Monday, February 21, 2011

BEIRUT: Lebanon must brace for more heavy rains and storms, coupled with long periods of drought and water shortages as the affects of global warming continue to take their toll, a Canadian climate expert has warned.

Professor John Pomeroy, the Canada research chair in water resources and climate change at Saskatchewan University, believes that the recent extreme weather could be more than just a “blip” and may well be the knock-on effects of climate change making themselves apparent decades ahead of existing forecasts.

“The intensity of rainfall is getting greater but the time between rainfalls is also getting greater,” Pomeroy, who completed a lecturing tour of the Middle East last week, told The Daily Star. “This means that ironically we will have more rain but also more droughts.

“It is terrible news for water management in Lebanon. Water, when it comes, comes too fast and causes erosion and floods,” he added.

Visiting at the request of the Water and Energy Ministry and the American University of Technology, Pomeroy has dedicated his career to studying the effects of climate change on snow and rain patterns.

“The difficulty for Lebanon is that with climate warming the snowpack is much less likely to persist and could almost entirely disappear. That means that Lebanon will have to manage its water resources completely differently,” he said.

Existing climate models predict temperatures in Lebanon rising between 4 to 5°Celsius within the century. Such an increase will almost certainly cause snowfall in mountainous areas to turn to heavy rainfall.

“This is happening faster than we predicted. We expected to see this kind of weather by mid-century, but it is happening now,” Pomeroy said.

The problem with more intense and less predictable precipitation is that it will have a devastating impact on Lebanon’s water reserves. The majority of Lebanon’s water comes from underground aquifers which are refilled annually by melting snowfall that provides a source of water in the dry summer months.

But heavy rains do not replenish the reservoirs at an equitable rate, leading to mass water shortages, far in excess of those seen last summer, Pomeroy said.

“[Lebanon is] going from a situation that is relatively fortunate to one that is going to be a huge challenge at a time when the Lebanese infrastructure for managing this water is not up to the levels it was in the 1970s,” he added. “Measures like building mountain reservoirs and damns can mitigate the worst impacts but the threat has to be taken very seriously.”

But Lebanese infrastructure has simply not been built to withstand this kind of climateological onslaught. With sea levels expected to rise by four meters, potentially within the next 100 to 200 years, much of the coastal infrastructure will be devastated.

“Having an airport on the coast is almost certainly not going to be viable in the next 50 years,” Pomeroy warned.

Lebanon faces the additional challenge of insufficient statistics, with weather monitoring in the country far below pre-Civil War levels, making it virtually impossible to gauge the true situation. This prevents the country from benefitting from climate prediction models and innovations like flood forecasting or drought monitoring systems that can warn of upcoming disaster months in advance.

“We have to start by getting the measurements right and getting the figures in order to tell how the future climate will affect water resources and then look at different scenarios for managing it,” Pomeroy said.

“We know it is getting more severe but we cannot reliably say how much more severe it is getting because we just don’t know how bad it is.”

http://www.dailystar.com.lb/article.asp?edition_id=1&categ_id=1&article_id=125103#axzz1Eb8dDrHU