Sentences with phrase «temperature changes over»

All they've really demonstrated is that GHG forcings and TSI alone can not account for temperature changes over the past century or so.

The second is is the claim that the pattern of temperature changes over the past century can be replicated by models including greenhouse gas forcing but not otherwise.

We'd expect to see the imprint of this large error in comparisons with observed surface temperature changes over the 20th century (37 - 42), and in comparisons with the observed cooling after large volcanic eruptions (30, 43, 44).

Climate models and efforts to explain global temperature changes over the past century suggest that the average global temperature will rise by between 1.5 º and 4.5 ºC if the atmospheric COconcentration doubles.

However some people probably won't be worried, because they simply can't seem to compute that small global temperature changes over time can have severe impacts like this that could reshape climate systems.

They tell the reader what natural factors are correlated with temperature changes over the period from which the data were used.

From the IPCC AR4: «The fact that climate models are only able to reproduce observed global mean temperature changes over the 20th century when they include anthropogenic forcings, and that they fail to do so when they exclude anthropogenic forcings, is evidence for the influence of humans on global climate.»

As a researcher in the field for more than 30 years, I am not aware of a single peer - reviewed paper or review, in a quality atmospheric science journal, that relates the temperature changes over this period to only natural causes such as changes in solar activity.

There have been numerous research papers and reviews published over the past 10 years, including several in prestigious journals such as Nature and Science, that conclude that the observed temperature changes over the past 100 years are consistent with the combined changes in atmospheric aerosols (volcanic and anthropogenic), land surface changes, variations in solar irradiance and increases in greenhouse gases.

Projected temperature changes over this century are too small to breach the latter two conditions.

Since the TAR, a number of additional proxy data syntheses based on annually or near - annually resolved data, variously representing mean NH temperature changes over the last 1 or 2 kyr, have been published (Esper et al., 2002; Crowley et al., 2003; Mann and Jones, 2003; Cook et al., 2004a; Moberg et al., 2005; Rutherford et al., 2005; D'Arrigo et al., 2006).

In April 2012, DJ Rowlands, from Oxford, published an article in Nature Geoscience that concluded, in part: «We find that model versions that reproduce observed surface temperature changes over the past 50 years show global - mean temperature increases of 1.4 - 3 K by 2050, relative to 1961 - 1990, under a mid-range forcing scenario».

The graph below represents Australian temperatures from multiple authoritative sources, including overseas agencies who prepare their own estimates of temperature changes over Australia.

On page 13255, Mann says: [Sparse proxies before 1500] «poses less of a challenge to the EIV approach, which makes use of nonlocal statistical relationships, allowing temperature changes over distant regions to be effectively represented through their covariance with climatic changes recorded by the network.»

I can not say whether a close examination of that data set will lead to any material change in the view of temperature changes over the past century, but checking the dataset seems a worthwhile exercise.

But it's a bit easier to define the average anomaly, and besides, this shows us what we're concerned with — how the temperature changes over time.

A paper published in the journal of the Italian Astronomical Society finds that solar geomagnetic activity was highly correlated to global temperature changes over the period from 1856 - 2000.

The first graph shows how the average daily temperature changes over the full time period — making it easy to see equilibrium being reached.

In terms of future radiative forcing and global - mean temperature changes over 1990 — 2100 they correspond to uncertainties of at least ± 0.2 Wm − 2 and ± 0.1 ° C, respectively.

Temperature changes over time can be affected by various factors, including changes in Solar Radiation (SR) and in the Radiative Forcing (RF) attributable to rising atmospheric concentrations of anthropogenic greenhouse gases.

However, the Prudent Path authors fail to reference a recent paper (Kaufmann et al. 2009) which analyzed Arctic temperature changes over a 2000 year period (0 to 1999 AD) and concluded that «the most recent 10 - year interval (1999 - 2008) was the warmest of the past 200 decades» and that «4/5 of the warmest decades occurred during the last century».

Every model has a different sensitivity and they all claim to «match» the observed surface temperature changes over the last century.

The regional model's predictions of surface temperature changes over the eastern United States were compared to parallel forecasts made by the same GCM.

«There have been many attempts to determine TCR and ECS values based on the history of temperature changes over the last 150 years and the measurements of important climate drivers, such as carbon dioxide.

Finds that the feedback for which the evidence of ongoing changes is most compelling is the surface albedo - temperature feedback, which is amplifying temperature changes over land (primarily in spring) and ocean (primarily in autumn — winter)

Therefore, I find it hard to see how a * living * upper treeline of very old trees can measure any temperature changes over their age greater than 1.2 C (ok, make it 1.5 C at most with unsaturated air).

It is assumed that a successful hindcast of temperature changes over the 20th century increases our confidence in projections of future warming.

This convergence of El Nino and solar effects has unfortunately confused many and is exactly the reason that temperature changes over a decade are not very meaningful in climate prediction.

(c) Scherhag (op.cit., 1937) states that a thorough research of the temperature changes over the whole northern half of the globe during the period 1921 - 1930 confirmed that the largest part of the investigated region had been, indeed, considerably warmer during the decade 1921 - 1930.

Now we can plainly see that all they tell much the same story, in terms of the temperature changes over time.

As the «sekptics» so frequently argue that PDO is largely responsible for the global temperature changes over the last ~ 100 years, I wonder if you did a follow up that looked at this claim, or if you might do an update in the near future.

This places recent global warming trends in the context of temperature changes over longer time scales.

«This chart shows Northern Hemisphere temperature changes over the last 10,000 years, based on ice core data.

Overall, the PAGES 2k paper provides the best overall reconstruction of local and global surface temperature changes over the past 1,000 — 2,000 years.

Gregory and Oerlemans (1998) applied local seasonal temperature changes over 1860 to 1990 calculated by the HadCM2 AOGCM forced by changing greenhouse gases and aerosols (HadCM2 GS in Table 9.1) to the glacier model of Zuo and Oerlemans.

The authors offered an example of the challenges faced in this undertaking: though changes to the Atlantic Meridional Overturning Circulation can be predicted, this did not necessarily translate to predictable temperature changes over land.

Weather fluctuations certainly exceed local temperature changes over the past half century.

Jones, P.D., Briffa, K.R., Osborn, T.J., Mann, M.E., Bradley, R.S., Hughes, M.K., Cover Figure for World Meteorological Organization (WMO) 50th Year Anniversary Publication: Temperature changes over the last Millennium, 2000.

In their paper, Swanson et al. use climate models to hash out the role internal variability has played in average global temperature changes over the past century (Figure 1).

Theory insists the bulk of the observed temperature changes over the past several decades were caused mostly by people.

Jim Steele, former biologist for the State of California, conducted a study of temperature changes over the past 100 years in the state and could find no evidence of climate change.

Cumulative distribution functions for temperature changes over 1900 — 2005 and 1950 — 2005 for a GHG - only and b all anthropogenic forcings.

Cumulative distribution functions for global - mean temperature changes over 1900 — 2005 and 1950 — 2005.

Additionally, the observed surface temperature changes over the past decade are within the range of model predictions (Figure 6) and decadal periods of flat temperatures during an overall long - term warming trend are predicted by climate models (Easterling & Wehner 2009).

Big temperature changes over few decades.

Antarctic temperature changes across the ice ages were very similar to globally - averaged temperatures, except that ice age temperature changes over Antarctica were roughly twice that of the global average.

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.

In March 2009, Michaels, under the auspices of the Cato Institute, circulated a draft advertisement that stated: «Surface temperature changes over the past century have been episodic and modest and there has been no net global warming for over a decade now... The computer models forecasting rapid temperature change abjectly fail to explain recent climate behavior.»

But for detecting climate change, the concern is not the absolute temperature — whether a station is reading warmer or cooler than a nearby station over grass — but how that temperature changes over time.

Despite its fundamental problems, Spencer's internal variability hypothesis was probably the best alternative presented to this point, and Dessler drove another nail into its coffin by demonstrating what a small effect clouds have had on global temperature changes over the past decade.