Times: Growth rates among corals on the Great Barrier Reef have slumped to their slowest in at least four centuries and growth is expected to cease within 26 years. The process of calcification, which gives the reefs their structure and strength, has slowed by 14.2 per cent in less than 20 years, researchers in Australia have discovered. The slowdown is so abrupt that they fear the natural process of reef-building will stop by 2050 and perhaps as early as 2035, when the Great Barrier …