Archive for the 'Coastal risks' Category

NASA: sea level rising faster than the UN predicted

Recently published research indicates that sea level rise is a bigger threat to us and our coastal regions than previously thought. The latest predictions were made public by a team of Nasa-related scientists in August 2015. This is a summary of the most recent views:

  • The global estimate before the new figures was that of experts associated with the UN. In 2013 a UN panel predicted that sea levels would rise from between 0.3 and 0.9 metres by the year 2100. The latest Nasa research indicates that the lower figures are likely to be unrealistic and the higher estimates for the year 2100 are the correct ones.
  • According to a comment made to CNN by Steven Nerem, a researcher based at the University of Colorado, the planet is “locked into at least 3 feet (nearly 1 metre) of sea level rise, and probably more”.
  • The changes differ from region to region. Based on satellite data, in some areas like the US west coast, sea levels have not been rising but actually falling in recent years. Natural cycles and ocean currents are likely to be behind the phenomenon in these areas of the Pacific. Nevertheless, a substantial sea level rise may take place on the US west coast in the coming 20 years.
Ice and glaciers in Greenland. In case all the ice here melts, we will have big problems in our coastal areas. Photographer and copyright (c) 2015 Erkki Siirila.

Ice and glaciers in Greenland. In case all the ice here melts, we will have big problems in our coastal areas. Photographer and copyright (c) 2015 Erkki Siirila.

  • On a global scale, low-lying regions (such as Kiribati, Bangladesh, the Maldives and Florida in the US) are the most vulnerable land areas.
  • The rule of thumb is that for every centimetre of sea level rise, the sea moves 50-100 centimetres inland (source NASA).
  • The most difficult question in forecasting is determining at what rate the polar ice sheets will melt when temperatures on the planet go up.
  • Approximately one-third of the sea level rise is due to the thinning and loss of the Greenland and Antarctic ice sheets, another third is caused by the expansion of ocean water, and the remaining third is a consequence of the melting of mountain glaciers.
  • The latest data, gathered by satellites, reveal that sea levels have risen nearly 7.5 centimetres since 1992.

Seas, coasts and climate change negotiations

In 2015 the countries of the world will hopefully agree on a binding climate treaty in Paris. The outcome should stop climate change, which is currently threatening the wellbeing of the inhabitants of this planet.

What are the threats facing the coastal area and the marine systems? The answer to this question was presented in the Summary for policymakers of the Intergovernmental Panel on Climate Change (IPCC) in 2014.

Coastal systems and low-lying areas

Due to sea level rise projected throughout the 21st century and beyond, coastal systems and low-lying areas will increasingly experience adverse impacts such as submergence, coastal flooding, and coastal erosion (very high confidence).

The population and assets projected to be exposed to coastal risks as well as human pressures on coastal ecosystems will increase significantly in the coming decades due to population growth, economic development, and urbanization (high confidence).

The relative costs of coastal adaptation vary strongly among and within regions and countries for the 21st century. Some low-lying developing countries and small island states are expected to face very high impacts that, in some cases, could have associated damage and adaptation costs of several percentage points of GDP.

Healthy mangroves and sea grass beds will be needed for coastal protection in Utila, Honduras also in the future. Photo copyright (c) 2015 Erkki Siirila.

Healthy mangroves and sea grass beds will be needed for well-functioning coastal ecology and storm protection in Utila, Honduras, also in the future. Photo copyright (c) 2015 Erkki Siirila.

Marine systems

Due to projected climate change by the mid 21st century and beyond, global marine-species redistribution and marine-biodiversity reduction in sensitive regions will challenge the sustained provision of fisheries productivity and other ecosystem services (high confidence).

Spatial shifts of marine species due to projected warming will cause high-latitude invasions and high local-extinction rates in the tropics and semi-enclosed seas (medium confidence).

Species richness and fisheries catch potential are projected to increase, on average, at mid and high latitudes (high confidence) and decrease at tropical latitudes (medium confidence).

The progressive expansion of oxygen minimum zones and anoxic “dead zones” is projected to further constrain fish habitat.

Open-ocean net primary production is projected to redistribute and, by 2100, fall globally under all scenarios.

Climate change adds to the threats of over-fishing and other nonclimatic stressors, thus complicating marine management regimes (high confidence).

For medium- to high-emission scenarios, ocean acidification poses substantial risks to marine ecosystems, especially polar ecosystems and coral reefs, associated with impacts on the physiology, behavior, and population dynamics of individual species from phytoplankton to animals (medium to high confidence).

Ocean acidification poses substantial risks to the health of reef-building corals. Photo from Utila, Honduras. Copyright (c) 2015 Erkki Siirila.

Ocean acidification poses substantial risks to the health of reef-building corals. Photo from Utila, Honduras. Copyright (c) 2015 Erkki Siirila.

Highly calcified mollusks, echinoderms, and reef-building corals are more sensitive than crustaceans (high confidence) and fishes (low confidence), with potentially detrimental consequences for fisheries and livelihoods.

Ocean acidification acts together with other global changes (e.g., warming, decreasing oxygen levels) and with local changes (e.g., pollution, eutrophication) (high confidence). Simultaneous drivers, such as warming and ocean acidification, can lead to interactive, complex, and amplified impacts for species and ecosystems.

Source: IPCC, 2014: Summary for policymakers. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L. White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1-32.

Coastal zone of Chile: ten management recommendations

Chile is a country with thousands of kilometres of coastline (the exact length of the coast depends on the definition applied). Naturally, moving towards integrated coastal zone management benefits a country like that.

The Coastal Challenges editor did a consultancy in the Fourth Region (Coquimbo Region) of Chile a few years ago. One of the results was a set of general guidelines for integrated coastal management in that region. In the ten conclusions/recommendations the local experiences were combined with the lessons learned in coastal management internationally.

A powerful tsunami in 2010 made Chileans aware of the need for sound coastal management. This Chilean government fax indicating there was a tsunami risk was not enough to result in massive coastal evacuations. As a result, lots of human lives were lost.

The conclusions and recommendations for integrated management of the Coquimbo coastal area are listed below:

  1. Integrated management of the coastal zone is a learning process with incremental implementation, feedback and adjustment mechanisms.
  2. At all levels of action, it is important to build the integrated management on a sustainable  financial and economic base, for example through self-funding.
  3. It is important to incorporate in the process the opinions of all the involved and interested parties, for example by applying conflict resolution mechanisms.
  4. It is essential that the actions keep focus on just a few issues which are understood by all the participants in the process. The focus on the issues means that an exact definition of the coastal zone is not a precondition for the action to begin.
  5. In general, construction on the local institutional roots is the safest option. E.g. the existing management systems, which are politically supported, can be modified instead of building totally new management institutions. Also in this case, the application of innovative ideas for real integration is important.
  6. A long-term vision is essential, and as part of this, opportunities should be left open for the future generations.
  7. The management should be based on good knowledge of the laws of nature. Implementation would need to be proactive instead of retroactive.
  8. It is important that the decision-making system is just and efficient.
  9. It is essential to understand that combining sustainable management with the poverty of resource users is difficult. Because of this, development of economic alternatives for the least favoured groups is needed.
  10. In sustainable coastal zone management, integration mechanisms are only one element. Specific action is needed also in the management of key species and habitats, pollution control, land use planning and environmental impact assessment. In addition to integration, sectoral activities in these and other action fields need to continue. (Naturally, sector-specific work needs to go on, but the sectoral actions should no more be implemented in isolation from other coastal zone activities.)

How to be prepared for tsunamis?

The powerful earthquake in Japan and the following tsunami in March 2011 remind us of the need to be prepared for tsunamis.  These are the instructions for individual citizens by the American Red Cross in an edited and summarized form:

How to be prepared?

  • Find out if you live or work in an area, which could be affected by a tsunami. Know the elevation of the area. Evacuation orders are often based on these numbers.
  • Plan evacuation routes. Areas 30 meters above sea level or 3 kilometers inland are often recommended.
  • Remember that school evacuation plan may require you to pick your children up. Know the plan.
  • Practice your evacuation plan.
  • When you travel, know the local tsunami evacuation protocols. Remember that the third or higher floors in reinforced concrete hotel structures may offer safety.

Preparedness for tsunamis is an important part of costal zone management programs. Set-back areas, land use planning, construction standards and contingency planning are some of the necessary elements. Photo copyright (c) 2011 Erkki Siirila.

What to do during a potential tsunami situation?

  • Get prepared, if you are in the coastal zone and there is an earthquake which lasts 20 seconds or longer.
  • During an earthquake you should first protect yourself: drop, cover and hold on.
  • When there is no more shaking, you and the people around you should quickly move  to higher ground away from the coast. A tsunami could hit you within minutes.
  • Remember that downed power lines and damaged bridges and buildings could be dangerous. Aftershocks increase the risk.

What to do during a tsunami watch?

  • Follow radio or television stations for emergency information.
  • Locate your family members. Review evacuation plans together. Get prepared for evacuation in case of a tsunami warning.

What to do during a tsunami warning?

  • After hearing an official tsunami warning or detecting signs of a tsunami, evacuate immediately.
  • Do not forget to take your emergency preparedness kit with you.
  • If it is not safe for you, it’s not safe for your pets. Take them with you.
  • To protect yourself from the tsunami, get to a location which is high enough or far away from the coast.
  • Watching a tsunami could put your life at risk.

What to do after a tsunami?

  • Follow radio or television stations for updated information.
  • Tsunami waves may continue attacking the coast for hours. It is safe to return home only after local officials tell you it is safe.
  • Get first aid as needed before helping others.
  • When you see complex emergency situations, call professionals with the right equipment to help. Trying to rescue others without appropriate equipment and knowledge is dangerous.
  • Offer help to people who require special assistance (e.g. children, elderly people and persons with disabilities).
  • Remember that your presence in disaster areas might interfere with emergency response operations and put you at further risk.
  • Avoid using the telephone when not necessary. Use it only for emergency calls.
  • Remember that in buildings tsunami water can cause floors to crack and walls to collapse. Be careful when re-entering buildings.
  • When cleaning up, be cautious and wear protective clothing.
  • Keep an eye on pets and domestic animals.

Mangroves and environmental impacts

Like the previous Coastal Challenges’ article, this summary of mangroves and environmental impacts is based on How to assess environmental impacts on tropical islands and coastal areas: South Pacific Regional Environment Programme (SPREP) training manual. The manual was edited by Richard A. Carpenter and James E. Maragos.  This handbook was prepared by Environment and Policy Institute, East-West Center, in 1989, and sponsored by Asian Development Bank.

The Carpenter and Maragos manual presents useful tips and background material for the management of mangrove communities in the tropics.  (The three most important marine ecosystems in the tropical coastal zones are the coral reefs, mangroves and seagrass beds.) The information on mangroves is summarised in a slightly edited form below: 

Sustainable uses and values of mangroves: Mangroves maintain nearshore fisheries and are an important area for fish & shellfish production in the sea. Mangrove communities also protect the coast from storms; especially low-lying areas benefit.  By trapping of nutrients and sediments from drainage, mangroves protect coral reefs, sea grass meadows and coastal waters in general. In addition, wood and other forest products are obtained from mangrove areas.

Sensitivity to environmental changes: Changes in tidal flushing patterns damage mangroves.  Oil spills can be extremely harmful to mangrove communities.  Mangroves are also sensitive to salinity changes.  Furthermore, excessive harvesting can weaken the natural production and regeneration capacity of the mangrove ecosystem.

Development hazards: Environmental impacts which change the topography and water flow in the mangrove areas can be considered development hazards (for example damming, dredging, bulk-heading and impoundment). Activities which result in excessive sediment production may also damage the mangroves. Freshwater discharges, freshwater diversions and groundwater pumping are other examples of possible development-related threats. Naturally, clear-cutting, deforestation and land reclamation may seriously damage or destroy a mangrove area.

Mitigation: Natural characteristics of water movement need to be maintained. Harvesting limits need to be set and enforced. Buffer zones are a useful tool in mangrove management.

Mangrove management is an important component of coastal zone management when we get prepared for global climate change and sea-level rise. Youtube provides access to a Wetlands International video highlighting these issues. The link to the video is here:

The worst oil spills are unpleasant memories

Oil is one of the most significant driving forces behind the modern society. Nevertheless, all the consequences of oil exploration cannot be defined as progress.  In addition to global climate change, oil disasters have adverse effects on our well-being.
Here is a list of the worst oil accidents in history (list updated on September 1, 2010):
  • Torrey Canyon (oil tanker), Europe/Atlantic, March 1967: 100,000-119,000 tons
  • Amoco Cadiz (oil tanker), Europe/Atlantic, March 1978: 223,000 tons
  • Ixtoc I (drilling platform), Gulf of Mexico, June 1979 to March 1980: 454,000 tons
  • Atlantic Empress (oil tanker), Caribbean, July 1979: 287,000 tons
  • Nowruz (drilling platform), Persian Gulf, February 1983: 260,000 tons
  • Castillo de Belver (oil tanker), Southern Africa/Atlantic, August 1983: 252,000 tons
  • Odyssey (oil tanker), North America/Atlantic, November 1988: 132,000 tons
  • Exxon Valdez (oil tanker), North America/Pacific, March 1989: 35,000-40,000 tons
  • The Gulf War (intentional spills from several sources, altogether the worst oil spill in history), Persian Gulf, January 1991: 1,000,000-1,500,000 tons
  • Haven (oil tanker), Mediterranean, April 1991: 144,000 tons
  • ABT Summer (oil tanker), Southern Africa/Atlantic, May 1991: 260,000 tons
  • Deepwater Horizon (drilling platform of British Petroleum), Gulf of Mexico, April 2010 – July 2010:  671,200 tons = 4,900,000 barrels. Of this total, 109,600 tons = 800,000 barrels were captured on-site and 561,600 tons = 4,100,000 barrels leaked into the Gulf of Mexico. The Deepwater Horizon spill is surpassed only by the intentional oil spills in 1991 during the Persian Gulf War. As to accidental spills, the Deepwater Horizon disaster is the worst of them.
All figures are approximates.  There are differences between information sources:  in many cases the information obtained is not 100 percent reliable. The sources used were YLE, BBC, AFP, Reuters, MSNBC, Wikipedia, Washington Post and ITOPF.
The amounts of oil listed above were mostly spilled; in some cases, like the ABT Summer accident and the Gulf War, a significant proportion of the oil was burnt.
The following Youtube video is a short additional introduction to marine oil spills:

Tsunami hits Juan Fernández archipelago in Chile

The powerful earthquake which hit Chile on 27 February, 2010, resulted in a tsunami.  Chilean coastal towns south of the capital Santiago suffered. In several communities the devastation was nearly complete.

The tsunami resulted in serious damage and lost lives also in the Juan Fernández archipelago, the home of Robinson Crusoe.  Eyewitness reports tell the megawaves caused destruction in places located 15 metres above the high-tide level. (Commonly tsunamis behave more like sudden and extreme high tides than normal waves.)

Sad events like these emphasise the importance of sound management of the coastal zone.  Wise people are proactive, while the less wise are reactive and pay a higher price: a well known fact in coastal risk management is that prevention costs less than reparation.

The wise never forget the power of the sea. Photo (c) 2010 Erkki Siirila.

In Chile, the government is aware that earthquakes are part of life. The Chileans cannot be critised for the lack of preparedness.

In any case, the first pictures taken after the earthquake in Juan Fernández in the Pacific Ocean show the power of tsunamis.  Lessons in coastal management can be learned by looking at the photos.

Wide construction-free zones on oceanic shores are one solution. Improving the tsunami warning systems would be another. Also better construction practices, which take into consideration the forces of nature, help minimise the damage.

Most of the people who suffered from the tsunami in Chile were not warned because of misunderstandings between authorities and hesitation during the crucial moments. Radio news had even transmitted messages telling there was no tsunami risk.

It is also possible that many people did not remember the simple safety rule the Chilean authorities use when they inform of precautionary measures: If you cannot keep your balance while experiencing an earthquake on the coast, the earthquake is so strong that it can produce a tsunami.  You should immediately escape.

The link to the first Chilean tsunami images, which are from Juan Fernández, is here:

Tsunami damage in the Juan Fernández archipelago, Chile  (Sorry, the photographer has removed the pictures from Flickr. This direct link is not working any more.)