Weekly Climate Science Roundup: Feb. 15 to 21

By David Kroodsma, Climate Central

A paper in Nature looked at the links between climate change and precipitation extremes. Credit: janGlas/flickr

Last week saw the publication of two high-profile studies in the journal Nature on the links between climate change and precipitation extremes. Taken together, the studies found that human-caused climate change has likely tipped the odds in favor of heavy rainfall events in parts of the Northern Hemisphere, and has increased the likelihood of at least one particular flood event that occurred in the U.K. during the fall of 2000.

Climate Central’s Alyson Kenward had a good summary of the papers, and there was some debate in the blogosphere about just how definitive these papers were.

Also published last week were articles about Arctic permafrost, tropical cyclones, extinction rates, the climatic history of the Pacific Northwest, and the poleward expansion of coral reefs.

Noteworthy climate science papers published between February 15th and 21st:

Paper Title: Anthropogenic greenhouse gas contribution to flood risk in England and Wales in autumn 2000
Journal: Nature
Authors: Pardeep Pall, Tolu Aina, Daith A. Stone, Peter A. Stott, Toru Nozawa, Arno G. J. Hilberts, Dag Lohmann, and Myles R. Allen

The Gist: In October and November of 2000, the United Kingdom experienced record flooding, and those months were the wettest ever recorded in the region. The deluge damaged nearly 10,000 homes and caused 1.3 billion £ in damage. Did global warming increase the likelihood that this flooding would occur? The abstract of this paper reads “… it is very likely that global anthropogenic greenhouse gas emissions substantially increased the risk of flood occurrence in England and Wales in autumn 2000.”

Paper Title: Human contribution to more-intense precipitation extremes
Authors: Seung-Ki Min, Xuebin Zhang, Francis W. Zwiers & Gabriele C. Hegerl
Journal: Nature

The Gist: Climate models agree that a warmer earth will have more heavy rains, largely because warmer air can hold more water vapor. Given that the planet has already warmed by about 1.5°F, we should already be seeing more heavy rains. By analyzing several decades of rainfall data for a portion of the Northern Hemisphere, the authors of this study say that (1) the frequency of heavy rainfall has increased and (2) the most plausible explanation for this fact is the increase in greenhouse gases in the atmosphere.

Paper Title: Implications of recent sea level rise science for low-elevation areas in coastal cities of the conterminous U.S..
Journal: Climatic Change
Authors: Jeremy L. WeissJonathan T. Overpeck, and Ben Strauss

The Gist: Using detailed elevation maps, these scientists estimated the area of major U.S. coastal cities at risk from a one meter rise in sea level — a likely amount of sea level rise for the 21st century. The authors found that, on average, about ten percent of major U.S. cities could be flooded. Climate Central’s Ben Strauss, a co-author of the study, summarizes the findings here.

Five percent of San Diego is below 6 m in elevation. Credit: Iring Chao/flickr

Paper Title: The Challenge of Extremes (editorial, not a paper)
Journal: Nature Geoscience
Author: Nature Geoscience Editors

The Gist: Because of the recent studies (above) attributing heavy rain to human-produced greenhouse gases, some people worry about the legal implications of climate change. If we can attribute stronger storms to pollution, does that mean we can hold polluters accountable for devastating storms? This editorial argues there is now enough evidence for lawyers to start considering the legal implications of these claims.

Paper Title: Amount and timing of permafrost carbon release in response to climate warming
Journal: Tellus
Authors: Kevin Schaefer, Tingjun Zhang, Lori Bruhwiler, and Andrew Barrett

The Gist: A vast amount of organic carbon is stored in permafrost in the northern parts of Alaska, Canada, Europe and Siberia. As the earth warms and this permafrost melts, microbes can start “digesting” this organic material, releasing carbon dioxide (CO2) and other greenhouse gases to the atmosphere. This study shows that by the year 2200, this extra CO2 could add up to about half as much (allowing for uncertainties) as we've produced through fossil-fuel burning since the dawn of the Industrial Revolution. Climate Central’s Michael Lemonick interviewed the lead author Kevin Schaefer.

Paper Title: Tropical cyclones, climate change, and scientific uncertainty: what do we know, what does it mean, and what should be done?
Journal: Climatic Change
Authors: Iris Grossmann and M. Granger Morgan

The Gist: This article summarizes what we know and what we don’t know about hurricanes and climate change: We know that hurricanes in the North Atlantic Ocean basin have become more powerful during the past few decades, but it isn’t yet clear if that increase is due to climate change. A related article in the Journal of Geophysical Research also notes that climate models don’t agree on whether tropical cyclones will increase or decrease in frequency.

Paper Title: Consequences of climate change on the tree of life in Europe
Journal: Nature
Authors: Wilfried Thuiller, Sebastien Lavergne, Cristina Roquet, Isabelle Boulangeat, Bruno Lafourcade, and Miguel. B. Araujo

The Gist: The “tree of life” in the title of this article refers to how biologists classify species. All species are related through evolution, with some more closely related than others, and one can draw a tree with branches to show how closely related each species is related. This study asks if certain branches of this tree are more vulnerable to climate change. That is, will climate change — which is expected to cause major extinctions — disproportionally prune some portions of the tree of life? These authors estimate that the answer is no: all branches will likely be equally affected by climate change.

Credit: iStockphoto

Paper Title: Rapid poleward range expansion of tropical reef corals in response to rising sea surface temperatures
Journal: Geophysical Research Letters
Authors: Hiroya Yamano, Kaoru Sugihara, and Keiichi Nomura

The Gist: As sea surface temperatures warm, tropical coral reefs should be able to survive farther away from the equator. This study is the first to show that reefs are already moving poleward because of warming temperatures. The paper, though, doesn’t speculate on whether this expansion could help offset the negative effects of global warming on reefs — most studies on climate change and coral reefs suggest a very bleak future because warmer temperatures damage reefs, and higher CO2 levels may make the oceans too acidic for their coral shells.


Paper Title: Drought variability in the Pacific Northwest from a 6,000-yr lake sediment record
Paper: Proceedings of the National Academy of Sciences (PNAS)
Authors: Daniel B. Nelson, Mark B. Abbott, Byron Steinman, Pratigya J. Polissarb, Nathan D. Stansell, Joseph D. Ortiz, Michael F. Rosenmeier, Bruce P. Finneye, and Jon Riedel

The Gist: By analyzing sediment in Washington State’s Castor Lake, these researchers estimated rainfall in the Pacific Northwest during the past 6,000 years. They found that the region naturally experiences decade-long shifts in rainfall, oscillating between relatively dry and wet periods, and they linked these natural cycles to changes in the cycle in the tropical Pacific Ocean that includes El Niño and La Niña. Future changes in rainfall due to climate change will likely depend on how this cycle changes. The authors also show that the 20th century was relatively wet when compared to the last 6,000 years.

Many more articles were published in the past week than we can report on here, ranging from a study on how climate change is affecting rodents in Yosemite National Park to the energy required to produce bottled water. If there is an important article you think we missed, or that you think we should be covering, let us know.