About 34 million years ago, Earth's climate shifted from a relatively ice-free world to one with glacial conditions on Antarctica characterized by substantial ice sheets. How Earth's temperature changed during this climate transition remains poorly understood, and evidence for Northern Hemisphere polar ice is controversial. Here, we report proxy records of sea surface temperatures from multiple ocean localities and show that the high-latitude temperature decrease was substantial and heterogeneous. High-latitude (45 degrees to 70 degrees in both hemispheres) temperatures before the climate transition were approximately 20 degrees C and cooled an average of approximately 5 degrees C. Our results, combined with ocean and ice-sheet model simulations and benthic oxygen isotope records, indicate that Northern Hemisphere glaciation was not required to accommodate the magnitude of continental ice growth during this time.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1126/science.1166368 | DOI Listing |
Ying Yong Sheng Tai Xue Bao
October 2024
Ningxia Helan Mountain National Nature Reserve Administration, Yinchuan 750021, China.
subsp. is an important resource plant with considerable medicinal, economic, and ecological value, and an indicator species in the transition zones between forests and grasslands. Predicting the potential geographic distribution of subsp.
View Article and Find Full Text PDFRisk Anal
December 2024
College of Business, Alfaisal University, Riyadh, Saudi Arabia.
Increasing awareness of climate change and its potential consequences on financial markets has led to interest in the impact of climate risk on stock returns and portfolio composition, but few studies have focused on perceived climate risk pricing. This study is the first to introduce perceived climate risk as an additional factor in asset pricing models. The perceived climate risk is measured based on the climate change sentiment of the Twitter dataset with 16 million unique tweets in the years 2010-2019.
View Article and Find Full Text PDFPLoS One
December 2024
Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy.
A high-resolution record of central Mediterranean Sea Surface Temperatures (SSTs) based on the alkenone UK'37 index and planktic δ18O values for the surface-dweller G. ruber has been reconstructed across the Pliocene/Pleistocene transition at Monte San Nicola (Sicily), reference area for the GSSP (Global Boundary Stratotype Section and Point) of the Gelasian Stage. Spectral analyses indicate that the SST record is predominantly paced by a cyclicity in the ~47 kyr time domain, consistent with the obliquity driven glacial-interglacial variability that is expected to dominate in the interval of relevance.
View Article and Find Full Text PDFThe rollout of electric vehicles and photovoltaic panels is essential to mitigate climate change. However, they depend on technology-critical elements (TCEs), which can be harmful to human health and whose use is rapidly expanding, while recycling is lacking. While mining has received substantial attention, in-use dissipation in urban areas has so far not been assessed, for example, corrosion and abrasion of vehicle components and weather-related effects affecting thin-film photovoltaic panels.
View Article and Find Full Text PDFJ Ind Ecol
December 2024
Department of Environmental Science, Radboud Institute for Biological and Environmental Sciences Radboud University Nijmegen Nijmegen The Netherlands.
The emerging field of prospective life cycle assessment (pLCA) offers opportunities for evaluating the environmental impacts of possible future consumption shifts. One such shift involves a transition from meat-based to plant-forward diets, acknowledged to mitigate environmental impacts of the food system under present day conditions. Current diets are often meat intensive ("meat-based"), whilst "plant-forward" diets include mainly plant-based foods, encompassing flexitarian, vegetarian, and vegan diets.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!