Sentences with phrase «century scale changes»

Not exact matches

If sexuality seems to be marking the twentieth century with its stamp, it is certainly not that man has changed but simply that he has a different consciousness of sex, and has given it a place of its own in his scale of values.1

«The study demonstrates a robust century - scale link between ocean circulation changes in the Atlantic basin and rainfall in the adjacent continents during the past 4,000 years,» said UTIG Director Terry Quinn, a co-author on the study.

They wrote that their comparisons of sea - level pressures, sea - surface temperatures and land - based air temperatures provided «consistent evidence for strong» regulation of temperatures by changes in ocean cycles «from monthly to century time scales.»

For significant periods of time, the reconstructed large - scale changes in the North Pacific SLP field described here and by construction the long - term decline in Hawaiian winter rainfall are broadly consistent with long - term changes in tropical Pacific sea surface temperature (SST) based on ENSO reconstructions documented in several other studies, particularly over the last two centuries.

«Ocean warming, acidification and deoxygenation are essentially irreversible on centennial time scales,» found the Royal Society, a London - based group specializing in scientific research, in a 2011 paper, «[O] nce these changes have occurred, it will take centuries for the ocean to recover.

This implies that large - scale observations — for example, of global mean sea - level change or of the change mass of the Antarctic ice sheet — will not on their own significantly narrow the range of late - century sea - level projections for decades to come.

The substantial uncertainties currently present in the quantitative assessment of large - scale surface temperature changes prior to about A.D. 1600 lower our confidence in this conclusion compared to the high level of confidence we place in the Little Ice Age cooling and 20th century warming.»

Climate system inertia also means that, if large - scale climate change is allowed to occur, it will be exceedingly long - lived, lasting for many centuries.

This 2006 study found that the effect of amplifying feedbacks in the climate system — where global warming boosts atmospheric CO2 levels — «will promote warming by an extra 15 percent to 78 percent on a century - scale» compared to typical estimates by the U.N.'s Intergovernmental Panel on Climate Change.

Here's the primary problem from my perspective: Succeeding with STEM education in the 21st century requires systemic change at a scale far larger than the Harvard professors had to envision 110 years ago.

«As the world rapidly stampedes into the future,» writes Richard Wells (@EduWells), «there can be no waiting for the large - scale organizations, founded in the 19th and 20th centuries, to form committees to discuss how all might cope with the change.

Section 4105 of the bill being considered makes changes to the 21st Century Community Learning Centers (21st CCLC) program, including language that would drastically alter funding for the initiative by allowing these funds to be diverted to support whole scale school reform.

Modernism is a philosophical movement that, along with cultural trends and changes, arose from wide - scale and far - reaching transformations in Western society during the late 19th and early 20th centuries.

In 2000, after a century of earlier efforts by scholars, scientists, and at least one journalist (me) to give a name to humanity's emerging role as a planet - scale force, one word emerged in a heated moment at a global change conference in Cuernavaca, Mexico — anthropocene.

Specifically, they say: «The implication is that, in the absence of efficient, large - scale capture and storage of airborne carbon (emphasis mine), carbon emissions that have already occurred or will occur in the near future result in a commitment to climate change that will be irreversible on timescales of centuries to millennia and longer.»

The sentence I just quoted implies pretty strongly that, in the presence of efficient (or for that matter inefficient) large - scale capture and storage of airborne carbon, carbon emissions that have already occurred or will occur in the near future might not result in a commitment to climate change that is irreversible on timescales of centuries to millennia and longer.

[Response: Here's a simple back - of - envelope consideration for the future: if the Greenland ice sheet melts completely over the next ~ 1,000 years (Jim Hansen argues in the current Climatic Change that the time scale could be centuries), this would contribute an average flux of ~ 0.1 Sv of freshwater to the surrounding ocean.

If I read it correctly, this says that the number of effectively independent stations needed to track century - scale changes is about 5, and for yearly changes the number is around 150.

If you look at rates of change already and that changes are from decades to a century ahead of schedule, and think Arctic permafrost and clathrates have a realistic probability of breaking down on a massive scale within years or decades, then you take another.

For the 20th Century, models show skill for the long - term changes in global and continental - scale temperatures — but only if natural and anthropogenic forcings are used — compared to an expectation of no change.

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).

Action on climate change needs to be scaled up and accelerated without delay if the world is to have a running chance of keeping a global average temperature rise below 2 degrees Celsius this century.

For weather predictions, accuracy disappears within a few weeks — but for ocean forecasts, accuracy seems to have decadal scale accuracy — and when you go to climate forcing effects, the timescale moves toward centuries, with the big uncertainties being ice sheet dynamics, changes in ocean circulation and the biosphere response.

Analysis of sea level changes during Eemian time, the last interglacial, show changes of several meters in time scales of a century.

Compare the year - to - year scale at which humans make policy decisions, reflected in our political frameworks, to the multi-millennial consequences of today's energy choices, as delineated in «Consequences of twenty - first - century policy for multi-millennial climate and sea - level change,» the important recent commentary in Nature Climate Change by a host of top climate scientists, including Pierrehuchange,» the important recent commentary in Nature Climate Change by a host of top climate scientists, including PierrehuChange by a host of top climate scientists, including Pierrehumbert.

There is high confidence that this has caused large - scale changes in the ocean, in the cryosphere, and in sea level in the second half of the 20th century.

1) Real temperature changes will incorporate auto - correlation, which can be on the scale of years, decades, centuries and so on.

2) How to explain a century - scale change in the human relationship with the planet in a way that fits into traditional journalism (of course, part of the answer is this blog).

Not only does the Earths magnetic field wander around on time scales of a century or so, but every 100,000 years or so it completely changes direction, with the north (magnetic) pole becoming the south (magnetic) pole.

Next point, changes in volcanic activity can affect decadal and century - scale temperatures due to the random occurence of eruptions of the right sort (though I don't think you dispute that).

Amid all the progress on this planet — declining losses from terrible diseases and war, rising literacy and the rest — there remain plenty of planet - scale risks requiring serious focus, from pandemic flu to centuries of locked - in climate change to, yes, collisions with space rocks.

Thus although I believe strongly in thinking hard about our paleolithic roots as indicators of our mental and civilizational capabilities (see my most recent novel «Shaman») I also think we are changing culturally, and can now think on the scale of centuries, and plan and act accordingly as a civilization.

The problem is really that SW assume that all climatic fluctuations in the 17th to the 19th centuries to solar activity, and hence neglect factors (natural forcings) such as landscape changes (that the North America and Europe underwent large - scale de-forestation), volcanism (see IPCC TAR Fig 6 - 8), and internal variations due to chaotic dynamics.

Because the analysis method and sparse data used in this study will tend to blur out most century - scale changes, we can't use the analysis of Marcott et al. to draw any firm conclusions about how unique the rapid changes of the twentieth century are compared to the previous 10,000 years.

``... it is now very likely that anthropogenic forcing has contributed to the observed changes in the frequency and intensity of daily temperature extremes on the global scale since the mid-20th century.

Although the simulation conditions in the MMD 20th - century simulations were not identical to those in the CMIP1 & 2 control runs, the differences do not alter the conclusions summarised below because the large - scale climatological features dominate, not the relatively small perturbations resulting from climate change.

The researchers predict that drylands will continue to move eastward with the century, as global temperatures continue to rise, and eventually trigger large - scale changes.

The terrestrial biosphere can respond slowly to large, regional - scale forcing, but may not always be in equilibrium with that forcing at any point in time, leading to subsequent commitments to significant future change for decades or centuries following stabilization of forcing.»

«Researchers working at the Australian National University Research School of Earth Sciences have discovered century - scale patterns in Pacific rainfall and temperature, and linked them with global climate changes in the past 2000 years.

The 2 °C target is a matter of substantial debate (too weak, too strong, too vague...), but it is a good yardstick for understanding the scale of climate change, and its impacts, that we are setting ourselves up for this century.

Ice cores show atmospheric CO2 variations to lag behind atmospheric temperature changes on a century to millenium scale, but modern temperature is expected to lag changes in atmospheric CO2, as the atmospheric temperature increase since about 1975 generally is assumed to be caused by the modern increase in CO2.

As for exagerating or minimizing the current temperature trend through choice of scale, it really depends on wether or not 1oC is a large change to occur over one century and all evidence suggests that it is.

Long - term natural variability has implications for the modeling of future climate changes, on the scale of decades to centuries.

for understanding the scale of climate change, and its impacts, that we are setting ourselves up for this century.

The overall level of consistency between attribution results derived from different models (as shown in Figure 9.9), and the ability of climate models to simulate large - scale temperature changes during the 20th century (Figures 9.5 and 9.6), indicate that such model differences are likely to have a relatively small impact on attribution results of large - scale temperature change at the surface.

Both the NAO and ENSO exhibited marked changes in their surface climate expressions on multi-decadal time scales during the 20th century (e.g., Power et al., 1999b; Jones et al., 2003).

For the entire Northern Hemisphere, there is evidence of an increase in both storm frequency and intensity during the cold season since 1950,1 with storm tracks having shifted slightly towards the poles.2, 3 Extremely heavy snowstorms increased in number during the last century in northern and eastern parts of the United States, but have been less frequent since 2000.11,15 Total seasonal snowfall has generally decreased in southern and some western areas, 16 increased in the northern Great Plains and Great Lakes region, 16,17 and not changed in other areas, such as the Sierra Nevada, although snow is melting earlier in the year and more precipitation is falling as rain versus snow.18 Very snowy winters have generally been decreasing in frequency in most regions over the last 10 to 20 years, although the Northeast has been seeing a normal number of such winters.19 Heavier - than - normal snowfalls recently observed in the Midwest and Northeast U.S. in some years, with little snow in other years, are consistent with indications of increased blocking (a large scale pressure pattern with little or no movement) of the wintertime circulation of the Northern Hemisphere.5 However, conclusions about trends in blocking have been found to depend on the method of analysis, 6 so the assessment and attribution of trends in blocking remains an active research area.

«If we were to switch into one of these century - scale patterns of drought, it would be a lot more severe, and it would be very difficult for people to adjust to the change,» says Shanahan.

Paleontological records indicate that global mean sea level is highly sensitive to temperature (7) and that ice sheets, the most important contributors to large - magnitude sea - level change, can respond to warming on century time scales (8), while models suggest ice sheets require millennia to approach equilibrium (9).

The study by Macias & Johnson (2008) provides not only evidence for the link between decadal - scale changes in the teleconnection patterns (e.g. the Pacific Decadal Oscillation (PDO) index) and the increased fire frequency in the late twentieth century but also an explanation of why the pattern of fire variability and fire - climate relationships changes at different time scales from centennial / decadal to interannual.....