Earth’s Temperature Warmest in 400 Years
The Environment News Service has just announced Expert Panel Concludes Earth’s Temperature Warmest in 400 Years.
The Earth is hotter today than it has been in four centuries and likely warmer than it has been in the past 1,000 years, according to a review of surface temperature research released Thursday by the U.S. National Academies of Science.
The 155 page report provides additional evidence that “human activities are responsible for much of the warming,” the authors said.
The study, written by a panel of 12 climate experts, assesses the state of scientific efforts to reconstruct surface temperature records for the Earth over approximately the last 2,000 years.
The report is called Surface Temperature Reconstructions for the Last 2,000 Years.
Starting in the late 1990s, scientists began combining proxy evidence from many different locations in an effort to estimate surface temperature changes averaged over broad geographic regions during the last few hundred to few thousand years. These large-scale surface temperature reconstructions have enabled researchers to estimate past temperature variations over the Northern Hemisphere or even the entire globe, often with time resolution as fine as decades or even individual years. This research, and especially the first of these reconstructions published in 1998 and 1999 by Michael Mann, Raymond Bradley, and Malcolm Hughes, attracted considerable attention because the authors concluded that the Northern Hemisphere was warmer during the late 20th century than at any other time during the past millennium. Controversy arose because many people interpreted this result as definitive evidence of anthropogenic causes of recent climate change, while others criticized the methodologies and data that were used.
In response to a request from Congress, this committee was assembled by the National Research Council to describe and assess the state of scientific efforts to reconstruct surface temperature records for the Earth over approximately the last 2,000 years and the implications of these efforts for our understanding of global climate change.
The report has some great charts, the key one being
Smoothed reconstructions of large-scale (Northern Hemisphere mean or global mean) surface temperature variations from six different research teams are shown along with the instrumental record of global mean surface temperature. Each curve portrays a somewhat different history of temperature variations, and is subject to a somewhat different set of uncertainties that generally increase going backward in time (as indicated by the gray shading). This set of reconstructions conveys a qualitatively consistent picture of temperature changes over the last 1,100 years, and especially the last 400.
That should put the skeptics back in their boxes for a while. Although I suspect the climate-change deniers will either ignore, or misrepresent this report too. But as more and more reports are released they all say the same basic thing. Human activity is heating the Earth with devastating consequences. Heck, I’d say ask the 9000 people who died in Paris in the 2003 heatwave if they thought climate change was real; but you can’t because they are dead. Killed by climate change. — DS
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