Future climate forcing potentially without precedent in the last 420 million years
Future climate forcing potentially without precedent in the last 420 million years
The evolution of Earth’s climate on geological timescales is largely driven by variations in the magnitude of total solar irradiance (TSI) and changes in the greenhouse gas content of the atmosphere. Here we show that the slow ∼50 Wm−2 increase in TSI over the last ∼420 million years (an increase of ∼9 Wm−2 of radiative forcing) was almost completely negated by a long-term decline in atmospheric CO2. This was likely due to the silicate weathering-negative feedback and the expansion of land plants that together ensured Earth’s long-term habitability. Humanity’s fossil-fuel use, if unabated, risks taking us, by the middle of the twenty-first century, to values of CO2 not seen since the early Eocene (50 million years ago). If CO2 continues to rise further into the twenty-third century, then the associated large increase in radiative forcing, and how the Earth system would respond, would likely be without geological precedent in the last half a billion years.
Foster, Gavin L.
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Royer, Dana L.
5fe4243b-ab93-4a13-bc89-874d4c2c212f
Lunt, Daniel J.
931ecfb5-1f50-412c-8f01-a46d69b1f82f
Foster, Gavin L.
fbaa7255-7267-4443-a55e-e2a791213022
Royer, Dana L.
5fe4243b-ab93-4a13-bc89-874d4c2c212f
Lunt, Daniel J.
931ecfb5-1f50-412c-8f01-a46d69b1f82f
Foster, Gavin L., Royer, Dana L. and Lunt, Daniel J.
(2017)
Future climate forcing potentially without precedent in the last 420 million years.
Nature Communications, 8, [14845].
(doi:10.1038/ncomms14845).
Abstract
The evolution of Earth’s climate on geological timescales is largely driven by variations in the magnitude of total solar irradiance (TSI) and changes in the greenhouse gas content of the atmosphere. Here we show that the slow ∼50 Wm−2 increase in TSI over the last ∼420 million years (an increase of ∼9 Wm−2 of radiative forcing) was almost completely negated by a long-term decline in atmospheric CO2. This was likely due to the silicate weathering-negative feedback and the expansion of land plants that together ensured Earth’s long-term habitability. Humanity’s fossil-fuel use, if unabated, risks taking us, by the middle of the twenty-first century, to values of CO2 not seen since the early Eocene (50 million years ago). If CO2 continues to rise further into the twenty-third century, then the associated large increase in radiative forcing, and how the Earth system would respond, would likely be without geological precedent in the last half a billion years.
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ncomms14845
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Accepted/In Press date: 6 February 2017
e-pub ahead of print date: 4 April 2017
Organisations:
Geochemistry
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Local EPrints ID: 410715
URI: http://eprints.soton.ac.uk/id/eprint/410715
PURE UUID: f14defee-dea0-4895-b020-f01c21d8a462
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Date deposited: 09 Jun 2017 09:26
Last modified: 16 Mar 2024 04:02
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Author:
Dana L. Royer
Author:
Daniel J. Lunt
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