In a recent paper James Hansen said, "Because climate responds slowly, we have felt so far only about half of the effect of gases already in the air." We are only beginning to understand what the huge inertia and thus slow response of the climate system means for our future.
This new data suggests that Arctic warming specifically, that's already in the pipeline, will be far greater than twice what we're seeing now. This data tells us that the Arctic will probably become 59 to 61 degrees F warmer in summer for thousands of years.
Analysis of a sediment core from a deep lake in the northeast Russian Arctic, located 100 km north of the Arctic Circle, gives new knowledge of Arctic climate from 2.2 to 3.6 million years ago. When the Earth had a similar level of CO2 to today, the Arctic was "very warm".
Results of analyses that provide "an exceptional window into environmental dynamics" never before possible were published this week in Science ...
"One of our major findings is that the Arctic was very warm in the middle Pliocene and Early Pleistocene [~ 3.6 to 2.2 million years ago] when others have suggested atmospheric CO2 was not much higher than levels we see today. This could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier climate models," the authors state.
... summer temperatures of about 59 to 61 degrees F [15 to 16 degrees C], about 14.4 degrees F [8 degrees C] warmer than today, and regional precipitation three times higher. "We show that this exceptional warmth well north of the Arctic Circle occurred throughout both warm and cold orbital cycles and coincides with a long interval of 1.2 million years when other researchers have shown the West Antarctic Ice Sheet did not exist," Brigham-Grette notes. Hence both poles share some common history, but the pace of change differed. [emphasis mine]
This image of Douglas Fir and hemlock represents the kind of vegetation that may be found 100 km north of the Arctic Circle after the full effects have been felt of the CO2 in the air today.
"This new data suggests that Arctic warming specifically, that's already in the pipeline, will be far greater than twice what we're seeing now. This data tells us that the Arctic will probably become 59 to 61 degrees F warmer in summer for thousands of years."
Let's assume this information is correct and the Arctic will be 59-61∘F for thousands of years, or similar to during the middle Pliocene and Early Pleistocene [~ 3.6 to 2.2 million years ago]. What was that weather like for the planet? To start that investigation, I found this article
"What will it take to change our way?"
"In that diagram we can see how the transition from the warmer Pliocene (on the right of the diagram) to the Pleistocene (the “Ice Age”, on the left of the diagram) was accompanied by a change in vegetation. There is no doubt that climate change does indeed change the biome.
"Whether we are discussing changes in ecosystems or sea level, it is important to remember that we humans have such a short life and even shorter attention span that large changes are often just overlooked if we rely upon casual glances at the world around us. As common in all areas of science, only careful and systematic observations and analyses can take us out of our biases and “common sense” to gain a greater knowledge of the world around us.
"That appears, though, by looking at our popular press and current political environment, to be quite a challenge for us today. There has been no substantive change in the production of CO2 in our modern industrialized world. Growth in CO2 output continues with only modest slowing during the deepest of economic recessions.
"What will it take to change our way?"
This article only tells us about the evidence from Lake El’gygytgyn, NE Arctic Russia; it tells us nothing of what happened in the Great Planes of N. America or other great food producing areas of Earth. There is a lot more to know and discover. We need to prepare for those changes. We may not be able to accomplish that, and if we don't try, we will not.
Ruth, you referred us to this: Ice-Free Arctic May Be in Our Future, International Researchers Say and it gives a little more detail about their data that "come from analyzing sediment cores collected in the winter of 2009 from ice-covered Lake El'gygytgyn, the oldest deep lake in the northeast Russian Arctic, located 100 km north of the Arctic Circle. "Lake E" was formed 3.6 million years ago when a meteorite, perhaps a kilometer in diameter, hit the Earth and blasted out an 11-mile (18 km) wide crater. It has been collecting sediment layers ever since. Luckily for geoscientists, it lies in one of the few Arctic areas not eroded by continental ice sheets during ice ages, so a thick, continuous sediment record was left remarkably undisturbed. Cores from Lake E reach back in geologic time nearly 25 times farther than Greenland ice cores that span only the past 140,000 years."
I was curious where there could be other ice core samples or ways of finding out about the Great Plains, realizing those soils had been disrupted by Ice Age floods only about 12,000 years ago. So I have been on a hunt to learn what I can about middle Pliocene and Early Pleistocene [~ 3.6 to 2.2 million years ago], and what might be a possible scenario for Earth.