As a raindrop falls through the atmosphere, it can attract tens to hundreds of tiny aerosol particles to its surface before hitting the ground. The process by which droplets and aerosols attract is coagulation, a natural phenomenon that can act to clear the air of pollutants like soot, sulfates, and organic particles. Atmospheric chemists at MIT have now determined just how effective rain is in cleaning the atmosphere. 

Global sea levels have risen nearly 3 inches in less than 25 years, with some locations around the world rising more than 9 inches, according to NASA’s latest satellite data. An intensive research effort now underway, aided by NASA observations and analysis, points to an unavoidable rise of several feet in the future.

Tracking mobile phone data is often associated with privacy issues, but these vast datasets could be the key to understanding how infectious diseases are spread seasonally, according to a study published in the Proceedings of the National Academy of Sciences. 

Princeton University and Harvard University researchers used anonymous mobile phone records for more than 15 million people to track the spread of rubella in Kenya and were able to quantitatively show for the first time that mobile phone data can predict seasonal disease patterns. 

Harnessing mobile phone data in this way could help policymakers guide and evaluate health interventions like the timing of vaccinations and school closings, the researchers said. The researchers' methodology also could apply to a number of seasonally transmitted diseases such as the flu and measles.

As Californians continue pumping groundwater in response to the historic drought, the California Department of Water Resources today released a new NASA report showing land in the San Joaquin Valley is sinking faster than ever before, nearly 2 inches (5 centimeters) per month in some locations.

Once mercury is emitted into the atmosphere from the smokestacks of power plants, the pollutant has a complicated trajectory; even after it settles onto land and sinks into oceans, mercury can be re-emitted back into the atmosphere repeatedly. This so-called “grasshopper effect” keeps the highly toxic substance circulating as “legacy emissions” that, combined with new smokestack emissions, can extend the environmental effects of mercury for decades.

Now an international team led by MIT researchers has conducted a new analysis that provides more accurate estimates of sources of mercury emissions around the world. The analysis pairs measured air concentrations of mercury with a global simulation to calculate the fraction of mercury that is either re-emitted or that originates from power plants and other anthropogenic activities. The result of this work, researchers say, could improve estimates of mercury pollution, and help refine pollution-control strategies around the world.

Whale songs are some of the most hauntingly beautiful and bizarre noises in the world. But if it hadn’t been for acoustic biologist Katy Payne, we’d probably still be dismissing them as mere sounds — like the noises our own cats and dogs make when they’re hungry, frightened, interested, or affectionate. Payne, however, realized that whales are actually composing songs, not just making noise under the sea, and moreover, she found that over time, whales change their tune. These majestic marine mammals interact with each other to create songs of escalating length and complexity over the years, in what one might compare to jazz riffing or Indigenous Australian songlines, the cultural, social, and physical maps passed down through generations.

The Maunder Minimum, between 1645 and 1715, when sunspots were scarce and the winters harsh, strongly suggests a link between solar activity and climate change. Until now there was a general consensus that solar activity has been trending upwards over the past 300 years (since the end of the Maunder Minimum), peaking in the late 20th century -- called the Modern Grand Maximum by some [1].

This trend has led some to conclude that the Sun has played a significant role in modern climate change. However, a discrepancy between two parallel series of sunspot number counts has been a contentious issue among scientists for some time.

As grasses grew more common in Africa, most major mammal groups tried grazing on them at times during the past 4 million years, but some of the animals went extinct or switched back to browsing on trees and shrubs, according to a study led by the University of Utah.

Researchers find new evidence that large eruptions were responsible for cold temperature extremes recorded since early Roman times

It is well known that large volcanic eruptions contribute to climate variability. However, quantifying these contributions has proven challenging due to inconsistencies in both historic atmospheric data observed in polar ice cores and corresponding temperature variations seen in climate indicators such as tree rings.

The U.S. Environmental Protection Agency (EPA) released updated environmental and public health indicators in an online database, making information about the current and historical condition of the nation’s environment and human health more accessible to the public. This is an online update to EPA’s Report on the Environment. Users can explore 85 individual indicators-- on our air, water, land, human exposure, health and ecological condition-- using interactive graphs, tables, and maps, and download the data for each indicator.