The Intergovernmental Panel on Climate Change (IPCC) recently warned that the average global temperature would exceed the two degree Celsius mark by 2100, higher than pre-industrial times.
To understand how quickly the climate could recover from this warming, an international team studied the global temperature rise that occurred 56 million years ago. Their findings suggest that it took about 20,000 to 50,000 years for the climate to stabilize after an increase of five to eight degrees Celsius. The results were recently published in the journal Science Advances.
About 56 million years ago, our Earth experienced a natural period of global warming triggered by volcanic eruptions. This period was known as the Paleocene–Eocene Thermal Maximum (PETM) and released massive amounts of carbon dioxide into the atmosphere. This warmed the surface oceans by about 8°C in the higher latitudes. Several studies have shown that ocean acidification during this period caused deep-sea mass extinctions and changes in surface ocean biota.
How did they study what happened millions of years ago?
The team analyzed rocks, single-celled marine organisms, clay minerals and lithium isotopes to understand what happened during this period.
The rocks would have weathered due to global warming. These dissolving rocks release lithium into the surrounding water bodies and by studying the isotopes of lithium we can understand the extent of erosion. Clay minerals from the ocean floor were used to study lithium isotopes stored in the water.
“Lithium has the advantage that it is one of the very few elements that is not used by biology or plants at all. So the signals that plants grow or die do not affect lithium. In addition, lithium isotopes (Li-6 and Li-7) have a relationship (ratio) to each other, which is changed by the weathering process – Li-6 is preferentially retained in the soil formed during weathering. Therefore, the original Basically, Li is a tracer that is only affected by weathering and nothing else, which is a huge advantage,” lead author Philipp Poge von Strandmann told indianexpress.com in an email. He is at the Institute of Geology, Johannes Gutenberg University, Professor in Sedimentary Geochemistry in Mainz, Germany.
They also examined planktonic foraminifera, or single-celled organisms, with chickpea shells that formed millions of years ago.
So will our temperature drop after thousands of years?
Pro. Philipp Poge von Strandmann points out that in terms of stabilization time, the difference between the PETM and the present is that the PetM had more warming (up to 8 °C) but was slower, but what we are seeing at the moment is probably 3-4 °C (worst case), but much faster than Paytm.
He points out that the recovery will probably be roughly the same in time (plus/minus a few thousand years). The findings will hold true only if there is a significant reduction in CO2 release.
Asked whether other greenhouse gases could delay our climate stabilization, he explained: “Methane and nitrous oxide are big problems in the short term, but they don’t stay in the atmosphere as long as CO2. In addition, methane is released into the atmosphere by weathering.” … if you’re looking at a timescale of more than a few hundred years, CO2 is the main player in warming.”
News bulletin | Click to get the best interpreters of the day delivered to your inbox
advanced weathering
Pro. There is now a major interest in studying whether we can use weathering to artificially remove CO2 from the atmosphere at a time more useful to us, says Philipp Pause von Strandmann. This process is known as ‘advanced weathering’. “You accelerate weathering by grinding the rock into powder (so it weaves faster) and plowing it into fields, where it must remove CO2 and act as a fertilizer. It is now used by many around the world. It is at the experimental stage at places.
“It will never remove all the CO2 we’re adding to the atmosphere, but if we manage to reduce emissions significantly, processes like increased weathering could remove the rest, and help us have ‘negative emissions’.” which is removing more CO2. We add and lower the CO2 concentration,” he explains.
.