Comprised of 450 instrumental records from temperature stations sheltered from ocean - air / urbanization / adjustment biases throughout the world, a new 20th / 21st century global temperature record introduced previously here very closely aligns with
paleoclimate evidence from tree rings, ice cores, fossil pollen and other temperature proxies.
Their conclusion: «If humanity wishes to preserve a planet similar to the one on which civilization developed and to which life on Earth is adapted,
paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm [in 2008] to at most 350 ppm.»
Paleoclimate evidence is simply one in a number of independent lines of evidence indicating the strong likelihood that human influences on climate play a dominant role in the observed 20th century warming of the earth's surface.
I hae no idea why you would think a CO2 response to temperature would be a negative feedback, this certainly contradicts
all paleoclimate evidence.
Arctic temperatures at the beginning of the first millennium were between 2 ° and 6 °C warmer than they are now, as
paleoclimate evidence suggests summer Arctic sea surface temperatures ranged between 3 °C and 7.5 °C about 2,000 years ago, whereas they average about 1.1 °C today.
Composed of 450 instrumental records from temperature stations sheltered from ocean - air / urbanization / adjustment biases throughout the world, a new 20th / 21st century global temperature record introduced previously here very closely aligns with
paleoclimate evidence from tree rings, ice cores, fossil pollen and other temperature proxies.
The primary objective here is to try to quantify the character of natural variability though the instrumental record of climate, through
paleoclimate evidence (e.g. ice cores), and in computer models that run for long periods of time without any change in climate forcing (i.e. constant sunlight and greenhouse gases).
Even issues which are typically taken to be the sign of a more legitimate skepticism (like arguing for a low sensitivity), are now constrained by data and
paleoclimate evidence, and mechanisms that could cause such model errors or misinterpretation of the paleo - record need to be shown by those who argue so confidently against it.
This is supported by multiple lines of evidence, including GCMs,
paleoclimate evidence (including climate response to forcing during glacial periods as well as millennial proxies), the instrumental record, and the climate response to volcanic forcings among others.
Starting in 2005, building on a sequence of events seeking to obtain raw data, leading ultimately to the FOIA events central to the CRU controversy, McIntyre builds an iconoclastic website which at least implicitly supports the false propositions that climate change concerns rest primarily on
paleoclimate evidence and that
paleoclimate evidence is systematically skewed.
«By flipping the data opposite to the interpretation of Tiljander et al, Mann shows the Little Ice Age in Finland as being warmer than the MWP, 100 % opposite to the interpretation of the authors and
the paleoclimate evidence.
So if more forcing means more feedback, even the harsh
Paleoclimate evidence is too conservative a measure.
Finite fossil hydrocarbon reserves (note I do not limit this definition to «fuel») plus robust physics of radiative transfer, plus
paleoclimate evidence plus uncertainty are, together, more than sufficient grounds to justify the rapid reduction in fossil HC use.
BBD writes - «Finite fossil hydrocarbon reserves (note I do not limit this definition to «fuel») plus robust physics of radiative transfer, plus
paleoclimate evidence plus uncertainty are, together, more than sufficient grounds to justify the rapid reduction in fossil HC use.»
That it is possible to construct a metric that doesn't show regional warming in a certain roughly specified region on a certain unspecified time scale with a certain unspecified statistical technique in no way contradicts the assertion that the balance of observational evidence shows unusual recent global warming, in first order agreement with theoretical, computational, and
paleoclimate evidence.
Paleoclimate evidence and ongoing global changes imply that today's CO2, about 385 ppm, is already too high to maintain the climate to which humanity, wildlife, and the rest of the biosphere are adapted.
The paleoclimate evidence detailing climate changes during the mid-Holocene is complex.
Can it be argued given
the paleoclimate evidence for abrupt climate changes that there is likely no strong negative feedback over any meaningful time scale?
The paleoclimate evidence from this new study supports the attribution of the tropical temperature trend to the ever - increasing greenhouse gas burden in the atmosphere.
I suspect that this obvious test of the validity of GCMs is not emphasized in public discussions because of the considerable influence of people who have an unshakable belief that the earth is 5000 or so years old, such that
paleoclimate evidence is unconvincing to them.
But to them, we offer the reminder that
paleoclimate evidence comprises only one of many independent lines of evidence indicating a primary role of human activity in modern climate change.
The paleoclimate evidence detailing climate changes during the mid-Holocene is complex.
For example, Jessica tell Mike how she and her colleagues pulled together a sweeping collection of
paleoclimate evidence to reveal how the jet stream contracted and twisted in glacial boundary conditions, rather than moving monolithically south.
However, studies evaluating model performance on key observed processes and
paleoclimate evidence suggest that the higher end of sensitivity is more likely, partially conflicting with the studies based on the recent transient observed warming.
Not exact matches
The findings, published in the journal Nature Communications, show that integrating
evidence from historical writings with
paleoclimate data can advance both our understanding of how the climate system functions, and how climatic changes impacted past human societies.
Evidence of these changes is found in many parts of the Southern Hemisphere and in different
paleoclimate archives, but what prompted these changes has remained largely unexplained.
«Our study has found
evidence to the contrary, suggesting that in fact, the future long - term trend based on
paleoclimate reconstructions is likely towards diminishing precipitation, with no relief in the form of increased Mediterranean storms, the primary source of annual precipitation to the region, in the foreseeable future.»
Paleoclimate derived from stacked benthic foraminifera δ18O or aeolian dust records has been unable explain the occurrence of discrete evolutionary phases in the hominin fossil record [2]--[3], [15], the incorporation of the Rift lakes as both a climate indicator and landscape feature provides this missing environmental
evidence.
It's a long paper with a long title: «Ice melt, sea level rise and superstorms:
evidence from
paleoclimate data, climate modeling, and modern observations that 2 oC global warming could be dangerous».
«Ice melt, sea level rise and superstorms:
evidence from
paleoclimate data, climate modeling, and modern observations that 2o C global warming could be dangerous»
The full title is: «Ice melt, sea level rise and superstorms:
evidence from
paleoclimate data, climate modeling, and modern observations that 2 o C global warming could be dangerous ``.
I would like to see this
evidence that models just based on known physics «model climate and
paleoclimate rather well».
It's based upon multiple lines of
evidence including (in no particular order) the
paleoclimate record, experimental
evidence, well - established physical theory, and observational
evidence.
He attacks Hansen without
evidence and utilizes proxy data after he criticizes middle and upper lay troposphere and his analysis of proxy data for
paleoclimate.
David B. Benson: The
evidence is that the GCMs, being based on physics, model climate and
paleoclimate rather well.
On July 23, I wrote about the rocky rollout, prior to peer review, of «Ice Melt, Sea Level Rise and Superstorms:
Evidence from
Paleoclimate Data, Climate Modeling, and Modern Observations that 2 °C Global Warming is Highly Dangerous.»
Natural (non-human-induced) variability is still likely the dominant cause of today's droughts, and clearly was for megadroughts
evidenced in the
paleoclimate record.
In terms of the comments about the Holocene record, etc, and Gavin's saying that there is «no
evidence» of such methane burps then: first, let us all also acknowledge that some of the world's major
paleoclimate and methane experts HAVE seen
evidence of exactly that [i.e., Nisbet, Have sudden large releases of methane from geological reservoirs occurred since the Last Glacial Maximum, and could such releases occur again?
What is true is that there is very very strong
evidence from
paleoclimate data (deep sea sediment cores) for changes in the distribution of chemical tracers that must reflect changes in the deep circulation in the Atlantic.
I also agree with you that
paleoclimate has been the strongest
evidence that the humans are doing something unprecedented with the Earth - that the current changes exceed those that appear on the timescales of millenia.
You ostensibly believe CO2 dominates despite not having the requisite scientific
evidence to back up that assertion, not to mention
paleoclimate data which heartily contradicts it (i.e., CO2 levels rose while ocean heat content declined, or OHC rose rapidly while CO2 levels were constant).
The effects on upper ocean pH. The high climate sensitivity
evidence from
paleoclimate and models.
On the first sentence stating that the WGI report considers
evidence of past and future climate change based on many independent scientific analyses from observations of the climate system,
paleoclimate archives, theoretical studies of climate processes, and simulations using climate models, Saudi Arabia proposed clarifying that
evidence of future climate change is based on models and simulations only.
«Ice melt, sea level rise and superstorms:
evidence from
paleoclimate data, climate modeling, and modern observations that 2 C global warming could be dangerous» J Hansen, M Sato, P Hearty, R Ruedy, M Kelley, V Masson - Delmotte,... Atmospheric Chemistry and Physics 16 (6), 3761 - 3812, 2016
The initial title of «Ice melt, sea level rise and superstorms:
evidence from
paleoclimate data, climate modeling, and modern observations that 2 °C global warming is highly dangerous» had the final phrase changed to «could be dangerous.»
Originally posted on Open Mind: A new paper by Hansen et al., Ice melt, sea level rise and superstorms:
evidence from
paleoclimate data, climate modeling, and modern observations that 2 °C global warming is highly dangerous is currently under review...
«Researchers first became intrigued by abrupt climate change when they discovered striking
evidence of large, abrupt, and widespread changes preserved in paleoclimatic archives... Modern climate records include abrupt changes that are smaller and briefer than in
paleoclimate records but show that abrupt climate change is not restricted to the distant past.»
The ONLY compelling convergent
evidence we see is in the field of climatology the picture of collusion and corruption in the field of
paleoclimate.
while there is undoubtedly scope for statisticians to play a larger role in
paleoclimate research, the large investment of time needed to become familiar with the scientific background is likely to deter most statisticians from entering this field... In the end, it's important not to lose sight of the forest for the trees, where the «forest» refers to the totality of scientific
evidence for global warming.
He thinks that we can look to
paleoclimate as
evidence for abrupt climate change — and indeed we can — but the examples he has to use are those of abrupt change during deglaciation (YD) or during glacial climate (D - O; Heinrich; Bond).