Indian Ocean sea-level rise threatens coastal areas


Indian Ocean sea levels are rising unevenly and threatening residents in some densely populated coastal areas and islands, a new study concludes. Sea-level rise is particularly high along the coastlines of the Bay of Bengal and the Arabian Sea, as well as the islands of Sri Lanka, Sumatra and Java, the authors found.

“Our results from this study imply that if future anthropogenic warming effects in the Indo-Pacific warm pool dominate natural variability, mid-ocean islands such as the Mascarenhas Archipelago, coasts of Indonesia, Sumatra and the north Indian Ocean may experience significantly more sea-level rise than the global average,” says scientist Weiqing Han of CU and lead author of a paper published this week in the journal Nature Geoscience.

The rise–which may aggravate monsoon flooding in Bangladesh and India–could have future impacts on both regional and global climate.

The complex circulation patterns in the Indian Ocean may also affect precipitation by forcing even more atmospheric air down to the surface in Indian Ocean subtropical regions than normal, Han speculates.

Cool Roofs Can Offset Co2 Emissions and Mitigate Global Warming


Because white colored roofs reflect far more of the sun’s heat than black ones, buildings with white roofs will stay cooler. If the building is air conditioned, less air conditioning will be required, thus saving energy. Even if there is no air conditioning, the heat absorbed by a black roof both heats the space below, making the space less comfortable, and is also carried into the city air by wind — raising the ambient temperature in what is known as the urban heat island effect. Additionally, there’s a third, less familiar way in which a black roof heats the world: it radiates energy directly into the atmosphere, which is then absorbed by the nearest clouds and ends up trapped by the greenhouse effect, contributing to global warming.

Flowering Plants makes tropics cooler and wetter


“The vein density of leaves within the flowering plants (angiosperm) is much, much higher than all other plants,” said the study’s lead author, C. Kevin Boyce, Associate Professor in Geophysical Sciences at the University of Chicago. “That actually matters physiologically for both taking in carbon dioxide from the atmosphere for photosynthesis and also the loss of water, which is transpiration. The two necessarily go together. You can’t take in CO2 without losing water.”

This higher vein density in the leaves means that flowering plants are highly efficient at transpiring water from the soil back into the sky, where it can return to Earth as rain.

Flowering species were latecomers to the world of vascular plants, a group that includes ferns, club mosses and confers. But angiosperms now enjoy a position of world domination among plants.