Lake Tanganyika, the second oldest and second deepest lake in the world, is now at its warmest in 1,500 years, threatening the fishing industry on which millions of lives depend, scientists said today. The evidence comes from cores drilled into sedimentary layers in the lake bottom that point to climate changes over many centuries. Tanganyika's surface waters, at 26 degrees Celsius, are now at temperatures that are "unprecedented since AD 500," they reported in the journal Nature Geoscience. Read more