Climate Sensitivity in the Anthropocene

Video: Dr. Kevin Trenberth explains general climate sensitivity on Earth. Study: Climate sensitivity in the Anthropocene M. Previdi, B. G. Liepert, D. Peteet, J. Hansen, D. J. Beerling, A. J. Broccoli, S. Frolking, J. N. Galloway, M. Heimann, C. Le Quere, S. Levitus and V. Ramaswamy | Source Climate sensitivity in its most basic form is…

Anoxia and Euxinia Ocean Environmental Change

Reconstructing the history of euxinia in a coastal sea Caroline P. Slomp, 2013 DOI 10.1130/focus0420131.1 Web http://geology.gsapubs.org/content/41/4/523.full Areas of the coastal ocean where oxygen is low or absent in bottom waters, so-called dead zones, are expanding worldwide (Diaz and Rosenberg, 2008). Increased inputs of nutrients from land are enhancing algal blooms, and the sinking of this…

Our Future In a World Without Ice Caps – Peter Ward

Brown Bag Lecture Series; Center for Student Engagement & Leadership; and Arts, Culture, and Civic Engagement Apr. 11, 2013: In honor of Earth Month: Peter D. Ward, Ph.D., is a paleontologist and professor of Geological Sciences at the University of Washington. Ward specializes in the Cretaceous-Tertiary extinction event (the one that killed the dinosaurs), the…

Methane hydrate destabilization a potential scenario

Excerpts from an episode of History Channel’s “Mega Disasters” series. This explores the paper published by Northwestern University’s Gregory Ryskin. His thesis: the oceans can produce massive eruptions of explosive methane gas. Methane distribution in the water column: Once released into the water column, methane is distributed by currents and aerobic methane oxidation by bacteria…

Mass Extinctions Cause Evolutionary Bottlenecks

Science World Report, Aug 14, 2013: Extinctions are occurring at a phenomenal rate these days. As our climate changes and environments are altered, species are disappearing from our planet. Now, scientists are examining mass extinctions more closely. They’ve discovered how after these events in the past, species and ecosystems managed to recover in the aftermath. About…

Arctic Death Spiral – Evolution to July 2013

Published on YouTube Aug 12, 2013: This is a visualization of the Arctic Death Spiral showing the evolution of the volume of sea-ice over time from 1979 to July 2013. Pitch of the notes are proportional to the average sea-ice volume for each month. Spectral filters are derived from the average sea-ice volume for each…

The Late Triassic Extinction, Persistent Photic Zone Euxinia, and Rising Sea Levels

Elevated pCO2 leading to Late Triassic extinction, persistent photic zone euxinia, and rising sea levels Caroline M.B. Jaraula, Kliti Grice, Richard J. Twitchett, Michael E. Böttcher, Pierre LeMetayer, Apratim G. Dastidar and L. Felipe Opazo doi:10.1130/G34183.1 Abstract The Late Triassic mass extinction event is the most severe global warming-related crisis to have affected important extant…

Most Comprehensive Paleoclimate Reconstruction Confirms Hockey Stick

By Stefan Rahmstorf via Scilogs The past 2000 years of climate change have now been reconstructed in more detail than ever before by the PAGES 2k project. The results reveal interesting regional differences between the different continents, but also important common trends. The global average of the new reconstruction looks like a twin of the…

Does Sea Ice loss create the condition for an emerging permanent El Nino state?

Recently Doug asked: “…my question is, how far could this phenomenon go? What is the “end” state? Is it possible for example that we could find the jet stream staying in place for months at a time, years, decades? How wavy could this waviness become?” A main theme of Sea ice loss seems to be…

Secrets of Abrupt Climate Shifts revisited

The understanding of the puzzle about what is going on with our climate system and possible implications improved recently. Let’s begin with going back to 2006, here i quote an excerpt from the blog post “Revealed: Secrets of Abrupt Climate Shifts” via RealClimate, describing more robust understanding of the bipolar / see-saw mechanism of the…

Last Time Carbon Dioxide Levels Were This High: 15 Million Years Ago

By analyzing the chemistry of bubbles of ancient air trapped in Antarctic ice, scientists have been able to determine the composition of Earth’s atmosphere going back as far as 800,000 years, and they have developed a good understanding of how carbon dioxide levels have varied in the atmosphere since that time. But there has been…

Catastrophic sea levels ‘distinct possibility’ this century

A breakthrough study of fluctuations in sea levels the last time Earth was between ice ages, as it is now, shows that oceans rose some three meters in only decades due to collapsing ice sheets. The findings suggest that such an scenario — which would redraw coastlines worldwide and unleash colossal human misery — is…

Sea-ice switches and abrupt climate change

We propose that past abrupt climate changes were probably a result of rapid and extensive variations in sea-ice cover. We explain why this seems a perhaps more likely explanation than a purely thermohaline circulation mechanism. We emphasize that because of the significant influence of sea ice on the climate system, it seems that high priority…

West Antarctic rapid glacier retreat may be exceptional during the Holocene

Ice loss from the marine-based, potentially unstable West Antarctic Ice Sheet (WAIS) contributes to current sea-level rise and may raise sea level by ≤3.3 m or even ≤5 m in the future. Over the past few decades, glaciers draining the WAIS into the Amundsen Sea Embayment (ASE) have shown accelerated ice flow, rapid thinning, and…