Milankovitch cycles that have so far allowed glacialinterglacial transitions through profoundly non-linear processes, can become inoperative in the future. Is it a bit
presumptuous though to think that a couple of hundred years
of ‘energy profligacy’ leading to a very large increase in
atmospheric CO 2 could still be felt tens of thousands of
years later? Maybe, but still, it is important to remember that
studies of the Earth past climates show that the presence of
ice sheets is associated with low CO 2 levels. It is therefore
logical to think that, in a world that sustains high CO 2
concentrations, the behavior of present-day ice sheets will
change in the short and medium term.
The world at the beginning of the Cenozoic (with
1120 ppm of CO 2 in the atmosphere) was much hotter than
today. Antarctica was already in its polar position since the
end of the Cretaceous (70 Ma ago), but far from forming an
ice sheet, it was covered with forests. There was no sign of
an ice sheet, until the CO 2 level dropped sufficiently to
trigger the progressive freeze-up of Antarctica (DeConto and
Pollard 2003). A planet with no ice sheet is not a figment of
the imagination, rather their presence being the exception
when viewed over geological times.
This book shows how the face of our planet changed over
these time scales: from plate tectonics (millions of years) to
the development of huge ice sheets at temperate latitudes
(hundreds of thousands of years), with very strong variability in glacial climates at the scale of a few thousand
years. Our own interglacial period, the Holocene, has been
much more stable in terms of climate and has contributed to
the extraordinary expansion of the human population. With
an Earth inhabited by more than 9 billion men and women, it
will be essential to manage climate change in order to protect
societies and their environment. The past teaches us that our
little blue planet has undergone many changes. It is not the
planet that is in danger, it is rather the populations, especially
as they do not have an equal standing in the face of climate
change. And so, paradoxically, if man has become a major
actor in climate change through industrial development and
massive use of fossil fuels, he could also suffer at his own
expense from upheavals and difficult situations that he has
created himself.
References
Adler, R. F., et al. (2003). The Version 2 Global Precipitation
Climatology Project (GPCP) monthly precipitation analysis (1979–
Present). Journal of Hydrometeorology, 4, 1147–1167.
Allen, R. J., & Sherwood, S. C. (2008). Warming maximum in the
tropical upper troposphere deduced from thermal winds. Nature
Geoscience, 1, 399–403.
Archer, D., et al. (1997). Multiple timescales for neutralization of fossil
fuel CO 2 . Geophysical Research Letters, 24, 405–408.
Archer, D., et al. (2009). Atmospheric lifetime of fossil fuel carbon
dioxide. Annual Review of Earth and Planetary Sciences, 37, 117–
134. https://doi.org/10.1146/annurevearth031208.100296.
Bony, S., et al. (2006). How well do we understand and evaluate
climate change feedback processes? Journal of Climate, 19(15),
3445–3482.
Bouttes, N., & Gregory, J. M. (2014). Attribution of the spatial pattern
of CO 2 -forced sea level change to ocean surface flux changes.
Environmental Research Letters, 9, 034004. https://doi.org/10.
1088/1748-9326/9/3/034004.
Bronselaer, B., et al. (2018). Change in future climate due to Antarctic
meltwater. Nature, 564, 53–58. https://doi.org/10.1038/s41586-0180712-z.
Cazenave, A., et al. (2009). Sea level budget over 2003-2008: A
reevaluation from GRACE space gravimetry; Satellite altimetry and
argo. Global and Planetary Change, 65, 83–88.
Charbit, S., et al. (2008). Amount of CO 2 emissions irreversibly leading
to the total melting of Greenland. Geophysical Research Letters, 35,
L12503. https://doi.org/10.1029/2008GLO33472.
Church, J. A., & White, N. J. (2011). Sea-level rise from the late 19th to
the early 21st century. Survey of Geophysics, 32, 585–602.
Christiansen, H. H., et al. (2010). The thermal state of permafrost in the
Nordic area during the International Polar Year 2007–2009.
Permafrost Periglacial Processes, 21, 156–181.
Clark, P. U., et al. (2016). Consequences of twenty-first-century policy
for multi-millennial climate and sea-level change. Nature Climate
Change, 6, 360–369.
DeConto, R. M., & Pollard, D. (2003). Rapid cenozoic glaciation of
Antarctica induced by declining atmospheric CO 2 . Nature, 421,
245–249. https://doi.org/10.1038/nature01290.
DeConto, R. M., & Pollard, D. (2016). Contribution of Antarctica to
past and future sea-level rise. Nature, 531, 591–597. https://doi.org/
10.1038/nature17145.
Defrance, D., et al. (2017). Consequences of rapid ice-sheet melting on
the Sahelian population vulnerability. In Proceedings of the
National Academy of Sciences (Vol. 114, Issue 25). https://doi.
org/10.1073/pnas.1619358114.
Dufresne, J.-L., & Bony, S. (2008). An assessment of the primary
sources of spread of global warming estimates from coupled
atmosphere-ocean models. Journal of Climate, 21(19), 5135–5144.
https://doi.org/10.1175/2008jcli2239.1.
Dufresne, J.-L., & Saint-Lu, M. (2016). Positive feedback in climate:
Stabilization or runaway, illustrated by a simple experiment.
Bulletin of American Meteorological. Society, 97(5), 755–765.
https://doi.org/10.1175/bams-d-14-00022.1.
Fourier, J.-B. (1824). Remarques générales sur les températures du
globe terrestre et des espaces planétaires. Annales de Chimie et de
Physique, 2e série, XXVII, 136–167.
Gallée, H., et al. (1992). Simulation of the last glacial cycle by a
coupled, sectorially averaged climate-ice-sheet model 2. Response
to insolation and CO 2 variations. Journal of Geophysical Research,
97(D14), 15713–15740.
Ganopolski, A., et al. (2016). Critical insolation-CO 2 relation for
diagnosing past and future glacial inception. Nature, 529, 200–203.
https://doi.org/10.1038/nature16494.
Garner, A. J., et al. (2018). Evolution of 21st century sea level rise
projections. Earth’s Future, 6, 1603–1615. https://doi.org/10.1029/
2018EF000991.
Gillet-Chaulet, F., et al. (2012). Greenland ice sheet contribution to
sea-level rise from a new-generation ice-sheet model. The Cryosphere, 6, 1561–1576. https://doi.org/10.5194/tc-6-1561-2012.
Golledge, N. R., et al. (2019). Global environmental consequences of
twenty-first-century ice-sheet melt. Nature, 566, 65–72. https://doi.
org/10.1038/s41586-019-0889-9.
476
S. Charbit et al.
presumptuous though to think that a couple of hundred years
of ‘energy profligacy’ leading to a very large increase in
atmospheric CO 2 could still be felt tens of thousands of
years later? Maybe, but still, it is important to remember that
studies of the Earth past climates show that the presence of
ice sheets is associated with low CO 2 levels. It is therefore
logical to think that, in a world that sustains high CO 2
concentrations, the behavior of present-day ice sheets will
change in the short and medium term.
The world at the beginning of the Cenozoic (with
1120 ppm of CO 2 in the atmosphere) was much hotter than
today. Antarctica was already in its polar position since the
end of the Cretaceous (70 Ma ago), but far from forming an
ice sheet, it was covered with forests. There was no sign of
an ice sheet, until the CO 2 level dropped sufficiently to
trigger the progressive freeze-up of Antarctica (DeConto and
Pollard 2003). A planet with no ice sheet is not a figment of
the imagination, rather their presence being the exception
when viewed over geological times.
This book shows how the face of our planet changed over
these time scales: from plate tectonics (millions of years) to
the development of huge ice sheets at temperate latitudes
(hundreds of thousands of years), with very strong variability in glacial climates at the scale of a few thousand
years. Our own interglacial period, the Holocene, has been
much more stable in terms of climate and has contributed to
the extraordinary expansion of the human population. With
an Earth inhabited by more than 9 billion men and women, it
will be essential to manage climate change in order to protect
societies and their environment. The past teaches us that our
little blue planet has undergone many changes. It is not the
planet that is in danger, it is rather the populations, especially
as they do not have an equal standing in the face of climate
change. And so, paradoxically, if man has become a major
actor in climate change through industrial development and
massive use of fossil fuels, he could also suffer at his own
expense from upheavals and difficult situations that he has
created himself.
References
Adler, R. F., et al. (2003). The Version 2 Global Precipitation
Climatology Project (GPCP) monthly precipitation analysis (1979–
Present). Journal of Hydrometeorology, 4, 1147–1167.
Allen, R. J., & Sherwood, S. C. (2008). Warming maximum in the
tropical upper troposphere deduced from thermal winds. Nature
Geoscience, 1, 399–403.
Archer, D., et al. (1997). Multiple timescales for neutralization of fossil
fuel CO 2 . Geophysical Research Letters, 24, 405–408.
Archer, D., et al. (2009). Atmospheric lifetime of fossil fuel carbon
dioxide. Annual Review of Earth and Planetary Sciences, 37, 117–
134. https://doi.org/10.1146/annurevearth031208.100296.
Bony, S., et al. (2006). How well do we understand and evaluate
climate change feedback processes? Journal of Climate, 19(15),
3445–3482.
Bouttes, N., & Gregory, J. M. (2014). Attribution of the spatial pattern
of CO 2 -forced sea level change to ocean surface flux changes.
Environmental Research Letters, 9, 034004. https://doi.org/10.
1088/1748-9326/9/3/034004.
Bronselaer, B., et al. (2018). Change in future climate due to Antarctic
meltwater. Nature, 564, 53–58. https://doi.org/10.1038/s41586-0180712-z.
Cazenave, A., et al. (2009). Sea level budget over 2003-2008: A
reevaluation from GRACE space gravimetry; Satellite altimetry and
argo. Global and Planetary Change, 65, 83–88.
Charbit, S., et al. (2008). Amount of CO 2 emissions irreversibly leading
to the total melting of Greenland. Geophysical Research Letters, 35,
L12503. https://doi.org/10.1029/2008GLO33472.
Church, J. A., & White, N. J. (2011). Sea-level rise from the late 19th to
the early 21st century. Survey of Geophysics, 32, 585–602.
Christiansen, H. H., et al. (2010). The thermal state of permafrost in the
Nordic area during the International Polar Year 2007–2009.
Permafrost Periglacial Processes, 21, 156–181.
Clark, P. U., et al. (2016). Consequences of twenty-first-century policy
for multi-millennial climate and sea-level change. Nature Climate
Change, 6, 360–369.
DeConto, R. M., & Pollard, D. (2003). Rapid cenozoic glaciation of
Antarctica induced by declining atmospheric CO 2 . Nature, 421,
245–249. https://doi.org/10.1038/nature01290.
DeConto, R. M., & Pollard, D. (2016). Contribution of Antarctica to
past and future sea-level rise. Nature, 531, 591–597. https://doi.org/
10.1038/nature17145.
Defrance, D., et al. (2017). Consequences of rapid ice-sheet melting on
the Sahelian population vulnerability. In Proceedings of the
National Academy of Sciences (Vol. 114, Issue 25). https://doi.
org/10.1073/pnas.1619358114.
Dufresne, J.-L., & Bony, S. (2008). An assessment of the primary
sources of spread of global warming estimates from coupled
atmosphere-ocean models. Journal of Climate, 21(19), 5135–5144.
https://doi.org/10.1175/2008jcli2239.1.
Dufresne, J.-L., & Saint-Lu, M. (2016). Positive feedback in climate:
Stabilization or runaway, illustrated by a simple experiment.
Bulletin of American Meteorological. Society, 97(5), 755–765.
https://doi.org/10.1175/bams-d-14-00022.1.
Fourier, J.-B. (1824). Remarques générales sur les températures du
globe terrestre et des espaces planétaires. Annales de Chimie et de
Physique, 2e série, XXVII, 136–167.
Gallée, H., et al. (1992). Simulation of the last glacial cycle by a
coupled, sectorially averaged climate-ice-sheet model 2. Response
to insolation and CO 2 variations. Journal of Geophysical Research,
97(D14), 15713–15740.
Ganopolski, A., et al. (2016). Critical insolation-CO 2 relation for
diagnosing past and future glacial inception. Nature, 529, 200–203.
https://doi.org/10.1038/nature16494.
Garner, A. J., et al. (2018). Evolution of 21st century sea level rise
projections. Earth’s Future, 6, 1603–1615. https://doi.org/10.1029/
2018EF000991.
Gillet-Chaulet, F., et al. (2012). Greenland ice sheet contribution to
sea-level rise from a new-generation ice-sheet model. The Cryosphere, 6, 1561–1576. https://doi.org/10.5194/tc-6-1561-2012.
Golledge, N. R., et al. (2019). Global environmental consequences of
twenty-first-century ice-sheet melt. Nature, 566, 65–72. https://doi.
org/10.1038/s41586-019-0889-9.
476
S. Charbit et al.