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The glaciers in the tropical Andes shrunk between 30 and 50% in 30 years, which represents the highest rate observed over the last three centuries. IRD researchers and their partners( 1) recently published a summary which chronicles the history of these glaciers since their maximum extension, reached between 1650 and 1730 of our era, in the middle of the Little Ice Age*. The faster melting is due to the rapid climate change which has occurred in the tropics since the 1950s, and in particular since the end of the 1970s, leading to an average temperature rise of 0.7°C in this part of the Andes. At the current pace of their retreat, small glaciers could disappear within the next 10 to 15 years, affecting water supply for the populations.
In February 2010, a violent earthquake struck Chile, causing a tsunami 10 m in height. Affecting millions of people, the earthquake and giant wave also transformed the appearance of the coastline: the dunes and sandbars were flattened, and the coast subsided in places by up to 1 m. But although the inhabitants are still affected for the long term, the shore system quickly rebuilt itself. A team from IRD and its Chilean partners( 1) showed that in less than a year, the sedimentary structures had reformed. The Chilean coast therefore represented a unique “natural laboratory” for studying coastal formation processes. The subsidence of the coast also revealed the effects of rising sea levels on shores.
The mangroves of Guyana, in South America, are gradually disappearing. Contrary to the coastline of its near neighbour, French Guiana, which is still relatively protected, that of Guyana has been largely developed. In order to develop agriculture and aquaculture, earth dikes were built, destroying the greater part of the mangrove forest.
A study( 1) conducted by IRD researchers and the University of Aix-Marseille shows that the reduced protection provided by mangroves against the swell will lead to the large-scale erosion of 370 km of the country's coastline. Only one ecosystem restoration programme will help contain this phenomenon.
El Niño is changing. This climatic troublemaker is increasingly appearing in a form known as Modoki, Japanese for 'similar but different'. The heart of the phenomenon is moved from the eastern tropical Pacific towards the centre of the Pacific basin. New research conducted by the IRD and its partners from the Legos( 1) laboratory details the biological aspects of Modoki in the equatorial zone. Such events reduce the levels of phytoplankton in the central Pacific area: Satellite images analysed between 1997 and 2010 show the ocean to be less green during the events of 2002-2007 and 2009-2010. This colouring demonstrates reduced levels of surface marine algae, synonymous with a low level of biological activity.
Another study conducted with Peruvian( 2) researchers and those from the Locean( 3) laboratory has revealed that Modoki, inversely to its larger cousin, might be responsible for upwelling( 4) the length of the South-American coastline. A high resolution oceanic model, linked to satellite and historic data from Imarpe( 5), indicates that recent episodes have seen an increase in this rising cold water, rich in nutrients. The predicted increase in frequency of Modoki( 6) events could thus influence fishing in the zone.
Who are the Latino-American migrants? What do they do in their host country? The new MICAL observatory( 1), led by IRD researchers, enables the day-to-day study of the movements of this diaspora across the world. Thanks to this data, sociologists are able to describe the massive exile of ‘brains’ that took place in the first half of the 2000s in Latin America. Between 2000 and 2006, the number of expatriate graduates doubled, and today has reached over 3 million. It’s a loss that may be damaging in the country of origin, but can also represent a generalised loss of knowledge: these exiles very often end up under-employed. The percentage of engineers, researchers and other high grades working at an under-qualified level has greatly increased as a result. This was the case in 2006, for example, for three quarters of Bolivian and Ecuadorian migrants
Today the crisis that is currently affecting Spain is modifying or even inverting the migratory trends. A return to the new Latin-American eldorados is increasingly being observed. The consequences of this on the graduates' situation should be monitored closely.