London CNN  —  At the start of the year, economists and corporate leaders expressed optimism that global economic growth might not slow down as much as they had feared. Positive developments included China’s reopening, signs of resilience in Europe and falling energy prices. But a crisis in the banking sector that emerged last month has changed the calculus. The International Monetary Fund downgraded its forecasts for the global economy Tuesday, noting “the recent increase in financial market volatility.” The IMF now expects economic growth to slow from 3.4{9f99fe44fce1aa3c813d0a0ce4da2fbea8a5a58e9d85c4a2927dd8140cb676b5} in 2022 to 2.8{9f99fe44fce1aa3c813d0a0ce4da2fbea8a5a58e9d85c4a2927dd8140cb676b5} in 2023. Its estimate in January had been for 2.9{9f99fe44fce1aa3c813d0a0ce4da2fbea8a5a58e9d85c4a2927dd8140cb676b5} growth this year. “Uncertainty is high, and the…