Peteet, D.M., 2001: Late
glacial climate variability GCM modeling experiments: An overview.
7) Holocene climate variability is characterized by periodic cooling events of reduced amplitude compared to
glacial climate variability.
EPICA community members, 2006: One - to - one coupling of
glacial climate variability in Greenland and Antarctica.
Not exact matches
Climate researchers from the Helmholtz Young Investigators Group ECUS at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI) in Potsdam have now investigated how temperature
variability changed as the Earth warmed from the last
glacial period to the current interglacial period.
«We started from scratch and she wanted to know
glacial cycles, rate of deforesting, solar
variability — all of the issues that could impact
climate and why I think that humans are the main driver of
climate change,» he explained afterward at a debriefing with colleagues at a pub on Capitol Hill.
Such close linkages between CO2 concentration and
climate variability are consistent with modelling results suggesting with high confidence that
glacial — interglacial variations of CO2 and other greenhouse gases [CH4, N2O] explain a considerable fraction of
glacial — interglacial
climate variability in regions not directly affected by the northern hemisphere continental ice sheets (Timmermann et al., 2009; Shakun et al., 2012).
A new research paper by Friedrich et al. looks at
glacial - interglacial
climate variability during the last 784,000 years to estimate Earth's
climate variability.
Within mountain ecosystems across Latin America, Africa and Asia, increasing
climate variability, gradual
glacial [continue reading...]
«We build on this insight to demonstrate directly from ice - core data that, over
glacial — interglacial timescales,
climate dynamics are largely driven by internal Earth system mechanisms, including a marked positive feedback effect from temperature
variability on greenhouse - gas concentrations.»
The 25 D - O events during the last
glacial, where temperatures rose and fell by 5 to 10 degrees C (10 - 15 degrees C for Greenland) within a span of decades that were «explained by internal
variability of the
climate system alone ``, deemed global in scale, and they occurred without any changes in CO2 concentrations, which stayed steady at about 180 ppm throughout the warming and cooling.
«The CCR - II report correctly explains that most of the reports on global warming and its impacts on sea - level rise, ice melts,
glacial retreats, impact on crop production, extreme weather events, rainfall changes, etc. have not properly considered factors such as physical impacts of human activities, natural
variability in
climate, lopsided models used in the prediction of production estimates, etc..
26) During the current interglacial the solar and oceanic cycles are broadlyoffsetting one another to reduce overall
climate variability but during
glacial epochs they broadly supplement one another to produce much larger
climate swings.
We could, of course, hit some bifurcation in the system where we lose all the summer Arctic sea ice or the Amazon forest, which is bad enough, and could possibly transition the
climate to a different «solution» on a hysteresis diagram... this to me would represent more of a step-wise jump (akin to a larger bifurcation that you get in a snowball Earth as you gradually reduce CO2 or the solar constant); but ultimately these represent different behavior than «the interannual
variability of the large scale dynamics will increase» or that for some reason the
climate should be susceptible to more «flip flops» (as in the
glacial Heinrich / D - O events), of which I am aware of no observational or theoretical support.
The PalMod project is funded by the Federal Ministry of Education and Science (BMBF) to understand
climate system dynamics and
variability during the last
glacial cycle.
The most likely candidate for that climatic variable force that comes to mind is solar
variability (because I can think of no other force that can change or reverse in a different trend often enough, and quick enough to account for the historical climatic record) and the primary and secondary effects associated with this solar
variability which I feel are a significant player in
glacial / inter-
glacial cycles, counter climatic trends when taken into consideration with these factors which are, land / ocean arrangements, mean land elevation, mean magnetic field strength of the earth (magnetic excursions), the mean state of the
climate (average global temperature), the initial state of the earth's
climate (how close to interglacial -
glacial threshold condition it is) the state of random terrestrial (violent volcanic eruption, or a random atmospheric circulation / oceanic pattern that feeds upon itself possibly) / extra terrestrial events (super-nova in vicinity of earth or a random impact) along with Milankovitch Cycles.
Contrary to the impression left by the IPCC Summary reports: - Recent observations of phenomena such as
glacial retreats, sea - level rise and the migration of temperature - sensitive species are not evidence for abnormal
climate change, for none of these changes has been shown to lie outside the bounds of known natural
variability.
The remaining slow drift to lower GMT and pCO2 over
glacial time, punctuated by higher - frequency
variability and the dust −
climate feedbacks, may reflect the consequences of the growth of continental ice sheets via albedo increases (also from vegetation changes) and increased CO2 dissolution in the ocean from cooling.
I think there must be at least two factors interacting to achieve the necessary switches so that they offset one another to minimise
climate variability during interglacials but supplement one another to increase
climate variability during
glacial periods.
1998 was near the tail end of a decade that jumped well above the mean average longer term rate of increase (there is a thing called
climate variability, it didn't disappear with
climate change, and if anything probably only intensified;, and ocean warming and
glacial melt both accelerated during this period, taking more energy out of the air — see below).
Higher elevation areas could experience altered water flow in some river basins if current rates of
glacial retreat continue, but shifts in the location, intensity, and
variability of rain and snow due to
climate change will likely have a greater impact on regional water supplies.
If it turned out that rapid
climate change events are caused by comets, it would imply the
climate system is far more stable than we thought, that abrupt
climate change events are not part of the inherent
variability of
climate during
glacial periods.