New York City’s public schools over two years will lose $724 million in state aid and as many as 2,500 teachers through attrition, because of a labor union conflict over a teacher evaluation system, Mayor Michael Bloomberg said on Monday, Reuters reports. The schools lost $250 million of that total earlier this month after the city and United Federation of Teachers failed to agree on a way to evaluate teacher performance. City schools would lose that same baseline funding amount in the state’s coming fiscal year, which begins April 1, plus another $224 million under the state budget proposed by New York Governor Andrew Cuomo last week, Bloomberg said at a joint legislative hearing. State legislators passed a law in 2010 that tied state aid to teacher evaluations. About 99 percent of the state’s school districts have implemented some kind of evaluation plan, Cuomo has said…