Temporal Scaling of Carbon Emission and Accumulation Rates: Modern Anthropogenic Emissions Compared to Estimates of PETM Onset Accumulation

The Paleocene‐Eocene thermal maximum (PETM) was caused by a massive release of carbon to the atmosphere. This is a benchmark global greenhouse warming event that raised temperatures to their warmest since extinction of the dinosaurs. Rates of carbon emission today can be compared to those during onset of the PETM in two ways: (1) projection of long‐term PETM rates for comparison on an annual time scale and (2) projection of short‐term modern rates for comparison on a PETM time scale. Both require temporal scaling and extrapolation for comparison on the same time scale. PETM rates are few and projection to a short time scale is poorly constrained. Modern rates are many, and projection to a longer PETM time scale is tightly constrained—modern rates are some 9–10 times higher than those during onset of the PETM. If the present trend of anthropogenic emissions continues, we can expect to reach a PETM‐scale accumulation of atmospheric carbon in as few as 140 to 259 years (about 5 to 10 human generations).Plain Language SummaryThe Paleocene‐Eocene thermal maximum (PETM) is a global greenhouse warming event that happened 56 million years ago, causing extinction in the world’s oceans and accelerated evolution on the continents. It was caused by release of carbon dioxide and other greenhouse gases to the atmosphere. When we compare the rate of release of greenhouse gases today to the rate of accumulation during the PETM, we must compare the rates on a common time scale. Projection of modern rates to a PETM time scale is tightly constrained and shows that we are now emitting carbon some 9–10 times faster than during the PETM. If the present trend of increasing carbon emissions continues, we may see PETM‐magnitude extinction and accelerated evolution in as few as 140 years or about five human generations.Key PointsRates are often time scale or denominator dependent and must be compared on the same scale of timeModern carbon emission rates on short time scales are 9–10 times higher than estimates for carbon accumulation during onset of the PETMIf carbon emissions continue at increasing rates, we can expect to reach PETM accumulations in as few as 140 to 259 yearsPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149219/1/palo20700_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149219/2/palo20700.pd

Functional significance of mandibular translation in vertebrate jaw mechanics

Fore-aft translatory freedom of jaw articulation and alignment of muscle fibers with the bite point make the chief adductor muscles of most reptile and mammal jaws mechanically very efficient. The force generated by the adductor muscles acts directly against the food at the bite point with no reaction force wasted at the jaw joint. The jaw is functionally a link and not a lever. Translatory freedom of the jaw joint is provided either by a sliding jaw joint (in most mammals, birds and some reptiles) or by a two-jointed jaw suspension (in most lizards and snakes)

New Partial Skeleton And Relative Brain Size In The Late Eocene Archaeocete Zygorhiza Kochii (Mammalia, Cetacea) From The Pachuta Marl of Alabama, With A Note on Contemporaneous Pontogeneus Brachyspondylus

http://deepblue.lib.umich.edu/bitstream/2027.42/113064/1/Contributions32No10-High Resolution.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113064/2/Contributions32No10-lowresolution.pd

Stromerius Nidensis, New Archaeocete (Mammalia, Cetacea) From The Upper Eocene Qasr El-Sagha Formation, Fayum, Egypt

http://deepblue.lib.umich.edu/bitstream/2027.42/57499/1/Vol 31 No 13 final 12-19-07.pd

Vertebrates And Evolution

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137436/1/evo05166.pd

Evolutionary Transition From Ammonite Subprionocyclus To Reesidites—Punctuated Or Gradual?

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137416/1/evo00660.pd

New Basal Perissodactyla (Mammalia) From The Lower Eocene Ghazij Formation of Pakistan

http://deepblue.lib.umich.edu/bitstream/2027.42/109436/1/Contributions32No8-12082014.pdfDescription of Contributions32No8-12082014.pdf : Contributions Volume 32, Number

Paleocene-Eocene Land Mammals From Three New Latest Clarkforkian And Earliest Wasatchian Wash Sites At Polecat Bench In the Northern Bighorn Basin, Wyoming

http://deepblue.lib.umich.edu/bitstream/2027.42/49356/1/Vol 31 No11 final 12-11-06.pd