here is more carbon dioxide in the atmosphere today than at any point during the last 650,000 years, says a major new study that let scientists peer back in time at "greenhouse gases" that can help fuel global warming.
By analyzing tiny air bubbles preserved in Antarctic ice for millenia, a team of European researchers highlights how people are dramatically influencing the buildup of these gases.
The remarkable research promises to spur "dramatically improved understanding" of climate change, said geosciences specialist Edward Brook of Oregon State University.
The study, by the European Project for Ice Coring in Antarctica, is published Friday in the journal Science.
Today, scientists directly measure levels of carbon dioxide and other greenhouse gases, which accumulate in the atmosphere as a result of fuel-burning and other processes. Those gases help trap solar heat, like the greenhouses for which they are named, resulting in a gradual warming of the planet, reports Seattle Post Intelligencer.
The researchers studied air bubbles preserved in ice drilled from the Antarctic ice sheet as part of the European Project for Ice Coring in Antarctica (EPICA). The ice core represents a logbook of the state of the world's climate and goes back 210,000 years further than previous records.
After searching ice spanning the period of 390,000-650,000 years before present, Stocker's team has discovered that carbon dioxide levels in the atmosphere did not exceed 290 parts per million during that time. Today, that figure is around 375 parts per million.
The situation is similar for methane: during this period, levels hovered around 600 parts per billion. Today's atmospheric methane concentration is well over 1,700, informs Nature.com. source