Climate change in the coming century poses both risks and opportunities for Britain, a first comprehensive government assessment says. The Department for Environment, Food and Rural Affairs released its Climate Change Risk Assessment as part of the government\'s strategy for dealing with global warming, the BBC reported Thursday. While the report warns flooding, heat waves and water shortages could become likely, it also points to possible benefits including new shipping lanes through the arctic, fewer cold-related deaths in winter and higher crop yields. Computer modeling of multiple future climate scenarios was employed in creating the assessment. Considerable uncertainties mean there is a wide range of possible results, the report authors caution. \"We do not know how fast greenhouse gas emissions will rise, how great the cooling effects are of other atmospheric pollutants or how quickly the ice caps may melt,\" the report says. Responding to questions about the reliability of the computer modeling, one researcher said, \"They\'re the best we\'ve got, they\'re all we\'ve got.\"