Earth in warmest period in 1,400 years, global climate panel says

Friday’s much anticipated release of the latest Intergovernmental Panel on Climate Change report contains some eye opening findings and projections from the latest and best available climate science.

Image: Intergovernmental Panel on Climate Change

The report confirms overall trends observed and projected in previous reports. Global temps are rising. Glaciers and ice sheets are shedding ice mass. Global carbon dioxide (CO2)  levels are the highest in at least 800,000 years, and rising.

Please join Kerri Miller and me for a special hour long Climate Cast Monday at 9 a.m. on MPR News stations for a deeper look at the latest IPCC report with University of St. Thomas climate expert  John Abraham.

There is a lot to process in the report, but here are a few key highlights from my early review.

Image: Intergovernmental panel on Climate Change

Eye catching numbers

+1.6F Global surface air temperature increase between 1901 and 2012

Image: IPCC

Comment: We’re already seeing some remarkable changes in the nature of our seasons, jet stream patterns and extreme weather events at just the +1.6F warming observed in the past century. Most of this warming has occurred in the past 40 years as the concentration of greenhouse gasses has accelerated.

+2.7F Most likely increase in global surface air temperature by 2081-2100

Image: IPCC Image: IPCC

Comment: The global climate models forecast global temp rise by 2100 ranges between 0.54°F to 8.64°F.  But the most likely global mean surface temperature change by 2100 is likely to push past 2.7°F when compared to 1850-1900 in all but one of the emissions scenarios.

Considering the effect we’re already observing with a +1.6F rise in global temps the past 100 years, even a conservative rise close to +2F by 2100 will cause continued and probably dramatic climate shifts.

1,400 years – The past 30 years (1983-2012) is likely the warmest 30 year period in the past 1,400 years globally.

Image: IPCC Image: Climate Central

Comment: This is perhaps the most eye opening and convincing data on the recent, accelerated and sustained temperature rise of the past 30 years. We are now living in the warmest time on planet earth in modern civilization. Looking back to 1850, the rapidly rising temperature trends of the past 30 years are off the charts. If future rises mirror those of the past 30 years, the IPCC’s future projections on global surface temperature and the effects will be significantly conservative.

The slight slowdown in the rate of warming the past 15 years is likely due to low solar activity, ocean absorption of heat and an increase in volcanic aerosols which reflect incoming sunlight. These effects are likely temporary,and are masking the rate of rise in global temps. It will take another 20 years to determine how the climate is responding.

10 to 32 inches – Global sea level is most likely to increase between 10 and 32 inches by 2081-2100

Image: IPCC

Image: IPCC

Image: IPCC

Comment: Global sea level rise projections seem to center around .5 meters, or 20″ by 2100. Even a 20″ rise in sea level over the next 85 years will pose major problems for cities like New York and Miami that straddle the coasts. Storm surges will be more dangerous than ever. And an increase in the severity of storm surge damage and costs with incoming hurricanes like Sandy will be a real risk. Many coastal cities will need to rethink the way they protect themselves from rising oceans, or relocate by choice…or by the force of nature.

400 ppm – Measurements of global CO2 concentrations reached 400 ppm in 2013. Global CO2 is now at the highest level in at least 800,000 years, and possibly in 3 million years.

Image: IPCC

Comment: A potential doubling of global CO2 by 2050-2100 is a frightening thought. The changes in oceans through increasing “acidification” are unknown. The changes in jet stream patterns and how it affects our weather could be extensive.

We’re moving into uncharted territory in the earth’s atmospheric system. Those of us who have studied and watched jet stream and “synoptic” weather patterns for the past 30 years know they are noticeably different that they were 30 year ago. What changes to jet stream patterns will another 30 years of increased CO2 and Arctic warming bring?

Here’s the IPCC trends chart for the overall effects of climate change, and the likelihood of each effect.

Image: IPCC

A total of 209 lead authors and 50 review editors from 39 countries and more than 600 Contributing Authors from 32 countries contributed to the preparation of the research.

The coming days and weeks will bring a much deeper analysis of this vast report.

Stay tuned!

  • notanotherskippy

    These would be the same models that have failed to predict the 15+ year flat global temps? The lack of a tropical tropospheric hotspot? The record Antarctic sea ice extent? It’s truly disturbing when a supposed scientific body can’t even accept hard empirical data over models or even apply basic statistical methods to their analysis. One might even call it denial…

    • Paul Weimer

      Let’s see, should I believe the new IPCC report report on climate change, and the chief meterologist for Minnesota Public Radio, or a random @MPRnews commenter named “notanotherskippy”?

      • Steve Ball

        If you have nothing to say about the _content_ of a post, I don’t see that an ad hominem adds anything to the discussion.

    • Gordon near Two Harbors

      Actually, the temporary slowdown of warming was addressed. It seems that a lot of heat is being absorbed by the oceans and the melting of ice.

      This is science, and not a “book of answers”. Just because a doctor can’t predict EXACTLY how a cancer will spread in your body doesn’t mean it’s not there or shouldn’t be treated.

  • Steve Ball

    “The past 30 years (1983-2012) is likely the warmest 30 year period in the past 1,400 years globally.” So that’s saying that 1,400 years ago there was a 30 years period at least as warm as the one in question. How much industry was there, exactly, 1,400 years ago?

    • Gordon near Two Harbors

      There is also natural variation in climate over varying time scales. By changing the chemistry of the atmosphere–and thereby its heat-trapping properties–humans have shifted that variability upward. A warm period becomes warmer, and a cool period less cool.

      • Steve Ball

        That flies in the face of the fact that there was a warmer warm period 1,400 years ago than the current warm period, doesn’t it?

        • Gordon near Two Harbors

          No, because that was likely part of the natural variation I mentioned above. If the same phenomenon that resulted in periodic warm periods in the past occurred today, it would likely be even warmer due to the 40 percent increase in greenhouse gasses since that time. It’s hard to argue with the Laws of Physics.

          • Steve Ball

            So the warming 1,400 years ago and, presumably, all previous warnings, were due to natural variation – and here I agree with you – but the current one isn’t? Here we part ways. How can you know that there wouldn’t currently be a warming independent of human CO2 production?

          • davehoug

            Thank you. I have been curious WHAT caused the warm up in the 1930’s. I understand you to say we expect variations, but the current variations are being done with “loaded dice” via greenhouse gas increase.