Sentences with phrase «by paleoclimate»

If you see and recognize these strong positive feedbacks to solar changes, wouldn't it make sense, just from the precautionary point of view, to assume the same is quite possible for other forcings, especially when backed up by paleoclimate (my 700 ppm comment above)?

JimD, «If you see and recognize these strong positive feedbacks to solar changes, wouldn't it make sense, just from the precautionary point of view, to assume the same is quite possible for other forcings, especially when backed up by paleoclimate (my 700 ppm comment above)?

Wallace S. Broecker, «Abrupt climate change: causal constraints provided by the paleoclimate record,» Earth - Science Reviews 51:137 - 154 (August 2000).

The research was funded by the Paleoclimate Program in NSF's Division of Atmospheric and Geospace Sciences.

We suggest that the best constraint on actual climate sensitivity is provided by paleoclimate data that imply a sensitivity 3 ± 1 °C for 2 CO2 [Hansen et al., 1984, 1993, 1997b; Hoffert and Covey, 1992].

We aren't warming slowly by paleoclimate standards, and human life was not around in a much warmer world.

Not exact matches

The researchers make their case in part by describing paleoclimate data from the Eemian, an interglacial (warm) period that lasted from about 130,000 to 115,000 years ago.

«This does not necessarily mean that a similar response would happen in the future with increasing CO2 levels, since the boundary conditions are different from the ice age,» added by Professor Gerrit Lohmann, leader of the Paleoclimate Dynamics group at the Alfred Wegener Institute.

The goal of the paper under review, as I take it, is an attempt to put an upper bound on the Charney climate sensitivity feedback by considering the LCM paleoclimate.

As the lakes appear to be a proxy for local climate pulses, we use the lake index to explicitly test the pulsed climate variability hypothesis [15] by evaluating the relationship between paleoclimate and hominin evolution.

By incorporating multiple records, we can identify which aspects of paleoclimate best predict hominin evolution.

In the response by raypierre - I agree about the problems with simple energy balance model and its lack of spatial representation, but it's tough to fault the authors for the lack of cloud detail, since the science is not up to the task of solving that problem (and doing so would be outside the scope of the paper; very few paleoclimate papers that tackle the sensitivity issue do much with clouds).

One reason why recognizing the importance of the fact that Mann's statistical methods and hence conclusions are faulty is that to demonstrate that the current warming is unprecedented and therefore likely anthropogenic is that sufficiently precise paleoclimate temperature indicators and data is hard to come by.

Early human evolution is characterised by pulsed speciation and dispersal events that can not be explained fully by global or continental paleoclimate records.

Human evolution is characterised by speciation, extinction and dispersal events that can not currently be explained by global or regional paleoclimate records [1]--[3].

Climate model studies and empirical analyses of paleoclimate data can provide estimates of the amplification of climate sensitivity caused by slow feedbacks, excluding the singular mechanisms that caused the hyperthermal events.

As we will show, Earth's paleoclimate record makes it clear that the CO2 produced by burning all or most of these fossil fuels would lead to a very different planet than the one that humanity knows.

Additional support for that target is provided by our analyses of ongoing climate change and paleoclimate, in later parts of our paper.

The detailed temporal and geographical response of the climate system to the rapid human - made change of climate forcings is not well - constrained by empirical data, because there is no faithful paleoclimate analog.

Although some earlier work along similar lines had been done by other paleoclimate researchers (Ed Cook, Phil Jones, Keith Briffa, Ray Bradley, Malcolm Hughes, and Henry Diaz being just a few examples), before Mike, no one had seriously attempted to use all the available paleoclimate data together, to try to reconstruct the global patterns of climate back in time before the start of direct instrumental observations of climate, or to estimate the underlying statistical uncertainties in reconstructing past temperature changes.

The need for prompt (urgent) action implied by these realities may not be a surprise to the relevant scientific community, because paleoclimate data revealed high climate sensitivity and the dominance of amplifying feedbacks.

The actual prevailing view of the paleoclimate research community that emerged during the early 1990s, when long - term proxy data became more widely available and it was possible to synthesize them into estimates of large - scale temperature changes in past centuries, was that the average temperature over the Northern Hemisphere varied by significantly less than 1 degree C in previous centuries (i.e., the variations in past centuries were small compared to the observed 20th century warming).

What about the feedbacks that are not normally well represented by ECS and normally fall into the Earth System Climate Sensitivity, stuff like the Arctic Ice cover, which now has trends over decades closer to what was seen on centuries in paleoclimate:

However, it is not foolproof — a deeply flawed paper can end up being published under a number of different potential circumstances: (i) the work is submitted to a journal outside the relevant field (e.g. a paper on paleoclimate submitted to a social science journal) where the reviewers are likely to be chosen from a pool of individuals lacking the expertise to properly review the paper, (ii) too few or too unqualified a set of reviewers are chosen by the editor, (iii) the reviewers or editor (or both) have agendas, and overlook flaws that invalidate the paper's conclusions, and (iv) the journal may process and publish so many papers that individual manuscripts occasionally do not get the editorial attention they deserve.

However, I would urge readers who are unconstrained by such beliefs to examine the paleoclimate literature.

In paleoclimate, I would say it is well established by now that things like the Younger Dryas event or the climatic response to Heinrich events are driven by high - latitude buoyancy (mainly freshwater) forcing.

But it could be even worse — with the GHG feedback added in, the full response from the paleoclimate effects looks like it could multiply the IPCC estimates by a factor of 4 to 6.

This might partly be explained by the fact that paleoclimate data is measuring a system in equilibrium, while models are predicting a climate in transition.

Firstly paleoclimate is not driven in any way by CO2 but by the proximity of planet Earth to supernova which Svensmark has helpfully converted into a nice graph that is a remarkable fit to global temperature reconstructions.

It would be desirable as well if journals publishing statistical paleoclimate articles followed econometric journal practices by requiring the archiving of working code as a condition of review.

Nate: Professional divers with the ability to operate underwater machinery are in demand by some, if not all paleoclimate labs.

This practice was most evident in paleoclimate reconstructions, either done by IPCC participants or chosen for inclusion in the IPCC Reports.

And according to a new paleoclimate comparison by James Hansen we could be in for meters of sea level rise within this century, due to expected non-linearity of the melting process.

The occurence of El Niño itself is — as far as science understands the phenomenon, based largely on Pliocene paleoclimate comparisons, even Eocene «clam studies «-- probably not strongly influenced by the trend of global climate warming.

In this study, which was led by Oregan State University, funded by the US National Science Foundation's Paleoclimate Program and just published in Science, researchers used «extensive sea and land surface temperature reconstructions» of around 21,000 years ago — in stead of the (late) Holocene temperature record that is mostly used.

CLIMAS Paleoclimate Tool: use the map to view reconstructed data by Arizona / New Mexico State Climate Divions

The study, «Assessing the Risk of Persistent Drought Using Climate Model Simulations and Paleoclimate Data,» was also co-authored by Julia E. Cole, David M. Meko and Jonathan T. Overpeck of University of Arizona; and Gregory T. Pederson of the U.S. Geological Survey.

When I hear this criticism of the paleoclimate record, namely that we have only indirect knowledge of it, which the «tool man» contrasts with the knowledge we gain of trends by means of satellites, I am reminded that all knowledge is from one perspective or another, indirect.

Once the above 13 votes were thrown, MBH was declared the winner of the election by 99 % of the votes — sort of like a paleoclimate Kim Il Jong.

One has only to look at the recent exchange of papers in Annals of Statistics (McShane and Wyner) on paleoclimate or the recent withdrawl of a paper claiming an «Australian hockey stick» caused by a blogger (Steve McIntyre) who had the gaul to approach the results skeptically to see what the problem is here.

Mann's PC1 has been used more by third parties AFTER the problems were identified than before; it's as if the paleoclimate community is showing solidarity with Mann because he's been criticized by outsiders.

Climate specialists performed simulations of paleoclimate and present climate conditions and came up with the theory that sea levels may rise by up to 10 feet.

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 paleoclimatology community seems to be tightly coupled as indicated by our social network analysis, has rallied around the [Mann] position, and has issued an extensive series of alternative assessments most of which appear to support the conclusions of MBH98 / 99... Our findings from this analysis suggest that authors in the area of paleoclimate studies are closely connected and thus «independent studies» may not be as independent as they might appear on the surface.

This is only suggested by ice - core paleoclimate data which is ultimately uncheckable by direct empirical observation.

Very interesting, Mr. S. For those of us unfamiliar with the literature can you answer for us the most pressing question about this as a reply to Alson's question: are the paleoclimate runs referred to in this abstract performed by one of the models used for contemporary climate prediction and informing the global political process — i.e., one of those referred to in the IPCC reports?

According to climate sensitivity and paleoclimate science, these volumes are already enough to increase global temperatures by between 1.5 to 2 C this century and 3 - 4 C long term.

The investigative blogger Deep Climate has been working to set the record straight on how an orchestrated campaign by members of Congress, industry - funded global warming denialist groups and PR operatives, and professional «skeptics» has spread misleading information about the paleoclimate... Continue reading →

OK, that looks like an opinion piece by someone with no understanding of anything that has ever happened in climate going back to paleoclimate.