Pollution linked to 1.2m famine victims

A STUDY says pollution from industrial nations was one of the possible causes of a devastating African famine that left 1.2 million people dead.

The starvation brought on by the 1970-85 drought stretched from Senegal to Ethiopia until rains finally returned.

A group of scientists in Australia and Canada says the drought may have been triggered by tiny particles of sulphur dioxide from factories and power plants thousands of miles away in North America, Europe and Asia.

Researchers said the short-lived pollution particles, called aerosols, were able to alter the physics of cloud formation miles away and reduce rainfall in Africa by as much as half. They used a computer to simulate the conditions.

Some scientists suspect the process, teleconnection, might help explain the drought gripping parts of the US.

But scientists stopped short of blaming industry’s effluent solely for the famine and starvation that wracked the region of Africa called the Sahel.

“The Sahelian drought may be due to a combination of natural variability and atmospheric aerosols,” said atmospheric scientist Leon Rotstayn, of the Commonwealth Scientific and Industrial Research Organization, a government research agency in Australia. The CSIRO study will be published in the August Journal of Climate.

The disastrous lack of rainfall over the Sahel has been blamed on everything from overgrazing to El Nino.

One interesting clue: In the 1990s, rain returned to the Sahel. During the same period, emissions laws in the industrialized West reduced aerosol pollution. A coincidence? Scientists do not think so.

“Cleaner air in the future will mean greater rainfall in the region,” Mr Rotstayn said.

Some researchers say the CSIRO study is intriguing, but that the computer simulation is too simple to solve the mystery by itself.

The sulfur dioxide pollution particles, which can remain in the air from five to 20 days, probably drifted over the North Atlantic where they created more condensation nuclei for cloud formation, the scientists theorize.

The additional nuclei remained suspended in clouds rather than forming fewer, larger droplets and falling as rain.

These clouds were brighter than normal, in part because of the added nuclei, and they reflected more of the Sun’s energy into space.

This cooled the surface of the North Atlantic, which reduced the normal evaporation rate from the ocean and further hampered the moisture cycle.

South of the Sahel, the sea surface remained warm and evaporation increased so more rain fell to the south.