The rate of deforestation in the Brazilian Amazon has plummeted by 77% in the past seven years, but annual carbon emissions associated with deforestation have not fallen nearly as much, says a Brazilian study that combines satellite data and biomass maps to model the change. The difference is in large part due to a natural lag as carbon stocks slowly decay and make their way into the atmosphere as carbon dioxide.

A measurement by satellite altimetry shows the Himalayan glaciers to be losing mass at only moderate rates, but raises broader questions about other methods for estimating mass balance.

Glaciers are among the best indicators of terrestrial climate variability, contribute importantly to water resources in many mountainous regions and are a major contributor to global sea level rise. In the Hindu Kush–Karakoram–Himalaya region (HKKH), a paucity of appropriate glacier data has prevented a comprehensive assessment of current regional mass balance. There is, however, indirect evidence of a complex pattern of glacial responses in reaction to heterogeneous climate change signals9.

In sharp contrast to the decreasing sea ice coverage of the Arctic, in the Antarctic the sea ice cover has, on average, expanded since the late 1970s. More specifically, satellite passive-microwave data for the period November 1978–December 2010 reveal an overall positive trend in ice extents of 17 100 ± 2300 km2 yr−1. Much of the increase, at 13 700 ± 1500 km2 yr−1, has occurred in the region of the Ross Sea, with lesser contributions from the Weddell Sea and Indian Ocean.

Glaciers of the Himalaya contribute significantly in the processes linking atmosphere, biosphere and hydrosphere, thus need to be monitored in view of the climatic variations. In this direction, many studies have been carried out during the last two decades and satellite-based multispectral data have been used extensively for this purpose throughout the world.

Groundwater is a life-sustaining resource that supplies water to billions of people, plays a central part in irrigated agriculture and influences the health of many ecosystems. Most assessments of global water resources have focused on surface water but unsustainable depletion of groundwater has recently been documented on both regional and global scales. It remains unclear how the rate of global groundwater depletion compares to the rate of natural renewal and the supply needed to support ecosystems.

The surface of Greenland has turned to slush. Satellite data shows that a warm spell earlier this month melted nearly the entire surface of the nation's ice cap. The melt is unusual: normally about half of the ice sheet melts at the surface during summer, mostly at low elevations.