The intertropical convergence zone is what scientists call a belt near the earth's equator where the winds and currents of the northern and southern hemispheres meet. Because of its rich biodiversity of species and ecosystems, the area is a natural lab for scientists to observe firsthand the effects of climate change. The hot spot on the belt is Palmyra Atoll, a 680-acre blip about 1,000 miles south of the Hawaiian Islands that is owned by the Nature Conservancy. The atoll is home to 29 bird species and a new $1.5 million research station. The researchers who gather there, mainly from universities, are studying rising sea levels, changes in species diversity and the effects of ocean acidification on submerged reefs. The station has already produced its first research paper: a study of the atoll's biomass levels in fish that has helped redefine a healthy coral reef.