Greenhouse gas emissions released directly from the movement of volcanic rocks are capable of creating massive global warming effects — a discovery that could transform the way scientists predict climate change, a new study reveals.
Scientists’ calculations based on how carbon-based greenhouse gas levels link to movements of magma just below Earth’s surface suggest that such geological changes have caused the largest temporary global warming of the past 65 million years.
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Large Igneous Provinces (LIPs) are extremely large accumulations of igneous rocks that occur when magma travels through the crust toward the surface. Geologists at the University of Birmingham have created the first mechanistic model of carbon emission changes during the Paleocene-Eocene Thermal Maximum (PETM) — a short interval of maximum temperature lasting around 100,000 years some 55 million years ago.
Global warming
They published their findings in Nature Communications, after calculating carbon-based greenhouse gas fluxes associated with the North Atlantic Igneous Province (NAIP) — one of Earth’s largest LIPs that spans Britain, Ireland, Norway, and Greenland. Dr. Stephen Jones, Senior Lecturer in Earth Systems at the University of Birmingham, said:
“Large Igneous Provinces are linked to spikes of change in global climate, ecosystems, and the carbon cycle throughout Mesozoic time — coinciding with the Earth’s most devastating mass extinctions and oceans becoming strongly depleted of oxygen.
“We calculated carbon-based greenhouse gas fluxes associated with the NAIP — linking measurements of the process that generated magma with observations of the individual geological structures that controlled gas emissions.
“These calculations suggest the NAIP caused the largest transient global warming of the past 65 million years.
“More geological measurements are required to reduce the uncertainty range of our solid Earth emissions model, but we believe clarification of this carbon cycle behaviour will impact modelling and management of future climate change.”
The researchers’ simulations predict peak emissions flux of 0.2-0.5 PgC yr–1 and show that the NAIP could have initiated PETM climate change. Their work is the first predictive model of carbon emissions flux from any proposed PETM carbon source directly constrained by observations of the geological structures that controlled the emissions.
During PETM initiation, the release of 0.3–1.1 PgC yr–1 of carbon as greenhouse gases to the ocean-atmosphere system drove 4°-5°C of global warming over less than 20,000 years — a relatively short period of time.
Associations between LIPs and changes in global climate, ecosystems, and the carbon cycle during the Mesozoic period imply that greenhouse gases released directly by LIPs can initiate global change that persists over 10,000-100,000 years.
The PETM is the largest natural climate change event of the Cenozoic time and is an important yardstick for theories explaining today’s long-term increase in the average temperature of Earth’s atmosphere as an effect of human industry and agriculture.
Provided by: University of Birmingham [Note: Materials may be edited for content and length.]
