SYDNEY (Reuters) - Islanders on tiny Tuvalu in the South Pacific last week saw the future of global warming and rising sea levels, as extreme high tides caused waves to crash over crumbling sea-walls and flood their homes. "Our island is sinking together with our hearts," wrote Silafaga Lalua in Tuvalu News (www.tuvaluislands.com). Tuvalu is a remote island nation consisting of a fringe of atolls covering just 10 sq miles, with the highest point no more than 17 ft above sea level, but most a mere 6.5 ft. Global warming (news - web sites) from greenhouse gas pollution is regarded...