Archives de catégorie : climate-debate

Solar Cycle 25 Has Started

by D Archibald, April 22, 2020 in WUWT


The heliospheric current sheet has flattened meaning that Solar Cycle 24 is over and we are now in Solar Cycle 25.

Figure 1: Heliospheric current sheet tilt angle 1976 -2020

The solar cycle isn’t over until the heliospheric current sheet has flattened. The data is provided by the Wilcox Solar Observatory at Stanford University. There were no observations from about 19 December to 5 February; so the values in between have been interpolated from the rotations before and after.

Systemic Misuse of Scenarios in Climate Research and Assessment

by Pielke R & Richtie J, April 21, 2020


Abstract

Climate science research and assessments have misused scenarios for more than a decade. Symptoms of this misuse include the treatment of an unrealistic, extreme scenario as the world’s most likely future in the absence of climate policy and the illogical comparison of climate projections across inconsistent global development trajectories. Reasons why this misuse arose include (a) competing demands for scenarios from users in diverse academic disciplines that ultimately conflated exploratory and policy relevant pathways, (b) the evolving role of the Intergovernmental Panel on Climate Change – which effectively extended its mandate from literature assessment to literature coordination, (c) unforeseen consequences of employing a nuanced temporary approach to scenario development, (d) maintaining research practices that normalize careless use of scenarios in a vacuum of plausibility, and (e) the inherent complexity and technicality of scenarios in model-based research and in support of policy. As a consequence, the climate research community is presently off-track. Attempts to address scenario misuse within the community have thus far not worked. The result has been the widespread production of myopic or misleading perspectives on future climate change and climate policy. Until reform is implemented, we can expect the production of such perspectives to continue. However, because many aspects of climate change discourse are contingent on scenarios, there is considerable momentum that will make such a course correction difficult and contested – even as efforts to improve scenarios have informed research that will be included in the IPCC 6th Assessment.

Keywords: climate, scenarios, assessment, research integrity

Editorial: Climate Impacts on Glaciers and Biosphere in Fuego-Patagonia

by C. Schneider et al., April 2020 in FrontierEarthScience


The regional climate in Southernmost South America is heavily influenced by the proximity to the oceans. This generates rather weak seasonal cycles with cool to cold summers and moderate to cold winters, especially on the western Pacific side. Slightly more pronounced, continental seasonal cycles are observed in the East of the Andes. While annual mean air temperatures across the region are decreasing from North to South precipitation patterns show very pronounced east-west gradients. The distinctive gradients in precipitation are caused by the north-south striking mountain ranges of the Patagonian Andes, and the northwest-southeast stretching mountain chains of the Cordillera Darwin. Both mountain ranges enforce heavy precipitation on the west and southwest exposed flanks by uplift and dry foehn-like conditions on the leesides (e.g., Holmlund and Fuenzalida, 1995; Schneider et al., 2003; Rasmussen et al., 2007) which produces extremely high drying ratios (Escobar et al., 1992; Carrasco et al., 2002; Smith and Evans, 2007). At inter-annual to decadal time scales atmospheric teleconnections such as the El Niño Southern Oscillation (ENSO) (Schneider and Gies, 2004), Southern Annular Mode (SAM), and Pacific Decadal Oscillation (PDO) are influencing spatial and temporal patterns of both, precipitation and air temperature. For example, positive SAM modes (Garreaud, 2009; Weidemann, Sauter, Kilian et al.) and the PDO (Villalba et al., 2003) are associated with higher air temperatures. Langhamer et al. show that the source of precipitation in the Southern Andes also depends on these teleconnections.

An important aspect is that Patagonia and Tierra del Fuego, together with the sub-Antarctic islands are the only regions where direct proximity between Antarctica and land masses north of the Southern Ocean is given. Such linkages are for example explored with investigations by Hebel et al. on the biosphere and Oppedal et al. for the regional glacier history.

New Studies Show Cloud Cover Changes Have Driven Greenland Warming And Ice Melt Trends Since The 1990s

by K. Richard, April 20, 2020 in NoTricksZone


Scientists now acknowledge cloud cover changes “control the Earth’s hydrological cycle”, “regulate the Earth’s climate”, and “dominate the melt signal” for the Greenland ice sheet via modulation of absorbed shortwave radiation.  CO2 goes unmentioned as a contributing factor.

 

 

Solar Winds Hitting Earth Are Hotter Than They Should Be–Here’s Why

by M. McCrae, April 21, 2020 in ClimateChangeDispatch


Our planet is constantly bathed in the winds coming off the blistering sphere at the center of our Solar System.

But even though the Sun itself is so ridiculously hot, once the solar winds reach Earth, they are hotter than they should be – and we might finally know why.

We know that particles making up the plasma of the Sun’s heliosphere cool as they spread out. The problem is that they seem to take their sweet time doing so, dropping in temperature far slower than models predict.

“People have been studying the solar wind since its discovery in 1959, but there are many important properties of this plasma which are still not well understood,” says physicist Stas Boldyrev from the University of Wisconsin–Madison.

“Initially, researchers thought the solar wind has to cool down very rapidly as it expands from the Sun, but satellite measurements show that as it reaches the Earth, its temperature is 10 times larger than expected.”

The research team used laboratory equipment to study moving plasma, and now think the answer to the problem lies in a trapped sea of electrons that just can’t seem to escape the Sun’s grip.

The expansion process itself has long been assumed to be subject to adiabatic laws, a term that simply means heat energy isn’t added or removed from a system.

This keeps the numbers nice and simple but assumes there aren’t places where energy slips in or out of the flow of particles.

Unfortunately, an electron’s journey is anything but simple, shoved around at the mercy of vast magnetic fields like a roller coaster from Hell. This chaos leaves plenty of opportunities for heat to be passed back and forth.

Climate Change – Ebb and Flow of the Tide –Part 2 of 3

by Dr K. Kemm, April 16, 2020 in WUWT


The topic of global warming and climate change is far more scientifically complex than the public is led to believe.

Myriads of newspaper, magazine and TV items over decades have tended to simplify the science to the point at which the general public believes that it is all so simple that any fool can see what is happening. Public groups often accuse world leaders and scientists of being fools, if they do not instantly act on simple messages projected by individuals or public groups.

One often hears phrases like: ‘The science is settled.’ It is not. Even more worrying is that the reality of the correct science is actually very different to much of the simple public perception.

An additional complicating factor is that there are political groupings wanting to change the world social order and who are using the climate change issue as a vehicle to achieve these objectives. They want the ‘science’ to say what they want it to say and are not interested in the truth. Sections of the public, with noble good intentions, then frequently do not realize that they are being induced by such elements to unwittingly support a political agenda, which in reality is unrelated to the climate issue.

I found myself in an informal social debate on these topics, with some people getting rather heated. Attempts to cool the conversation temperature were not so successful. The political aspects of the climate change issue, as always, entered into the discussion. Points like: ‘saving mankind from disaster’ were made with much emotion, and UN and various government political votes on the science were referred to, as if a political vote settled the scientific facts.

Sadly, so much of the climate debate is the result of votes and not of sound science, as determined by scientific methodology and protocol which has been developed over centuries.

 

Continuer la lecture de Climate Change – Ebb and Flow of the Tide –Part 2 of 3

GREENLAND HAS GAINED 27+ GIGATONS OF SNOW AND ICE OVER THE PAST 5 DAYS ALONE — MSM SILENT

by Cap Allon, April, 2020 in Electroverse


Despite decades of doom-and-gloom prophecies, Greenland’s Ice Sheet is currently GAINING monster amounts of “mass” — 27 gigatons over the past 5 days alone (April 14 – 18, 2020).

Crucial to the survival of a glacier is its surface mass balance (SMB)–the difference between accumulation and ablation (sublimation and melting). Changes in mass balance control a glacier’s long-term behavior, and are its most sensitive climate indicators (wikipedia.org).

On the back of substantial SMB gains over the past few years, the Greenland ice sheet looks set to continue that trend in 2019-20. From April 14 through April 18, 2020, the world’s largest island added a monster 27+ gigatons to its ice sheet. According to climate alarmists, this simply shouldn’t be happening in a warming world. In fact, it might as well not be happening as developments like these NEVER receive MSM attention, meaning alarmists are NEVER privy to the full and unalarming picture…

‘Arctic April’ Grips N. America Breaking Hundreds Of Cold Records

by Cap Allon, April 16, 2020 in ClimateChangeDispatch


Record cold and snowfall hit many parts of North America over the Easter weekend, continuing what has so far been a largely Arctic April.

Records were toppled across many U.S. states, with Montana, Iowa, South Dakota, and Colorado seemingly worst hit.

A winter storm system moved through Iowa on Sunday delivering between three inches and a foot to the majority of locations — several northern Iowa towns saw all-time records tumble:

The 3.7 inches that fell at Sioux Gateway Airport broke the record for April 12th; it also made it the second-highest Easter snowfall ever behind the 4.7 inches during Easter 1929.

The town of Ringsted in Emmet County (also Iowa) came in with a record-busting 11 inches.

Robert “Lightning” Petersen was the man to log the accumulation — he uses his back yard measuring equipment to keep track of snow and rainfall. He works in concert with the National Weather Service out of Johnston.

UK State Of The Climate Report 2019

by P. Homewood, April 16, 2020 In NotaLotofPeopleKnowThat


London, 16 April: The floods that affected northern England in the autumn of 2019 were nothing out of the ordinary. That’s according to a new review of the UK’s 2019 weather.

Author Paul Homewood says that although rainfall in the region was high, it has been exceeded several times in the past, right back to the 19th century.

Key findings

* After a rising trend between the 1980s and early 2000s, temperature trends have stabilised in the UK.

* Heatwaves are not becoming more intense, but extremely cold weather has become much less common.

* There is little in the way of long-term trends in rainfall in England and Wales.

* Sea-level rise around British coasts is not accelerating.

The UK’s Weather in 2019: More of the same, again (PDF)

Melting Glaciers Uncover Medieval Artefacts In Norway

by P. Homewood, April 16, 2020 in NotaLotofPeopleKnowThat


Melting glaciers in Norway have revealed ancient artefacts dropped by the side of a road more than 1,000 years ago.

Clothes, tools, equipment and animal bone have been found by a team at a lost mountain pass at Lendbreen in Norway’s mountainous region.

A haul of more than 100 artefacts at the site includes horseshoes, a wooden whisk, a walking stick, a wooden needle, a mitten and a small iron knife.

The team also found the frozen skull of an unlucky horse used to carry loads that did not make it over the ice.

The objects that were contained in ice reveal that the pass was used in the Iron Age, from around AD 300 until the 14th century.

Activity on the pass peaked around AD 1000 and declined after the black death in the 1300s, due as well to economic and climate factors.

The researchers say the melting of mountain glaciers due to climate change has revealed the historical objects, with many more to come.

https://www.dailymail.co.uk/sciencetech/article-8224817/Melting-ice-reveals-lost-Viking-mountain-path.html

 

Unfortunately neither the journalist nor the scientists seem to be capable of adding 2+2!

 

The existence of the Medieval Warm Period in Norway, followed by glacial advance in the Little Ice Age has been long known about, as HH Lamb wrote in 1982:

New Studies: Europe Is No Warmer Today Than It Was During Medieval Times

by K. Richard, April 13, 2020 in NoTricksZone


Two new papers use tree ring proxy evidence to suggest modern European temperatures are neither unusual nor higher than they were during the Medieval Warm Period.

Esper et al. (2020) have produced a new temperature reconstruction for Southern Europe to complement past reconstructions for Northern and Central Europe.

They find “the warmest 30-year period since 730 CE occurred during high Medieval times (876–905 CE=+0.78 °C w.r.t. 1961–1990) and has been slightly warmer than the recent period from 1985–2014 (+0.71 °C)“.

The proxy evidence and instrumental record also show there has been no obvious net warming in Southern Europe since the 1940s.

Past reconstructions for Northern and Central Europe also show no unusual warming has occurred over the last century, with as-warm or warmer temperatures during the 1940s.

Ljungqvist et al., 2020  cite tree ring temperature studies from Scandinavia, Scotland, Continental Europe, and the Pyrenees that also show the 1930s and 1940s were as-warm or warmer than recent decades.

While NASA Alters/Warms Greece Temperature Data, Cold And Unusual Snow Keep Coming Anyway!

by Kirye and P. Gosselin, April 10, 2020 in NoTricksZone


So what’s going on?

NASA and other government agencies keep telling us that the globe is warming and ice becoming more rare, yet when look out the window, things often appear to be going the opposite direction.

Rare cold, snow grip Greece

For example, the Greek Reporter here informed how a “rare spring snow” blanketed large parts of northern Greece. It reported: “Of course, Northern Greece is used to low temperatures and snow, but even for their standards, such an intense snowfall in April is rare.”

Moreover, the widely read Electroverse weather site here reported how southeast Europe had seen its “coldest April morning in a decade”, potentially causing widespread crop damage.

So why are such events happening when they aren’t supposed to be?

Altering: from cooling to warming

Today we look at the NASA data from two stations in Greece: Makedonia and Larissa, shown below:

IP: Award-Winning Atmospheric Scientist Dr. Fred Singer Dies – Pioneering Scientist & The Dean of Climate Skeptical Scientists

by C. Rotter, April 7, 2020 in WUWT


Marc Morano’s personal note: “I have known Fred Singer for almost two decades. He was as kind as he was brilliant. He had an encyclopedic acknowledge of people, facts, institutions, and science. I was honored to be his friend and attend Fred’s 95th birthday in the fall of 2019. In 2018, Craig Rucker and I presented Fred CFACT’s 2018  ‘DAUNTLESS Purveyor of Climate Truth’ Lifetime Achievement Award. I traveled with Fred to the UN Paris climate summit in 2015 and we met up at many international destinations to fight the UN’s corruption of climate science.  My condolences to Fred’s family and my condolences the world of science. You lost a great one. Rest in Peace Fred, you earned it. Cheers to an honorable man of science and a life well-lived. You will be missed Fred.”

By: Marc MoranoClimate Depot

Les glaces terrestres, la cryosphère 3/3

by JC Maurin, 10 avril 2020 in ScienceClimatEnergie


Partie 3/3 : La diminution de la cryosphère est-elle démontrée dans l’AR5?

La contribution de la cryosphère à la hausse du niveau des mers est abordée dans le chapitre 4 du rapport AR5 du GIEC [1]. Les banquises [2] ne figurent pas parmi les contributeurs car leur fonte ne peut affecter les niveaux marins.

Le GIEC est persuadé que la masse de la cryosphère a diminué entre 1992 et 2012. Cette certitude de l’organisme intergouvernemental est fondée sur sa grande confiance dans des modèles gravimétrique/altimétrique et sur des marges d’erreur très optimistes, particulièrement en Antarctique [3] et sur les glaciers [4].

Causes of the Rapid Warming of the North Atlantic Ocean in the Mid-1990s

by P. Homewood, April 9, 2020 in NotaLotofpeopleKnowThat


http://ocean.dmi.dk/arctic/icecover_30y.uk.php

Most of us are probably familiar with the pattern of Arctic sea ice decline between 1979 and 2007, followed by a period of relative stability. Most of the decline took place after the mid 1990s.

The decline is nearly always explained away as the result of global warming, but a couple of old studies show this not to be the case.

In 2011, Robson & Sutton found that the sub polar gyre underwent remarkable and rapid warming in the mid 1990s, and that this was linked to changes in the North Atlantic Oscillation:

Science team points out a new failure of climate models

by A. Watts, April 6, 2020 in WUWT


From Nature Climate Change:

Ill-sooted models by Baird Langenbrunner

Atmospheric black carbon (BC) or soot — formed by the incomplete combustion of fossil fuels, biofuel and biomass — causes warming by absorbing sunlight and enhancing the direct radiative forcing of the climate. As BC ages, it is coated with material due to gas condensation and collisions with other particles. These processes lead to variation in the composition of BC-containing particles and in the arrangement of their internal components — a mixture of BC and other material — though global climate models do not fully account for these heterogeneities. Instead, BC-containing particles are typically modelled as uniformly coated spheres with identical aerosol composition, and these simplifications lead to overestimated absorption.

Full article here

Here, the PNAS paper

Carbon soot in from industrial process in the air. Licensed from 123rf.com

The Next Solar Cycle

by David Whitehouse.(pdf), April 6, 2020 in GWPF


London, 6 April: A former BBC science correspondent says that there remains a real possibility that unusual solar behaviour could influence the Earth’s climate, bringing cooler temperatures  for the next decade.

Despite rising levels of atmospheric carbon dioxide, the reduction in solar activity along with cooling from other long-term terrestrial climate variables could mean we might see a slowdown in global warming for years.

Dr Whitehouse says:  “It is clear that the solar influence on climate is about 0.1 °C a decade so it is important to know when there are low solar activity periods. We have a grasp of the basic mechanism that drives long-term solar activity, but many of the specifics still elude us. Successful predictions of solar cycle strength are therefore few and far between.”

Whitehouse adds that although NASA are predicting that solar cycle 25, which is just beginning, might be moderate-to-weak, the possibility of a very weak cycle, with a measurable effect on the terrestrial climate, remains a real one.

Dr Whitehouse reviews the history of solar cycle predictions in a new paper by the Global Warming Policy Foundation which is published today.

The paper, entitled The Next Solar Cycle, And Why It Matters For Climatecan be downloaded here (pdf)

Contact

Dr David Whitehouse
e: david.whitehouse@thegwpf.com

Is Greenland Warming, Melting? Hell No! NASA Data Show No Warming In Nearly 100 Years!

by Kirye & Gosselin, April 3, 2020 in NoTricksZone


But then NASA adjusted the V3 data and called it GHCN V4 “unadjusted”. The chart shown above in my tweet toggles between the prior V3 chart and the “unadjusted” V4. See the difference?

Note how the lack of warming has been removed and now the V4 data show modest warming. The missing heat was found – in the statistics! So in a sense, global warming has been “man-made” – done through statistical fudging and not human activity.

Extra warm U.S. winter had nature’s thumbprint on it–Joe Bastardi

by P. Homewood, April 3; 2020 in NotaLotofPeoppleKnowThat


Joe Bastardi explains why this winter has been so mild in the US, but also across N Europe, at CFACT.

Two points:

1) I will make the case for why such winters like this happen

2) I will point out that nowhere in this article did the massive natural physical drivers that far outweigh the effect of CO2, which is only .041% of the atmosphere. Pointedly, of which man is only responsible for  25% and the US only 15% of that total.

I am not going to waste time attacking here, except to say this kind of one-sided journalism and the fact that nowhere did anyone show what I am about to reveal to you, should raise questions of any objective person.

Basically the rules of the game are, if its warm like this winter, its climate change, if it is cold, its climate change. It is typical of everyone gets a trophy in that any answer even if opposite, means you get credit.

I won’t copy the whole article as it is a bit technical, but it can be seen here. However these are the main points Joe raises, starting with the role of El Nino and water vapour:

Water vapor is by far the most important greenhouse gas when it comes to the planetary weather and climate. Meteorologist look at “saturation mixing ratios” which show a correlation of water vapor to temperature. Basically the colder and drier the air mass, the more the introduction of water vapor will lead higher temperatures, there is no place like the arctic to prove this is the case. The cyclically warmed oceans have put more water vapor (and CO2) into the air. When Super El Niño’s go off, the immense amounts dispersed lead to a step up of the temperature. The colder regions leading the way as will be opined on below.

Magma Flood Linked To Sudden Ancient Global Warming Event

by H. Lee, April 1, 2020 in ClimateChangeDispatch


A study has cemented the link between an intense global warming episode 56 million years ago and volcanism in the North Atlantic, with implications for modern climate change.

Roughly 60 million years ago, circulation changes deep within our planet generated a hot current of rock — the Iceland plume — causing it to rise from the heart of Earth’s mantle.

 

The Giant’s Causeway in Northern Ireland is a geologic feature consisting of thousands of interlocking basalt columns that formed from volcanic eruptions 60 million years ago.

The Wrong Kind Of Carbon

Although a great deal of North Atlantic volcanism happened close in time to the PETM, scientists were initially skeptical that it could have driven the warming.

Sedimentary layers that formed at the time had the wrong kind of carbon — they were rich in the isotope carbon-12, indicating an organic carbon source rather than a volcanic one.

The leading theory was that fluctuations in Earth’s orbit around the sun melted a type of frozen methane just beneath the seabed called methane clathrates.

Yet scientists found scant evidence that enough clathrates existed in the pre-PETM world, or that they could have melted fast enough to drive the warming.

A possible missing link between the North Atlantic Igneous Province and organic carbon was spotted in 2004 in seismic scans through the seabed off the coast of Norway.

Continuer la lecture de Magma Flood Linked To Sudden Ancient Global Warming Event

Ships’ emissions create measurable regional change in clouds

by  University of Washington, March 24, 2020 in ScienceDaily


A container ship leaves a trail of white clouds in its wake that can linger in the air for hours. This puffy line is not just exhaust from the engine, but a change in the clouds that’s caused by small airborne particles of pollution.

New research led by the University of Washington is the first to measure this phenomenon’s effect over years and at a regional scale. Satellite data over a shipping lane in the south Atlantic show that the ships modify clouds to block an additional 2 Watts of solar energy, on average, from reaching each square meter of ocean surface near the shipping lane.

The result implies that globally, cloud changes caused by particles from all forms of industrial pollution block 1 Watt of solar energy per square meter of Earth’s surface, masking almost a third of the present-day warming from greenhouse gases. The open-access study was published March 24 in AGU Advances, a journal of the American Geophysical Union.

EARTH’S TEMPERATURE PLUNGED IN MARCH — GLOBAL COOLING FROM HERE ON OUT

by Cap Allon, April 2, 2020 in Electroverse


The Global Lower Atmosphere plunged 0.28C in March to 0.48C, from its (expected early-year) high of 0.76C in February. Looking at the Sun, the cycles, the past, and the graphs, it is reasonable to assume there’s only one trend from here on out, and that’s down…

Take the previous anomalous “warming spikes” on the UAH Satellite-Based Temperature of the Global Lower Atmosphere chart (below) — they generally occur at the beginning of a year, and then are quickly followed by a sharp downward plunge:

www.drroyspencer.com/

The Next Great Extinction Event Will Not Be Global Warming – It Will Be Global Cooling

by A. MacRae, September 1, 2019 in WUWT


CATASTROPHIC GLOBAL WARMING IS A FALSE CRISIS – THE NEXT GREAT EXTINCTION WILL BE GLOBAL COOLING

Forget all those falsehoods about scary global warming, deceptions contrived by wolves to stampede the sheep. The next great extinction event will not be global warming, it will be global cooling. Future extinction events are preponderantly cold: a glacial period, medium-size asteroid strike or supervolcano. Humanity barely survived the last glacial period that ended only 11,500 years ago, the blink-of–an-eye in geologic time.

Cold, not heat, is by far the greater killer of humanity. Today, cool and cold weather kills about 20 times as many people as warm and hot weather. Excess Winter Deaths, defined as more deaths in the four winter months than equivalent non-winter months, total over two million souls per year, in both cold and warm climates. Earth is colder-than-optimum for humanity, and currently-observed moderate global warming increases life spans.

“Cold Weather Kills 20 Times As Many People As Hot Weather”

By Joseph D’Aleo and Allan MacRae, September 4, 2015

https://friendsofsciencecalgary.files.wordpress.com/2015/09/cold-weather-kills-macrae-daleo-4sept2015-final.pdf

However, Excess Winter Deaths are not the worst threats to humanity. The glacial cycle averages about 100,000 years, consisting of about 90,000 years of the glacial period, when mile-thick continental glaciers blanketed much of the Northern and Southern Hemispheres including Canada, Russia, Northern Europe and Northern USA, and about 10,000 years of interglacial, the warm period of the present. Earth is now 11,500 years into the current warm interglacial, and our planet may re-enter the glacial period at any time.

“Glacial-Interglacial Cycles”

https://www.ncdc.noaa.gov/abrupt-climate-change/Glacial-Interglacial%20Cycles

https://www.ncdc.noaa.gov/sites/default/files/styles/716px_width/public/glacial-interglacial.jpg?itok=19bwFcU9

The UAH Global Temperature Dataset at 30 Years: A Look Back at the Early Days

by Dr. Roy Spencer, March 31, 2020 in GlobalWarming


Today (Monday, March 30) is the 30th anniversary of our publication in Science describing the first satellite-based dataset for climate monitoring.

While much has happened in the last 30 years, I thought it might be interesting for people to know what led up to the dataset’s development, and some of the politics and behind-the-scenes happenings in the early days. What follows is in approximate chronological order, and is admittedly from my own perspective. John Christy might have somewhat different recollections of these events.

Some of what follows might surprise you, some of it is humorous, and I also wanted to give credit to some of the other players. Without their help, influence, and foresight, the satellite temperature dataset might never have been developed.

 

Continuer la lecture de The UAH Global Temperature Dataset at 30 Years: A Look Back at the Early Days

Coral tells own tale about El Niño’s past

by Rice University, March 27, 2020 in WUWT


HOUSTON – (March 26, 2020) – There is no longer a need to guess what ocean temperatures were like in the remote tropical Pacific hundreds of years ago. The ancient coral that lived there know all.

A study in Science led by Rice University and Georgia Tech researchers parses the record archived by ancient tropical Pacific coral over the past millennium. That record could help scientists refine their models of how changing conditions in the Pacific, particularly from volcanic eruptions, influence the occurrence of El Niño events, which are major drivers of global climate.

They found the ratio of oxygen isotopes sequestered in coral, an accurate measure of historic ocean temperatures, shows no correlation between estimates of sulfate particles ejected into the atmosphere by tropical volcanic eruptions and El Niño events.

That result could be of particular interest to scientists who suggest seeding the atmosphere with sun-blocking particles may help reverse global warming.

According to Rice climate scientist and primary author Sylvia Dee, previous climate model studies often tie volcanic eruptions, which increase sulfate aerosols in the atmosphere, to increased chances for an El Niño event. But the ability to analyze climate conditions based on oxygen isotopes trapped in fossil corals extends the climatological record in this key region across more than 20 ancient eruptions. Dee said this allows for a more rigorous test of the connection.

“A lot of climate modeling studies show a dynamical connection where volcanic eruptions can initiate El Niño events,” Dee said. “We can run climate models many centuries into the past, simulating volcanic eruptions for the last millennium.

“But the models are just that — models — and the coral record captures reality.”

Coral data that Georgia Tech climate scientist Kim Cobb and her team arduously collected on trips to the Pacific show little connection between known volcanoes and El Niño events over that time. Like tree rings, these paleoclimate archives hold chemical indicators, the oxygen isotopes, of oceanic conditions at the time they formed.

The coral data yields a high-fidelity record with a resolution of less than a month, tracking the El Niño-Southern Oscillation (ENSO) in the heart of the central tropical Pacific.