Sentences with phrase «age orbital changes»

Not exact matches

Periods of volcanism can cool the climate (as with the 1991 Pinatubo eruption), methane emissions from increased biological activity can warm the climate, and slight changes in solar output and orbital variations can all have climate effects which are much shorter in duration than the ice age cycles, ranging from less than a decade to a thousand years in duration (the Younger Dryas).

While natural global warming during the ice ages was initiated by increased solar radiation caused by cyclic changes to Earth's orbital parameters, there is no evident mechanism for correcting Anthropogenic Global Warming over the next several centuries.

The response of that model to volcanic forcings, the last ice age, changes in orbital parameters etc. are all «out - of - sample» tests that are not fixed by adjusting parameters.

The ice age orbital correlation is old knowledge; there all those years ago in my high school geology text *, along with the observation that the insolation change is way too small to provide a simplistic explanation.

1966 Emiliani's analysis of deep - sea cores shows the timing of ice ages was set by small orbital shifts, suggesting that the climate system is sensitive to small changes.

Based on the comparison between reconstructions and simulations, there is high confidence that not only external orbital, solar and volcanic forcing, but also internal variability, contributed substantially to the spatial pattern and timing of surface temperature changes between the Medieval Climate Anomaly and the Little Ice Age (1450 to 1850).

The important point here is that a small external forcing (orbital for ice - ages, or GHG plus aerosols & land use changes in the modern context) can be strongly amplified by the positive feedback mechanism (the strongest and quickest is atmospheric water vapor - a strong GHG, and has already been observed to increase.

Cochelin et al used a model of intermediate complexity to show that the orbital variations over the next 100,000 years are weak enough that even a little human CO2 remaining in the atmosphere is enough to keep the earth out of an ice age («Simulation of long - term future climate changes with the green McGill paleoclimate model: The next glacial inception»).

Climate model simulations confirm that an Ice Age can indeed be started in this way, while simple conceptual models have been used to successfully «hindcast» the onset of past glaciations based on the orbital changes.

Changes in insolation due to the sun's orbital cycles, or Milankovitch cycles, correspond with the recent 100,000 - year cycles of past major ice ages.

The paper also notes that orbital changes are one initial cause for ice ages.

The orbital changes that caused the ice ages are far too weak and slow to cause a warming as rapid as the current one.

Another fascinating question relates to the triggers for ice ages, which are generally thought to involve reduced summer insolation at 65 N as consequence of orbital forcing changes.

As the Earth came out of the ice age the primary forcing which caused the initial warming was due to changes in the Earth's orbital pattern.

In the case of the 100 kyr ice age cycles, that forcing is high northern latitude summer insolation driven by predictable changes in Earth's orbital and rotational parameters — aka, Milankovitch theory — which has the intial effect of melting glaciers, thereby reducing albedo at those latitudes.

When orbital wiggles and rising greenhouse gases warmed the earth from the last ice age, proxy records show that smooth changes were interspersed with abrupt coolings and warmings, wettings and dryings.

Have a look at this updated version of one of the articles here about past temperatures, it has good graphics and more detail about determining the past, plus links to good sources: http://gristmill.grist.org/story/2006/10/26/20495/240 The warming that ended the ice age was caused by changes in the earth's orbital inclination (Milankovich cycles).

wili, I've often pondered about the ice age cycles, how a bit - o - carbon equivalent in orbital changes can cause a 100ppm increase in atmospheric carbon.

As the gas level rose, temperature would rise with a time lag — although only a few decades, not centuries, for the rates of change were now enormously faster than the orbital shifts that brought ice ages.

1966 Emiliani's analysis of deep - sea cores and Broecker's analysis of ancient corals show that the timing of ice ages was set by small orbital shifts, suggesting that the climate system is sensitive to small changes.

Posted in Musings, Science Lessons, tagged astronomy, climate change, education, fantasy, game of thrones, george r r martin, glaciers, global warming, hbo, ice age, orbital mechanics, science, song of ice and fire on June 2, 2014 8 Comments»

The most clear evidence of change is from retreating ice escarpments in the southern hemisphere and it is thought this is mostly the result of Mars» own orbital cycles similar to those that controled the timing of Earth's ice ages.

As for the cause of the ice ages, it is generally but cautiously accepted that they were triggered by cyclical changes in the earth's orbital inclinations.

But if climate really is as insensitive as he claims it to be, the climate forcing producing the ice ages must have been huge, much larger than the radiative forcing from orbital changes, surface albedo, and greenhouse gases.

We can vote on whether or not we want to make weather to produce an ice age, given orbital and tectonic changes.

Besides demonstrating his firm grasp of the power of these various factors to change temperatures, this remarkable matching of theory to real - world data also tells us just how ornery the climate beast may be: the orbital changes that paced the ice ages were incredibly small.