Gender inequity in speaking opportunities at the American Geophysical Union Fall Meeting.

Implicit and explicit biases impede the participation of women in science, technology, engineering, and mathematic (STEM) fields. Across career stages, attending conferences and presenting research are ways to spread scientific results, find job opportunities, and gain awards. Here, we present an analysis by gender of the American Geophysical Union Fall Meeting speaking opportunities from 2014 to 2016. We find that women were invited and assigned oral presentations less often than men. However, when we control for career stage, we see similar rates between women and men and women sometimes outperform men. At the same time, women elect for poster presentations more than men. Male primary conveners allocate invited abstracts and oral presentations to women less often and below the proportion of women authors. These results highlight the need to provide equal opportunity to women in speaking roles at scientific conferences as part of the overall effort to advance women in STEM.

Late Miocene decoupling of oceanic warmth and atmospheric carbon dioxide forcing.

Deep-time palaeoclimate studies are vitally important for developing a complete understanding of climate responses to changes in the atmospheric carbon dioxide concentration (that is, the atmospheric partial pressure of CO(2), p(co(2))). Although past studies have explored these responses during portions of the Cenozoic era (the most recent 65.5 million years (Myr) of Earth history), comparatively little is known about the climate of the late Miocene (∼12-5 Myr ago), an interval with p(co(2)) values of only 200-350 parts per million by volume but nearly ice-free conditions in the Northern Hemisphere and warmer-than-modern temperatures on the continents. Here we present quantitative geochemical sea surface temperature estimates from the Miocene mid-latitude North Pacific Ocean, and show that oceanic warmth persisted throughout the interval of low p(co(2)) ∼12-5 Myr ago. We also present new stable isotope measurements from the western equatorial Pacific that, in conjunction with previously published data, reveal a long-term trend of thermocline shoaling in the equatorial Pacific since ∼13 Myr ago. We propose that a relatively deep global thermocline, reductions in low-latitude gradients in sea surface temperature, and cloud and water vapour feedbacks may help to explain the warmth of the late Miocene. Additional shoaling of the thermocline after 5 Myr ago probably explains the stronger coupling between p(co(2)), sea surface temperatures and climate that is characteristic of the more recent Pliocene and Pleistocene epochs.