Hysteresis of the intertropical convergence zone to CO2 forcing

Contrasting Hysteresis Behaviors of Northern Hemisphere Land Monsoon Precipitation to CO2 Pathways

“…The interhemispheric energy asymmetry between the RDN and RUP periods supports the southward ITCZ shift (Figure S5b in Supporting Information S1; Broccoli et al., 2006; Kang et al., 2009). The interhemispheric energy imbalance, which is closely linked to changes in surface temperature over various regions such as the North Atlantic Ocean, Northern Hemisphere land, and the Southern Ocean, is responsible for the changes in the zonal mean ITCZ position (Bischoff & Schneider, 2014; Kug et al., 2022). However, further southward shifts of the zonal mean ITCZ during the RUP are inconsistent with the enhanced precipitation over the ID and NAF regions.…”

Centennial Memory of the Arctic Ocean for Future Arctic Climate Recovery in Response to a Carbon Dioxide Removal

“…Previous studies have examined climate responses to atmospheric CO 2 removal in terms of reversibility and hysteresis based on CO 2 ramp‐up and ‐down experiments by using climate models (An et al., 2002, 2021; Boucher et al., 2012; Bouttes et al., 2013; Garbe et al., 2020; Jackson et al., 2014; Jeltsch‐Thömmes et al., 2020; Kug et al., 2021; Long et al., 2020; Oh et al., 2022; Sgubin et al., 2015; Song et al., 2022; Wu et al., 2011, 2015). While some components have shown irreversible or clear hysteresis behaviors, such as thermosteric sea level (Boucher et al., 2012; Bouttes et al., 2013; Long et al., 2020), the Antarctic ice sheet (Garbe et al., 2020), the Intertropical Convergence Zone (Kug et al., 2021), and Atlantic meridional overturning circulation (AMOC) (An et al., 2021; Jackson et al., 2014; Sgubin et al., 2015; Wu et al., 2011), the global mean surface air temperature (GSAT), a representative metric to measure the extent of global warming, has exhibited a roughly linear response, although it also exhibits a delayed cooling response to atmospheric CO 2 reduction (Boucher et al., 2012; Jeltsch‐Thömmes et al., 2020; Kug et al., 2021; Wu et al., 2015). Although delayed cooling or temperature hysteresis is a robust response in most climate models, how fast our climate will recover after carbon neutrality and carbon removal is quite uncertain and differs among climate models (Boucher et al., 2012; Jeltsch‐Thömmes et al., 2020; Kug et al., 2021; Wu et al., 2015).…”

“…While some components have shown irreversible or clear hysteresis behaviors, such as thermosteric sea level (Boucher et al., 2012; Bouttes et al., 2013; Long et al., 2020), the Antarctic ice sheet (Garbe et al., 2020), the Intertropical Convergence Zone (Kug et al., 2021), and Atlantic meridional overturning circulation (AMOC) (An et al., 2021; Jackson et al., 2014; Sgubin et al., 2015; Wu et al., 2011), the global mean surface air temperature (GSAT), a representative metric to measure the extent of global warming, has exhibited a roughly linear response, although it also exhibits a delayed cooling response to atmospheric CO 2 reduction (Boucher et al., 2012; Jeltsch‐Thömmes et al., 2020; Kug et al., 2021; Wu et al., 2015). Although delayed cooling or temperature hysteresis is a robust response in most climate models, how fast our climate will recover after carbon neutrality and carbon removal is quite uncertain and differs among climate models (Boucher et al., 2012; Jeltsch‐Thömmes et al., 2020; Kug et al., 2021; Wu et al., 2015). In particular, the temporal evolution of temperature has a strong regional dependency; therefore, how fast regional temperatures recover under a CO 2 reduction pathway is a critical part of climate adaptation and future policy decisions.…”

General circulation and global heat transport in a quadrupling CO2 pulse experiment

“…The CO 2 pulse and CDRMIP experiments could provide a clue on a climate reversibility, which is an ability for restoring toward its initial climate state [19][20][21] . The opposite case refers irreversibility.…”

“…Such irreversible climate change usually accompanies a hysteresis behavior. For example, a strong hysteresis behavior of Atlantic Meridional Overturning Circulation (AMOC) could lead to an irreversible climate change 19,22,23 , and a strong oceanic thermal inertia over Southern Ocean could be a cause for irreversible climate change 21,24 . In this regard, the investigation of OHT gives a sense of where the irreversible climate change would occur by showing a place for the oceanic heat accumulation.…”