Agence France-Presse: Carbon dioxide emissions must fall sharply to avoid inflicting acid damage to the world’s marine ecosystems, more than 150 scientists warned on Friday. Acidification of ocean waters caused by greenhouse gases was already wreaking havoc on coral ecosystems and would have a huge knock-on impact on human communities, they said. “We are deeply concerned by recent, rapid changes in ocean chemistry and their potential, within decades, to severely affect marine organisms, food webs, …