Arab leaders should take urgent action to address water shortages, air and marine pollution, and other environmental problems, a new report warns. Released at a conference of the Arab Forum for Environment and Development in Bahrain, the report is a first-ever look at the region’s eco-challenges by independent experts. It estimates the cost of environmental degradation — caused by population growth, urbanization, and climate change — at 5 percent of the region’s GDP. (One striking example: Illness caused by transportation-related air pollution alone costs more than $5 billion a year.) Yet government spending to tackle those problems falls well below 1 percent. While the region is responsible for only about 5 percent of global climate change, its greenhouse gas emissions are rising rapidly, and the area is experiencing severe water shortages, increasing drought, and rising seas that threaten loss of agricultural land. Other root causes of the region’s ecological crisis include wars, weak environmental-protection laws, and lack of scientific research, according to the study, which was reported in the Daily Star of Lebanon.