Marcel Leroux
Encyclopedia
Marcel Leroux was a French climatologist, a former Professor of Climatology at Jean Moulin University in Lyon, France, and director of the Laboratory of Climatology, Risk, and Environment.
Leroux argues in his book "Global Warming: Myth or Reality? The Erring Ways of Climatology" that the case for global warming
is based on models which, with their insufficiencies in the understanding and explanation of weather phenomena, are not reliable to support this prediction. He also poses the question if warming may be considered a benefit in some regions.
On the causes of climate change
, he writes in a section entitled "Conclusion: The greenhouse effect
is not the cause of climate change": "The possible causes, then, of climate change are: well-established orbital parameters on the palaeoclimatic scale, with climatic consequences slowed by the inertial effect of glacial accumulations; solar activity, thought by some to be responsible for half of the 0.6°C rise in temperature, and by others to be responsible for all of it, which situation certainly calls for further analysis; volcanism and its associated aerosols (and especially sulphates), whose (short-term) effects are indubitable; and far at the rear, the greenhouse effect, and in particular that caused by water vapor, the extent of its influence being unknown. These factors are working together all the time, and it seems difficult to unravel the relative importance of their respective influences upon climatic evolution. Equally, it is tendentious to highlight the anthropic factor, which is, clearly, the least credible among all those previously mentioned."
This migration and the extent of the Meteorological Equator are the consequence of continuous meridional exchanges in the denser, lower layers of the atmosphere, which circulation is governed by the incessant ballet of the Mobile Polar Highs or Anticyclone Mobile Polaire, 1.5 km high, 3,000 km diameter discoid, lenticular cold air-masses anticyclones originating from the poles, whose strength and frequency depends directly on the thermal polar deficit. Cooling spurns an accelerated circulation while warming will slow the general circulation and exchanges.
The aerological spaces of circulation, zones of continuous circulation from the pole to the equator are bound by relief over 2,000m and the present position of continents. In light of direct observations , Leroux’s reconstruction exposes the inconsistencies of previous general circulation models, of oscillation indexes and of frontological, dynamical, reductionist and diagnostic schools of Meteorology. This made him a controversial figure.
In doing so, Leroux refutes the artificial separation between Meteorology
and Climatology
and through the MPH concept, redefines both disciplines in a similar way Plate Tectonics
revolutionized Earth Sciences in the 1960s. He reconstructed the geometry of the troposphere general circulation and demonstrated that very little is owed to hazard or chaos: there is no ‘unruly climate’ but intensity shifts of the sum of weather processes that constitute the climate.
This research confirmed that the climatic shift observed since the 1970s corresponds to the setting of an accelerated mode of circulation, always associated with cooling during the late Quaternary palaeoclimatic evolution, and its meteorological consequences: contrasted weather, stronger mid-latitude storms, increase water vapour in the troposphere and impermanent anticyclonic stability over continents leading to vigorous cold snaps in winter and heatwaves in summer.
In consequence, his results refute the validity of a Global Mean Temperature curve as a major climatic proxy and contradict the assumption that weather changes observed in the second half of the 20th century were the consequence of an Anthropogenic Global Warming climatic change brought by the release of greenhouse gases due to industrial and human activities.
Furthermore, his work provides the meteorological mechanism for past glaciations and de-glaciations, improves meteorological prediction models and climate simulation accuracy in constraining them through the real geometry of atmospheric circulation, its discontinuities, energy exchanges and their associated clouds.
In his approach, Leroux was a true disciple of Descartes and his books are highly didactic. The English 2nd edition of “Dynamic Analysis of Weather and Climate, Atmospheric Circulation, Perturbations, Climatic Evolution” was completed in 2008 two months before his passing and published in January 2010.
Leroux argues in his book "Global Warming: Myth or Reality? The Erring Ways of Climatology" that the case for global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
is based on models which, with their insufficiencies in the understanding and explanation of weather phenomena, are not reliable to support this prediction. He also poses the question if warming may be considered a benefit in some regions.
On the causes of climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
, he writes in a section entitled "Conclusion: The greenhouse effect
Greenhouse effect
The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface, energy is transferred to the surface and the lower atmosphere...
is not the cause of climate change": "The possible causes, then, of climate change are: well-established orbital parameters on the palaeoclimatic scale, with climatic consequences slowed by the inertial effect of glacial accumulations; solar activity, thought by some to be responsible for half of the 0.6°C rise in temperature, and by others to be responsible for all of it, which situation certainly calls for further analysis; volcanism and its associated aerosols (and especially sulphates), whose (short-term) effects are indubitable; and far at the rear, the greenhouse effect, and in particular that caused by water vapor, the extent of its influence being unknown. These factors are working together all the time, and it seems difficult to unravel the relative importance of their respective influences upon climatic evolution. Equally, it is tendentious to highlight the anthropic factor, which is, clearly, the least credible among all those previously mentioned."
Scientific Contribution
Leroux demonstrated through the analysis of synoptic maps, satellite imagery, meteorological and palaeoenvironmental data over Tropical Africa that the seasonal and palaeoclimatic migration of the Meteorological Equator represents a reliable proxy of the Earth’s climate evolution.This migration and the extent of the Meteorological Equator are the consequence of continuous meridional exchanges in the denser, lower layers of the atmosphere, which circulation is governed by the incessant ballet of the Mobile Polar Highs or Anticyclone Mobile Polaire, 1.5 km high, 3,000 km diameter discoid, lenticular cold air-masses anticyclones originating from the poles, whose strength and frequency depends directly on the thermal polar deficit. Cooling spurns an accelerated circulation while warming will slow the general circulation and exchanges.
The aerological spaces of circulation, zones of continuous circulation from the pole to the equator are bound by relief over 2,000m and the present position of continents. In light of direct observations , Leroux’s reconstruction exposes the inconsistencies of previous general circulation models, of oscillation indexes and of frontological, dynamical, reductionist and diagnostic schools of Meteorology. This made him a controversial figure.
In doing so, Leroux refutes the artificial separation between Meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...
and Climatology
Climatology
Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time, and is a branch of the atmospheric sciences...
and through the MPH concept, redefines both disciplines in a similar way Plate Tectonics
Plate tectonics
Plate tectonics is a scientific theory that describes the large scale motions of Earth's lithosphere...
revolutionized Earth Sciences in the 1960s. He reconstructed the geometry of the troposphere general circulation and demonstrated that very little is owed to hazard or chaos: there is no ‘unruly climate’ but intensity shifts of the sum of weather processes that constitute the climate.
This research confirmed that the climatic shift observed since the 1970s corresponds to the setting of an accelerated mode of circulation, always associated with cooling during the late Quaternary palaeoclimatic evolution, and its meteorological consequences: contrasted weather, stronger mid-latitude storms, increase water vapour in the troposphere and impermanent anticyclonic stability over continents leading to vigorous cold snaps in winter and heatwaves in summer.
In consequence, his results refute the validity of a Global Mean Temperature curve as a major climatic proxy and contradict the assumption that weather changes observed in the second half of the 20th century were the consequence of an Anthropogenic Global Warming climatic change brought by the release of greenhouse gases due to industrial and human activities.
Furthermore, his work provides the meteorological mechanism for past glaciations and de-glaciations, improves meteorological prediction models and climate simulation accuracy in constraining them through the real geometry of atmospheric circulation, its discontinuities, energy exchanges and their associated clouds.
In his approach, Leroux was a true disciple of Descartes and his books are highly didactic. The English 2nd edition of “Dynamic Analysis of Weather and Climate, Atmospheric Circulation, Perturbations, Climatic Evolution” was completed in 2008 two months before his passing and published in January 2010.