Amateur Climate Change

Sea Level Rise , “High Tide in the Main Street” book

Photo from Perito Moreno Glazier in Argentina

I have recently finished High tide in the Main Street book, by John Englander, both Oceanographer and great blogger. It is the perfect opportunity to talk about one of the most evident and important consequences of climate change: Sea Level Rise. In this post I am not going to review the book, the short summary is that I liked it because it is clear, short and well explained. So, highly recommended. Instead of talking about the book itself I prefer to make a short list of ideas/data about sea level rise, some are from the book but the list is like a personal compilation. So let’s go:

• Sea Level Rise is one of the most clear and stronger consequences of climate change.
• The reason for sea level rise is mostly the melting of land ice. The ice over water does not change seal level. So the places to watch are, in strict order, Antartica, Greenland and Glaziers around the world. The water thermal expansion is a small effect in comparison.
• Meters (the key factor and the most difficult):
  • The total range of melting is quite impressive. If all that ice is melted the sea level can rise mode than 60 m. In the ice ages the sea level was almost 200 m lower than today. A rule of thumb from historical records is 10 m with a temperature 2ºC more than now.
  • Greenland ice alone is 7 m of sea level rise.
  • In this moment the measurements are in order of mm or cm.
  • The projections for this century are a bit uncertain and depend on what we do but are in the range of 0.5 m to 1 m.
  • Those meters are in vertical. The translation in area lost in the cost strongly depends on the particular case, but it can be much more in flat lands.
• Time:
  • Sea level rise needs some time, the melting is not immediate but lasts for a long time and it can not be stopped.
  • There are important tipping points difficult to predict. When some parts of Greenland or Antartica start to melt they will go fast to the sea and sea level will accelerate. It is difficult to say at which temperature will occur and this adds a lot of uncertainty.
• Consequences:
  • Most problems start before too much rising: Stronger storms, coastal flooding, high tides, freshwater salinization,…
  • Economical consequences will be huge and will start in the moment we get convinced of sea level rise.
  • Many beautiful and expensive coastal areas will loose their property value.
  • The most extreme case are the islands that will become inhabitable. Some countries will disappear. How do we value them?
  • Some coastal zones will be protected with dams or other means but that is quite expensive too and the grade of protection will depend on the amount of sea level rise.
  • Only countries or regions with enough money and vision will be able to prepare protection measurements.
  • Some zones just cannot be protected due to soil structure.
  • Many specific infrastructures will have to be adapted many times
• We have developed our civilization with a stable sea level and many infrastructures like harbours are built very precisely for a sea level.
• Our civilization is concentrated in the coastal areas, for many reasons. Their change will have a deep effect.