Peter Huybers

Glaciation

What causes the variability in Plio-Pleistocene glaciation?

A global survey of mid-ocean ridge spacing shows the influence of Late-Pleistocene sea-level variations on ridge spacing, supporting a link between glacial sea-level variations and mid-ocean ridge magmatic variations 2022.
Parker Liautaud made a prediction of what Early‐Pleistocene atmospheric CO2 values should look like based on the observed relationship between CO2 and sea level during the Late-Pleistocene 2022.

References

Huybers, Liautaud, Proistosescu, Boulahanis, Carbotte, Katz, and Langmuir, Influence of late Pleistocene sea-level variations on mid-ocean ridge spacing... link.

Crops

We study how water shapes farming in a changing climate. Our work shows that crop losses often come from water stress linked with heat, and that better tracking of soil moisture can both improve predictions and guide practices that help protect yields.

A major question is the degree to which hot or dry conditions limit crops yields. The answer is hard to empirically infer because dry and hot conditions are strongly coupled. Lucas Zeppetello has put forward a strong argument that water limitation is the root cause 2025.
There is an expectation that climate change entails greater variablity in crop production because of higher sensitivity to temperature anomalies with warming. Jon Proctor showed that, in addition, increased covariability between temperature and moisture availability will also contribute to increased production volatility 2025.
An examination of the implicatons of weather shocks in agricultural regions found that the implications for net migration are miniimal, but that this reflects offsetting influences between how people migrate according to their education and income status 2025.
Angela Rigden showed that trends toward diminished rainfall, soil moisture, and NDVI during the early portion of Southern Madagascar's rainy season are attributable to climate change 2024.
Jon Proctor showed that crops are generally sensitive to variations in water availability globally by using satellite observations of soil moisture as opposed to a more typical approach of using precipitation records 2022.
Although obvious that moisture availability is critical to crop yields, this intuitive fact has been surprisingly difficult to quantify. For example, empirical models generally fail to significantly improve yield predictions when accounting for rainfall. In a pair of papers, Angela Rigden shows that observations from the Soil Moisture Active Passive (SMAP) satellite changes this situation both for corn yield in the US Midwest 2020a and Tea Yield in Kenya 2020b. SMAP observations allow for significantly improved yield predictions. Moreover, Angela is able to quantify the nonlinear interactions between demand for moisture (indicated either by temperature of vapor pressure deficit) and supply of moisture (root-zone moisture levels estimated from SMAP observations), and that oversupply and undersupply of moisture both have major consequences for yield outcomes. A Nature News and Views piece by Michelle Tigchelaar (here) gives a good summary of the US Midwestern work.
Nathan Mueller showed that the hottest summer temperatures in the U.S. Midwest have been cooling over the last century because of increasing agricultural intensification and associated increases in transpiration (2015). Ethan Butler showed that this suppression of high-temperature extremes, along with a longer growing season, account for about a quarter of the trend in maize yields since 1981 (2018). Whether such peculiarly pleasant changes will continue, however, is far from certain. Nathan and colleagues also showed that this cooling phenomena occurs in regions across the globe coincident with agricultural intensification, with the curious exception of Western Europe (2015). The degree to which global agricultural may have been boosted by local climate modifcation remains to be determined.
Ethan Butler demonstrated that sensitivity of maize yield to high temperatures varies according to climatology across the U.S. (2013). Using this spatial adaptation as a proxy for adaptability to future warming suggests substantial scope for mitigating damage from climate change, though changes in temperature variance and rainfall are still wild cards. More recently, Ethan showed that maize cultivars adapted to hotter climate tend to increase time spent in the grain-filling stage of development in response to high temperatures, whereas cultivars that are more sensitive to high temperatures tend to shorten this stage of development (2015).

References

Proctor, Vargas Zeppetello, Chan, and Huybers, Climate change increases the interannual variance of summer crop yields globally through changes in temperature and water supply, Science Advances, 11(36), 2025. link
Benveniste, Huybers, and Proctor, Global climate migration is a story of who and not just how many, Nature Communications, 16(1), 2025. link
Vargas Zeppetello, Proctor, and Huybers, Is Water Stress the Root Cause of the Observed Nonlinear Relationship Between Yield Losses and Temperature?, AGU Advances, 6(4), 2025. link
Rigden, Golden, Chan, and Huybers, Climate change linked to drought in Southern Madagascar, npj Climate and Atmospheric Science, 7(1), 2024. link
Rigden, Mueller, Holbrook, Pillai, and Huybers , Combined influence of soil moisture and atmospheric evaporative demand is important for accurately predicting US maize yields, Nature Food, 2020. link
Rigden, Ongoma, and Huybers, Kenyan tea is made with heat and water: how will climate change influence its yield?, Envrionmental Reseeach Letters, 2020. link
Butler, Mueller, and Huybers, Peculiarly pleasant weather for US maize , Proceedings of the National Academy of Sciences, 2018. link, pdf
Mueller, Rhines, Butler, Ray, Siebert, Holbrook, and Huybers Global Relationships Between Cropland Intensification and Summer Temperature Extremes Over the Last 50 Years, Journal of Climate, 2017. link, pdf
Mueller, Butler, McKinnon, Rhines, Tingley, Holbrook, and Huybers Cooling of US Midwest summer temperature extremes from cropland intensification, Nature Climate Change, 2015. pdf
Butler and Huybers Variations in the sensitivity of US maize yield to extreme temperatures by region and growth phase, Environmental Research Letters, 2015. pdf
Myers et al. Increasing CO2 threatens human nutrition, Nature, 2014. pdf
Butler and Huybers Adaptation of US maize to temperature variations, Nature Climate Change, 2013. pdf
Lin and Huybers Reckoning wheat yield trends, Environmental Research Letters, 2012. pdf and supplemental material