New study finds sea level rise accelerating

Global sea level rise has been accelerating in recent decades, rather than increasing steadily, according to a new study based on 25 years of NASA and European satellite data.

This acceleration, driven mainly by increased melting in Greenland and Antarctica, has the potential to double the total sea level rise projected by 2100 when compared to projections that assume a constant rate of sea level rise, according to lead author Steve Nerem. Nerem is a professor of Aerospace Engineering Sciences at the University of Colorado Boulder, a fellow at Colorado’s Cooperative Institute for Research in Environmental Sciences (CIRES), and a member of NASA’s Sea Level Change team.

If the rate of ocean rise continues to change at this pace, sea level will rise 26 inches (65 centimeters) by 2100 — enough to cause significant problems for coastal cities, according to the new assessment by Nerem and colleagues from NASA’s Goddard Space Flight Center in Greenbelt, Maryland; CU Boulder; the University of South Florida in Tampa; and Old Dominion University in Norfolk, Virginia. The team, driven to understand and better predict Earth’s response to a warming world, published their work Feb. 12 in the journal Proceedings of the National Academy of Sciences.

“This is almost certainly a conservative estimate,” Nerem said. “Our extrapolation assumes that sea level continues to change in the future as it has over the last 25 years. Given the large changes we are seeing in the ice sheets today, that’s not likely.”

Rising concentrations of greenhouse gases in Earth’s atmosphere increase the temperature of air and water, which causes sea level to rise in two ways. First, warmer water expands, and this “thermal expansion” of the ocean has contributed about half of the 2.8 inches (7 centimeters) of global mean sea level rise we’ve seen over the last 25 years, Nerem said. Second, melting land ice flows into the ocean, also increasing sea level across the globe.

These increases were measured using satellite altimeter measurements since 1992, including the Topex/Poseidon, Jason-1, Jason-2 and Jason-3 satellite missions, which have been jointly managed by multiple agencies, including NASA, Centre national d’etudes spatiales (CNES), European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Oceanic and Atmospheric Administration (NOAA). NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the U.S. portion of these missions for NASA’s Science Mission Directorate. The rate of sea level rise in the satellite era has risen from about 0.1 inch (2.5 millimeters) per year in the 1990s to about 0.13 inches (3.4 millimeters) per year today.

“The Topex/Poseidon/Jason altimetry missions have been essentially providing the equivalent of a global network of nearly half a million accurate tide gauges, providing sea surface height information every 10 days for over 25 years,” said Brian Beckley, of NASA Goddard, second author on the new paper and lead of a team that processes altimetry observations into a global sea level data record. “As this climate data record approaches three decades, the fingerprints of Greenland and Antarctic land-based ice loss are now being revealed in the global and regional mean sea level estimates.”

Even with a 25-year data record, detecting acceleration is challenging. Episodes like volcanic eruptions can create variability: the eruption of Mount Pinatubo in 1991 decreased global mean sea level just before the Topex/Poseidon satellite launch, for example. In addition, global sea level can fluctuate due to climate patterns such as El Niños and La Niñas (the opposing phases of the El Niño-Southern Oscillation), which influence ocean temperature and global precipitation patterns.

Nerem and his team used climate models to account for the volcanic effects and other datasets to determine the El Niño/La Niña effects, ultimately uncovering the underlying rate and acceleration of sea level rise over the last quarter century.

The team also used tide gauge data to assess potential errors in the altimeter estimate.

“The tide gauge measurements are essential for determining the uncertainty in the global mean sea level acceleration estimate,” said co-author Gary Mitchum, University of South Florida College of Marine Science. “They provide the only assessments of the satellite instruments from the ground.” Others have used tide gauge data to measure sea level acceleration, but scientists have struggled to pull out other important details from tide-gauge data, such as changes in the last couple of decades due to more active ice sheet melt.

In addition to NASA’s involvement in missions that make direct sea level observations from space, the agency’s Earth science work includes a wide-ranging portfolio of missions, field campaigns and research that contributes to improved understanding of how global sea level is changing. Airborne campaigns such as Operation IceBridge and Oceans Melting Greenland gather measurements of ice sheets and glaciers, while computer modeling research improves our understanding of how Antarctica and Greenland will respond in a warming climate.

In 2018, NASA will launch two new satellite missions that will be critical to improving future sea level projections: the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission, a partnership with GeoForschungsZentrum (GFZ) in Germany, will continue measurements of the mass of the Greenland and Antarctic ice sheets; while the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) will make highly accurate observations of the elevation of ice sheets and glaciers.

Mekong Delta provinces fail to meet Paris agreement.

The Mekong Delta province of An Giang is being helped to produce a detailed and workable draft plan to implement the Paris Agreement on Climate Change. Vũ Minh Hải, chairwoman of the Climate Change Working Group, said this yesterday at a workshop in the province organised by Oxfam Việt Nam and the provincial People’s Committee. Hải said the draft plan seemed to lack detailed targets, such as how many tonnes of carbon dioxide (CO2) the province could cut down by 2030. It also failed to engage local farmers, especially vulnerable groups, who suffered the most from climate change, she said.

Continue reading “Mekong Delta provinces fail to meet Paris agreement.”

Communications strategy launched for Mekong Delta Plan

The Ministry of Natural Resources and Environment (MoNRE) in collaboration with IUCN Vietnam and Can Tho University launched a project entitled “Development and Implementation of a Communication and Information Dissemination Strategy for the Principles and Recommendations in the Mekong Delta Plan” in the Delta’s Can Tho city on November 15.

The project is part of the Strategic Partnership Arrangement on Climate Change Adaptation and Water Management between the Governments of Vietnam and the Netherlands, with financial support from the Netherlands Enterprise Agency (RVO).

The main objective of the launch is to introduce the project and a comprehensive communications strategy to disseminate the principles of the Mekong Delta Plan (MDP) to the 13 cities and provinces in the Delta. With the message “The future of the Delta is in our hands”, the communications strategy aims to provide guidance on the implementation of communications campaigns, including a training of trainers (ToT) program and training workshops involving the 13 cities and provinces.

The Mekong Delta has played an important role in Vietnam’s economic development over the last few decades but the impact of climate change, poor development, and the over-exploitation of natural resources are now seriously threatening its future.

The government and the international community have been developing various strategies and programs to adapt to and mitigate the impact of climate change, of which the MDP has been a key initiative. Written in 2013 within the framework agreement between the Governments of Vietnam and the Netherlands, it has become a key reference document and source of guidance for the Vietnamese Government. The Plan recommends principles for sustainable development, taking into account both economic prospects and environmental considerations, including climate change.

The MDP has been endorsed by high-level leaders of the government, donors, and implementing partners. There is limited exposure and understanding, however, of the principles and recommendations of the MDP at the lower levels of government and in the community. The understanding as well as endorsement of these principles will leverage the effect of the MDP on the development of the Mekong Delta. It is therefore critical to enhance awareness among grassroots levels, which are identified as civil servants at the provincial and district levels and farmers.

The project is being led by MoNRE and has been endorsed by the Ministry of Agriculture and Rural Development and the Ministry of Planning and Investment. Implementing partners are made up of a consortium that includes UNESCO-IHE (Lead), Can Tho University, IUCN Vietnam, Water.NL, Fresh Studio, the Vietnam Farmers’ Union, Royal Haskoning DHV, Wageningen University and KnowH2O.

Source: Vietnam Economic Times