Everyone is familiar with the “hockey stick” chart of global warming. It’s called that because it shows relatively flat global temperatures over the past millennium followed by a sudden sharp rise over the past century.
Well, here’s the latest version, based on a reconstruction of enormous amounts of data over a much longer time frame. It very dramatically shows how different the past century is from the past 12,000 years. Over that period, global temperatures gradually rose as we exited our last ice age and then gradually started to fall about 5,000 years ago. But there’s nothing gradual about what happened next: Starting around 1900, global temperatures suddenly spiked almost straight up. The LA Times reports:
New research into 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 today.
….In a study 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….“By the year 2100, we will be beyond anything human society has ever experienced,” said study leader Shaun Marcott, a postdoctoral researcher at Oregon State University’s College of Earth, Ocean and Atmospheric Sciences.
Michael Mann, a climate researcher who has endured a blizzard of attacks from climate deniers over his original hockey stick graph, figures the team who published this work will suffer the same fate. “I am certain that professional climate-change deniers will attack the study and the authors, in an effort to discredit this important work,” he told the Times.
No doubt. Tim McDonnell has more here.