Sentences with phrase «paleoclimate data for»

, has her group at the Yale School of Forestry and Environmental Studies, considered the paleoclimate data for afforestation?

Based on these data, the 10 - year period, 1146 — 1155, was selected as a scenario of worst - case warm drought from the paleoclimate data for the past 12 centuries over the Southwest.

We consider several important climate impacts and use evidence from current observations to assess the effect of 0.8 °C warming and paleoclimate data for the effect of larger warming, especially the Eemian period, which had global mean temperature about +2 °C relative to pre-industrial time.

Just a quick note to say that the paleoclimate data for earlier warm periods 125,000 years ago and even 8 - 10,000 years ago in northern Alaska (paleoclimate warmer than now, [from] different forcings) document the northward advance of the treeline from Nome to Barrow, Alaska, and the Canadian border at different times of change in Earth's orbital parameters (without a significant change in CO2).

Paleoclimate data for sea level change indicate that sea level changed at rates of the order of a meter per century [81]--[83], even at times when the forcings driving climate change were far weaker than the human - made forcing.

Not exact matches

The paleoclimate data, which included mainly changes in the oxygen isotopes of the calcium carbonate deposits, were then compared to similar records from other caves, ice cores, and sediment records as well as model predictions for water availability in the Middle East and west central Asia today and into the future.

He has served on national and international advisory committees for paleoclimate research, ocean research, and data management issues, and has contributed to national reports on abrupt climate change and climate extremes.

In Eos now... three early - career scientists report on the PAGES 2nd YSM in Goa, and discuss future directions for the paleoclimate field, e.g. the need for network building, more quantitative proxy - based reconstructions, fast and efficient data sharing, securing funding, and communicating results.

This is being actively investigated for the current human - caused global warming scenario with models and paleoclimate data.

Here Professor Kaufman talks about the importance of community - endorsed data compilations for accelerating discovery in paleoclimate science.

A best estimate of climate sensitivity close to 3 °C for doubled CO2 has been inferred from paleoclimate data [51]--[52].

http://arxiv.org/pdf/0804.1126 «Paleoclimate data show that climate sensitivity is 3 °C for doubled CO2, including only fast feedback processes.

Alternatively, more direct observations of that radiative imbalance would be nice, or better theoretical and observational understanding of the water vapor and cloud feedbacks, or more paleoclimate data which can give us constraints on historical feedbacks, but my guess is that ocean heat content measurements would be the best near term bet for improving our understanding of this issue.

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.

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 amount of available data is very sparse, and so while these kind of «deep time» paleoclimate questions are a lot of fun, the lack of detail means that they have limited implications for today's climate.

This is a touchy topic for advocates of Broecker's theories, but the paleoclimate data collected in the tropics just don't support that scenario.

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.

This is being actively investigated for the current human - caused global warming scenario with models and paleoclimate data.

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.

In fact some at IPCC have argued the paleoclimate data are irrelevant to the case for precautionary action.

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].

Ongoing field and laboratory programs in palynology, paleoclimate reconstruction, and other geophysical sciences provide fundamental climate data for evaluating model predictions.

Fully independent reconstructions will allow mutual validation during their overlapping time intervals and spectral ranges and will help test methods for fusing high - and low - resolution paleoclimate data.

Verdon and Franks (2006)-- for instance — used «proxy climate records derived from paleoclimate data to investigate the long - term behaviour of the PDO and ENSO.

Among the communities targeted by the EarthCube program, some communities, including scientists using marine annually resolved proxy archives, have yet to establish a cyberinfrastructure with improved standards for storage and sharing of paleoclimate data and archive - specific metadata on the physical samples.

A best estimate of climate sensitivity close to 3 °C for doubled CO2 has been inferred from paleoclimate data [51]--[52].

Best we currently have for a comparable time using paleoclimate data is not the Eemian but much further back — to the Pliocene.

Paleoclimate data are not as helpful for defining the likely rate of sea level rise in coming decades, because there is no known case of growth of a positive (warming) climate forcing as rapid as the anthropogenic change.

Third, our calculations are for a single fast - feedback equilibrium climate sensitivity, 3 °C for doubled CO2, which we infer from paleoclimate data.

However, paleoclimate data are used as a foundation for climate scientists by providing crucial information such as rates of past climate change and how vegetation and animal populations responded to the change.

However, as Hansen notes, empirical estimates of climate sensitivity based on paleoclimate data are consistent with the sensitivity in climate models of approximately 3 °C for doubled atmospheric CO2.

Hansen and Sato argue that the probable range of climate sensitivity values is not as large as currently believed (unlikely to fall outside the range of 2 to 4 °C for doubled CO2)- both very high and very low values can effectively be ruled out using paleoclimate data.

Our best guide here is probably the paleoclimate data, which tends to indicate we're headed for mid-Pliocene to Miocene - like conditions as we go toward 560 ppm, which again, are about 3C or higher than pre-industrial temperatures.

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.

«We show that paleoclimate data from the Miocene, Pliocene and Pleistocene epochs provide evidence for changing sensitivity through time, probably due to changing boundary conditions due to tectonics.

Although O18 data is a workhorse of paleoclimate, O18 data from Alaska (or, for that matter, anywhere in the Arctic hemisphere between 90E and 90W — going east) is very scarce.

However, in my opinion, NSF (paleoclimate) has become a cheerleader for the small paleoclimate industry and abdicated its obligations to ensure compliance with US federal data archiving policies.

In fact, climate scientists have used paleoclimate data such as that for the ice ages to show that climate sensitivity is likely to be close to the range the IPCC favors.

-- paleoclimate data reflecting past climate states very different from today — climate response to volcanic eruptions, solar changes and other non-greenhouse gas forcings — timescales different from those relevant for climate stabilization, such as the climate response to volcanic eruptions

If it were restricted to 30 years, for instance, the paleoclimate data should show that the average temperature should follow very closely the forcing (Milankovitch) curve, which is obviously not the case.

Although it has been a common practice in studying paleoclimate data to use proxy data from, for example, an ice core in Antarctica, to represent global climate after dividing the former by a factor of ∼ 2 or by a model - determined, latitude - dependent scaling factor, theoretical justification is only beginning to be emphasized (22).

Idso's calculations for climate sensitivity are greatly at odds with the paleoclimate data; if sensitivity were as small as he proposes, the Milankovic changes in solar forcing wouldn't be enough to kickstart the climb out of an ice age, but this still presupposes AGW, that CO2 emissions will increase the temperature by some amount.

And by the way, I am not aware of any event in the Paleoclimate record where CO2 in the atmosphere rises this much this fast although, to be fair, paleoclimate data from the distant past often lacks the fine resolution required for such a dePaleoclimate record where CO2 in the atmosphere rises this much this fast although, to be fair, paleoclimate data from the distant past often lacks the fine resolution required for such a depaleoclimate data from the distant past often lacks the fine resolution required for such a demonstration.

Hansen and Sato (2012), using paleoclimate data rather than models of recent and expected climate change, warn that «goals of limiting human made warming to 2 °C and CO2 to 450 ppm are prescriptions for disaster» because significant tipping points — where significant elements of the climate system move from one discrete state to another — will be crossed.

As far as # 2 goes, ice core data is used for recent paleoclimate data on CO2 concentration, nothing much earlier than about 1000 years ago, because of the errors inherent in the ice core data.

Finally, we comment on several policy issues arising from this controversy: the lack of consistent requirements for disclosure of data and methods in paleoclimate journals, and the need to recognize the limitations of journal peer review as a quality control standard when scientific studies are used for public policy.

For the further comparison with other paleoclimate data, therefore, the MXD reconstruction is used; although the reader should take note that the relatively low sample replication in the MXD data generally gives a wider error band (Fig. 5).

Edward Wegman is a statistician at George Mason University known for producing a report disputing paleoclimate data and models concerning the «hockey stick» temperature graph relating to climate change.

The scientific evidence for human influence on current climate comes from a large body of independent lines of evidence of which paleoclimate data is but a small part.