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2020 EarthTalks: Chris Forest - Shared screen with speaker view
sue brantley
58:54
I forgot to let the audience know that you can type in your questions here. I will read them at the end to Chris...thanks..type them in any time
James Kasting
01:09:20
Why do none of these scenarios warm by more than 2 degrees C by 2100?
Ken Davis
01:11:53
These are scenarios where society acts to limit warming.
James Kasting
01:12:29
Got it. Thanks!
James Kasting
01:17:12
How does refrigeration lead to drawdown?
jdfuentes
01:19:59
Why educating girls ‘only’ is a drawdown solution? How about ‘boys’ or men?
Ken Davis
01:21:40
A bunch of the refrigerant discussion online is related to replacing
Ken Davis
01:21:48
HFCs
James Kasting
01:22:24
OK, that makes sense..
Ken Davis
01:22:27
Or reducing HFC emissions, sorry.
Hui Yang
01:27:53
I might have missed it but I was wondering how people quantify the impacts of those drawdown measures.
GUIDO CERVONE
01:29:00
Satellite observations show a decrease in emissions related to the COVID-19 emergency in Europe and China. Can these observations improve climate models with examples of lower emission scenarios?
James Kasting
01:29:01
You didn't miss it. One has to make lots of assumptions..
Ken Davis
01:30:36
We make observations of atmospheric GHGs and see if they agree with what we expect emissions to be, go back to our models and inventories, improve, iterate….
James Kasting
01:31:22
Guido, the lifetime of even the shortest-lived greenhouse gas, CH4, is ~13 years, so the concentrations of these gases cannot change on such short time scales.
Ken Davis
01:31:59
But the spatial gradients change in response to changing emissions. We can measure changes in emissions on very short time scales, given appropriate data.
Ken Davis
01:32:25
That’s what my group does.
James Kasting
01:32:50
Agreed. But that doesn't change the instantaneous radiative forcing.
Ken Davis
01:33:01
agreed
GUIDO CERVONE
01:35:38
I was thinking more about optical dimming vs resident gases in the atmosphere. There should be an almost instantaneous changes in fluxes due to clearing in optical dimming.
Armen Kemanian
01:40:13
oh yes, we can see changes in solar radiation, easily.
Armen Kemanian
01:40:26
I mean irradiance on a horizontal surface.