SAEON Snippets

Earth observation science indicates that ice is melting faster than anticipated

Picture © Beneke de Wet, compliments of the NRF's SA National Antarctic Programme (SANAP)

The frozen continent is shedding about 152 km³ of ice every year - enough to supply a big city with water for 35 years - according to research that suggests global sea levels could rise more rapidly than predicted.

This week's findings, from the twin satellites of the Gravity Recovery and Climate Experiment launched in 2002, are a concern because the ice sheet would increase sea levels by as much as 45 m if it were all released.

The results indicate that rising temperatures are having an impact on both the world's ice caps: two weeks ago, a study found that the amount of ice dumped into the sea by glaciers in Greenland has doubled over five years.
- The Times News Service, London

2005 was the warmest year on record

2005 was the warmest year on record, according to a new NASA report. And the year's record warmth is more notable than previous record-breaking years as there was no boost from the tropical El Niño phenomenon.

The annual analysis by NASA's Goddard Institute for Space Studies (GISS) found the highest global surface temperature in more than a century of instrumental measurements was recorded in 2005. The analysis incorporates measurements on land, satellite measurements of the sea surface and ship-based analyses.

"Recent warming coincides with rapid growth of human-made greenhouse gases," says James Hansen, who led the study. And the warming seen is in line with that predicted by climate models, he says. "The observed rapid warming thus gives urgency to discussions about how to slow greenhouse gas emissions."

Other recent estimates did not put 2005 as the warmest year. For example, a December 2005 report by the UK's Meteorological Office and researchers from the University of East Anglia said it was the second warmest on record. But the GISS report says it differs from other analyses by including temperature estimates up to 1 200 kilometres away from the nearest measurement station. In this way, it has been able to include data from the Arctic, where there are very few weather stations. This resulted in 2005 surpassing the previous record-holder, 1998, as the hottest year, although they were very close.

"We believe the remarkable Arctic warmth of 2005 is real, and the inclusion of estimated Arctic temperatures is the primary reason for our rank of 2005 as the warmest year," say the researchers.

High latitudes

The strongest El Niño of the last century lifted the temperature in 1998 by 0.2°C above the trend, whereas there was no such phenomenon to boost temperatures in 2005.

The GISS team warn that global warming is now 0.6°C in the past three decades, and 0.8°C in the past century. "It is no longer correct to say that 'most global warming occurred before 1940'," they note.

The largest warmings in the last 50 years have occurred in Alaska, Siberia and the Antarctic Peninsula, they add.

However, while 2005 was the warmest year on record, the start of 2006 has brought extreme cold temperatures to parts of Europe and Asia. Russia, Ukraine and Poland have blamed scores of deaths on the freezing weather. In Moscow, Russia, temperatures below -30°C are the lowest in decades and a similar chill is holding the Baltic countries in its grip.

A cold snap earlier in January brought some of the heaviest snowfall on record to Japan - killing about 89 people, according to local reports.
- NewScientist.com news service