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Arctic Warming and Increased Weather Extremes: The National Research Council Speaks

A new report from the National Research Council details the findings of recent Arctic research: Arctic sea ice in all seasons is declining and the rate of loss is increasing.

(Photo: US Geological Survey, Department of the Interior/USGS, Patrick Kelley, US Coast Guard)

Part of the Series

Arctic warming is happening at twice the average level of global warming in a process called arctic amplification, where more warming occurs as ice is lost because less of the sun’s energy is reflected back into space.

A new report from the National Research Council (NRC) details the findings of recent Arctic research: Arctic sea ice in all seasons is declining and the rate of loss is increasing. Multiple lines of study show this is impacting weather outside of the Arctic. Increased energy (heat) in the Arctic is slowing the progress of the jet stream around globe, allowing weather systems to linger, increasing the risk of severe weather happening more often in any one place. Increased warmth also means increased moisture in the Arctic – which increases the amount of snow, which in turn causes the jet stream to concentrate winter weather in North America and Eurasia.

The tone of the NRC report is embodied in the lead workshop presentation by Dr. James Screen of Exeter University in the UK. Because of the uncertainties associated with research in this rapidly evolving field, Screen proposed an “ACID” test to validate research findings. The test asks if research findings are: “Attributable to Arctic forcing; Corroborated by multiple lines of evidence; Informed by mechanistic understanding; and Detectable in the real world.”

Science … systematically understates evidence.

Screen said the current state of science is in its infancy, and few if any of the lines of research pass the test, but the workshop summary adds: “Other participants noted that the ACID test approach is sound, but, given the limitations of available information, there are inherent limitations to the analyses that can be conducted.” (1) In other words, to be absolutely certain, more research is needed.

Science is a conservative industry that classically understates fact. One of the big reasons is that old maxim, “Publish or perish.” If a scientist is wrong in his or her published findings, the scholarly journals will think twice about publishing that scientist’s work again. Science therefore systematically understates evidence.

The consensus process, like that of the Intergovernmental Panel on Climate Change (IPCC), is even more conservative (underestimating) in their statements because of the large number of individual scientists who must agree on the consensus position.

This consensus opinion on climate is generally not a thing of fact. It is a thing of acceptance by the broad scientific community. (2) Scientists are specialists. Almost all of them specialize in minute sectors of science as a whole. For large numbers of climate scientists to agree on a statement, they must be familiar with the leading edge of science that that statement discusses. In the highly compartmentalized world of research science, details of all disciplines are seldom understood by all.

The kind of familiarity it takes to bring new knowledge into the consensus can take years and even decades. The consensus opinion is therefore constantly behind the leading edge of science. With a rapidly changing climate, this can be a problem. A profound example of how the climate science consensus understates the current state of the science comes from the IPCC reports.

Winter weather over land areas in the Northern Hemisphere becomes more extreme with less Arctic sea ice.

The 2007 IPCC report said that Antarctica was not supposed to begin losing ice until after 2100. The 2013 IPCC report however says that Antarctic ice loss has now nearly caught up with Greenland’s. Published findings dating back to the 1990s have always shown Antarctica to be losing ice. It is not as if Antarctica has suddenly started losing ice. But because the IPCC is a consensus driven organization, it takes time for “new” knowledge to infiltrate the entire industry. This is one of the main reasons why the IPCC systematically underestimates the current state of climate science. (3)

Some of the details of this National Research Council publication are:

• A panel discussion led by a researcher at the University of Alaska relayed that there has been a decrease in wind speed in that part of our atmosphere that moves storm systems around the world from 1979 to the present. This is one of the results of decreasing Artic sea ice in computer models. This speaker also notes that an increase in wind speeds in the 1950s was not found to be associated with an increase in Arctic sea ice. (4)

• Work by Atmospheric and Environmental Research (a commercial climate consultant working mostly for organizations like NOAA, NASA , the Department of Defense, insurance corporations and investment and energy companies) was presented that shows that: “Siberian snow cover has also been shown to influence mid-latitude winter weather . . . and [this]correctly predicted the cold winter in 2013 across Northern Eurasia and the United States.” (5)

• A researcher from Rutgers discussed seven things that “connect observed rapid warming of the Arctic with changing weather patterns in the mid-latitude Northern Hemisphere.” These items were mostly related to a decrease in the speed of the progression of storm systems caused by weakening steering winds. The seventh item states: “Slower moving upper level [winds] cause more persistent weather patterns, which increase the likelihood of extreme weather events associated with [these] prolonged weather conditions.” (6)

• Research from Penn State shows that stronger tropical weather activity in the South Seas enhances the flow of heat and moisture into the Arctic. (7) This fascinating phenomenon is called a teleconnection, and it has been found to exist in numerous places, causing numerous things to happen literally on the other side of the planet. A good example is the known connection between El Nino in the South Pacific and decreased hurricane activity in the Atlantic basin. El Nino increases upper level winds in the Atlantic. Increased upper level winds decrease important factors that allow hurricanes to develop.

• A review of research given by the National Oceanic and Atmospheric Administration’s (NOAA) Pacific Marine Environmental Laboratory says: “Loss of Arctic sea ice, record negative values of the winter Arctic Oscillation atmospheric circulation index, earlier summer snow melt, and increasing extreme weather events at mid-latitudes – both heat waves and cold snowstorms – have been observed over the last decade.” Shifts in the wind patterns that move storms across the planet have resulted in more extreme early winter weather in 2009, 2010 and 2012 in North America, northern Europe and far eastern Asia (the research did not evaluate the 2013 season). (8)

• A workshop talk titled “Warm Arctic – Cold Continents” describes how decreased sea ice extents, decreased storm steering winds and early Siberian snow cover enhanced the winter weather extremes in 2012/2013. The summary for this discussion “suggests that the dramatic decrease in sea ice contributed to extreme weather events observed during that [2012/2013 winter] period.” (9)

• More discussion from Rutgers University addresses snow cover across the Northern Hemisphere. The last four Mays have been four of the five lowest on record. The last six Junes had the lowest snow cover coverage over the Northern Hemisphere and Eurasia with five of the last six in North America. (10)

• Modeling out of the University of California, Irvine has some unexpected results compared to what we have become accustomed to. Generally, the models tell us that Arctic warming spreads south, but historic modelling is based on long-term patterns. These researchers looked at the last six years of Arctic sea ice decline (2007 through 2012) and extended this short-term trend into the future. What they found was quite similar to what we have been experiencing. Winter weather over land areas in the Northern Hemisphere becomes more extreme with less Arctic sea ice. (11)

• More modeling from NOAA and the Geophysical Fluid Dynamic Laboratory shows that Arctic sea ice models cannot predict what these researchers call “very rare occurrence” of record low Arctic sea ice coverage of the 21st century. (12)

• Another modeling exercise, this one from the University of California at San Diego, looks at changes in rainfall and snowfall globally and at high latitudes, with and without sea ice in the Arctic. Ice and snow reflects up to 90 percent of the sun’s light energy back into space without warming the planet, but open water absorbs up to 90 percent of that energy where it stays on Earth, creating warming. A warmer planet is able to have more moisture in the atmosphere and this means that more precipitation could possibly be the result. This report says that many studies have found that overall precipitation will increase (and has already increased in some areas) but this is the first effort to look at the problem as these researchers did. What they found was that their modeling predicted more precipitation in cold areas but no change in warmer areas. The changes begin with global conditions very similar to what they are today. (13)

• Research from Niigata University in Japan that compares sea ice conditions between 2005-2009 and 1979-1983 shows significant cooling in eastern Siberia with lesser cooling in Eastern Europe and northeastern North America. (14) Work from the University of Alaska shows that most climate models underestimate actual detailed conditions of daily sea ice movement in the Arctic. Modeling with actual sea ice movements shows increased occurrences of winter weather outbreaks in northeastern North America – an impact that current modeling does not reproduce. (15)

• One of the breakout groups at this workshop discussed a point that seems particularly poignant to this discussion: “It is possible that recent Arctic changes have pushed the atmosphere into a new state with different variability. The strong Arctic forcing [warming] has emerged only in the past few years, and development of new methods and approaches may be required to test or account for it.”

Because we are warming faster, the risk of climate tipping points is higher. . . the extremes get more extreme.

In a rapidly changing climate this is a given. In our old climate, we sort-of knew how it behaved. We had decades and even centuries of records to use to project changes into the future. But all of this historical data may be of much less use in the future as the baseline physics have now changed. Even more critical, the short term is now very important as tipping points may appear at any time.

Because of 20 years of delay in controlling climate pollution, we are experiencing more warming faster than we would have if we had of begun to address climate pollutants as was suggested decades ago. Because we are warming faster, the risk of climate tipping points is higher. This discussion point states that recent Arctic changes may have “pushed the atmosphere into a new state with different variability.” What they mean by variability is that the extremes get more extreme. This includes more extreme droughts, floods and winter weather. An example is that in the southeastern United States, droughts and floods have doubled over the last 30 years. (16)

Much of the challenge with evaluating climate change is based on modeling. We know how to operate climate models based on our old climate, and they work quite well reproducing our old climate. Arctic climate though has likely advanced to a state that is not represented by our old climate.

The reality of science also tells us that because our baseline conditions are now rapidly changing, we may never be able to project future changes with accuracy – it’s difficult to hit a moving target. This is another reason why the IPCC and other consensus-based climate reporting often underestimates the speed and extremeness of climate change.

Into the future we must rely more on history. Since the mid-1990s we have been discovering highly accurate evidence that shows ancient abrupt climate changes have happened repeatedly across our planet in ways that dwarf current modeling projections. But this evidence lacks many details about why these changes occurred – only that they occurred.

A running theme in this report is that we must develop new techniques that can better deal with our new climate. Prehistory evidence is one of these tools. Over 20 times in the last 100,000 years, highly accurate evidence from ice cores in Greenland and Antarctica have shown abrupt climate changes of 9 to 14 degrees F across the globe in as little as a few decades and astonishingly, in as little as a few years. In Greenland these changes were 25 to 35 degrees F. (17)

Because our baseline conditions are now rapidly changing, we may never be able to project future changes with accuracy – it’s difficult to hit a moving target.

We know that massive abrupt climate changes are a regular occurrence on earth, and we are finding that arctic amplification is changing our climate faster than has previously been projected by the consensus opinion. At some point, the scientific tendency to conservatively wait until enough evidence has accumulated must acquiesce to expert opinion and logic.

Expert opinion in the late 1990s said that Antarctica was losing ice 100 years ahead of the consensus opinion. But the main voice of climate policy on this planet, the IPCC consensus, did not agree until 2013. Today, expert opinion exists to say that arctic amplification is causing our weather to become more extreme and that these extremes will become even more profound as our climate continues to warm.

Time is short. Environmental tipping points tend to be more extreme if the environmental system is pushed harder. We have already delayed addressing climate pollution 20 years or more and the Arctic has just begun to lose ice. The extreme weather events that are “likely” caused by Arctic warming today have the capacity to become much, much worse as the Arctic has a lot of warming yet to come even if we ceased all greenhouse gas emissions today. Climate policy should be driven by logic and expert opinion, not the consensus.


National Research Council Report:
Thomas et al., “Linkages between Arctic Warming and Mid-latitude Weather Patterns,” National Research Council, June 2014.

1. ACID approach is sound…
Thomas et al., “Linkages between Arctic Warming and Mid-latitude Weather Patterns,” National Research Council, June 2014, page 34, paragraphs four and five.

2. The climate science consensus is conservative and understates the latest knowledge of climate science . . .

From the University of Alberta: Universities of California at San Diego and St. Benedict/St. Johns and the Woodrow Wilson School of Public affairs tells us; “Over the past two decades, skeptics of the reality and significance of anthropogenic climate change have frequently accused climate scientists of ‘alarmism’ . . . However, the available evidence suggests that scientists have in fact been conservative in their projections of the impacts of climate change. … We suggest, therefore, that scientists are biased not toward alarmism but rather the reverse: toward cautious estimates, where we define caution as erring on the side of less rather than more alarming predictions.” Scientific American: “Checking 20 years of projections shows that the Intergovernmental Panel on Climate Change has consistently underestimated the pace and impacts of global warming.”

Brysse et al., Climate change prediction: Erring on the side of least drama?, Global Environmental Change, February 2013, abstract.

From the University of California, Santa Barbara: “Mass media in the U.S. continue to suggest that scientific consensus estimates of global climate disruption, such as those from the Intergovernmental Panel on Climate Change (IPCC), are ‘exaggerated’ and overly pessimistic. By contrast, work on the Asymmetry of Scientific Challenge (ASC) suggests that such consensus assessments are likely to understate climate disruptions.” A National Research Council report prepared by the Committee on Strategic Advice on the U.S. Climate Change Science Program: Brysse and team reports in section 2.3: “IPCC projections have systematically underestimated key climate change drivers and impacts. This committee found that ‘The Intergovernmental Panel on Climate Change (IPCC) projections may have been too conservative in several areas, including CO2 emissions by various countries, increases in surface temperatures, and sea level rise.”

Freudenburg and Muselli, “Global warming estimates, media expectations, and the asymmetry of scientific challenge,” Global Environmental Change, August 2010. see abstract.

Scientific American: “Across two decades and thousands of pages of reports, the world’s most authoritative voice on climate science has consistently understated the rate and intensity of climate change and the danger those impacts represent, say a growing number of studies on the topic.”Climate Science Predictions Prove Too Conservative,” Scientific American, December 6, 2012, first sentence.

3. Antarctica has begun to lose ice 100 years or more ahead of IPCC predictions . . . Antarctic surface mass balance (SMB) in the 2007 IPCC Report was supposed to increase, not decrease, for all scenarios, through 2100. This means that snow accumulation was supposed to be more than melt, evaporation and iceberg discharge combined: “All studies for the 21st century project that Antarctic SMB changes will contribute negatively to sea level, owing to increasing accumulation exceeding any ablation increase (see Table 10.6).”

Intergovernmental Panel on Climate Change, Fourth Assessment Report, “Climate Change 2007: Working Group I: The Physical Science Basis,”, Surface Mass Balance, fifth paragraph.

The 2013 IPCC report tells us that Antarctic ice loss has almost caught up with Greenland. Summary for Policy Makers, E.3 Cryosphere, page 9, third bullet. “The average rate of ice loss from the Antarctic ice sheet has likely increased from 30 [–37 to 97] Gt yr–1 over the period 1992–2001 to 147 [72 to 221] Gt yr–1 over the period 2002 to 2011.” Greenland, second bullet: “The average rate of ice loss from the Greenland ice sheet has very likely substantially increased from 34 [–6 to 74] Gt yr–1 over the period 1992 to 2001 to 215 [157 to 274] Gt yr–1 over the period 2002 to 2011.”

4. Decrease in winds 1979 to present . . . Thomas et al., Linkages between Arctic Warming and Mid-latitude Weather Patterns, National Research Council, June 2014, page 47, paragraph five.

5. Siberian snow cover and the cold winter or 2013… ibid. page 48, paragraph two.

6. Seven things that point to Arctic Warming increasing Northern Hemisphere extreme weather . . . ibid. page 48, paragraph six.

7. Stronger weather systems in the South Seas enhance warming in the Arctic… ibid. page 49, paragraph two.

8. More extreme early winter weather and its association with changing storm steering wind patterns…
ibid., page 49, paragraph five.

9. Warm Arctic – Cold Continents…ibid., page 52, paragraph one.

10. Record low snow cover…ibid., page 53, paragraph four.

11. Lower Arctic Sea ice coverage and more extreme winter weather over land areas in the northern Hemisphere…
ibid., page 54, paragraph one and two.

12. Very rare occurrence of record low Arctic sea ice coverage…
ibid., page 55, paragraph 4.

13. More rain and snow in cold areas with less sea ice…ibid., page 56 paragraph two.

14. Research from Niigata university in Japan…ibid., page 56, third paragraph.

15. Comparing models to actual; models underestimate cold winter outbreaks in the northeastern U.S…
ibid., page 57, paragraph 2.

16. Floods and drought have doubled in the U.S. southeast in the last 30 years…
Li, et. al., “Changes to the North Atlantic Subtropical High and Its Role in the Intensification of Summer Rainfall Variability in the Southeastern United States,” Journal of Climate, October 2010, abstract.

17. Abrupt climate change 23 times in the last 100,000 years . . . Alley, Wally Was Right – Predictive ability of the North Atlantic Conveyor Belt Hypothesis for Abrupt Climate Change, “Annual Review of Earth and Planetary Science,” February 2007, Figure 1 shows the 23 abrupt climate changes.

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