A landmark study published this month in the science journal Nature combined the work of 80 scientists from 42 institutions including some of the leading experts in Antarctic climate research and concluded that Antarctica has lost nearly 3 trillion tons of ice since 1992. According to CBS News, this is enough water to cover the state of Texas 13 feet deep. While it is no surprise that the Antarctic continent is losing land mass, it is surprising to learn how quickly the ice has been melting.
Using decades of satellite measurements, the researchers found that that from 1992 through 2011, the Antarctic continental ice melted at a rate of 76 billion tons per year. Since that time however, the rate has jumped to 219 billion tons per year. This data indicates that the rate of ice melt has nearly tripled in the past 5 years.
The study provides extraordinary evidence of how and why Antarctica’ glaciers, ice shelves and sea ice are changing and triggering an increase in the continent’s contribution to global sea level rise. Warm ocean water is melting the ice shelves and causing them to collapse. This rapid melting of the Antarctic ice shelves is already having a serious impact on coastal cities, especially on the east coast of the United States. A recent editorial in the Washington Post warned, “As Antarctica melts, North America will take a particularly hard wallop. Melting ice shrinks Antarctica and, therefore, its gravitational field. Without as much mass pulling ocean water south, sea levels will rise farther north as the oceans redistribute … Coastal cities need to start preparing now.”
This concern was echoed in a report published earlier this year by the National Oceanic and Atmospheric Administration (NOAA) which warned that high tide flooding will become routine by 2100. The report says that “high tide flooding will occur every other day (182 days of the year) or more often … in coastal areas along the East Coast and Gulf of Mexico.” NOAA recommended that coastal cites need guidance about flooding to inform preparedness and resource budgeting. Flooding affects low-lying areas and puts at risk exposed assets or infrastructure such as roads, harbors, beaches, public storm-, waste- and fresh-water systems and private and commercial properties. The report discusses how more and more cities are becoming increasingly exposed and more vulnerable to high tide flooding, which is rapidly increasing in frequency, depth and extent along many U.S. coastlines. Dramatic coastal flooding events have already become common events in the Mid-Atlantic States, the Carolinas, Florida and the Northeast.
The Antarctic study is the second in a series of assessments planned by a team of international scientists working with NASA. This study is unique in that the research team looked at ice loss in 24 different ways using 10 to 15 satellites, as well as ground and air measurements and computer simulations. The data generated by multiple measuring techniques were evaluated and the differences reconciled until the group came to agreement on the estimates.
While the Washington Post commented that the study “produced findings that even the most circumspect critics of climate science should not be able to ignore,” many climate deniers will still choose to ignore this report. There is consistently new and overwhelming evidence that climate change is impacting many lives and economies. It’s good that many cities and states can see the handwriting on the wall along with the water line left by the receding flood water and are taking action.