This talk is available at https://youtu.be/0e1oioze-9e Plate tectonics controls global climate change by determining the frequency of major explosive, subductionrelated volcanic eruptions causing incremental global cooling versus Peter L. Ward U.S. Geological Survey retired Science Is Never Settled peward@wyoming.com Jackson, Wyoming WhyClimateChanges.com the extent of subaerial, rift-related, effusive, flood basaltic lava flows causing sudden global warming, ocean acidification, mass extinctions, and often the ends of geologic eons, eras, periods, etc.
Key points 1. Climate change is controlled primarily by sub-aerial volcanism 2. Frequent major explosive eruptions cause incremental GLOBAL cooling 3. Flood basaltic eruptions, on the other hand, cause sudden GLOBAL warming 4. Sudden major warming followed by slow cooling occurs as often as every 1000 years in erratic sequences that are clearly not cyclic. Rate is surprising 5. Plate tectonics determines which type of volcanism is dominant at any time 6. These distinctive sequences of volcanism appear to provide another tool, much like magnetic anomalies, for interpreting the geologic record including cross-correlation and dating
Aerosol forming explosive eruptions Occur above subduction zones Form aerosols cooling Earth GLOBALLY ~0.5 o C for ~3 years versus Aerially extensive flood-basaltic eruptions Pinatubo 1991 Bárðarbunga 2014 Occur in rift zones Deplete ozone warming Earth GLOBALLY many degrees within years Climate effect is determined by number of eruptions per century Climate effect is determined by duration and aerial extent
Major cooling when there is major subduction Ocean crust production Izu-Bonin-Mariana, Aleutians, southern Rocky Mountains, Sierra Madre Occidental Ocean temperature Himalayan mountain building 23-16 Ma Major Pacific Plate subduction Veizer Et al. 1999 Onset Antarctic glaciation Mid-miocene climate optimum Cogné & Humler 2006 Ward 2009
18 18 Stack of 57 globally distributed deep sea δ O records 125 100 75 50 25 Thousand years before present Lisiecki et al. 2005
Erratic sequences of rapid warming followed by slower cooling Dansgaard-Oeschger events observed in Greenland ice Footprints Sudden warming Slow cooling Erratic sequences
Holocene temperatures and volcanism
Basaltic volcanism ended the last ice age Greenland Ice Sheet Project 2 Mayewski et al., 1995 Bolling warming 12 of 13 best dated tuyas were active during this time White Et al. 1997 12,000 to 9500 Zielinski et al. 1996
Paleozoic brachiopod habitat temperatures Peter S. Giles, 2012
Examples of flood basalts and large igneous provinces Siberian Basalts Deccan Basalts 7,000,000 km 2 11,000,000 km 2 500,000 km 2 Siberian Basalts 96% marine 70% terrestrial vertebrates Central Atlantic Magmatic Province Deccan Basalts
Paleocene-Eocene Association with end of time units Thermal Maximum Extrusion of basaltic magma reached a peak 56 million years ago during the rifting of the Greenland-Norwegian Sea Ages of mass extinctions Typically end geologic eras, periods, and epochs Ages of effusive flood basalts Storey et al. 2007 Courtillot and Renne 2003
Large Igneous Provinces punctuate the geologic time scale Pleistocene Only 104 ages since 540 Ma Columbia Ethiopia Deccan basalts Madagascar Kerguelen Parana Jurassic ice age Siberian basalts Emeishan basalts Karoo Kola-Dnieper Snowball Earth Guibei Umkondo Mackenzie 17 largest out of >200 LIPS Uatuma Karoo Hirnation CAMP Katian? Geological Society of America Time Scale PETM The balance of effusive and explosive Kalkarindji volcanism explains climate change in detail Ages of LIPs from Ernst 2014
1. Climate change is controlled dominantly by sub-aerial volcanism 2. Frequent major explosive eruptions cause incremental GLOBAL cooling 3. Flood basaltic eruptions cause sudden GLOBAL warming 4. Sudden major warming and slow cooling occurs as often as every 1000 years in erratic sequences that are clearly not cyclic 5. Plate tectonics determines which type of volcanism is dominant at any time 6. These distinctive sequences of volcanism appear to provide another tool, much like magnetic anomalies, for interpreting the geologic record including cross-correlation and dating peward@wyoming.com
Broad continuum of frequencies Greenhouse gases simply do not absorb a broad enough range of frequencies, known of as heat, to be a significant cause of global warming LED Selected frequencies Planck s law (1900) A light bulb emits a broad range of frequencies (heat) just to produce a narrow range of visible light LEDs emit a narrow range of visible frequencies without emitting heat Less than 16% Frequencies absorbed by carbon dioxide Greenhouse-warming theory appears to be mistaken