Climate Impacts

Arctic Ice Recovery Starts Sept. 2023

Posted on by Ron Clutz

The animation above shows the minimum daily extent for 2023 occurred on September 15.  In the next six days ~450k km2 of ice extent was added (nearly half a Wadham). The Arctic ice extent yesterday was 4.53M km2 approaching the 17 year average for the day.

The graph for September shows the first two weeks 2023 was well below the average and tracking with 2007. After hitting bottom day 258, a sharp recovery lifted extents close to average and much higher than 2007.  (SII  has not yet posted a value for day 264).

Note that typically September ends the month slightly higher than it begins, though 2023 is already matching its Sept. 1 value.  If this year’s ice growth continued at the same rate of losses during the first two weeks of September (50k per day), the extent would reach  ~5M km2 at month end.  That would result in a 2023 September monthly average of 4.5M km2.  Such extent would be close to the median prediction, somewhat lower than 2022, but much higher than 2007 or 2020, and 800k km2 higher than 2012 (the year of the great August Cyclone.)

The table for day 264 shows how the ice extent is distributed across the Arctic regions, in comparison to 17 year average and 2007.

Region 2023264 264 Average 2023-Ave. 2007264 2023-2007
 (0) Northern_Hemisphere 4530862 4603044  -72183  4129308 401554 
 (1) Beaufort_Sea 353539 514036  -160497  507235 -153697 
 (2) Chukchi_Sea 135936 167774  -31839  30316 105620 
 (3) East_Siberian_Sea 48471 262691  -214220  311 48160 
 (4) Laptev_Sea 381662 127644  254018  223595 158067 
 (5) Kara_Sea 43989 34853  9136  27950 16038 
 (6) Barents_Sea 2394 14654  -12260  4851 -2457 
 (7) Greenland_Sea 273632 202253  71379  336388 -62756 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 66853 34768  32085  31731 35122 
 (9) Canadian_Archipelago 177101 302976  -125875  237555 -60454 
 (10) Hudson_Bay 0 4119  -4119  2270 -2270 
 (11) Central_Arctic 3046145 2936249  109896  2725832 320313 

The table shows the main deficits are in Beaufort, East Siberian seas and CAA.  Offsetting surpluses are in Laptev, Greenland and Central Arctic seas. The total deficit on this day is 72k km2 or 1.6%.  Note that 2007 did not add more ice as September ended.

Illustration by Eleanor Lutz shows Earth’s seasonal climate changes. If played in full screen, the four corners present views from top, bottom and sides. It is a visual representation of scientific datasets measuring Arctic ice extents and snow cover.

Confirmed: Temperature Drives CO2, not the Reverse

Posted on by Ron Clutz

From notrickszone New Study: The Rising-CO2-Causes-Warming Perception Not Supported By Real-World Observation.  Excerpts in italics with my bolds.

One of the most basic concepts in physics is that causes precede effects and effects follow causes. Determining the directionality sequence is thus essential in any causality analysis.

The assumed CO₂→T causality direction cannot be scientifically supported

The assumption in climate models is that CO₂ causes changes in temperature, or T. More specifically, it is assumed modern global warming has been caused by increases in anthropogenic CO₂ emissions.

However, scientists (Koutsoyiannis et al., 2023) have now expanded upon last year’s 2-part study on stochastics-formulated causality published in The Royal Society (Koutsoyiannis et al., 2022 (1) and Koutsoyiannis et al., 2022 (2)) where they notably contend:

“Clearly the results […] suggest a (mono-directional) potentially causal system with T as the cause and [CO₂] as the effect. Hence the common perception that increasing [CO₂] causes increased T can be excluded as it violates the necessary condition for this causality direction.”

The analysis is in complete agreement with several posts here, especially:

Temps Cause CO2 Changes, Not the Reverse. 2023 Update

The paper is On Hens, Eggs, Temperatures and CO2: Causal Links in Earth’s Atmosphere by Demetris Koutsoyiannis et al.  Excerpts in italics with my bolds.

Abstract

The scientific and wider interest in the relationship between atmospheric temperature (T) and concentration of carbon dioxide ([CO2]) has been enormous. According to the commonly assumed causality link, increased [CO2] causes a rise in T. However, recent developments cast doubts on this assumption by showing that this relationship is of the hen-or-egg type, or even unidirectional but opposite in direction to the commonly assumed one. These developments include an advanced theoretical framework for testing causality based on the stochastic evaluation of a potentially causal link between two processes via the notion of the impulse response function. Using, on the one hand, this framework and further expanding it and, on the other hand, the longest available modern time series of globally averaged T and [CO2], we shed light on the potential causality between these two processes.

All evidence resulting from the analyses suggests a unidirectional,
potentially causal link with T as the cause and [CO2] as the effect.

That link is not represented in climate models, whose outputs are also examined using the same framework, resulting in a link opposite the one found when the real measurements are used.

Discussion and Further Results

The mainstream assumption of the causality direction [CO2] → T makes a compelling narrative, as everything is blamed on a single cause, the human CO2 emissions. Indeed, this has been the popular narrative for decades. However, popularity does not necessarily mean correctness, and here we have provided strong arguments against this assumption.

Since we have identified atmospheric temperature as the cause and atmospheric CO2 concentration as the effect, one may be tempted to ask the question: What is the cause of the modern increase in temperature? Apparently, this question is much more difficult to reply to, as we can no longer attribute everything to any single agent.

We do not claim to have the answer to this question, whose study is far beyond the article’s scope. Neither do we believe that mainstream climatic theory, which is focused upon human CO2 emissions as the main cause and regards everything else as feedback of the single main cause, can explain what happened on Earth for 4.5 billion years of changing climate.

The examined processes in the Appendices are internal to the climatic system. Other processes affecting T, not examined here, could also be external (e.g., solar and astronomical [43,44] and geological [45,46,47,48,49]). Generally, in complex systems, an identified causal link, even though it gives some explanation of a phenomenon, raises additional questions, e.g., what caused the change in the identified cause, etc. In turn, causal links in complex systems may form endless sequences.

For this reason, it is naïve to expect complete answers to problems related to complex systems or to assume that a complex system is in permanent equilibrium and that an external agent is needed to “kick” it out of the equilibrium and produce change. Yet the investigation of a single causal link between two processes, as is the focus of this paper, provides useful information, with possible significant scientific, technical, practical, epistemological and philosophical implications. These are not covered in this paper. 

As already clarified, the scope of our work is not to provide detailed modeling of the processes studied but to check causality conditions. We highlight the fact that the relationship we established explains only about 1/3 of the actual variance of Δln[CO2]. This is not negligible for investigating causality, but also leaves a margin for many other climatic factors to act.

Conclusions

With reference to points 1–7 of the Introduction setting the paper’s scope, the results of our analyses can be summarized as follows.

  1. All evidence resulting from the analyses of the longest available modern time series of atmospheric concentration of [CO2] at Mauna Loa, Hawaii, along with that of globally averaged T, suggests a unidirectional, potentially causal link with T as the cause and [CO2] as the effect. This direction of causality holds for the entire period covered by the observations (more than 60 years).
  2. Seasonality, as reflected in different phases of [CO2] time series at different latitudes, does not play any role in potential causality, as confirmed by replacing the Mauna Loa [CO2] time series with that in South Pole.
  3. The unidirectional 𝑇→ln[CO2] potential causal link applies to all timescales resolved by the available data, from monthly to about two decades.
  4. The proposed methodology is simple, flexible and effective in disambiguating cases where the type of causality, HOE or unidirectional, is not quite clear.
  5. Furthermore, the methodology defines a type of data analysis that, regardless of the detection of causality per se, assesses modeling performance by comparing observational data with model results. In particular, the analysis of climate model outputs reveals a misrepresentation of the causal link by these models, which suggest a causality direction opposite to the one found when the real measurements are used.
  6. Extensions of the scope of the methodology, i.e., from detecting possible causality to building a more detailed model of stochastic type, are possible, as illustrated by a toy model for the T-[CO2] system, with explained variance of [CO2] reaching an impressive 99.9%.
  7. While some of the findings of this study seem counterintuitive or contrary to mainstream opinions, they are logically and computationally supported by arguments and calculations given in the Appendices.

 

 

Don’t Buy “Planetary Boundaries” Hype

Posted on by Ron Clutz

Latest diagram from Stockholm Resilience Centre

The usual suspects are beating on their “planetary boundaries” drum to scare up submission to Zero Carbon restrictions.  Remember these are the same climate justice warriors pushing the notion of a new geological era named “Anthropocene”.  For example, cue the following:

Six of nine planetary boundaries now exceeded–Phys.org

Humans Have Crossed 6 of 9 ‘Planetary Boundaries’–Scientific American

Earth is now outside most of the “planetary boundaries” under which human civilization emerged–TechSpot

Six out of 9 planetary boundaries breached, Earth increasingly becoming uninhabitable for humans–MSN.com

Humanity deep in the danger zone of planetary boundaries: study–YAHOO!News

Etc., Etc. Etc.

Background

In 2009, a group of 29 scholars published an article in Nature, advancing an approach to define a “safe operating space for humanity” (1). The group argued that we can identify a set of nine “planetary boundaries” that humanity must not cross at the cost of its own peril. Since this 2009 publication, the concept of planetary boundaries has been highly influential in generating academic debate and in shaping research projects and policy recommendations worldwide. At the same time, the concept has come under heavy scrutiny as well, and many critics have taken the floor contesting the broader framework as well as its implementation and interpretation. Partially because of this critique, the original proposition of nine planetary boundaries has undergone various reformulations and updates by their proponents and an emerging network of scholars specializing in planetary boundary research.

The original 2009 paper in Nature suggested nine boundary conditions in the earth system that could, if crossed, result in a major disruption in (parts of) the system and a transition to a different state, which is likely to be hostile to human prosperity. The proposed planetary boundaries included:

♦  climate change,
♦  biodiversity loss,
♦  the nitrogen cycle,
♦  the phosphorus cycle,
♦  stratospheric ozone depletion,
♦  ocean acidification,
♦  global freshwater use,
♦  land use change,
♦  atmospheric aerosol loading, and
♦  chemical pollution.

For each of these planetary boundaries, one or more control variables were identified (e.g., atmospheric carbon dioxide concentration), which in turn were assigned with numerical boundary values at a “safe” distance from dangerous levels, or where applicable, “tipping points” in earth system processes (1).

Eventually, the framework should allow for quantification of threshold parameters, as a guide also for political responses. For some planetary boundaries, the group in 2009 suggested that the current state of knowledge was too uncertain to allow for quantification. Yet, for other earth system processes, the group felt confident enough to suggest a specific boundary value. In this endeavor, they erred on the side of caution and a strict interpretation of the precautionary principle: Where they saw remaining uncertainties, the group suggested the lower values for the boundary that they identified.

They concluded that three planetary boundaries had been crossed already.

On climate change, for instance, the boundary value proposed was 350 ppm, which had been passed long ago in the second half of the twentieth century. Regarding biodiversity, the current extinction rate is more than 100 extinct species per million species per year, whereas the suggested boundary was 10 extinctions. As for the nitrogen cycle, humans remove today approximately 121 million tons of nitrogen per year from the atmosphere, whereas a safe rate would be a maximum of 35 million tons. In these three areas, therefore, this analysis suggested that humankind had pushed the earth system past planetary boundaries and possibly dangerous levels, into a new—and unknown—world.  Source: The Boundaries of the Planetary Boundary Framework: A Critical Appraisal of Approaches to Define a “Safe Operating Space” for Humanity.  Annual Review of Environment and Resources October 2020

We don’t know how long we can keep transgressing these key boundaries before combined pressures lead to irreversible change and harm.–Johan Rockström, co-author and Centre researcher

Critics of the Planetary Boundaries Framework

Leaving aside those who want the boundaries to be tighter and harder than presented, let’s hear from critics challenging the whole enterprise. Shortly after the invention of “planetary boundaries,” Breakthrough Institute published a thorough critique of the notion and the framework.  Planetary Boundaries: A Review of the Evidence.  Linus Blomqvist (2012)

The planetary boundaries hypothesis – embraced by United Nations bodies and leading nongovernmental organizations like Oxfam and WWF – has serious scientific flaws and is a misleading guide to global environmental management, according to a new report by the Breakthrough Institute. The hypothesis, which will be debated this month at the UN Earth Summit in Brazil, posits that there are nine global biophysical limits to human development. But after an extensive literature review and informal peer review by leading experts, the Breakthrough Institute has found the concept of “planetary boundaries” to be a poor basis for policy and for understanding local and global environmental challenges.

KEY FINDINGS

♦   Six of the “planetary boundaries” — land-use change, biodiversity loss, nitrogen levels, freshwater use, aerosol loading, and chemical pollution — do not have planetary biophysical boundaries in themselves.

♦   Aside from their impacts on the global climate, these non-threshold “boundaries” operate on local and regional, not global, levels.

♦   There is little evidence to support the claim that transgressing any of the six non-threshold boundaries would have a net negative effect on human material welfare.  The full report is linked below:

A new report from the Breakthrough Institute highlights scientific flaws
of the “planetary boundaries” hypothesis

Planetary Boundaries as Power Grab–Giving Political Decisions a Scientific Sheen–Roger Pielke Jr. (2013)

When the cover of the Economist famously announced ‘Welcome to the anthropocene’ a couple of years ago, was it welcoming us to a new geological epoch, or a dangerous new world of undisputed scientific authority and anti-democratic politics?

The basis for the power grab by the experts – really old wine in new bottles – is the fashionable idea of “planetary boundaries“ which holds that there are hard and fast ecological limits within which human activity must be constrained. The concept is much contested scientifically — such as in this excellent review by my colleagues at The Breakthrough Institute.

A real-world example of the implications of the planetary boundaries political philosophy is vividly seen through the issue of global energy access. Future global development, at least in the short term, necessarily will involve trade offs between expanded use of carbon-emitting fossil fuels and the expansion of energy access to the world’s poorest. The planetary boundaries advocates, consist with their hierarchical values framework, call for “universal clean energy” and recommend development targets focused not on measuring expanded energy access, but rather carbon dioxide emissions (here in PDF).

In other words, expanded energy access to the world’s poorest is deemed acceptable
only if it first satisfies the demands of planetary boundaries – in other words,
the political demands of the scientists couched in the inviolable authority of science.

An major recent critique was: Planetary Boundaries for Biodiversity:  Implausible Science, Pernicious Policies  by Montoya, Donohue and Pimm. Trends in Ecology and Evolution (2018)

The notion of a ‘safe operating space for biodiversity’ is vague and encourages harmful policies. Attempts to fix it strip it of all meaningful content. Ecology is rapidly gaining insights into the connections between biodiversity and ecosystem stability. We have no option but to understand ecological complexity and act accordingly.

How best should environmental science articulate its concerns, set research agendas, and advise policies?One solution embraces the notion of planetary boundaries [1] arguing that global environmental processes very generally have ‘tipping points’. These are catastrophes involving thresholds beyond which there will be rapid transitions to new states that are very much less favorable to human existence than current states. The associated notion is that humanity’s ‘business as usual’ can only continue so long as it remains within some ‘safe operating space’.

We show that notions of planetary boundaries add no insight into our understanding
of the threats to biodiversity and ecosystem functioning, have no evidence to support them,
are too vague for use by those who manage biodiversity, and promote pernicious policies.

Fatally, the boundaries framework lacks clear definitions, or it has too many conflicting definitions, does not specify units, and fails to define terms operationally, thus prohibiting application by those who set policy or manage natural resources. Moreover, recent reviews indicate that tipping points occur only rarely in
natural systems [6], while policies related to boundaries are unlikely to be evidence based. A need for operational definitions to aid managers is self-evident [7].

At the heart of the problem are terms such as ‘planetary boundaries’, but also ‘sustainability’, ‘health’, ‘harmony’, and others, that are emotionally appealing but rarely, if ever, defined. They all speak to the urgent need to understand how human impacts change ecosystems, when at best we aspire to protect only
half of it. We must set policies and establish management for the vast tracts of land and sea that we do not protect. Fatally, those who do so often use language that does not borrow from the existing knowledge about ecosystem processes, nor readily translates its aspirations to those who study them [7].

See Also:

Planetary Boundaries as Millenarian Prophesies  Malthusian Echoes

The identification of the planetary boundaries is dependent on the normative assumptions made, for example, concerning the value of biodiversity and the desirability of the Holocene. Rather than non-negotiables, humanity faces a system of trade-offs – not only economic, but moral and aesthetic as well. Deciding how to balance these trade-offs is a matter of political contestation (Blomqvist et al, 2012:37). What counts as “unacceptable environmental change” is not a matter of scientific fact, but involves judgments concerning the value of the things to be affected by the potential changes. The framing of planetary boundaries as being scientifically derived non-negotiable limits, obscures the inherent normativity of deciding how to react to environmental change. Presenting human values as facts of nature is an effective political strategy to shut down debate.

Beyond Planetary Boundaries by Michael Shellenberger, Ted Nordhaus, and Linus Blomqvist (2012)

There are useful implications for environmental change science that can be drawn from where planetary boundaries went wrong. First, any pragmatic framework on environmental change must look at benefits and costs. Some of the hypothesis’s authors have said that their motivation was to provide a useful framework for helping global leaders manage environmental change. We applaud and support this motivation. But for any environmental change framework to be useful, it must seek to understand not only the costs of change but also its benefits.

One of the implications of this is that simply measuring variance from Holocene baselines is a highly misleading metric of human sustainability. Since so much variance from the Holocene has been good for humans, future environmental change cannot be assumed, as planetary boundaries does, to be negative for our welfare.

 

History Shows Today’s Ocean at Cool End of Range

Posted on by Ron Clutz

You may have heard claims recently that the ocean is now “boiling”.  Fortunately, a world expert in ocean heat uptake provides a deep dive into oceanic temperature history, thereby putting that fear to rest.

Geoffrey Gebbie of Woods Hole Oceanographic Institution has published an highly informative study Combining Modern and Paleoceanographic Perspectives on Ocean Heat Uptake in Annual Review of Marine Science (2021).  H/T Kenneth Richard.  Below are the main findings, along with some excerpts in italics with my bolds, explaining some oceanography for the rest of us.

The large climatic shifts that started with the melting of the great ice sheets have
involved significant ocean heat uptake that was sustained over centuries and millennia,
and modern-ocean heat content changes are small by comparison.

Abstract

Monitoring Earth’s energy imbalance requires monitoring changes in the heat content of the ocean. Recent observational estimates indicate that ocean heat uptake is accelerating in the twenty-first century. Examination of estimates of ocean heat uptake over the industrial era, the Common Era of the last 2,000 years, and the period since the Last Glacial Maximum, 20,000 years ago, permits a wide perspective on modern-day warming rates. In addition, this longer-term focus illustrates how the dynamics of the deep ocean and the cryosphere were active in the past and are still active today. The large climatic shifts that started with the melting of the great ice sheets have involved significant ocean heat uptake that was sustained over centuries and millennia, and modern-ocean heat content changes are small by comparison.

Objective

This review seeks to put the most recent ocean heat uptake estimates of 0.5–0.7 W m−2 into the context of longer (multidecadal to millennial) timescales. Such timescales put a wider perspective on present-day heat uptake. In addition, the dynamics of these longer timescales may still have some expression today. This research direction leads to the long temperature time series of paleoceanographic proxies that predate the instrumental record. Ocean heat uptake over the last deglaciation (∼20,000–10,000 years ago) and the Common Era (previous two millennia) will serve as examples to explore the longer-timescale dynamics of ocean heat uptake.

Common Era Evolution of Mean Ocean Temperature

The Ocean2k global-mean SST compilation is derived from 57 marine proxy records that, in aggregate, show a statistically significant cooling trend from 700 to 1700 CE over the MCA–LIA transition (Medieval Climate Anomaly, Little Ice Age). The data compilation contains a time series of 200-year averages that have been nondimensionalized. Here, we dimensionalize the values with the recommended values of McGregor et al. (2015) to obtain temperature anomalies, and the inferred global-mean surface cooling over the MCA–LIA transition is near the high end of the expected 0.4–0.6°C range (Figure 4a).

Figure 4  The Common Era. (a) The evolution of Ocean2k SST (blue circles, with σ/2 error bars) and mean ocean temperature, , as inferred from noble-gas measurements (red circles, with σ/2 error bars), the Gebbie & Huybers (2019) Common Era inversion (red line), and a power-law estimate (black line, with 2σ error shown in gray), referenced to global-mean SST in 1870. (b,c) Average ocean heat uptake over a running 50-year interval (panel b) and a 500-year interval (panel c) plotted from the Gebbie & Huybers (2019) inversion (red line) and a power-law estimate (black line, with 1σ error shown in gray). Heat uptake is expressed in terms of an equivalent planetary energy imbalance. Abbreviation: SST, sea-surface temperature.

One realization of the Common Era was produced by an inversion that attempted to reconstruct the three-dimensional evolution of oceanic temperature anomalies over the last 2,000 years (Gebbie & Huybers 2019). The inversion fits an empirical ocean circulation model to modern-day tracer observations, historical temperature observations from the HMS Challenger expedition of 1872–1876 (Murray 1895), and the global-mean Ocean2k SST. The resulting ocean temperature evolution is dominated by the propagation of surface climate anomalies from the MCA and LIA into the subsurface ocean, where the propagation is coherent for several centuries (red line in Figure 4a). Although the Gebbie & Huybers (2019) inversion was not constrained with oceanic power laws, the resulting mean ocean temperature is consistent with a power-law estimate over the Common Era.

Early-twenty-first-century SST may already be warmer than MCA SST, but it is
less likely that modern mean ocean temperature has surpassed MCA values.

From the Gebbie & Huybers (2019) inversion, it was inferred that the MCA ocean stored 1,000 ZJ more than the ocean of the year 2000, and that the ∼500 ZJ of heat uptake during the modern warming era is just one-third of what is required to reach MCA levels. Amplification of the high-latitude SST signal relative to the global mean can produce a greater MCA–LIA mean ocean cooling, which explains the greater MCA heat content relative to the present day. When considering the range of Common Era scenarios consistent with a power law, however, some cases are admitted where the MCA and the present day have similar oceanic heat content.

Deep-Ocean Heat Uptake During Modern Warming

Figure 6  Ocean heat uptake below 2,000-m depth, in terms of a planetary energy imbalance, for 50-year averages given by Zanna et al. (2019) (blue line), Gebbie & Huybers (2019) (red line), and the power-law estimate from this review (black line, with 2σ error in gray). An observational estimate (purple, with 2σ error bar) for 1990–2010 is also included (Purkey & Johnson 2010).

The confidence in upper-ocean heat content during the modern warming era starkly contrasts with the remaining uncertainties in heat content below 2,000-m depth (Figure 6). Observational estimates have indicated a deep-ocean heat uptake of 68 ± 61 mW m−2 (2σ) when differencing hydrographic sections between 1990 and 2010 (Purkey & Johnson 2010, Desbruyères et al. 2017). Estimation of deep-ocean heat uptake over the entire instrumental era relies to a greater extent on circulation models. Simulations of modern warming that are initialized from equilibrium in 1870 suggest that heat penetrates downward (Gregory 2000) and that average deep-ocean heat uptake is small over 50-year time intervals (Zanna et al. 2019). These estimates would not capture ongoing trends from the earlier Common Era, if any existed. An inversion that accounts for the LIA found a deep-ocean heat loss of 80 mW m−2 early in the modern warming era (Gebbie & Huybers 2019), and our power-law estimate suggests that an even greater cooling is possible, although the uncertainties are large. These discrepancies highlight the ongoing effect that Common Era variability could play in the modern-day ocean. Unfortunately, recent observations do not appear to be sufficient to distinguish between these scenarios, as they all suggest a weak deep-ocean heat uptake in the early twenty-first century.

Deep-ocean cooling could exist as the result of
disequilibrium between the upper and deep ocean.

Oceanic disequilibrium exists at a range of spatial and temporal scales, from local, short-term variability to longer-term changes that are anticipated to generally have greater spatial extent. Oceanic disequilibrium has been anticipated as a result of the 1815 Tambora (Stenchikov et al. 2009) and 1883 Krakatoa (Gleckler et al. 2006) volcanic eruptions and their lingering effects on energy imbalance. More generally, ocean disequilibrium can result from the differing adjustment times of the interior ocean to surface forcing, where the deep-ocean response may take longer than 1,000 years (e.g., Wunsch & Heimbach 2008). Accordingly, some influence of changes in surface climate over the last millennium is potentially present today. The most isolated waters of the mid-depth Pacific, for example, should still be adjusting to the MCA–LIA transition. In this scenario, these deep waters are cooling, but they are anomalously warm due to the residual influence of the MCA. 

The degree to which the ocean’s long memory affects today’s ocean is uncertain due to difficulties in integrating state-of-the-art circulation models over the entire Common Era. An accurate assessment may also require a model that can skillfully predict ocean circulation changes in both the past and the future. The climate history of the Common Era should also be better constrained by recovering additional observations, such as historical subsurface temperature observations and paleoceanographic data. Proper inference of climate sensitivity depends on the past oceanic heat uptake, which this review suggests is tied to the long timescale of deep-ocean dynamics.

Do notice the scale on the left axis. As though we can measure the whole ocean (71% of earth surface) to 0.05 C. It’s a formula converting zettajoules to temp change.

 

Climate Ambulance Chasers

Posted on by Ron Clutz

Holman Jenkins reports at WSJ Maui Sees Off the Climate-Change Ambulance Chasers.  Excerpts in italics with my bolds and added images.  H/T  climate depot

Making climate policy the answer to weather risks
is a distraction & fraud on the public

It was modestly funny when Hurricane Sandy, after it came ashore in 2012, had to be hurriedly renamed Superstorm Sandy (a title with no formal meteorological meaning) because it was no longer a hurricane.

Local politicians blabbed in the aftermath about climate change to help unlock Obama disaster aid, and also to duck questions about inadequate preparation. But the storm itself was no different from many that had battered the Northeastern seaboard for centuries. The difference was how many people and structures were in its path.

Nothing is funny in the aftermath of the Maui wildfire, which swept through a town and killed at least 115. But it’s noteworthy that Joe Biden refrained from his usual clamor about a climate crisis. He didn’t even mention the word climate in his speech when visiting the island.

Perhaps Mr. Biden’s off-key anecdote about a kitchen fire at his Delaware home was his ad-lib substitution. Whatever the reason, his aides apparently understood that climate talk would come across as criminal and cowardly in the face of the true causes of the Maui disaster.

High winds are a common occurrence. Dry conditions are a common occurrence.
Invasive grasses taking over abandoned pineapple and sugar plantations
were a known menace, complicated by unhelpful land-use policy.

Emergency sirens weren’t sounded. Water wasn’t available due to political squabbles over allocation rights. The local utility was instructed by Hawaii’s Legislature to meet ambitious renewables targets rather than spend on reducing fire risk. Firefighters reportedly left the scene early believing they had extinguished the initial blaze.

Maui itself is an island surrounded by the Pacific Ocean, with vagaries
more immediate and potent than any caused by a 0.3% fluctuation
in the planet’s long-term energy balance due to atmospheric CO2.

Blue-green algae gave us oxygen to breathe and yet we don’t blame blue-green algae for everything oxygen-breathing organisms do. Likewise, nothing very useful comes from trying to explain every weather-related misfortune in terms of human-caused carbon dioxide in the atmosphere.

Weather is a product of climate, we should specify; our climate is currently influenced by atmospheric CO2 of 419 parts per million.

But hurricanes, fires, floods and heat waves also occurred when the concentration
was 280 parts per million, and tended to claim more lives than they do now.

Whatever man’s role in climate change, whatever the merits of regulating CO2, making climate policy the answer to weather risks is a distraction and fraud on the public. Nearly one-third of all greenhouse gases have been released since Al Gore won his 2007 Nobel Peace Prize for a climate movie. These emissions have an estimated half-life in the atmosphere of 120 years. Your electric car isn’t going to change that.

By now, though, activists and lobbyists have a picture on the wall, blown up to five times life-size, of a certain type of voter willing to believe anything, even that Joe Biden’s pork-ridden Inflation Reduction Act meaningfully addresses a warming planet.

Meanwhile, a Nobel Prize laureate in physics who decries the “application of scientific disinformation for opportunistic purposes” can expect to be disinvited from giving a speech to the International Monetary Fund, as the 2022 laureate John Clauser recently was. His offending words, which are hard to dispute in the dictionary sense: “I believe that climate change is not a crisis” (emphasis added).

A crisis, after all, usually calls for concerted, immediate action. Why is it that nothing is ever seriously proposed or enacted, including Mr. Biden’s bag of handouts for “green” energy interests, that would actually have a detectable effect on weather and climate now or in the future?

To stress something not usually emphasized, the science is still largely a science of computer simulations. For now, though, it suggests a relatively manageable human adaptation to a slowly warming planet, mainly through everyday decisions about where and how to live, build and work. Once again, a weather-related disaster is too important to cheapen for the sake of the ‘narrative.”

Australia Academy of Science Now a Woke Joke

Posted on by Ron Clutz

The GBR is the largest reef system on Earth and runs for over 1,400 miles down the eastern side of Australia.

Peter Ridd explains at Spectator Australia The astonishingly woke Australian Academy of Science.  Excerpts in italics with my bolds and added images

The Australian Academy of Science (AAS) recently released a report Reef Futures Roundtable, which is ostensibly about the doomed Great Barrier Reef. However, the report only demonstrates that the AAS, Australia’s peak science body, has become not just unscientific, but anti-scientific. Perhaps unsurprisingly, it has also become astonishingly Woke.

The AAS report predictably concluded that the Great Barrier Reef
could already be ‘irreversibly’ damaged.

The fact that UNESCO has just declared it not endangered did not rate a mention, and neither did the latest two years of statistics showing the reef is at record high coral levels. Remarkably, the report does not contain a single fact or figure to support any of its claims about the reef – except the area of the reef is 340,000 square kilometres. There are no figures, no percentages.

The recovery in the northern GBR actually started around 2017. Last year the coral declined slightly from 36.5% to 35.7%, and was easily within the margin of error calculated by the AIMS. Typhoon Tiffany passed through at the end of the previous reporting season, and could have been responsible for some loss. Central and Sounthern sections of GBR showed similar gains.

Nowhere does it mention that coral grows 30 per cent faster for every degree increase in water temperatures. Or that there is 100 per cent more coral on the reef today than in 2012. Or that just 1 per cent of the reef has the potential to be impacted by farm sediment, fertiliser or pesticides, even in the slightest way. Or that the sea level has fallen by 1 metre in the last 5,000 years.

The problem with this completely unanalytical approach
is seen in the ‘interventions’ it recommends to fix the reef.

Their impracticality is breathtaking. For example, it suggests ‘solar radiation management’ – shading the reef from the sun with man-made fog and clouds to prevent the water heating up and causing coral bleaching. The only number cited in the entire report – the area of the reef, which is as big as Germany – should have given them a hint that this is crazy. How are you going to make a cloud as big as Germany and keep it anchored over the reef for the whole summer over the next few hundred years? And you will also have to stop hot water flowing into the reef from the Coral Sea at the same time. That would require a dam 2,000 kilometres long and 100 metres high.

While a simple calculation is all that is required to reveal the absurdity of this idea, modern science is full of people who are almost completely non-quantitative and, as such, impractical and virtually useless as scientists.

Next there is rubble stabilisation. The supposed experts worry that the Great Barrier Reef will break up from climate change. Each of the 3,000 reefs is an almost solid lump of calcium carbonate rock (fragments of coral glued together over eons) a few kilometres wide and 100 metres high. How this is going to be broken up by some climate change magic is unexplained. But even if that were to happen, are they seriously suggesting we can wire it back together with steel reinforcing and concrete? Just do the calculation on how much concrete and steel this would entail.

The unscientific nature of the AAS report is largely a result of its anti-scientific approach. The report is actually a parody of wokeness and romantic mythology. This starts with the way the roundtable committees of ‘experts’, whom they questioned about the reef, were formed. Each roundtable had two chairs, a non-Indigenous chair, and a specially selected Aboriginal and Torres Strait Islander chair. The romantic mythology about the special knowledge of any person with Indigenous heritage pervades the entire document, and starts in the foreword by the head of the AAS.

As the Academy approached the task of planning this project it became immediately obvious that there was no separating nature and culture when it comes to the GBR. Land and sea cannot be separated. No priority can be selected on an ecological basis alone. Having a Traditional Knowledges co-Chair in each roundtable allowed for different sources of knowledge to be shared and to form a basis for a number of the observations featured in this report.

Having a diversity of ideas and scientific thought would have gone some of the way to curing the AAS of the groupthink which renders its report risible. And the views and experience of people from the coral islands of the Torres Straits and northern Great Barrier Reef could have been used to great effect. These people tend to be deeply practical about the reef – like almost all seafaring people who live and work on the reef. And practical people know you cannot bolt the reef, which is the size of Germany, down to the seafloor.

But selecting people for their ‘roundtables’ on the basis of their ethnicity
rather than their scientific or real-world experience
is a fundamentally anti-scientific approach.

But it gets worse. The dearth of statistics about the reef are made up for by an abundance of data on the gender identification of all those who participated in the ‘roundtables’. There is also the Indigenous percentage. And not just of those who participated, but also of those who were invited to participate but did not. One could quibble and point out that those claiming to be male or female added up to exactly 100 per cent in all categories, indicating a terrifying lack of diversity on the LGBQTI+++ spectrum. But there is no question, on the important matters for the Woke brigade, that this report is brimming with instructive statistics.

The AAS ascribes such importance to facts and figures on gender and race,
but not to scientific facts.

This demonstrates it is anti-science. Science is about evidence and logic. It does not matter whether one is male or female or whatever else, it is still impossible to make clouds as big as Germany for the next hundred years. That is called a fact, and facts do not vary with race, gender, or any ideology.

I have been saying for some time that many of our science institutions have become totally untrustworthy. By its wilful abandonment of quantitative analysis, the AAS has destroyed its reputation as a source of useful scientific advice. The media loves a bad news story – they should focus on what has happened to a once-esteemed organisation.

The Australian Academy of Science is now a joke.

Peter Ridd is an Adjunct Fellow at the Institute of Public Affairs.

See Also Barrier Reef Great Again

Recently I watched an extraordinary netflix documentary which took us on a journey discovering the rich variety of reef life, including microscopic creatures not shown in videos before. It was highly educational and thoroughly delightful . . . until suddenly it wasn’t. Spoiler Alert: Puff returns as an adult to the reef where he was born after leaving it to mature in a mangrove marsh. Alas, he finds the coral dead and blackened, and the narrator warns us: Warming oceans killed the reef and we must change the way we live for the sake of Puff and the other reef creatures. There may have been more to the fire and brimstone ending, but I was so turned off that I turned it off.

Coral at the Great Barrier Reef (GBR) faces another year of exile from the climate scare headlines with news that the record levels reported in 2021-22 have been sustained in the latest annual period to May 2023. A small drop in the three main areas of the reef was well within margin of error territory, with the Australian Institute of Marine Science (AIMS) reporting that regional average hard coral cover in 2022-2023 was similar to last year at 35.7%. Most reefs underwent little change during the year.

X-Weather is Climate Scoundrels’ Last Refuge

Posted on by Ron Clutz

John Ray posted on his blog an update of climatists power play against scientific facts contrary to their beliefs. The saga is about the Alimonte et al. (2022) analysis of extreme weather events and the lack of evidence to attribute them to global warming.  In italics with my bolds Ray’s post is:

The “extreme events” issue

The very gradual process of global warming that we have seen so far has produced no direct ill-effects that we can see. Crops are more abundant than ever and some Pacific islands are growing rather than shrinking. So “extreme events” are the last refuge of the warmists. Bad weather generally is routinely branded as an extreme event and is attributed to global warming without any shred of evidence for the link.

Any causal statement requires controls.

You have to show that the “caused” event would not have happened without the “cause” specified. But that would require you to show what would have happened WITHOUT global warming — and that is impossible.

Single events might or might not be due to some influence or other but you have no way of showing what the influence was. It is known as the “attribution” problem and is in principle unsolvable where the event is a “one-off”, a hurricane, for instance. You have to have variations in the causal condition to correlate with the alleged caused condition. Would this hurricane have happened in the absence of global warming? We cannot know. We can only surmise. And a surmise is no proof.

So the attribution of individual extreme events to global warming is LOGICALLY false. It CANNOT be shown as be fact. But science is at ease with hypotheses so it remains a hypothesis that COULD be true even if proving it is currently impossible.

And an hypothesis can be tested in various ways. It is commonly tested by asking if it generates accurate predictions. And it could be held as preliminary support for an hypothesis that the incidence of extreme events has systematically increased as the globe has warmed. Is there a correlation? So has it? There are some claims to that effect but how well-founded are they? Have extreme events in fact become more frequent?

A recent study has addressed that hypothesis. They have looked at a big range of reports about extreme events and asked are such events becoming more frequent. For each of a range or event extremes they have gathered published information about whether such events are increasing in frequency over time. An abstract of the report concerned is given below.

It finds no evidence that any extreme event has become more frequent.
So the claimed connections are not only logically false
but they are empirically false too.

The study was published 18 months ago and various climate skeptics have quoted it approvingly. That approval has eventually got under the skin of the Warmists so they have tried to discredit the research concerned. And their antagonism to the paper has borne fruit. The paper was “withdrawn” by its publisher, which counts as evidence that it is faulty.

But is it faulty? A much quoted attack on the paper in “The Guardian” lists a whole array of orthododox Warmists who say it is faulty but detailed evidence of the faults is conspicuously missing. No detailed numbers are quoted and the issue is entirely a matter of numbers. The Guardian makes clear that orthodox scientists disagree with the paper but does not give chapter and verse why. Link to The Guardian below:

https://www.theguardian.com/environment/2022/sep/22/sky-and-the-australian-find-no-evidence-of-a-climate-emergency-they-werent-looking-hard-enough

Note that some of the attacks from Warmists are of the most intellectually discreditable kind: “Ad hominem” attacks — attacking the motives of the authors rather than the evidence they put forward

And that none of the critics quote the detailed numbers is a major scientific fault.

If a scientist disagrees with the conclusions of a particular paper — as I have often done — he goes over the ground covered by the paper and shows where it went wrong. In this case the paper at issue is a meta-analysis so the data behind it is readily available. Its conclusions are readily tested by repeating the meta-analysis in some more cautious way. Nobody seems to have attempted that. “Do better” is the obvious retort to the Warmists but none seem even to have attempted that.

The next link takes you to an extensive discussion of whether the paper deserved withdrawal:

https://rogerpielkejr.substack.com/p/thread-extended-peer-review-of-the/comments

The abstract of the deplored paper follows:

A critical assessment of extreme events trends in times of global warming

Gianluca Alimonti et al.

Abstract

This article reviews recent bibliography on time series of some extreme weather events and related response indicators in order to understand whether an increase in intensity and/or frequency is detectable. The most robust global changes in climate extremes are found in yearly values of heatwaves (number of days, maximum duration and cumulated heat), while global trends in heatwave intensity are not significant. Daily precipitation intensity and extreme precipitation frequency are stationary in the main part of the weather stations. Trend analysis of the time series of tropical cyclones show a substantial temporal invariance and the same is true for tornadoes in the USA. At the same time, the impact of warming on surface wind speed remains unclear. The analysis is then extended to some global response indicators of extreme meteorological events, namely natural disasters, floods, droughts, ecosystem productivity and yields of the four main crops (maize, rice, soybean and wheat). None of these response indicators show a clear positive trend of extreme events. In conclusion on the basis of observational data, the climate crisis that, according to many sources, we are experiencing today, is not evident yet. It would be nevertheless extremely important to define mitigation and adaptation strategies that take into account current trends.

A 2015 study by 22 scientists from around the world found that cold kills over 17 times more people than heat. Thus the planet’s recent modest warming has been saving millions of lives.

Springer website reports the paper retracted August 23, 2023.  The article was revised by the authors and published at Environmental Hazards journal on August 3, 2023 as reported at Taylor & Francis online

Is the number of global natural disasters increasing?

We analyze temporal trends in the number of natural disasters reported since 1900 in the Emergency Events Database (EM-DAT) from the Center for Research on the Epidemiology of Disasters (CRED). Visual inspection suggests three distinct phases: first, a linear upward trend to around mid-century followed by rapid growth to the turn of the new century, and thereafter a decreasing trend to 2022. These observations are supported by piecewise regression analyses that identify three breakpoints (1922, 1975, 2002), with the most recent subperiod 2002–2022 characterized by a significant decline in number of events. A similar pattern over time is exhibited by contemporaneous number of geophysical disasters – volcanoes, earthquakes, dry landslides – which, by their nature, are not significantly influenced by climate or anthropogenic factors. We conclude that the patterns observed are largely attributable to progressively better reporting of natural disaster events, with the EM-DAT dataset now regarded as relatively complete since ∼2000. The above result sits in marked contradiction to earlier analyses by two UN bodies (FAO andUNDRR), which predicts an increasing number of natural disasters and impacts in concert with global warming. Our analyses strongly refute this assertion as well as extrapolations published by UNDRR based on this claim.

Conclusion Alimonte et al.

Fearing a climate emergency without this being supported by data, means altering the framework of priorities with negative effects that could prove deleterious to our ability to face the challenges of the future, squandering natural and human resources in an economically difficult context, even more negative following the COVID emergency. This does not mean we should do nothing about climate change: we should work to minimize our impact on the planet and to minimize air and water pollution.

Whether or not we manage to drastically curtail our carbon dioxide emissions in the coming decades, we need to reduce our vulnerability to extreme weather and climate events. Leaving the baton to our children without burdening them with the anxiety of being in a climate emergency would allow them to face the various problems in place (energy,agricultural-food, health, etc.) with a more objective and constructive spirit, with the goal of arriving at a weighted assessment of the actions to be taken without wasting the limited resources at our disposal in costly and ineffective solutions.

How the climate of the twenty-first century will play out is a topic of deep uncertainty. We need to increase our resiliency to whatever the future climate will present us.We need to remind ourselves that addressing climate change is not an end in itself, and that climate change is not the only problem that the world is facing. The objective should be to improve human well-being in the twenty-first century, while protecting the environmentas much as we can.  And it would be a nonsense not to do so: it would be like not taking care of the house where we were born and raised.

Tony Thomas describes the climate scoundrels and their machinations at the Quadrant:  How Science is Done These Days

Footnote Add Another Scoundrel

 

Arctic Ice Surprise in East Siberia

Posted on by Ron Clutz

Oil tanker NS Arctic sailing in icy waters. Photo: Dmitry Lobusov, icebreaker captain for Rosatomflot

With the warmer water temperatures in the North Atlantic this summer, we can expect lower Arctic sea ice extents.  But maybe not.  Barents Observer reports A month after they set out on Arctic voyage, two Russian oil tankers still battle with sea-ice.  Excerpts in italics with my bolds.

The ships that are loaded with more than 200,000 tons of oil
might have been surprised by ice pack in the East Siberian Sea.

The Primorsky Prospect and NS Arctic on the 12th and 14th of July respectively set out from St.Petersburg with course for the Chinese ports of Dalian and Rizhao. They were to arrive at destinations by the middle of August.  That schedule is now significantly postponed. Shipping data show that the ships will make it to the Chinese ports no earlier than 26th of August.

Although the tankers both have ice classification Arc3, their voyage across the Laptev Sea and East Siberian Sea have been marred with troubles with the sea-ice.   For several days, the tankers were at standstill off the New Siberian Islands, and later also in the southern part of the East Siberian Sea.

Nevertheless, the long and icy voyage of the two oil tankers raises new questions about the actual benefits of sailing on the Northern Sea Route, as well as security in the area.

Sea-ice in thee East Siberian Sea in period 6-8th of August 2023. Map by Arctic and Antarctic Research Institute

Both the NS Arctic and Primorsky Prospect have ice classification Arc3, but neither of them have permission to sail independently through the most complex parts of the Northern Sea Route in anything but light ice conditions.  Growing parts of the East Siberian Sea are ice-free. But changes can quickly occur in this region and a sudden emergence of ice pack might have taken the ships by surprise.

But in medium ice conditions, the ships are obliged to hire icebreaker escort. It is not clear to what extent the tankers have made it into medium ice conditions. But ice maps from the Russian Arctic and Antarctic Research Institute show that major parts of the East Siberian Sea have a white sheet.

“Perhaps the wind has pushed the ice pack towards the coast, increasing the concentration locally so that there’s no longer continuous green strip along the coast?” an anonymous industry expert says to the Barents Observer.

According to the expert, there appears to be no imminent risk for a dangerous situation.

Nuclear icebreaker Sibir escorts ships through the Vilkitsky Strait. Photo: Rosatom/Kirill Razin

Climate Hype Backfires on Greens

Posted on by Ron Clutz

Mark Higgie reports Europe’s summer of climate hysteria in Spectator Australia.  Excerpts in italics with my bolds and added images.

But voters continue to move against the Green tide

If the British weather were a person with bank accounts, it would by now likely find itself, like Nigel Farage, ‘de-banked’ for political incorrectness. While the BBC has gone into hysterics over the hot summer in southern Europe, further north the British weather has stubbornly refused to co-operate with the Green warming narrative. Temperatures for much of the summer have barely reached those of a winter’s day in Canberra. Much of the British media has tied itself in knots trying to explain why, if the world just had its hottest July ever, and is, in the words of UN Secretary-General Gutteres, ‘boiling’, everyone in Britain is wearing jumpers and has the heating on.

Where has UK summer gone?

As the media have pulled out all the stops to stir climate fear, Australians will recognise echoes of the ABC’s coverage of the 2019-20 bushfires – especially the silence about revelations that Europe’s recent ‘wildfires’ were fuelled by Green-tinged failures to backburn and were started in many cases by arsonists.

Sadly a watershed moment has been reached: you can no longer trust
Europe’s weather forecasts and readings.

Many of the BBC’s forecasts in mid-July for southern Europe proved wildly exaggerated. For example, on 18 July, it reported Sardinia was expected that day to see a high of 46 degrees and that ‘there are warnings that extreme heat could continue for a further 10 days’. In fact, Sardinia peaked at 40 and temperatures then fell steadily to the low-30s over the following week.

Much of the hyperbole appears to have been based on a swifty pulled by the European Space Agency (ESA), on which many media outlets rely for weather forecasts. On 13 July it issued a press release claiming that the ‘air temperature’ of Sardinia and Sicily was ‘expected’ to climb to 48 degrees, ‘potentially the hottest temperatures ever recorded in Europe’. In Sicily in fact it never went above 35 degrees. Unusually, the 13 July ESA press release, updated five days later, claimed that land temperatures in the 40s and 50s had been recorded across southern Europe in the previous days. The standard measurement of temperature is that of the air, made two metres above the ground. Land temperatures will of course always be many degrees higher, as anyone who has walked barefoot on a concrete footpath in summertime Australia will know. The ESA’s 48 degree forecast of the ‘air’ temperature in southern Italy was obviously an error – in reality it was the forecast land temperature.

The forecast was never corrected, went unnoticed by most in the media
and was repeated around the world.

When the weather map went crazy in Arizona

Yet despite the unrelenting propaganda, European voters continue to defy the climate lobby’s plan to make them colder and poorer. Voters over the past year have given the Green-left a bloody nose at virtually every opportunity – in national and regional elections in Italy, Sweden, Finland, Greece and Germany. The Netherlands might join that list after elections later this year – the Farmer-Citizen Movement recently came out of nowhere against the government’s Green jihad on farming and is on course to influence policy as the country’s equal-largest party. Meanwhile in Spain, the elections in July saw a major swing to the right against the ultra-eco Socialists, even if it wasn’t enough this time to unseat them.

By contrast Britain’s left defeated the Tories at two of last month’s three by-elections – largely because grumpy Conservative voters failed to turn out. But the result which has had the most political impact is the Tories’ surprise retention of Boris Johnson’s former seat in outer London, Uxbridge and South Ruislip. Fought more or less solely on London’s Labour Mayor Sadiq Khan’s planned expansion of the city’s ‘Ultra Low-emission Zone’ (ULEZ) – which would mean owners of older cars would be hit with green levies – it has allowed the Tories to glimpse a possible path to victory at next year’s general election.

While ULEZ is not directly related to the net-zero agenda, it has only now dawned on the Tories that while the vast majority of Britons want a cleaner environment, they oppose Green measures involving cost and/or inconvenience. A recent YouGov poll found that while net zero in principle attracted 70 per cent support, if net zero entailed ‘costs for ordinary people’, support fell to just over a quarter.

Since Uxbridge, Prime Minister Sunak has suddenly started portraying himself as ‘pro-motorist’, now opposing ULEZ-like schemes across the country and the proliferation of 20mph speed limits. He’s also suddenly approving new North Sea oil and gas development projects, while attacking Labour as eco-fanatics in bed with extremists like Just Stop Oil.

Over 40 Tory MPs and peers have told Sunak they want him to go further and to defer Boris Johnson’s ban on the sale of new petrol and diesel cars from 2030 – a planned measure opposed by 83 per cent of Tory members, according to an opinion poll. Sunak and other members of the Tory establishment for the moment flatly reject this.

If the opinion polls don’t shift, panic could lead the Conservatives to shift more dramatically on their net-zero policies. The obvious options are to delay the looming bans on non-electric cars and gas boilers. An even bolder move would be to announce a referendum on net zero, as championed by Nigel Farage and the Daily Telegraph. That would provoke meltdown by much of the British establishment but isn’t inconceivable.

Arctic Ice Surplus Wiped Out in 5 Days? Mid August 2023

Posted on by Ron Clutz

 

An incredible turn of events in Arctic Ice extent reporting in the last five days.  As the chart above shows, it is not unusual in August to have sharp downturns in ice extents.  However, the 2023 drop is unprecedented and looks suspiciously like an adjustment to bring MASIE in line with SII.  Note that for 25 days, MASIE showed much more ice than SII, ranging as much as +622k km2 on August 1 and +572k km2 on day 222. Moreover, those two days were in surplus to MASIE 17 year average:  +460k km2, and + 265k km2 respectively.

Then on day 223 MASIE dropped 466k km2, unprecendented for a single day.   And further declines resulted a five day total loss exceeding 1 Wadham, 1.05M km2.  In just five days, a surplus of  +265k turned into a deficit of -448k.  And MASIE is now 170k lower than SII. 

I have asked for an explanation and am awaiting a reply from NSIDC.

The table for day 227 shows a distribution of ice extent across the Arctic regions, in comparison to 17 year average and 2007.  2023 was 448k km2 below average, or 8% of total extent.

Region 2023227 Day 227 Average 2023-Ave. 2007227 2023-2007
 (0) Northern_Hemisphere 5483921 5932184  -448263  5673110 -189189 
 (1) Beaufort_Sea 508614 724117  -215503  770413 -261799 
 (2) Chukchi_Sea 477947 429182  48765  260048 217899 
 (3) East_Siberian_Sea 336549 569134  -232585  172718 163831 
 (4) Laptev_Sea 327171 238108  89064  292592 34579 
 (5) Kara_Sea 149411 95286  54126  201115 -51703 
 (6) Barents_Sea 10737 24019  -13282  17324 -6587 
 (7) Greenland_Sea 221710 229025  -7315  316155 -94445 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 50784 58004  -7220  86165 -35380 
 (9) Canadian_Archipelago 289715 418748  -129033  375984 -86268 
 (10) Hudson_Bay 44528 67445  -22917  91653 -47125 
 (11) Central_Arctic 3066518 3077985  -11466  3087687 -21168 

The table shows the bulk of the deficit appears in Beaufort and East Siberian seas and CAA, with smaller surpluses in Chukchi, Laptev and Kara seas.

Illustration by Eleanor Lutz shows Earth’s seasonal climate changes. If played in full screen, the four corners present views from top, bottom and sides. It is a visual representation of scientific datasets measuring Arctic ice extents and snow cover.