Navigation Links
Tropical Atlantic cooling and African deforestation correlate to drought, report scientists

Against the backdrop of the Montreal Summit on global climate being held this week, an article on African droughts and monsoons, by a University of California, Santa Barbara scientist and others, which appears in the December issue of the journal Geology, underlines concern about the effects of global climate change.

Tropical ocean temperatures and land vegetation have an important effect on African monsoon systems, explains first author Syee Weldeab, a post-doctoral fellow in the Department of Earth Science at the University of California, Santa Barbara. The monsoons are critical to sustaining agriculture in equatorial Africa.

Weldeab says that man's reduction of inland vegetation cover through deforestation and overgrazing in equatorial Africa and increases in global temperatures through the emission of greenhouse gases will likely strongly affect the African monsoon system in the future.

"The weakening of the monsoon has a huge effect," says Weldeab, "resulting in shortages of harvests and hunger."

As vegetation is cleared, the land loses its capacity to retain heat and becomes cooler. As the land cools relative to the ocean, there is a larger gradient between the ocean temperature and the land causing less moisture to be pulled from the ocean air toward the land.

Weldeab and his colleagues studied cores from beneath the ocean floor of the Gulf of Guinea, in the tropical Atlantic just off the coast of Cameroon, to understand the history of climate in the area for the past 10,000 years. The cores contain foraminifera, tiny plankton shells that are composed of calcium and trace elements. By studying the ratios of magnesium and calcium in the shells, the scientists are able to correlate that information to past temperature changes in the ocean. In analyzing these records for the past 10,000 years, the scientists found three pronounced cooling periods which indicate drought.

Besides the ocean records, the scientists a nalyzed data from four lakes that are distributed across central Africa on the monsoon belt. The three sea surface cooling periods found by the scientists correlate to records of low lake levels. These clearly were times of drought; the land became more arid.

The authors state, "periods of drought likely brought about environmental hardship, triggering population migration, giving rise to changes in the modes of agricultural production, and influencing the fall or rise of civilizations."

Weldeab points out that the past 50 years are marked by deforestation and overgrazing much greater than that of the past, thus disturbing the climate system that results from the coupling of sea surface temperature and vegetation cover on land.

"We can't predict how, but it is clear that this human-induced change will change the terrestrial and ocean system," he says. He notes that droughts in this region are currently occurring more frequently than in the past few thousand years, although the frequency of the droughts is unpredictable.

"People in less developed countries live from rain, harvests and animal husbandry," says Weldeab. "Drought directly affects them; they run out of food for people and animals."


'"/>

Source:University of California - Santa Barbara


Related biology news :

1. Finding Cures For Tropical Diseases: Is Open Source An Answer?
2. Tropical Deforestation affects rainfall in the U.S. and around the globe
3. Tropical dry forests receive international recognition
4. Tropical forest CO2 emissions tied to nutrient increases
5. Tropical forests -- Earths air conditioner
6. FSU scientist warns North Atlantic right whale facing extinction
7. Ancient trans-Atlantic swarm brought locusts to the New World
8. Microbes hitchhike across Atlantic on desert dust
9. How satellite tracking revealed the migratory mysteries of endangered Atlantic loggerhead turtles
10. Brazil creates buffer zone around coral reefs off Atlantic coast
11. A dichotomy in migration patterns found for sea turtles in east Atlantic
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/22/2016)... ANGELES , June 22, 2016 /PRNewswire/ ... identity management and verification solutions, has partnered ... edge software solutions for Visitor Management, Self-Service ... provides products that add functional enhancements ... partnership provides corporations and venues with an ...
(Date:6/15/2016)... New York , June 15, 2016 /PRNewswire/ ... a new market report titled "Gesture Recognition Market by ... and Forecast, 2016 - 2024". According to the report, ... USD 11.60 billion in 2015 and is estimated ... reach USD 48.56 billion by 2024.  ...
(Date:6/2/2016)... LONDON , June 2, 2016 ... has awarded the 44 million US Dollar project, ... Security Embossed Vehicle Plates including Personalization, Enrolment, and IT Infrastructure ... world leader in the production and implementation of Identity Management ... in January, however Decatur was selected ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the ... at the Arkansas State Crime Laboratory, has joined STACS DNA as a Field Application ... team,” said Jocelyn Tremblay, President and COO of STACS DNA. “In further expanding our ...
(Date:6/23/2016)... June 23, 2016 Apellis Pharmaceuticals, Inc. ... clinical trials of its complement C3 inhibitor, APL-2. ... multiple ascending dose studies designed to assess the ... subcutaneous injection in healthy adult volunteers. ... as a single dose (ranging from 45 to ...
(Date:6/23/2016)... 2016 Andrew D ... http://doi.org/10.17925/OHR.2016.12.01.22 Published recently in ... from touchONCOLOGY, Andrew D Zelenetz , discusses ... care is placing an increasing burden on healthcare ... therapies. With the patents on many biologics expiring, ...
(Date:6/23/2016)... ... June 23, 2016 , ... ClinCapture, the only free validated ... will showcase its product’s latest features from June 26 to June 30, 2016 ... on Disrupting Clinical Trials in The Cloud during the conference. DIA (Drug ...
Breaking Biology Technology: