A supplement to "What's Natural about Steele's Greenland conundrum? Pacifica Tribune 3/20/2019." Since I found way more information than I had room for I've decided to add this appendix of valuable science information about Greenland and our global heat and moisture distribution engine.
REPRINTED UNDER PROTECTION OF FAIR USE COPYRIGHT LAWS.
My intention is a point by point review of 'libertarian' deception in action.
Click on image for better viewing and comparing.
#A) Wrote about this in a previous post.
MARCH 29, 2019
#B) Steele’s confusion about CarbonDioxide,
On the causal structure between CO2 and global temperature
Adolf Stips, Diego Macias, Clare Coughlan, Elisa Garcia-Gorriz & X. San Liang
Scientific Reports, volume 6, Article number: 21691 (2016)
… Our study unambiguously shows one-way causality between the total Greenhouse Gases and GMTA. Specifically, it is confirmed that the former, especially CO2, are the main causal drivers of the recent warming. …
#C) Steele continues,
Guest post: How the Greenland ice sheet fared in 2017
Dr Ruth Mottram, Dr Peter Langen and Dr Martin Stendel are climate scientists at the Danish Meteorological Institute (DMI) in Copenhagen, which is part of the Polar Portal.
Overall, initial figures suggest that Greenland may have gained a small amount of ice over the 2016-17 year. If confirmed, this would mark a one-year blip in the long-term trend of year-on-year declines over recent decades.
(Note, the SMB (Surface Mass Balance!) doesn’t take into account the breaking off, or “calving” of icebergs from the ice sheet’s edge, which we’ll come to later. Calving losses have averaged around 500bn tonnes of ice per year this century. This means the ice sheet has been losing mass overall across recent years.)
(Left) we are comparing 2016 to 2017 increase in millimeters,
to June 2006 to January 2017 ice losses measured in meters, (Right)
Here we're comparing 2017 left with 2018 right (in mm),
looks like Steele's icy growth trend is already fizzling.
Guest post: How the Greenland ice sheet fared in 2018
For this year, we calculated a total SMB of 517bn tonnes, which is almost 150bn tonnes above the average for 1981-2010, ranking just behind the 2016-17 season as sixth highest on record.
By contrast, the lowest SMB in the record was 2011-2012 with just 38bn tonnes, which shows how variable SMB can be from one year to another. …
Greenland Ice Sheet's 2017 weigh-in suggests a small increase in ice mass
Rebecca Lindsey September 14, 2017
#D) “How much sea level rise should we plan for”
First you must honestly face the reality before you can hope to successfully plan for it.
Sea-level Rise for the Coasts of California, Oregon, and Washington: Past, Present, Future
Published on Jun 22, 2012
Read the full report: http://www.nap.edu/catalog/13389/sea-...
Sea Level Rise Will Threaten Thousands of California Homes
Chronic flooding will impact areas around San Francisco and Los Angeles by 2035
- By Anne C. Mulkern, E&E News on June 18, 2018
Rising Seas in California
AN UPDATE ON SEA-LEVEL RISE SCIENCE
This document was produced by a Working Group of the California Ocean Protection Council Science Advisory Team (OPC-SAT), supported and convened by the California Ocean Science Trust. The State of California Sea-Level Rise Guidance Document, initially adopted in 2010 and updated in 2013, provides guidance to state agencies for incorporating sea-level rise projections into planning, design, permitting, construction, investment and other decisions. …
Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future (2012)
#F) “We should protect homes with seawalls”
Walls Won't Save Our Cities From Rising Seas. Here's What Will.
By Joseph Bennington-Castro | July 27, 2017
The devil is in the details:
Marin County Residents Concerned Over an Eroding Sea Wall.
By Mark Mathews | Published Dec 4, 2018
“Leaders of the Marin County town decided Monday to wait until January to make the needed repairs. But the specialized steel needed for the wall won’t be delivered until early next year.”
#G) “Understanding Greenland’s contribution is critical.”
Rain is melting Greenland’s ice, even in winter, raising fears about sea level rise
By Alex Fox | March. 7, 2019
Pakalolo, April 01, 2019
Thwaites glacier in West Antarctica is enormous and is often referred to as the most dangerous glacier on Earth. It has also been dubbed the Doomsday glacier. The glacier holds two feet of sea level but, more importantly, it is the “backstop” for four other glaciers which holds an additional 10-13 feet of sea level rise. When Thwaites collapses it will take most of West Antarctica with it. This is not new information for those of us that follow the science. For example, Eric Rignot in 2014, stated that the loss of West Antarctica is unstoppable. (You can listen to an excellent interview from 2019 between Rignot and Radio Eco-shock on Antarctica).
According to researchers at the University of Washington back in 2014, Thwaites is already collapsing. “The simulations indicate that early-stage collapse has begun,” notes their news presser. What’s more, the Thwaites Glacier is a “linchpin” for the rest of the West Antarctic Ice Sheet; its rapid collapse would “probably spill over to adjacent catchments, undermining much of West Antarctica.” …
These might be the oldest (1947!) pictures around of Thwaites Glacier,
one of Antarctica's fastest flowing and most rapidly thinning glaciers.
Link to the series of images taken in 1947 of Thwaites Glacier tongue/ocean.
Simulation of the future sea level contribution of Greenland
with a new glacial system model
The Cryosphere, 12, 3097-3121, 2018
Okay, so what can we learn from this?
How about, SLR (Sea level rise) will go any where from very disruptive to catastrophically disruptive.
It’s not pleasant, but reality is what it is.
Hiding from the truth is only going to make it hurt that much more.
It’s not pleasant, but reality is what it is.
Hiding from the truth is only going to make it hurt that much more.
Lots more about Greenland:
#H) If you remove the ice, “the land would reveal a bowl-shape.”
Published on Dec 14, 2017
A new map of what lies beneath the Greenland Ice Sheet produced by researchers at British Antarctic Survey (BAS), University of Bristol and University of California at Irvine (UCI).
NASA | Greenland's Ice Layers Mapped in 3D
NASA Goddard | Published on Jan 23, 2015
#K) “Greenland oscillated between gaining and losing ice."
Greenland ice flow
#L) No Steele, clouds were not "the cause”
Clouds are an important component among the interplay of many components:
October 2, 2018
Impact of Atmospheric Circulation on Temperature, Clouds, and Radiation at Summit Station, Greenland, with Self-Organizing Maps
Cooperative Institute for Research in Environmental Science, and NOAA/Earth System Research Laboratory, Boulder, Colorado
06/28/2017, by Matt Smith
Less Cloud Cover May Be Causing Greenland’s Ice to Melt More Rapidly
An increase in clear, sunny days over the world's largest island may be contributing to accelerated ice melt, which has big implications for global sea level rise.
June 28, 2017,
Decreasing cloud cover drives the recent mass loss on the Greenland Ice Sheet
Stefan Hofer, Andrew J. Tedstone, Xavier Fettweis and Jonathan L. Bamber
Vol. 3, no. 6, e1700584
January 12, 2016, by Chelsea Harvey
Scientists just found an unexpected factor that could be driving Greenland’s ice loss
April 8, 2016, by Suzanne Jacobs
The science around clouds and climate change is, well, cloudy
The next time you’re gazing up at a cloud, wondering whether that perfect heavenly orb looks more like a heart or a bunny rabbit, do the world a favor, and give it one of these:
But don’t do it because there’s a big new study showing that clouds might not slow global warming as much as we once thought. Do it because despite this important new finding, clouds remain a big wispy wild card when it comes to making climate predictions. …
January 12, 2016, by University of Wisconsin-Madison
Clouds, like blankets, trap heat and are melting the Greenland Ice Sheet
April 4, 2013, by John Upton
New culprit in sea-level rise: Pretty Arctic clouds
“Of course, there is more than one cause for such widespread change,” said University of Wisconsin atmospheric and oceanic sciences professor Ralf Bennartz, one of the authors of a study published today in Nature that concludes that the clouds that drifted over Greenland last summer bore properties that could be likened to a perfect ice-melting storm. “We focused our study on certain kinds of low-level clouds.”
At the critical surface melt time, the clouds were optically thick enough and low enough to enhance the downwelling infrared flux at the surface. At the same time they were optically thin enough to allow sufficient solar radiation to penetrate through them and raise surface temperatures above the melting point. ….
“… Above all, this study highlights the importance of continuous and detailed ground-based observations over the Greenland ice sheet and elsewhere,” he says. “Only such detailed observations will lead to a better understanding of the processes that drive Arctic climate.”
April 3, 2013, by Mark Hobson
Thin clouds drove Greenland’s record-breaking 2012 ice melt
But wait, there’s more.
Dust from Melting Glaciers Could Create Clouds
Arctic ice is disappearing at some of the fastest rates in centuries as global temperatures rise. Now, scientists suggest that melting glaciers may, in turn, be influencing the Arctic climate. …
#L) “Cause of rapidly melting since 1990s fewer clouds."
Greenland warming of 1920–1930 and 1995–2005
June 13, 2006
“… The response of the Greenland ice sheet to changing environmental conditions is a result of a complicated nonlinear interaction between variable solar radiation, atmospheric composition, atmospheric and ocean circulation, state of ice sheet dynamics, cloudiness, precipitation, near surface air temperature and amount of aerosols suspended in the atmosphere as well as deposited on the surface of the ice sheet. …”
#M) … Steele, what about the “GBI”?
Greenland Blocking Index 1851–2015: a regional climate change signal
May 2, 2016
High‐pressure blocking over Greenland has been of great interest to weather forecasters and climatologists for many years. This blocking has traditionally been discussed in quite descriptive terms but more recently a Greenland Blocking Index (GBI) has been defined by Fang (2004) and popularized by Hanna et al. (2013, 2014, 2015), where GBI is the mean 500 hPa geopotential height for the 60–80°N, 20–80°W region (Figure 1). A basic GBI dataset has recently been made available on the US National Oceanographic and Atmospheric Administration (NOAA)'s Earth System Research Laboratory Physical Sciences Division at: http://www.esrl.noaa.gov/psd/data/timeseries/daily/GBI/ but, in common with the above‐referenced work, it only extends back to 1948. The GBI represents, and clearly depicts changes in, blocking across the entire Greenland region.
April 26, 2016 by University of Sheffield
Climate change and extreme weather linked to high pressure over Greenland
New research, led by Professor Edward Hanna from the University's Department of Geography, has identified changes in weather systems over Greenland that have dragged unusually warm air up over the western flank of Greenland's Ice Sheet.
These weather systems are also linked to extreme weather patterns over northwest Europe, such as the unusually wet conditions in the UK in the summers of 2007 and 2012.
The study analysed changes in weather systems over Greenland since 1851, using a measure called the Greenland Blocking Index (GBI).
National Weather Servicer - Climate Prediction Center
Numerous definitions of atmospheric blocking exist in the literature and all involve a level of subjectivity. We use the blocking index of Tibaldi and Molteni (1990) modified from that of Lejenas and Okland (1983). The index is local and instantaneous, ideally suited for real-time atmospheric monitoring, isolating regions of easterly flow at 500 hPa associated with high-latitude blocks.
Greenland Blocking Index (GBI)
GBI is the mean 500 hPa geopotential height for the 60-80°N, 20-80°W region. It measures blocking over Greenland which impacts both climate and weather in the Northern Hemisphere.
Human Fingerprints Visible in Atmospheric Changes
By Brian Kahn, September 16th, 2013
The latest discovery, announced Monday in a paper in the Proceedings of the National Academy of Sciences, makes the case that those emissions are causing changes to the climate in the lower and upper reaches of the atmosphere.
The new paper examines the role of emissions from human activities — largely from the burning of fossil fuels such as coal and oil — in causing the seemingly contradictory phenomenon of warming in the troposphere, which is the layer of the atmosphere closest to the ground, where most weather occurs, and cooling in the stratosphere, which lies above the troposphere at an altitude of between 40,000 to 160,000 feet. …
#N) "They admittedly can't differentiate between anthropogenic forcing and natural fluctuations.”
Nonsense, scientists certainly have learned how to differentiate between natural and anthropogenic influences, take a look at the foot notes.
March 18, 2010
Fingerprinting the climate
Interview by Patrick Lynch,
NASA Langley Research Center
NASA Langley Research Center
"People want to talk in certainty. They want to say climate change is a certainty. Or, climate change is nonsense. That doesn’t work. Predicting future climate change is about offering a range of potential scenarios based on a range of present-day factors, and then determining the most likely scenario.”
Scientists detect a human fingerprint in the atmosphere's seasonal cycles
John Abraham, July 23, 2018
We know that humans are causing Earth’s climate to change. It used to be that “climate change” mostly referred to increasing temperatures near the Earth’s surface, but increasingly, climate change has come to mean so much more. It means warming oceans, melting ice, changing weather patterns, increased storms, and warming in other places.
A recent study has just been published that finds ‘fingerprints’ of human-caused warming someplace most of us don’t think about – in the higher atmosphere. Not only that, but these scientists have found changes to the seasonal climate – how much the temperature varies from winter to summer to winter – and the changes they found matched expectations.
The paper was authored by a top group of scientists including Benjamin Santer, Stephen Po-Chedley, Mark Zelinka, Ivana Cvijanovic, Celine Bonfils and Paul Durack from Lawrence Livermore National Laboratory; Carl Mears and Frank Wentz from Remote Sensing Systems; Qiang Fu from the University of Washington; Jeffrey Kiehl from the University of California, Santa Cruz; Susan Solomon from MIT; and Cheng-Zhi Zou from the University of Maryland. …
PUBLIC RELEASE: 19-JUL-2018
A 'fingerprint' for anthropogenic climate change in a new place
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE
How Do We Know that Humans Are the Major Cause of Global Warming?
Union of Concerned Scientists.
- Unprecedented warming
- Direct evidence of human contribution to atmospheric CO2
- Natural and human factors that influence the climate (known as “climate drivers”)
- Natural drivers + human drivers best match reality
- Solutions within our reach
#O) “Similar Warming … decades earlier.”
Nope, there was nothing similar to it.
Then it was a convergence of natural oscillations producing a regional impact. Current warming is global, driving by increasing atmospheric insulation because of increasing greenhouse gases. Very different mechanisms.
The Early Twentieth-Century Warming in the Arctic—A Possible Mechanism
LENNART BENGTSSON, VLADIMIR A. SEMENOV, OLA M. JOHANNESSEN | October 15, 2004
The huge warming of the Arctic that started in the early 1920s and lasted for almost two decades is one of the most spectacular climate events of the twentieth century. During the peak period 1930–40, the annually averaged temperature anomaly for the area 60–90N amounted to some 1.7C.
Whether this event is an example of an internal climate mode or is externally forced, such as by enhanced solar effects, is presently under debate. This study suggests that natural variability is a likely cause, with reduced sea ice cover being crucial for the warming. A robust sea ice–air temperature relationship was demonstrated by a set of four simulations with the atmospheric ECHAM model forced with observed SST and sea ice concentrations.
An analysis of the spatial characteristics of the observed early twentieth-century surface air temperature anomaly revealed that it was associated with similar sea ice variations. Further investigation of the variability of Arctic surface temperature and sea ice cover was performed by analyzing data from a coupled ocean–atmosphere model. By analyzing climate anomalies in the model that are similar to those that occurred in the early twentieth century, it was found that the simulated temperature increase in the Arctic was related to enhanced wind-driven oceanic inflow into the Barents Sea with an associated sea ice retreat.
The magnitude of the inflow is linked to the strength of westerlies into the Barents Sea.
This study proposes a mechanism sustaining the enhanced westerly winds by a cyclonic atmospheric circulation in the Barents Sea region created by a strong surface heat flux over the ice- free areas. Observational data suggest a similar series of events during the early twentieth-century Arctic warming, including increasing westerly winds between Spitsbergen and Norway, reduced sea ice, and enhanced cyclonic circulation over the Barents Sea. At the same time, the North Atlantic Oscillation was weakening. …
MARCH 8, 2016
Human influence on the climate dates back to 1930s
#R) “current trend is too short.”
Factcheck: What Greenland ice cores say about past and present climate change
ZEKE HAUSFATHER | April, 3, 2019
A misleading graph purporting to show that past changes in Greenland’s temperatures dwarf modern climate change has been circling the internet since at least 2010. …
This modern temperature reconstruction, combined with observational records over the past century, shows that current temperatures in Greenland are warmer than any period in the past 2,000 years. That said, they are likely still cooler than during the early part of the current geological epoch – the Holocene – which started around 11,000 years ago.
However, warming is expected to continue in the future as human actions continue to emit greenhouse gases, primarily from the combustion of fossil fuels.
Climate models project that if emissions continue, by 2050, Greenland temperatures will exceed anything seen since the last interglacial period, around 125,000 years ago. …
#R) “Greenland is now entering a cooling cycle”
Not much of one, and there's no future in it.
Arctic Report Card: Update for 2017
Arctic shows no sign of returning to reliably frozen region of recent past decades
Greenland Ice Sheet
M. Tedesco, J. E. Box, J. Cappelen, R. S. Fausto, X. Fettweis, K. Hansen, T. Mote, I. Sasgen, C. J. P. P. Smeets, D. van As, R. S. W. van de Wal, I. Velicogna
- The 2017 summer season over the Greenland ice sheet was characterized by below-average (1981-2010) melt extent and above-average surface albedo.
- The net 2017 ablation was below the 2008-2017 average at all ~20 PROMICE ablation area sites but still above the average for the 1961-1990 reference period, when the ice sheet was in steady equilibrium.
- The cumulative ice sheet mass balance up until April 2017 (end of GRACE observations) was close to the average of the years 2003-2016.
- Glacier area in 2017 continued a period of relative stability that started in 2012/2013.
Arctic Report Card: Update for 2018
Effects of persistent Arctic warming continue to mount
- Estimates of the spatial extent of melt across the Greenland ice sheet (GrIS) were unexceptional for most of the summer (i.e., June, July, August) melt season of 2018.
- Surface ice mass balance for the 2017/18 season was below or near the long-term mean (relative to the period 1961-90), consistent with a snow cover that survived late into the spring and average/low surface melting during summer.
- Summer 2018 albedo (a measure of surface reflectivity), averaged over the whole ice sheet, tied with the record high set in 2000 for the 2000-18 period. Relatively high albedo was associated with the reduced surface melting and extended survival of the snow cover, which reduced the exposure of darker, bare ice.
- Surface air temperatures set new high records in winter (up to +14.4° C above the mean) and low records in summer (-46.3° C at Summit).
The Greenland ice sheet plays a crucial role on our planet and in the Arctic. The high albedo (i.e., the fraction of incident solar radiation reflected by a surface) of the ice sheet contributes to modulating the amount of solar energy absorbed by the Earth and controls atmospheric circulation because of its location and topography. Moreover, Greenland represents a major contributor to current and projected sea level rise, through surface runoff and calving.
Regarding that “cooling cycle”
If it were a real cooling cycle, shouldn’t it at least be reflected throughout the Arctic Circle?
North Pole surges above freezing in the dead of winter, stunning scientists
By Jason Samenow, February 26, 2018
“The sun won’t rise at the North Pole until March 20, and it’s normally close to the coldest time of year, but …
Temperatures may have soared as high as 35 degrees Fahrenheit (2 degrees Celsius) at the pole, according to the U.S. Global Forecast System model. While there are no direct measurements of temperature there, Zack Labe, a climate scientist working on his PhD at the University of California at Irvine, confirmed that several independent analyses showed “it was very close to freezing,” which is more than 50 degrees (30 degrees Celsius) above normal. …”
#T) “the mythical 97% consensus”
Scientific consensus: Earth's climate is warming
Multiple studies published in peer-reviewed scientific journals1 show that 97 percent or more of actively publishing climate scientists agree*: Climate-warming trends over the past century are extremely likely due to human activities. In addition, most of the leading scientific organizations worldwide have issued public statements endorsing this position. The following is a partial list of these organizations, along with links to their published statements and a selection of related resources.
Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
Posted on 16 May 2013 by dana1981, John Cook
A new survey of over 12,000 peer-reviewed climate science papers by our citizen science team at Skeptical Science has found a 97% consensus among papers taking a position on the cause of global warming in the peer-reviewed literature that humans are responsible. …
Understanding the Forecast
Professor David Archer PhD, University of Chicago
I have been a professor in the Department of The Geophysical Sciences at the University of Chicago since 1993. I have worked on a wide range of topics pertaining to the global carbon cycle and its relation to global climate, with special focus on ocean sedimentary processes such as CaCO3 dissolution and methane hydrate formation, and their impact on the evolution of atmospheric CO2. I teach classes on global warming, environmental chemistry, and global geochemical cycles.
- Archer, D., and Blum, J. A model of mercury cycling and isotopic fractionation in the ocean. Biogeosciences, 15, 6297-6313, 2018, https://doi.org/10.5194/bg-15-6297-2018
- Archer, D. "Near miss: The importance of the natural atmospheric CO2 concentration to human historical evolution". Climatic Change 138 (1-2), 1-11 (2016).
- T. Jokulsdottir and D. Archer. "A stochasitc Lagrangian model of sinking biogenic aggregates in the ocean (SLAMS 1.0): model formulation, validation, and sensitivity. Geoscientific Model Development 9 (4), 1455-1476 (2016)
- Archer, D. "A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin." Biogeosciences 12.10 (2015): 2953-2974 (2015)
- Global Warming: Understanding the Forecast, a textbook for non-science major undergraduates, Blackwell-Wiley, 2006 with Second Edition 2011. The book is supplemented with a web page of =on-line interactive models which provide the basis for exercises in the book.
- The Warming Papers: The Scientific Foundation for the Climate Change Forecast, co-edited with Ray Pierrehumbert, 2010, Wiley-Blackwell.
- The Global Carbon Cycle (Princeton Primers in Climate), 2010, Princeton University Press.
- The Long Thaw: How Humans are Changing the Next 100,000 Years of Earth's Climate, published by Princeton University Press, 2009.
- The Climate Crisis: An introductory guide to climate change, December, 2009, Cambridge University Press.
Free Open-access Online Classes (MOOCS)
- Global Warming I: The Science of and Modeling of Climate Change, on Coursera.org. Open now for anytime, "on demand" enrollment. The class uses the same web page of on-line interactive models as is used in my UChicago classes.
- Global Warming II: Create Your Own Models in Python or Fortran
Online Interactive Models
- Climate and Carbon Cycle Models teaching suite
- SpongeBOB basin-scale deep sediment carbon cycle model movies
- Muds early diagenesis model
- Near Miss: The importance of the natural atmospheric CO2 concentration to human historical evolution. 2016 - 7th annual UW-AOS Robock Lecture, Madison, WI, 2016.
- "The Long Thaw", April 9, 2013, Notre Dame University
- Class lectures from PHSC 13400, Global Warming for non-science majors, Fall, 2009, as well as the videos from the Coursera class
- My Realclimate Blog Posts
- Archer Data Server
- Scientific debate on climate change, a cartoon by Jill and David Archer
#U) “Absolutely no consensus regards climate’s sensitivity to a doubling of CO2.”
I’m plenty content with the 3°C most studies keep hovering around. Sure, it’s not exact, what in life is? Besides, it’s starting to look as though, if anything it’ll turn out to be a bit higher, so what the heck.
Published on Oct 8, 2018
Equilibrium Climate Sensitivity is the measure of how much the planet will warm in response to a given amount of Greenhouse gas pollution. It is the most important number in climate change science, and past estimates of increased warming may have been too low.
Posted on 6 November 2018 by greenman3610
Andrew Dessler’s Climate Sensitivity Lecture: Some Observations
By Robert Bradley Jr. -- March 20, 2019
CLIMATE SENSITIVITY June 19, 2018
Explainer: How scientists estimate ‘climate sensitivity’
The sensitivity of the Earth’s climate to increases in atmospheric CO2 concentration is a question that sits at the heart of climate science.
Essentially, it dictates how much global temperatures will rise in response to human-caused CO2 emissions, but it is a question that does not yet have a clear answer.
For many years, estimates have put climate sensitivity somewhere between 1.5C and 4.5C of warming for a doubling of pre-industrial CO2 levels. This range has remained stubbornly wide, despite many individual studies claiming to narrow it.
Here, Carbon Brief examines studies of climate sensitivity published over the past two decades. These studies use climate models, recent observations and palaeoclimate data from the Earth’s more distant past to estimate climate sensitivity.
There appears to be no evidence that recent studies show a substantially different range of sensitivity than in the past, though some approaches generally result in lower or higher sensitivity than others.
While narrowing the range of sensitivity will not change the need for rapid decarbonisation, it may help policymakers fine-tune their plans for the future. …
Improving Estimates of Long-Term Climate Sensitivity
SOURCE: Journal of Advances in Modeling Earth Systems (JAMES)
By Terri Cook 5 March 2019
One of the fundamental metrics in climate change research is equilibrium climate sensitivity: the amount that Earth’s long-term, near-surface temperatures will change in response to a doubling of atmospheric carbon dioxide concentrations. Previous research has shown that two spatially dependent processes—the variability of sea surface temperatures and the organization of initially scattered convection (known as convective aggregation)—largely control climate sensitivity by regulating feedbacks related to clouds and water vapor that can amplify or moderate Earth’s ability to radiate heat into space.
Most modeling studies investigating the role of convective aggregation on climate sensitivity have used sea surface temperatures that are spatially uniform. But recent research has questioned whether this is appropriate and suggested that aggregation could actually depend upon sea surface temperature patterns.
ACS Climate Science Toolkit | How Atmospheric Warming Works
The concept of “climate sensitivity” is deceptively simple. How much would the average surface temperature of the Earth increase (decrease) for a given positive (negative) radiative forcing?
#U…) “most people are unaware of that.”
Yeah, tell me about it.
Climate change science marks 40th anniversary of three key events that signified turning point
Lawrence Livermore National Laboratory
The events were the release of an influential National Academy of Sciences report, the publication of a key paper on anthropogenic signal detection and the start of satellite temperature measurements. All three events occurred in 1979. “We showed how scientific advances that grew out of these three events paved the way for scientists to identify human influences on atmospheric temperature,” said Céline Bonfils, an LLNL climate scientist and a co-author of the paper.
The Charney report
In 1979, the U.S. National Academy of Sciences published the findings of the Ad Hoc Study Group on Carbon Dioxide and Climate. This is frequently referred to as the Charney report, named after the lead author of the report, Jule Charney of the Massachusetts Institute of Technology. …
Hasselmann’s optimal detection paper
The second scientific anniversary marks the publication of a paper by Klaus Hasselmann entitled “On the signal-to-noise problem in atmospheric response studies.” This was one of the first serious efforts to provide a sound statistical framework for identifying a human-caused warming signal.
A key insight in Hasselmann’s 1979 paper was that analysts should look at the statistical significance of global geographical patterns of climate change (rather than focusing on purely local changes). …
Forty years of satellite temperature data
In November 1978, Microwave Sounding Units (MSUs) on NOAA satellites began monitoring the temperature of broad atmospheric layers. Microwave sounders provided estimates of global changes in the temperature of the troposphere (the lowermost layer of Earth’s atmosphere) and the layer above the troposphere (the stratosphere). Signal detection studies with these measurements revealed that human fingerprints were identifiable in the warming of the troposphere and cooling of the lower stratosphere, confirming early computer model projections. …
The First Climate Model Turns 50, And Predicted Global Warming Almost Perfectly
Ethan Siegel, March 15, 2017
“… But headlines are never as reliable as going to the scientific source itself, and the ultimate source, in this case, is the first accurate climate model ever: by Syukuro Manabe and Richard T. Wetherald. 50 years after their groundbreaking 1967 paper, the science can be robustly evaluated, and they got almost everything exactly right..”
“The title of their paper, Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity (full download for free here), describes their big advances: they were able to quantify the interrelationships between various contributing factors to the atmosphere, including temperature/humidity variations, and how that impacts the equilibrium temperature of Earth. Their major result, from 1967?
According to our estimate, a doubling of the CO2 content in the atmosphere has the effect of raising the temperature of the atmosphere (whose relative humidity is fixed) by about 2 °C. …”