Sentences with phrase «orbital variations»

Those are paced by orbital variations, which have nothing to do with solar activity.

The glacial cycle of the past million years was forced by long - term orbital variations.

There is good evidence and physical grounds for CO2 and orbital variations influencing glacial cycles, but that by no means shows that they completely control the glacial system.

The time scale of concern here is that of decades to centuries, and excludes the longer millennial scale in which orbital variations play a dominant role.

We know there are many factors that can affect our climate, such as orbital variations, shifts in geographical features, volcanos, GHGs, etc..

«Milankovitch cycles» — natural orbital variations which primarily determine the timing of Ice Ages.

Moreover, it offers a better understanding of the link between orbital variations and climate change over geologic time scales.

Over the last 30 years of direct satellite observation of the Earth's climate, many natural influences including orbital variations, solar and volcanic activity, and oceanic conditions like El Nino (ENSO) and the Pacific Decadal Oscillation (PDO) have either had no effect or promoted cooling conditions.

Although orbital variations instigate the glacial - interglacial swings, the mechanisms for climate change are changes in GHG amount and surface albedo (as we show in Fig. 1 of our paper)-- those mechanisms are now under the control of humans.

Reality: Whilst there are many areas of interesting research with respect to the glacial - interglacial cycles of the Quaternary, we have a good understanding of the primary drivers i.e. orbital variations occurring over cycles of tens of thousands of years.

Do orbital variations in insolation drive ice - age cycles if you have a strong negative cloud feedback?

The National Research Council of the U.S. National Academy of Sciences has embraced the Milankovitch Cycle model... orbital variations remain the most thoroughly examined mechanism of climatic change on time scales of tens of thousands of years and are by far the clearest c...

Croll's «Climate and Time, in Their Geological Relations» (1875) explained how orbital variations could cause cycles of ice ages.

It's also worth remembering that the «cradle of civilization'took place when orbital variations gave Mesopotamia (and the rest of the Northern Hemisphere) much hotter summers.

But some time around 850,000 years ago, the cycle grew to 100,000 years, and ice sheets reached greater extents than they had in several million years — a change too great to be explained by orbital variation alone.

«orbital variations control the timing but not the amplitude.»

When I look at all of this, I see a handful of the 100 large solar system bodies showing some evidence of local warming (Jupiter's spot), some evidence of systemic warming with known causes that are a lot more likely than the Sun heating up (like well - understood orbital variations), and some evidence that any warming experienced by these bodies is possibly being exaggerated in the reporting.

At a later time, a CO2 threshold is crossed, initiating ice - sheet height / mass - balance feedbacks that cause the ice caps to expand rapidly with large orbital variations, eventually coalescing into a continental - scale East Antarctic Ice Sheet.

I'll mention that although orbital variation (precession) causes opposite insolation changes in the two hemispheres, axial tilt (obliquity) variation causes synchronous insolation changes in the two hemispheres.

The fundamental driver has long been thought, and continues to be thought, to be the distribution of sunshine over the Earth's surface as it is modified by orbital variations.

This was particularly true at more distant dates as the Indian monsoons were stronger, thanks to more sunlight hitting Earth due to orbital variations.

It is well - established in climatology that different causes and mechanisms have caused climate changes in the past (orbital variations, plate tectonics, solar variability, volcanic eruptions, etc.), so that a cause - effect relationship has to be determined for each individual case, rather than looking for one overall «driver».

If it had always been stable in the face of orbital variations, changes in atmospheric conditions and so on, then it would indicate a very robust climate that could well stand up to whatever we throw at it.

These orbital variations, which can be calculated from astronomical laws (Berger, 1978), force climate variations by changing the seasonal and latitudinal distribution of solar radiation (Chapter 6).

And yes, there is such evidence — in the predicted response to volcanic forcing, the ozone hole, orbital variations, the sun, paleo - lake outbursts, the response to ENSO etc. that all show models matching the observations skillfully (which is not to say they match perfectly).