Skip to Main Content

Colloquium: Dr. Mark Zelinka, Lawrence Livermore Nat. Labor

Off Campus: via WEBEX

Wednesday, February 24, 2021
3:30 PM – 4:30 PM
TITLE:   

Global warming is larger in the latest climate models than in their predecessors. Do we trust them?

ABSTRACT: 

How much will Earth warm in response to increased concentrations of greenhouse gases in the atmosphere? Answering this question is a key goal of climate science, given its importance for society.  CO2 quadrupling experiments routinely conducted by global climate modeling centers around the world yield a wide range of climate sensitivities to carbon dioxide. In this talk, I will discuss why climate sensitivities in the latest state-of-the-art models are substantially larger than in their predecessors. The primary culprit is clouds: Planetary warming causes low-level clouds to become less extensive and less reflective, inducing further warming ��� an amplifying feedback that has strengthened in the latest models.  This stronger positive cloud feedback arises due to changes in model physics and may be related to improved representation of cloud ice and liquid water content. Given the prominence of low cloud feedback in driving uncertainty in climate sensitivity, I will then discuss our efforts to constrain the global marine low cloud feedback using satellite observations of how low cloud properties respond to meteorology. This work indicates that the observed sensitivity of low clouds to their environmental controls is incompatible with very high or very low values of climate sensitivity.


WEBEX INFO

Meeting Information
Click Meeting Link to directly join the webex video

Meeting link:
https://umbc.webex.com/umbc/j.php?MTID=m45d19437a4d9c82599b14b737366ea5c 
120 945 7958
Password: 
physics


More ways to join
Tap to join from a mobile device (attendees only)   
+1-202-860-2110,,1209457958## United States Toll (Washington D.C.)  

Join by phone   
+1-202-860-2110 United States Toll (Washington D.C.)   
Global call-in numbers  


Join from a video system or application
Dial 1209457958@umbc.webex.com  
You can also dial 173.243.2.68 and enter your meeting number.