Word: carbonization
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Without oxygen to aerate tissues and make vital structural components like collagen, notes Knoll, animals simply cannot grow large. But for most of earth's history, the production of oxygen through photosynthesis - the metabolic alchemy that allowed primordial algae to turn carbon dioxide, water and sunlight into energy - was almost perfectly balanced by oxygen-depleting processes, especially organic decay. Indeed, the vast populations of algae that smothered the Precambrian oceans generated tons of vegetative debris, and as bacteria decomposed this slimy detritus, they performed photosynthesis in reverse, consuming oxygen and releasing carbon dioxide, the greenhouse gas that traps heat...
...oxygen to rise, then, the planet's burden of decaying organic matter had to decline. And around 600 million years ago, that appears to be what happened. The change is reflected in the chemical composition of rocks like limestone, which incorporate two isotopes of carbon in proportion to their abundance in seawater - carbon 12, which is preferentially taken up by algae during photosynthesis, and carbon 13, its slightly heavier cousin. By sampling ancient limestones, Knoll and his colleagues have determined that the ratio of carbon 12 to carbon 13 remained stable for most of the Proterozoic Eon, a boggling expanse...
...COUNTY'S CARVER SOUNDS LIKE A carbon copy of a contemporary fixture: the blowhard with the warmest stool and coldest coffee in any cafe in the rural West. His newfound celebrity has made him untouchable, a sort of O.J. of the Purple Sage, as he and his cronies come dangerously close to joining the ranks of the cop killers. All assaults on public employees, regardless of weapon, should be vigorously prosecuted. JOHN WALKER, Coaldale, Colorado...
...Baku, capital of the former Soviet republic of Azerbaijan, a malfunctioning electrical cable ignited gases trapped in a subway tunnel, sparking an explosion that killed 288 people and injured 200 more; most of the victims died from carbon-monoxide poisoning. Officials blamed the accident on outdated Soviet equipment...
Last April brought representatives from 130 countries to Berlin for 11 days. They made exactly one decision: to spend two more years negotiating on how to meet the standards set by the 1992 Rio Earth Summit for reducing carbon-dioxide emissions into the atmosphere. In Mexico 18 different U.N. agencies are supposed to be running programs to help solve some of the country's worst problems, such as environmental pollution and drug smuggling. But Mexican officials working on the same troubles are hard put to cite anything significant that the U.N. agencies have done to help...