Himalayan glaciers lost 28% of ice in last 40 years

Change in ice loss in Himalayan glaciers — Ice thickness change (meters per year) at different elevations for 1975-2000 (blue) and 2000-2016 (red)

A new study of ice mass loss in 650 Himalayan glaciers over the past 40 years has revealed accelerating ice loss. The study recent extracted digital elevation models from declassified spy films which were compared with recent ASTER stereo imagery to quantify ice loss for the periods 1975–2000 and 2000–2016. The glaciers included in the study comprising approximately 34% of the total glacierized area in the region, or roughly 55% of the total glacial ice volume. The observed annual mass losses suggest that of the total ice mass present in 1975, about 87% remained in 2000 and 72% remained in 2016. The results also indicate that the average rate of ice loss was twice as rapid in 2000-2016 compared to 1975-2000.

Acceleration of ice loss across the Himalayas over the past 40 years, J. M. Maurer, J. M. Schaefer, S. Rupper and A. Corley, Science Advances 19 Jun 2019: Vol. 5, no. 6, eaav7266 DOI: 10.1126/sciadv.aav7266

From Our Files

Accelerating ocean warming revealed by extensive oceanic buoy network

Improved data coverage and analysis has made it possible to reconstruct temperature profiles across most ocean basins and at all depths to 6000 meters (m) from 1960 to 2015. The reconstructions reveal accelerating heating in the upper layers above 2000 m. Ocean warming is stronger since the late 1980s compared to the 1960s to the 1980s.

Solar variability less important than greenhouse gases in global warming

Based on the trend that greenhouse gases are increasing rapidly whereas solar irradiance is changing much more slowly, the evidence reveals that the climate impact of changes in solar irradiance are much smaller in magnitude than the increase in warming due to greenhouse gases.

Upward revision of methane emissions from shale gas production could erode natural gas’ cleaner energy advantage

Evidence that methane emissions from natural gas production have been considerably underestimated by the EPA was recently reinforced by the initiation of an investigation into how the EPA estimates methane emissions by the EPA’s Inspector General. If it is found that emissions of methane from natural gas production are considerably greater than current estimates, the advantage that natural gas has over coal will be eroded and the advantage of switching to natural gas as a cleaner form of energy diminished.

Greenland ice cores reveal warming of 10 °C in three years

High-resolution Greenland ice core records reveal two warming events at the end of the last ice age involved warming of more than 10 °C. Furthermore the warming transition beginning 14,700 years ago occurred within only three years.