Nature Climate Change

Zhou, Wenyu; Yang, Da; Xie, Shang-Ping; Ma, Jing

doi: 10.1038/s41558-020-0814-0pmid: N/A

The Madden–Julian Oscillation (MJO) is a slow-moving tropical mode that produces a planetary-scale envelope of convective storms. By exciting Rossby waves, the MJO creates teleconnections with far-reaching impacts on extratropical circulation and weather. Although recent studies have investigated the response of the MJO to anthropogenic warming, not much is known about potential changes in its teleconnections. Here, we show that the MJO teleconnection pattern in boreal winter will likely extend further eastward over the North Pacific. This is primarily due to an eastward shift in the exit region of the subtropical jet, to which the teleconnection pattern is anchored, and assisted by an eastward extension of the MJO itself. The eastward-extended teleconnection enables the MJO to have a greater impact downstream on the Northeast Pacific and North American west coast. Over California specifically, the multi-model mean projects a 54% increase in MJO-induced precipitation variability by 2100 under a high-emissions scenario.

Terrer, César; Jackson, Robert B.; Prentice, I. Colin; Keenan, Trevor F.; Kaiser, Christina; Vicca, Sara; Fisher, Joshua B.; Reich, Peter B.; Stocker, Benjamin D.; Hungate, Bruce A.; Peñuelas, Josep; McCallum, Ian; Soudzilovskaia, Nadejda A.; Cernusak, Lucas A.;

Skagseth, Øystein; Eldevik, Tor; Årthun, Marius; Asbjørnsen, Helene; Lien, Vidar S.; Smedsrud, Lars H.

doi: 10.1038/s41558-020-0772-6pmid: N/A

Dense water masses from the Barents Sea are an important part of the Arctic thermohaline system. Here, using hydrographic observations from 1971 to 2018, we show that the Barents Sea climate system has reached a point where ‘the Barents Sea cooling machine’—warmer Atlantic inflow, less sea ice, more regional ocean heat loss—has changed towards less-efficient cooling. Present change is dominated by reduced ocean heat loss over the southern Barents Sea as a result of anomalous southerly winds. The outflows have accordingly become warmer. Outflow densities have nevertheless remained relatively unperturbed as increasing salinity appears to have compensated the warming inflow. However, as the upstream Atlantic Water is now observed to freshen while still relatively warm, we speculate that the Barents Sea within a few years may export water masses of record-low density to the adjacent basins and deep ocean circulation.

doi: 10.1038/s41558-020-0846-5pmid: N/A

Research addressing compound and connected events, and their integrated risk to the natural and built world, is gaining momentum. Paradigms are now evolving to classify and analyse the processes forming such links — whether physical or societal, direct or indirect — and the role of climate change in their ultimate impacts.

Le Quéré, Corinne; Jackson, Robert B.; Jones, Matthew W.; Smith, Adam J. P.; Abernethy, Sam; Andrew, Robbie M.; De-Gol, Anthony J.; Willis, David R.; Shan, Yuli; Canadell, Josep G.; Friedlingstein, Pierre; Creutzig, Felix; Peters, Glen P.

Edwards, Ian; Yapp, Kiri; Mackay, Sam; Mackey, Brendan

doi: 10.1038/s41558-020-0785-1pmid: N/A

Expectations for the Task Force on Climate-related Financial Disclosure’s framework to drive climate action in the private sector are high, and there is growing interest in its relevance for guiding public sector climate action. However, consideration of the framework’s limitations is critical prior to public sector application.

Ouyang, Zhangxian; Qi, Di; Chen, Liqi; Takahashi, Taro; Zhong, Wenli; DeGrandpre, Michael D.; Chen, Baoshan; Gao, Zhongyong; Nishino, Shigeto; Murata, Akihiko; Sun, Heng; Robbins, Lisa L.; Jin, Meibing; Cai, Wei-Jun

Liu, Yanlan; Kumar, Mukesh; Katul, Gabriel G.; Feng, Xue; Konings, Alexandra G.

doi: 10.1038/s41558-020-0781-5pmid: N/A

Transpiration, the dominant component of terrestrial evapotranspiration (ET), directly connects the water, energy and carbon cycles and is typically restricted by soil and atmospheric (for example, the vapour pressure deficit (VPD)) moisture stresses through plant hydraulic processes. These sources of stress are likely to diverge under climate change, with a globally enhanced VPD but more variable and uncertain changes in soil moisture. Here, using a model–data fusion approach, we demonstrate that the common empirical approach used in most Earth system models to evaluate the ET response to soil moisture and VPD, which neglects plant hydraulics, underestimates ET sensitivity to VPD and compensates by overestimating the sensitivity to soil moisture stress. A hydraulic model that describes water transport through the plant better captures ET under high VPD conditions for wide-ranging soil moisture states. These findings highlight the central role of plant hydraulics in regulating the increasing importance of atmospheric moisture stress on biosphere–atmosphere interactions under elevated temperatures.

Klöck, Carola

doi: 10.1038/s41558-020-0816-ypmid: N/A

Pacific Islands are already responding to the adverse effects of climate change, but it is unclear to what extent these responses effectively and sustainably improve local resilience. New research seeks to understand how local beneficiaries evaluate adaptation projects and what this teaches us for future adaptation.

Bui, Hien X.

doi: 10.1038/s41558-020-0828-7pmid: N/A

The Madden–Julian oscillation causes teleconnections that impact mid-latitudes. Now research predicts dramatic eastward shifts of these impacts in the Pacific–North America region as the climate warms, leading to higher winter rainfall variability along the US West Coast and California in particular.