Non-linear feedbacks

...and Then There's Physics

I thought I would just briefly mention a recent paper by Bloch-Johnson, Pierrehumbert & Abbot called Feedback temperature dependence determines the risk of high warming. As I understand it, the basic idea is to consider what would happen if the feedback response has a temperature dependence. If the feedback response is linear, then you can estimate the climate sensitivity, $latex lambda$, at any time using

$latex lambda = -dfrac{Delta F}{Delta T}.$

Credit : Figure 1 from Bloch-Johnson et al. (2015) Credit : Figure 1 from Bloch-Johnson et al. (2015) However, it is clear that feedbacks do have a temperature dependence. The Planck response ($latex dF = 4 epsilon sigma T^3 dT$) is clearly temperature dependent. What we don’t know – given all the feedbacks – is the strength of this possible non-linearity. What Bloch-Johnson et al. do is simply assume that the climate sensitivity has a non-linear term,

$latex -Delta F = lambda Delta T + alpha Delta…

View original post 280 more words

Appreciate your comments John

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s