural variability.
“Since these are the exact features imprinted on observed surface-temperature changes over 1980–2022, our work suggests that natural variability is an important component of several noteworthy differences between models and observations,” said Aodhan Sweeney, a graduate student and lead author of the study from the University of Washington (UW).
“The cause of observed cooling over the tropical eastern Pacific and Southern Ocean in the last few decades is a hotly debated topic in climate science. This study provides compelling evidence that the natural variability could be largely responsible for the observed cooling over these regions,” said Qiang Fu, a professor and co-author of the publication from UW.
The team found that a rare configuration (<3%) of natural climate variability contributes to enhanced Arctic warming and simultaneous cooling of the tropical eastern Pacific and Southern Ocean, which mimic the exact features that are imprinted on the observational record. While this pattern of temperature change is not seen in the average simulation over the CMIP6 models, each of the climate models examined in the study does infrequently (0.4–2.8% of the time) produce a pattern similar to observations.
“By attributing model deviations in the pattern of surface warming to natural climate variability, our study reinvigorates confidence in climate models’ ability to produce realistic projections of future climatic change,” said Hailong Wang, a co-author and research scientist at Pacific Northwest National Laboratory (PNNL).
The team concluded that although more research is needed to fully attribute the causes of modeled-versus-observed differences in the pattern of global surface air temperature change, the identified pattern of internal variability and its similarity to features imprinted on the observational record suggests that natural climate variability did indeed reduce global warming and enhance Arctic warming over 1980–2022.
More information: Aodhan J. Sweeney et al, Unique Temperature Trend Pattern Associated With Internally Driven Global Cooling and Arctic Warming During 1980–2022, Geophysical Research Letters (2024). DOI: 10.1029/2024GL108798
Journal information: Geophysical Research Letters
Journal information: Geophysical Research Letters
Provided by Lawrence Livermore National Laboratory
Explore further
Facebook
Twitter
Email
Feedback to editors
8 hours ago
0
8 hours ago
0
9 hours ago
0
10 hours ago
0
Jun 9, 2024
1
2 hours ago
2 hours ago
2 hours ago
2 hours ago
3 hours ago
3 hours ago
3 hours ago
3 hours ago
3 hours ago
3 hours ago
Jun 6, 2024
Jun 4, 2024
Jun 3, 2024
Jun 3, 2024
May 29, 2024
May 23, 2024
More from Earth Sciences
Nov 22, 2022
Mar 23, 2021
Nov 6, 2018
Apr 22, 2022
Apr 4, 2024
Dec 30, 2021
5 hours ago
Jun 8, 2024
Jun 7, 2024
Jun 7, 2024
Jun 7, 2024
Jun 7, 2024
Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form. For general feedback, use the public comments section below (please adhere to guidelines).
Please select the most appropriate category to facilitate processing of your request
Thank you for taking time to provide your feedback to the editors.
Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.
Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient’s address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.
Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we’ll never share your details to third parties.
More information Privacy policy
We keep our content available to everyone. Consider supporting Science X’s mission by getting a premium account.
Medical research advances and health news
The latest engineering, electronics and technology advances
The most comprehensive sci-tech news coverage on the web