Sentences with phrase «many warm periods»

There was no explanation of why both the medieval warm period and the little ice age, very clearly shown in the 1990 report, had simply disappeared eleven years later.

This warm period was followed by the «little ice age» when the Thames would frequently freeze over during the winter.

There is no evidence for significant increase of CO2 in the medieval warm period, nor for a significant decrease at the time of the subsequent little ice age.

Great flood: the filly of a large basin by raising oceans during the warming period after the last ice age.

We had a Midevil warm period and a mini ice age that ended in the 1700's.

The White House approved a report that found the earth is experiencing the warmest period in the history of civilization and humans are to blame, despite the fact that it directly contradicts much of the Trump administration's position on climate change.

For the last 2.5 million years, Earth settled into a rather unusual period of potential instability as we rocked back and forth between ice ages and intervening warm periods, or interglacials.

Scientists may also become able to distinguish between different scenarios sooner by studying the physics of local ice - sheet changes and refining reconstructions of changes during warm periods in geological history.

So far, ice cores from Greenland and marine sediment cores from Antarctica show that a notable warming period occurred from 3,000 to 8,000 years ago.

Then they lugged them back to Ohio to begin independent study (IS) projects on characterizing the change in sea levels during the last interglacial warming period.

Today, we are in a warm period at the end of an ice age.

In a paper published in Geophysical Research Letters, researchers found that interactions between methane, carbon dioxide and hydrogen in the early Martian atmosphere may have created warm periods when the planet could support liquid water on the surface.

Heavier rainfall at the study sites from the year 0 to 400, and again during Europe's Medieval Warm Period, just before the Little Ice Age from about the year 800 to 1300, was probably caused by a centuries - long strengthening of El Niño.

If the onset of maturity comes earlier in the season, it means that grapes ripen during a warmer period — affecting sugar levels, aromas and flavors and changing the unique identity that connoisseurs look for in regional wines.

«Our study really changes the general concept that before the last warming period you had a massive grass steppe that was fundamental to sustaining a huge diversity of mammals,» says Willerslev.

Its peak extent came in a warm period before the last ice age.

Scientists are learning about how previous warm periods altered sea levels, and what that past may tell us about the future.

«In winters when it's quite cold but there are warm periods, the plants lose the blanket of snow that covers them,» Doak explains.

These big ice sheets have frozen and melted many times in the past (producing ice ages with low sea levels and warm periods with high sea levels).

Until recently, that was also true of the ice sheet's past: Scientists have long debated whether it might have shrunk away to nothing during Earth's warmest periods.

The surge in melt events corresponds to a summer temperature increase of at least 1.2 - 2 degrees Celsius (2.2 - 3.6 degrees Fahrenheit) relative to the warmest periods of the 18th and 19th centuries, with nearly all of the increase occurring in the last 100 years.

«During last warming period, Antarctica heated up two to three times more than planet average: Amplification of warming at poles consistent with today's climate change models.»

The samples» ratios told him the camel roamed 3.8 million years ago and the beavers set up their dam 3.4 million years ago, give or take half a million years — age ranges accurate enough to place them in the middle of the mid-Pliocene warm period.

But Rybczynski and her colleagues have unearthed evidence of a balmier Arctic from a slice of time referred to as the mid-Pliocene warm period, roughly 3 million to 3.3 million years ago.

The Norse settled Greenland from Iceland during a warm period around 1000 C.E..

And in many places, it's moving faster than the ice is thought to have retreated during the warming period at the end of the last ice age, around 20,000 years ago.

«It is possible that Svalbard may have provided one such important refuge during warming periods, in which small polar bear populations survived and from which founder populations expanded during cooler periods,» argues biologist Charlotte Lundqvist of the University at Buffalo, The State University of New York, who is a co-author of the new study.

For example, the ice ages during the last several million years — and the warmer periods in between — appear to have been triggered by no more than a different seasonal and latitudinal distribution of the solar energy absorbed by the Earth, not by a change in output from the sun.

At last week's meeting here of the Society of Vertebrate Paleontology, another team of U.S. - based researchers looked at a slightly later but somewhat less severe warming period, which happened about 53 million years ago.

«Unlike habitat generalists that can expand their distribution because they do not have very specific habitat requirements, Sungazers likely do not even enter the process of producing sperm and eggs without the correct cooling and warming periods that they experience seasonally in the wild,» says Parusnath.

During the warm periods between recent ice ages, temperatures in Antarctica reached substantially higher levels than scientists had previously thought.

Integrating geological archives and climate models for the mid-Pliocene warm period.

Under the model they developed, the scientists say the likelihood of Bd occurrence is predicted to decrease during warmer periods, and when precipitation exceeds an annual rainfall threshold above 1,800 mm per year.

So parts of these ice sheets, but not all, must have melted during the long - ago warm period.

All this research into the last great warm period is helping scientists think more deeply about how the future might play out.

«We all grew up with the idea that if today is a warm day, tomorrow will be a warm day, too — but we probably won't be stuck in a warm period for three weeks,» Weatherhead said.

Over the last decade, rock avalanches and landslides have become more common in high mountain ranges, apparently coinciding with the increase in exceptionally warm periods (see «Early signs»).

During the warm period, the core also shows a large increase in organic matter from plants growing in and around the lake.

DeConto and Pollard's study was motivated by reconstructions of sea level rise during past warm periods including the previous inter-glacial (around 125,000 years ago) and earlier warm intervals like the Pliocene (around 3 million years ago).

Additionally, the decade was at least one - half degree Fahrenheit warmer today than the warmest periods of that 11,000 - year time frame, even counting for uncertainties, Shuman says.

The study also provides new evidence for just how sensitive glaciers are to temperature, showing that they responded to past abrupt cooling and warming periods, some of which might have lasted only decades.

The nutritional diversity of these sites allowed hominins to colonise the Atlantic fringe of north west Europe during warm periods of the Pleistocene.

And they note that freezing to death could be a danger if early - spring warming periods, followed by cold snaps, become common — something they observed in the spring of 2012.

For example, if a proxy record indicated that a drier condition existed in one part of the world from 800 to 850, it would be counted as equal evidence for a Medieval Warming Period as a different proxy record that showed wetter conditions in another part of the world from 1250 to 1300.

Soon and Baliunas are «mindful» that the Medieval Warming Period and the Little Ice Age should be defined by temperature, but «we emphasize that great bias would result if those thermal anomalies were to be dissociated» from other climatic conditions.

In contrast, the consensus view among paleoclimatologists is that the Medieval Warming Period was a regional phenomenon, that the worldwide nature of the Little Ice Age is open to question and that the late 20th century saw the most extreme global average temperatures.

During warm periods in the North Atlantic, on the other hand, the Titicaca region experienced drought.

The most significant criticism is that Soon and Baliunas do not present their data quantitatively — instead they merely categorize the work of others primarily into one of two sets: either supporting or not supporting their particular definitions of a Medieval Warming Period or Little Ice Age.

Dubbed the «Medieval Warm Period,» it was the last time before the present that agriculture could flourish in Greenland.

The warmest period occurred in the late 20th century — too short to meet Soon and Baliunas's selected requirement.