Sentences with phrase «paleoclimate temperature»

7) How central is the debate over the paleoclimate temperature record to the overall scientific consensus on global climate change (as reflected in previous reports from the Academy)?

5) Explain how central the debate over the paleoclimate temperature record is to the state of scientific knowledge on global climate change.

The MBH98 and MBH99 papers are focused on paleoclimate temperature reconstruction and conclusions therein focus on what appear to be a rapid rise in global temperature during the 1990s when compared with temperatures of the previous millennium.

We can obtain this «long - term» climate sensitivity from paleoclimate data by finding the scale factor that causes the GHG forcing to match the paleoclimate temperature change as accurately as possible.

the committee will summarize current scientific information on the temperature record for the past 1,000 - 2,000 years, describe the main areas of uncertainty and how significant they are, describe the principal methodologies used and any problems with these approaches, and explain how central the debate over the paleoclimate temperature record is to the state of scientific knowledge on global climate change.

MM05a was critiqued by Wahl and Ammann (2006) and the Wahl et al. (2006) based on the lack of statistical skill of their paleoclimate temperature reconstruction.

In fact, as noted above, Bradley is cited not once and not in «another section», but six times all in section 2.1 «Background on Paleoclimate Temperature Reconstruction», as well as in the bibliography.

That allows complex spectra to be understood through a process of parametrization - but each of those parameters (governing the gaps between different energy levels of the same type) can not be obtained from an underlying theory, but must be found through measurements, for which statistics applies just as it does for any of these paleoclimate temperature proxies.

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.

Previous large natural oscillations are important to examine: however, 1) our data isn't as good with regards to external forcings or to historical temperatures, making attribution more difficult, 2) to the extent that we have solar and volcanic data, and paleoclimate temperature records, they are indeed fairly consistent with each other within their respective uncertainties, and 3) most mechanisms of internal variability would have different fingerprints: eg, shifting of warmth from the oceans to the atmosphere (but we see warming in both), or simultaneous warming of the troposphere and stratosphere, or shifts in global temperature associated with major ocean current shifts which for the most part haven't been seen.

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.

The NRC asked the committee to summarize current scientific information on the temperature record for the past two millennia, describe the main areas of uncertainty and how significant they are, describe the principal methodologies used and any problems with these approaches, and explain how central is the debate over the paleoclimate temperature record to the state of scientific knowledge on global climate change.

The committee has prepared a report that, in my view, provides policy makers and the scientific community with a critical view of surface temperature reconstructions and how they are evolving over time, as well as a good sense of how important our understanding of the paleoclimate temperature record is within the overall state of scientific knowledge on global climate change.

The linear trend line is now at +1.06 °C, which is perhaps the best temperature to compare to paleoclimate temperatures, because the latter are «centennially - smoothed,» i.e., the proxy measures of ancient temperature typically have a resolution not better than 100 years.

Examinations of paleoclimate temperatures and other variables recorded in both North Atlantic ocean sediments and Greenland ice cores (e.g., Lehman and Keigwin, 1992; Alley et al., 1993; Taylor et al., 1993) have led to suggestions that the AMOC

A: Even 20 years ago there was work on time series modeling of recent and paleoclimate temperatures (Ghil and Vautard, etc.) The tools of (then current) large scale Kalman filtering were well understood by climate scientists from the dynamic meteorology side of the game (I think Eugene Isaacson brokered some of that deal).

The main objection to the comic, among the scientists I surveyed, is to the way Munroe displays the paleoclimate temperatures — that is, everything in the comic before 1850.

Not exact matches

Paleoclimate data point to a warm tropical ocean with a clear east - west temperature gradient during the warm climates of the Pliocene and Miocene.

To estimate the amount of precipitation, Ghosh's team measured a common paleoclimate proxy for temperature, humidity, and atmospheric circulation.

Call that output temperature a signal which goes into box with the CO2 feedback; the output of this second box is the observable temperatures from paleoclimate proxies.

Mike Wallace's talk was about the «National Research Council Report on the «Hockey Stick Controversy»... The charge to the committee, was «to summarize current information on the temperature records for the past millennium, describe the main areas of uncertainty and how significant they are, describe the principal methodologies used and any problems with these approaches, and explain how central is the debate over the paleoclimate record within the overall state of knowledge on global climate change.»

We use Earth's measured energy imbalance, paleoclimate data, and simple representations of the global carbon cycle and temperature to define emission reductions needed to stabilize climate and avoid potentially disastrous impacts on today's young people, future generations, and nature.

As changes in temperature and light can be excluded as reasons for the decline in magnesium concentrations, the researchers interpret it as a clear reaction to ocean acidification — with implications for paleoclimate reconstructions.

Ice core paleoclimate isotope data are indirect indications of temperature (proxies) over millions of years compared to instrumental temperature measurements with high resolution of hours, days and decades.

These long - term trends show the largest increase in temperatures of any paleoclimate event during the past millions of years.

That is the case whether you are extrapolating from paleoclimate data or from any recent temperature dataset vs atmospheric CO2 concentration measurements (eg Keeling curve).

Paleoclimate characteristics and trends provide the overarching framework and climate history to better understand centennial temperature fluctuations and potential future global temperature tipping points.

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 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).

Oerlemans's reconstruction of global temperatures (largely from mid latitude glaciers) is entirely independent of the much talked about temperature records from other paleoclimate proxy data (e.g. Moberg and others, Mann and others, Crowley and others).

The paleoclimate record (8.2 kyr, and earlier «large lake collapses») shows a dramatic drop in surface temperatures for a substantial period of time when the ocean circulation shuts off or changes, but is that actually what would be expected under these warming conditions?

One other point on cloud feedbacks from a paleoclimate perspective — if a strong negative cloud feedback begins at modern earth temperatures, it would be unlikely for past temperatures to have exceeded modern ones.

This paper takes a novel approach to the problem of reconstructing past temperatures from paleoclimate proxy data.

Any small «upticks» or «downticks» in temperature that last less than several hundred years in our compilation of paleoclimate data are probably not robust, as stated in the paper.

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've also analyzed data (not conclusions, but raw data) relating to paleoclimate reconstructions such as tree rings, ice cores, and (my personal favorite) borehole temperature profiles.

That is the case whether you are extrapolating from paleoclimate data or from any recent temperature dataset vs atmospheric CO2 concentration measurements (eg Keeling curve).

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.

If you refer to the fact that CO2 levels rise after temperature rises (from paleoclimate sediment core studies, etc.), this MOST CERTAINLY DOES NOT imply anything in the way of causality.

A U.S. government CCSP report on Arctic paleoclimates a few years ago (to which I contributed)[If anyone is thinking that this paper means we can crank up the temperature without worrying about sea level, they should seriously re-think.

I think the AGW problem is actually more serious if the natural variability is as large as more recent paleoclimate reconstructions suggest: Not only do you have significant temperature swings, you can't even predict them.

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.

I've done a fair amount of calculations trying to estimate this bias, and in the case of paleoclimate 3C estimates, an upward of at least 0.5 C due to this bias is not unreasonable, especially when the «consensus» position is to basically ignore milankovitch cycles when explaining temperature changes over the pleistocene, even though milankovitch cycles are the ultimate causes of those temperature changes.

They have proved that TEX86 in Lake Tanganyika is teleconnected to global temperature without realizing it and thus this single proxy can be used to reconstruct global paleoclimate, similar to, and perhaps more robust in this teleconnection, to the Graybill Bristlecones.

In fact, Marohasy points out that a lack of rising temperatures for recent decades is so common in paleoclimate reconstructions that tendentious climate scientists have necessarily added heavily adjusted, hockey - stick - shaped instrumental records (e.g., from NASA GISS, HadCRUT) on to the end of the trend so as to maintain the visualization of an ongoing dangerous warming.

Figure 4 Figure 5 Figure 7 (Source CDIAC) A never before western published paleoclimate study from China suggests warmer temperatures in the past.

There are these aspects of paleoclimate where CO2 levels changed due to geological processes and the temperature followed, only now it is us instead of geology doing it.

A useful gauge of the impact of a change of a few degrees in global mean temperature can be found in Tom Crowley's article on paleoclimate in this issue of CONSEQUENCES.

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.

22 This study includes 73 records derived from multiple paleoclimate archives and 23 temperature proxies (Fig.