The last interglacial (LIG, ∼130-116 ka, ka Combining double low line 1000 yr ago) is characterized by high-latitude warming and is therefore often considered as a possible analogue for future warming. However, in contrast to predicted future greenhouse warming, the LIG climate is largely governed by variations in insolation. Greenhouse gas (GHG) concentrations were relatively stable and similar to pre-industrial values, with the exception of the early LIG when, on average, GHGs were slightly lower.
We performed six time-slice simulations with the low-resolution version of the Norwegian Earth System Model covering the LIG. In four simulations only the orbital forcing was changed. In two other simulations, representing the early LIG, additionally the GHG forcing was reduced.
With these simulations we investigate (1) the different effects of GHG versus insolation forcing on the temperatures during the LIG; (2) whether reduced GHGs can explain the low temperatures reconstructed for the North Atlantic; and (3) the timing of the observed LIG peak warmth.
Langebroek P.M.,Nisancioglu K.H.. Simulating last interglacial climate with NorESM: Role of insolation and greenhouse gases in the timing of peak warmth[J]. Climate of the Past,2014-01-01,10(4)