Home / Science / The high climate sensitivity in the new climate model was seen as less likely.

The high climate sensitivity in the new climate model was seen as less likely.

High levels of climate sensitivity in new climate models seen to be less likely.

The researchers found that the low-climate-sensitive model would correspond to the observed temperature difference, especially between the Northern and Southern Hemisphere. The graph shows the change in surface temperature, the annual global mean (a), and the temperature difference between the Northern and Southern Hemisphere (b) from 1850 to 2000.The red line represents a sensitive model. To high weather conditions, while the blue line represents a model with Low weather sensitivity The black line shows observed temperature fluctuations, collected by NASA’s Goddard Institute for Space Studies Surface Temperature Analysis Program, which tracks the blue line more closely when it comes to inter-hemispherical temperatures. A gray background indicates a year in which the difference between the high and low climate-sensitive models is significant.credit: Chenggong Wang, Program in Atmospheric and Oceanic Sciences, Princeton University.

The latest analysis of the latest climate models, known as CMIP6, provides a warning story about the interpretation of climate simulations as scientists develop more sensitive and complex predictions of how the world will respond to gas levels. How does carbon dioxide increase in the atmosphere?

Researchers from Princeton and the University of Miami reported that the new model with “Weather sensitivity” means they predict more global warming from the same atmospheric carbon dioxide as other models – not providing a possible scenario of the Earth’s future climate.

These models exaggerate the cooling effects of the Earth arising from the interactions between clouds and aerosols, and projects that clouds will help reduce global warming caused by greenhouse gases, especially in the hemispheres. The northern world, where more than what climate record actually takes, researchers report in the journal Geophysical Research Letters.

The researchers found that the low climate-sensitive model was consistent with the observed temperature difference between the northern and southern hemispheres, thus portraying the projected climate change. More accurately than the newer models, the study was supported by the Carbon Mitigation Initiative (CMI), located in Princeton’s High Meadows Environmental Institute (HMEI).

The findings could be significant when it comes to climate change policy, explains Gabriel Vecchi, co-author, professor of geosciences at the Princeton and High Meadows Environmental Institute and CMI principal investigator, because the model is sensitive to the condition. Higher air is predicted to produce more global warming from greenhouse gas emissions, and therefore more dire impacts such as rising sea levels and heat waves are expected.

The high climate sensitivity model predicts that the global average temperature will rise from 2 to 6 degrees Celsius under current carbon dioxide levels. The current scientific consensus is that increases must be under 2 degrees to avoid catastrophic consequences. The 2016 Paris Agreement sets the threshold at 1.5 degrees Celsius.

“The higher climate sensitivity will make a more aggressive reduction in carbon,” Vecchi said. “Society must reduce carbon emissions more rapidly to meet the goals of the Paris Agreement and maintain climate change.” Global warming below 2 degrees Celsius. Reducing the uncertainty in climate sensitivity allows us to have more reliable and accurate strategies for dealing with climate change. ”

The researchers found that both the high and low climate sensitivity models matched the observed global temperatures during the 20th century. The interaction of aerosols and clouds compensates for greater heat due to greenhouse gases. Additionally, the model had aerosol emissions, most of which occurred in the Northern Hemisphere, which was inconsistent with observations.

“Our results remind us that we should be cautious about the model results even if the model accurately represents past global warming,” said first author Chenggong Wang. A candidate in the Princeton program in the field of atmospheric and ocean science. “We show that the global average hides important details about patterns of temperature change.”

In addition to the core findings, the study highlights how clouds can reduce heat, both in models and in the real world, on large and small scale.

“Clouds can amplify global warming and potentially accelerate warming over the next century,” said co-author Wenchang Yang, Princeton research scientist in geoscience. Cloud accurately is the key to forecast a more reliable future. “

Recently, scientists from Princeton and other institutions have turned their attention to the impact clouds have on climate change. Relevant research includes two papers by Amilcare Porporato, Princeton Professor Thomas J. Wu ’94 of the Princeton of Civil and Environmental Engineering and the High Meadows Environmental Institute, and members of the CMI leadership team, which report on the future impact of clouds caused by disruption. Hot to the sun Power and how climate models underestimate the cooling effects of daily cloud cycles

“Understanding how clouds modify climate change is an important part of climate research,” said co-author Brian Soden, a professor of atmospheric science at the University of Miami. “It is encouraging that this study shows that there are still many properties that we can take advantage of from past climate observations that can help refine the interpretation we have obtained from the mean temperature change of the climate change.” world”

The document “Compensation between cloud feedback and interactions with aerosols in CMIP6 format” was published in the Feb. 28 issue of Aerosol. Geophysical Research Letters

Ice Age testing reveals challenges in climate models’ susceptibility.

More information:
Chenggong Wang et al, Compensation between Cloud Feedback and Aerosol – Cloud Interaction in the CMIP6 model, Geophysical Research Letters (2021) .doi: 10.1029 / 2020GL091024

Provided by Princeton University

Reference: High climate sensitivity in a new climate model seen to be less likely (2021, March 3) .Retrieved March 3, 2021 from https://phys.org/news/2021- 03-high-climate-sensitivity-plausible.html

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