Imagine your home or your place of employment get flooded. Not only some days a year, but every day of the year. Will you sell your car and buy a boat to travel to work? What else will happen? Whole cities relocate from basement to attic, public transport regulated by maritime law, reinstallation of municipal waste water and electrical power supply. Will you adapt and pay for a living in water world? (more…)
Archive for the 'Oceans' Category
Ongoing global climate change causes changes in the species composition of marine ecosystems, especially in shallow coastal oceans. During evolution, animals have specialised on environmental conditions and are often very limited in their tolerance to environmental change.
In this context, fish species from the North Sea which experience large seasonal temperature fluctuations, are more tolerant to higher temperatures and display wider thermal windows than, for instance, fishes from polar regions living at constant low temperatures. The latter are able to grow and reproduce only within a very limited thermal tolerance window.
A new investigation, leaded by scientists of the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, reveals that a warming induced deficiency in oxygen uptake and supply to tissues is the key factor limiting the stock size of a fish species under heat stress.
The paper ‘Climate change affects marine fishes through the oxygen limitation of thermal tolerance’ is published on January 5, 2007 in the scientific journal Science.
aiw-bremerhaven.de: Press release
Camille Parmesan: Ecological and Evolutionary Responses to Recent Climate Change
Picture credit: Stephen Ausmus, ars.usda.gov
Since 1873 the temperature of the North Sea is measured, but the length of current warm period is unique. With an average of 0.13°C every year temperature rises, 1.7 degree since 1993. (more…)
Bruce Lieberman, Union Staff writer, reports about acidification of the oceans caused by human activities in the SignOnSanDiego.com science section.
Though using only 15% total capacity today most carbon dioxide has been absorbed from the upper oceans. (more…)
A huge oil slick caused by Israeli bombing has already polluted 100km of the Lebanese coast, may reach beaches in Turkey, Cyprus and Greece. Picture taken by Daily Terra, 2006-08-01.
Today latimes.com starts a five parts interactive Flash presentation about the fundamental changes of the oceans. During his 5 years exploration Kenneth R. Weiss documented the impact of human civilisation like overfishing and nutrients influx.
First part shows how in many regions the altered chemical balance leads to explosive growth of marine algae, bacteria and jellyfish and pictures low oxygen dead zones.
The series continues every day with impressive photos, videos and graphs and substantiate how the transformation of the source of all live on this planet affects us all.
Part One: A Primeval Tide of Toxins
NOAA (National Oceanic & Atmospheric Administration, US) report about changes in the chemistry of the oceans when they absorb more and more CO2. Corals and other marine organisms that produce calcium carbonate skeletal structures will suffer when the oceans become more acidic.
Oceans have already absorbed approximately 118 billion metric tons of carbon between 1800 and 1994 produced by burning oil and coal.
This is leading to the most dramatic changes in marine chemistry in at least the past 650,000 years.
[Richard Feely, oceanographer, PMEL]
High bandwidth version of the report:
Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers Report
To measure the average sea level is a challenge for scientists. The surface changes every day and second due to waves, temperature, salinity, wind and gravity forced by the moon and the sun. Regional effects like melting glaciers make it even more complicated.
In the long term current Earth’s ice shields mostly located at Greenland and Antarctica may rise sea level up to 4-6 meters when they melt which is a common discussed value. Alex Tingle’s Flood maps uses Google Maps and elevation data from NASA to simulate the changes to the land shape of continents. See the impact of 6 meters for the Netherlands, Tokio, Bangladesh or New York all places millions of people are living and working.
44 % of the world’s population live within 150 kilometres of the coast. [UNEP]. Living near water has significant advantages and more and more people are attracted. 11 of 15 mega cities (population > 10mill) will be affected by a rising sea level and changes here will trigger migration and economic issues.
NASA scientists use satellites and floats to get a clearer picture of the ocean’s behavior in different parts of the world. A sophisticated experiment measures changes in the mass of Antarctica [GRACE]. Since the launch of the twin satellites March 2002 collected data shows that Antarctica ice lost enough mass to raise global sea level by 1.5 millimeters.
Read more: Earth Observatory, ARGO, PNAS, NASA JPL, GLOSS, SEDAC, More about Flood Maps or google.
Credits background graph: Robert Simmon from Leuliette, E., Nerem, R., and Mitchum, G. (2004). Calibration of TOPEX/Poseidon and Jason altimeter data to construct a continuous record of mean sea level change. Marine Geodesy, 27(1-2), 79-94.
