The claim: The IPCC said that ‘long-term prediction of future climatic states is not possible’
The Intergovernmental Panel on Climate Change is a group brought together by the United Nations to produce regular scientific assessments of the implications and risks of climate change, as well as potential mitigation options.
in a IPCC Report 2001the authors said that “long-term prediction of future climatic states is not possible” because “the climate system is a coupled nonlinear chaotic system.”
Some social media users are using this statement to challenge the idea that reliable climate projections can be made.
“It is hard to believe that any rational person can still believe that climate models can work, given the IPCC statement that ‘long-term prediction of future climatic states is not possible,'” says a Facebook post from March 29.
The post garnered hundreds of interactions, and USA TODAY found versions of the claim dating back to 2019. Similar claims spread in Twitter.
However, the publication misrepresents the IPCC statement by treating the phrase “climate states” as if it were interchangeable with the word “climate”. That is not the case.
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The word “climate” refers to the range of expected weather conditions, including temperature and precipitation levels. In contrast, “weather states” refer to the presence or absence of relatively discrete weather events, such as a storm.
The phrase also refers to natural climatic fluctuations, such as the El Niño-Southern Oscillationwhich can cause temporary warming and cooling trends.
“What this quote is about is the limits of weather forecasts and forecasts of other variability, such as El Niño,” Baylor Fox Kemper, an associate professor at Brown University who has written other IPCC reports, told USA TODAY. It’s not an attack on the accuracy of climate models, which project broad climate trends over time, he said.
USA TODAY reached out to social media users who shared the claim for comment.
Social media claim misconstrues IPCC statement
The social media post fundamentally misunderstands the 2001 IPCC statement, Zeke Hausfatherresearch scientist of berkeley land and author of the IPCC, he told USA TODAY.
The statement correctly indicates that climate models cannot predict exact “climate states,” such as a particular weather event, on a given day in the distant future, he said in an email.
Fact check: Warming varies across oceans and atmosphere, does not contradict climate change
But they can successfully predict important broader trends.
“We can never predict whether it will rain on March 2, 2055 in San Francisco, or even know for sure that 2055 will be warmer or cooler than 2054 given internal variability in climate due primarily to El Niño and La Girl,” Hauspadre said. “However, we can be absolutely certain that, barring a massive volcanic eruption, 2055 will be much warmer than 2022.”
Reliable climate models
One of the ways that climate scientists confirm the validity of climate models is by examining models that were created in the past to see if they accurately predicted subsequent global temperatures, Fox-Kemper said.
For example, researchers from NOAA, NASA, the Massachusetts Institute of Technology, and Berkeley Earth recently analyzed projections made by climate models published between 1970 and 2007.
The researchers compared the temperature projections from each model with the actual observed temperatures that occurred after the model results were published.
They found that most models made warming predictions consistent with subsequent temperature rise. For some of the models, the authors overestimated or underestimated model inputs, such as the amount of CO2 that humans would produce in the future.
For these models, the results were consistent with the actual warming observed when the models were re-run with inputs corrected for, for example, actual CO2 emissions.
“We found that climate models published over the last five decades were generally quite accurate in predicting global warming in the years after publication, particularly when differences between modeled and actual changes in atmospheric CO2 and other factors were taken into account. climatic”. the study authors wrote.
While many of these older climate models reliably predicted warming, the newer models benefit from powerful computing technology that has come online in recent years. Elizabeth Garneta climate scientist and assistant professor at the University of Wisconsin, Madison, told USA TODAY.
Fact check: Short-term global temperature fluctuations don’t negate climate science, global warming
“Because we have more computational power, you can have higher resolution. You can have more detail in your climate model,” Maroon said. “If anything, we have become more confident, not less, in more recent times, with what the range of our projections is.”
Our Rating: Missing Context
Based on our research, we rate the statement that the IPCC said “long-term prediction of future climate states is not possible” as LACK OF CONTEXT, because without additional information, the statement is misleading. The IPCC statement accurately states that “climate states”, such as weather events or the onset of El Niño, cannot be predicted very far in advance. However, this does not mean that climate models are unreliable, according to the IPCC researchers.
Our fact-checking sources:
- Elizabeth GarnetMay 5, telephone interview with USA TODAY
- Robert KoppApril 26, Email exchange with USA TODAY
- Baylor Fox KemperMay 6-10, telephone interview and email exchange with USA TODAY
- Zeke HausfatherMay 6-11, email exchange with USA TODAY
- IPCC, accessed May 5, TAR Climate Change 2001: The Scientific Basis
- Geophysical Research Letters, December 4, 2019, Evaluation of the performance of projections of previous climate models
- Berkeley Earth, accessed May 9, About
- NOAA, May 5, 2014, What is El Niño-Southern Oscillation (ENSO) in a nutshell?
- High Meadows Environmental Institute, October 5, 2021, Princeton’s Syukuro Manabe receives Nobel Prize in Physics for modeling climate change
- Max-Planck-Gesellschaft, October 5, 2021, Nobel Prize in Physics 2021 for Klaus Hasselmann
- IPCC, accessed May 12, homepage
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Reference-www.usatoday.com