Climate Change

[Michael Scally MD]

Steffen W, Rockström J, Richardson K, et al. Trajectories of the Earth System in the Anthropocene. Proceedings of the National Academy of Sciences 2018. http://www.pnas.org/content/early/2018/07/31/1810141115.abstract

We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced.

Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene.

We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies.

Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.

 

[Michael Scally MD]

Steffen W, Rockström J, Richardson K, et al. Trajectories of the Earth System in the Anthropocene. Proceedings of the National Academy of Sciences 2018. http://www.pnas.org/content/early/2018/07/31/1810141115.abstract

We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced.

Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene.

We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies.

Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.

 

[Michael Scally MD]

Ni X, Groffman PM. Declines in methane uptake in forest soils. Proceedings of the National Academy of Sciences 2018. http://www.pnas.org/content/early/2018/07/31/1807377115.abstract

Forest soils are a sink for atmospheric methane (CH4) and play an important role in modulating the global CH4 budget. However, whether CH4 uptake by forest soils is affected by global environmental change is unknown. We measured soil to atmosphere net CH4 fluxes in temperate forests at two long-term ecological research sites in the northeastern United States from the late 1990s to the mid-2010s. We found that annual soil CH4 uptake decreased by 62% and 53% in urban and rural forests in Baltimore, Maryland and by 74% and 89% in calcium-fertilized and reference forests at Hubbard Brook, New Hampshire over this period. This decrease occurred despite marked declines in nitrogen deposition and increases in atmospheric CH4 concentration and temperature, which should lead to increases in CH4 uptake. This decrease in soil CH4 uptake appears to be driven by increases in precipitation and soil hydrological flux. Furthermore, an analysis of CH4 uptake around the globe showed that CH4 uptake in forest soils has decreased by an average of 77% from 1988 to 2015, particularly in forests located from 0 to 60 °N latitude where precipitation has been increasing. We conclude that the soil CH4 sink may be declining and overestimated in several regions across the globe.

 

[Michael Scally MD]

Steffen W, Rockström J, Richardson K, et al. Trajectories of the Earth System in the Anthropocene. Proceedings of the National Academy of Sciences 2018. http://www.pnas.org/content/early/2018/07/31/1810141115.abstract

We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced.

Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene.

We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies.

Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.

 

[Michael Scally MD]

 

[Michael Scally MD]

Potential Surprises – Compound Extremes and Tipping Elements

Key Finding 1

Positive feedbacks (self-reinforcing cycles) within the climate system have the potential to accelerate human-induced climate change and even shift the Earth’s climate system, in part or in whole, into new states that are very different from those experienced in the recent past (for example, ones with greatly diminished ice sheets or different large-scale patterns of atmosphere or ocean circulation). Some feedbacks and potential state shifts can be modeled and quantified; others can be modeled or identified but not quantified; and some are probably still unknown. (Very high confidence in the potential for state shifts and in the incompleteness of knowledge about feedbacks and potential state shifts).


Key Finding 2

The physical and socioeconomic impacts of compound extreme events (such as simultaneous heat and drought, wildfires associated with hot and dry conditions, or flooding associated with high precipitation on top of snow or waterlogged ground) can be greater than the sum of the parts (very high confidence). Few analyses consider the spatial or temporal correlation between extreme events.


Key Finding 3

While climate models incorporate important climate processes that can be well quantified, they do not include all of the processes that can contribute to feedbacks, compound extreme events, and abrupt and/or irreversible changes. For this reason, future changes outside the range projected by climate models cannot be ruled out (very high confidence). Moreover, the systematic tendency of climate models to underestimate temperature change during warm paleoclimates suggests that climate models are more likely to underestimate than to overestimate the amount of long-term future change (medium confidence).


Kopp, R.E., K. Hayhoe, D.R. Easterling, T. Hall, R. Horton, K.E. Kunkel, and A.N. LeGrande, 2017: Potential surprises – compound extremes and tipping elements. In: Climate Science Special Report: Fourth National Climate Assessment, Volume I [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 411-429, doi: 10.7930/J0GB227J. Climate Science Special Report: Potential Surprises: Compound Extremes and Tipping Elements

 

[Michael Scally MD]

Atmospheric carbon last year reached levels not seen in 800,000 years
http://www.sciencemag.org/news/2018...ast-year-reached-levels-not-seen-800000-years

The concentration of carbon dioxide (CO2) in Earth’s atmosphere reached 405 parts per million (ppm) last year, a level not seen in 800,000 years, according to a new report. It was also the hottest year on record that did not feature the global weather pattern known as El Niño, which is driven by warmer than usual ocean waters in the Pacific Ocean, concludes the State of the Climate in 2017, the 28th edition of an annual compilation published by the National Oceanic and Atmospheric Administration (NOAA). https://www.ametsoc.net/sotc2017/StateoftheClimate2017_lowres.pdf

Overall, 2017 ranked as the second or third warmest year, depending on which measure is used, since researchers began keeping robust records in the mid-1800s.

Even if humanity “stopped the greenhouse gasses at their current concentrations today, the atmosphere would still continue to warm for next couple decades to maybe a century,” said Greg Johnson, an oceanographer at NOAA’s Pacific Marine Environmental Laboratory in Seattle, Washington, during a press call yesterday about the report.

The hefty document includes data compiled by 524 scientists working in 65 countries. A few highlights:

Atmospheric concentrations of CO2—the primary planetary warming gas—last year rose by 2.2 ppm over 2016. Similar levels were last reached at least 800,000 years ago, according to data obtained from air bubbles trapped in ancient ice cores.

· Atmospheric concentrations of methane and nitrous oxide—both potent warming gases—were the highest on record. Levels of methane increased in 2017 by 6.9 parts per billion (ppb), to 1849.7 ppb, compared with 2016. Nitrous oxide levels increased by 0.9 ppb, to 329.8 ppb.

· Last year also marked the end of a world-wide coral bleaching event that lasted 3 years. Coral bleaching occurs when seawater warms, causing corals to release algae living within their tissues, turning the coral white and sometimes resulting in the death of the coral. It was the longest documented bleaching event.

· Global precipitation in 2017 was above the long-term average. Russia had its second wettest year since 1900. Parts of Venezuela, Nigeria, and India also experienced heavier than usual rainfall and flooding.

· Warmer temperatures contributed to wildfire outbreaks around the world. The United States suffered an extreme wildfire season that burned 4 million hectares and caused more than $18 billion in damages. The Amazon region experienced some 272,000 wildfires.

· In Alaska, record high permafrost temperatures were reported at five of six permafrost observatories. When thawed, permafrost releases CO2 and methane into the atmosphere and can contribute to global warming.

· Arctic sea ice took a hit. The extent of sea ice hit a 38-year low, and was 8% below the mean extent reported for 1981 to 2010. Spring snow cover in the Arctic, however, was greater than the 1981 to 2010 average, and the Greenland Ice Sheet recovered from a record low mass reported in 2016. 2017 was also the second warmest year on record for the Arctic.

· Many countries reported setting high-temperature records, including Argentina, Uruguay, Spain, Bulgaria, and Mexico.

 

[Dr JIM]

http://en.wikipedia.org/wiki/Henny_Penny_(fable)

Invent a crisis
Scar the hell out of people
Use it to tax and control the people
Belittle the cattle (people) that dare to take their faces out of the grass they have been told to eat
And of course, tell them its to save the children.

Dare you chide those who wanna
save our children the mantra of our failing public school system.

 

[Michael Scally MD]

 

[Dr JIM]

View attachment 95596

If the cause of global warming was unifacorial the remedy would be simple, we could all ride bikes
for work, school and play.

And while the cyclical effects of GW are undeniable, the degree to which humans have contributed
remains highly contested among scientists on the right and left.

 

[Michael Scally MD]

[Also, The Nobel Prize in Chemistry 1903 was awarded to Svante Arrhenius "in recognition of the extraordinary services he has rendered to the advancement of chemistry by his electrolytic theory of dissociation". The Nobel Prize in Chemistry 1903 ]

In early 1896, Svante Arrhenius published two articles presenting the first model of the influence of carbonic acid (CO2) in the air on the temperature on the ground. One appeared in the Supplement to the Proceedings of the Royal Swedish Academy of Sciences, the other in the Philosophical Magazine. As he often did, Arrhenius had written similar articles in German and English, in order to make his work known to the two major scientific language groups of his time.

The article in the Philosophical Magazine contained two distinct parts: the first presented computations allowing Arrhenius to predict the variations in temperature which would result from variations of C02; the second discussed such variations as the cause of climatic change in geological times, especially the Ice Ages. This second part contained a translation from Swedish of part of an article by Arvid Hogbom on the geological carbon cycle.


Arrhenius S. On the influence of carbonic acid in the air upon the temperature on the ground. The Philosophical Magazine. 1896;41:237-76. http://www.rsc.org/images/Arrhenius1896_tcm18-173546.pdf


[Svante Arrhenius] The father of climate change
The father of climate change

Between 10,000 and 100,000 calculations later, Arrhenius had some rough, but useful, results that he published in 1896. If CO2 levels halved, he concluded, the the Earth's surface temperature would fall by 4-5C. There was a flipside to his calculations: doubling CO2 levels would trigger a rise of about 5-6C.

Beyond the argument over ice ages it wasn't lost on Arrhenius that human activity, in the form of widespread burning of coal, was pumping atmospheric CO2 above the natural levels that help make the Earth habitable. Almost as a passing comment, he estimated that coal burning would drive a steady rise in CO2 levels of about 50% in 3,000 years, a prospect he found entirely rosey. At a lecture that same year, he declared: "We would then have some right to indulge in the pleasant belief that our descendants, albeit after many generations, might live under a milder sky and in less barren surroundings than is our lot at present."

As the first to put hard figures on the greenhouse effect, it's unsurprising Arrhenius's estimates weren't spot on. He thought it would take millenia to see a 50% rise in CO2 - but modern measurements show a 30% rise during the 20th century alone. He thought a doubling of CO2 would raise temperatures by 5-6C. Scientists now say 2-3C is more likely.

 

[Michael Scally MD]

 

[Michael Scally MD]

 

[Michael Scally MD]

The oft-quoted "97% of climate scientists agree that climate change is real and caused by humans" number bugs me. Who are those 3%?

OK, there's Richard Lindzen and (maybe) Judith Curry. But wouldn't that make it like 99.99%? Maybe it's still correct; maybe it needs revisiting.

This isn't "groupthink" on my part, either. Over the course of my career, I've seen precisely no convincing evidence for non-warming, and precisely no convincing explanation for warming other than human emissions. And I can't imagine that 3% of my colleagues have.

There's evidence that those 3% are mainly cranks, and should therefore probably be filtered out. But I suppose applying that filter in a fair and objective way is difficult.

 

[Michael Scally MD]

 

[Michael Scally MD]

 

[NorthMich]

We’ve never had a pres that cared so little for the people and the land.

We’ve never had a president so selfish

 

[Michael Scally MD]

 

[Michael Scally MD]

 

[Michael Scally MD]