Loss of ice in Antarctica has caused global sea levels to rise by 7.6 millimeters since 1992, with 40 percent of the increase happening in just the past five years, according to a major new international climate assessment funded by NASA and ESA (European Space Agency).
According to the Ice Sheet Mass Balance Inter-Comparison Exercise – published in the Nature journal, ice losses from Antarctica is causing sea levels to rise faster today than at any time in the past 25 years.
One of the most comprehensive assessment of Antarctic ice mass changes to date, the study involved 80 scientists from 42 international organizations and some 24 satellite surveys of Antarctica.
The team looked at the mass balance of the Antarctic ice sheet from 1992 to 2017 and found ice losses from Antarctica raised global sea levels by 0.3 inches (7.6 millimeters), with a disproportionately higher ice loss in recent years.
West Antarctica experienced the greatest ice loss. Most of this loss came from the huge Pine Island and Thwaites Glaciers, which are retreating rapidly due to ocean-induced melting.
Antarctica’s contribution to global sea level rise is 7.5 times greater than all other sources of land-held ice in the world. The continent stores enough frozen water to raise global sea levels by 190 feet (58 meters), if it were to melt entirely. Knowing how much ice it’s losing is key to understanding the impacts of climate change now and its pace in the future.
Data from these missions will help scientists connect the environmental drivers of change with the mechanisms of ice loss to improve our projections of sea level rise in the coming decades.
Gravity measurements from the GRACE [Gravity Recovery & Climate Experiment] — a joint mission of NASA and German Aerospace Center — track the loss of ice mass in the Polar Regions and its impact on sea level around the planet. The data collected by GRACE’s twin satellites show us not only that the problem not only exists, but the fact that it is growing in severity with each passing year.
Antarctica stores enough frozen water to raise global sea levels by 58 meters. Knowing how much ice it’s losing is key to understanding the effects of climate change today and in the future.
The threefold jump in ice loss from the continent as a whole is a combination of increased melting in West Antarctica and the Antarctic Peninsula, with a small signal from the ice sheet in East Antarctica.
West Antarctica experienced the largest change, with ice losses growing annually from 53 billion tons per year in the 1990s to 159 billion tons since 2012. Most of this came from the huge Pine Island and Thwaites glaciers, which are retreating rapidly due to melting by warm ocean waters.
At the northern tip of the continent, ice shelf collapse at the Antarctic Peninsula has driven a 25 billion-ton increase in ice loss since the early 2000s. The East Antarctica ice sheet is thought to have remained relatively stable over the past 25 years.
“With the number of scientific studies focusing on this region, the technological tools we have at our disposal and data sets spanning several decades, we have an unequivocal picture of what’s happening in Antarctica,” said Eric Rignot, Donald Bren Professor and chair of Earth system science at UCI. “We are confident in our understanding of ice mass change in Antarctica and its impact on sea levels. We view these results as another ringing alarm for action to slow the warming of our planet.”
Rignot, who led the ice mass budget studies for the assessment, and Velicogna, who directed gravity measurement, also serve as research scientists at NASA’s Jet Propulsion Laboratory. The project was supported by NASA and the European Space Agency.
Giraffe (Giraffa Camelopardalis) with an average height of around 5 m (16-18 ft.) is one of the tallest mammals living on planet Earth. It has over 6 feet long legs which make it taller than most human beings….
Giraffe’s long neck allows it to eat leaves located at much higher level than other animals can reach. A long tongue helps them pull leaves from the trees and eat them. A full-grown giraffe usually consumes over 45 kg of leaves and twigs a day.
The male giraffe is taller and heavier than the female.
Giraffes sleep less than two hours a day with their feet tucked under them and their head resting on their hindquarters. Female giraffes usually become pregnant after they are 5 years old. The pregnancy period generally lasts 15 months and newborns are about 6 ft. tall and weigh 70 kg
The life expectancy of Giraffes is 25 years
Giraffes are classified by IUCN’s Red List as vulnerable to extinction. The number of giraffes has plummeted 40% since 1985. Some subspecies are in even more dire situation with their population declining by nearly 80%.
Has excellent eyesight which allows it to see predators like lions and hyenas from far away
Can clean its ears with its 21 inch long tongue
Can run faster than 56 km/ph over short distances, or cruise at 16 km/ph over longer distances
Has to awkwardly spread its front legs or kneel to reach the ground to drink water
Needs to drink only once in few days. Most of this water comes from the plants they eat
Can spend most of their lives standing up- even sleep and give birth
A new born calf can stand up and walk after about an hour and eat vegetation within a week
Have distinct spots on the body like fingerprints. No two giraffes have the same spots
Male and female giraffes have two distinct, hair-covered horns called ossicones. Male giraffes use their horns to fight with other males
Needs just a short 5-30 minute sleep in 24-hours. Each short nap may last only 1-2 minute
Produce low pitched sounds which are beyond the range of human hearing range