Study of 11,300 years of weather suggests record warming ahead [View all]

[n2doc]

By Monte Morin, Los Angeles Times
March 7, 2013, 2:01 p.m.
First the good news: In the last 11,300 years, humans have endured a planet warmer than today's, even as they set about building their earliest civilizations.

Now the bad news: That will no longer be true 87 years from now, according to scientists who have conducted a comprehensive analysis of the planet's climate history since the world's ice sheets began their most recent retreat from North America and Europe.

New research into the Earth's ancient climate is providing a clearer, more detailed view of how the planet's average surface temperature fluctuated over the period known as the Holocene epoch, which continues through to the present day. It's the time in which humans truly began making their mark on the planet, abandoning their hunting and gathering traditions and adopting a settled, agricultural lifestyle.

In a study being published in Friday's edition of the journal Science, researchers used eight indirect temperature indicators — such as pollen and shells from marine organisms — to chart long-term global warming and cooling trends. The research team concluded that temperatures in the last decade have not exceeded the Holocene's steamiest periods from thousands of years ago. However, if current warming trends hold, those records will be broken by the end of the century.

"By the year 2100, we will be beyond anything human society has ever experienced," said study leader Shaun Marcott, a post-doctoral researcher at Oregon State University's College of Earth, Ocean and Atmospheric Sciences.

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http://www.latimes.com/news/science/la-sci-climate-warming-20130308,0,1220004.story