As in years past, the annual rollout of the GISTEMP, NOAA, HadCRUT and Berkeley Earth analyses of the surface temperature record have brought forth many stories about the long term trends and specific events of 2022 – mostly focused on the impacts of the (ongoing) La Niña event and the litany of weather extremes (UK and elsewhere having record years, intense rainfall and flooding, Hurricane Ian, etc. etc.).
But there are a few things that don’t get covered much in the mainstream stories, and so we can dig into them a bit here.
What influence does ENSO really have?
It’s well known (among readers here, I assume), that ENSO influences the interannual variability of the climate system and the annual mean temperatures. El Niño events enhance global warming (as in 1998, 2010, 2016 etc.) and La Niña events (2011, 2018, 2021, 2022 etc.) impart a slight cooling.
GISTEMP anomalies (w.r.t. late 19th C) coded for ENSO state in the early spring.
Consequently, a line drawn from an El Niño year to a subsequent La Niña year will almost always show a cooling – a fact well known to the climate disinformers (though they are not so quick to show the uncertainties in such cherry picks!). For instance, the trends from 2016 to 2022 are -0.12±0.37ºC/dec but with such large uncertainties, the calculation is meaningless. Far more predictive are the long term trends which are consistently (now) above 0.2ºC/dec (and with much smaller uncertainties ±0.02ºC/dec for the last 40 years).
It’s worth exploring quantitatively what the impact is, and this is something I’ve been looking at for a while. It’s easy enough correlate the detrended annual anomalies with the ENSO index (maximum correlation is for the early spring values), and then use that regression to estimate the specific impact for any year, and to estimate an ENSO-corrected time series.
The HadCRUT3 global temperature trend was recorded as 0.03°C per decade during the global warming hiatusyears of 2000-2014 (Scafetta, 2022).
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This was increased to 0.08°C per decade by version 4, as the overseers of the HadCRUT data conveniently added 0.1°C to 0.2°C to the more recent anomalies.
Today, in HadCRUT5, the 2000-2014 temperature trend has been adjusted up to 0.14°C per decade when using the computer model-infilling method.
So, within the last decade, a 15-year temperature trend has been changed from static to strong warming.
Each year, we invite Net Zero Watch readers to enter our annual Global Temperature Prediction Competition, in which we try to outdo the Met Office for the accuracy of our soothsaying.
For 2022, the Met Office predicted an average of between 0.97 and 1.21°C (midpoint 1.09°C) above pre-industrial temperatures for the HadCRUT5 index. However, Net Zero Watch readers, as is their wont, went slightly lower, with the median prediction coming in at 1.00°C, and the mode at 1.03°C. This is all shown in the graph below, alongside the correct value, just announced by the Met Office, of 1.16°C.
As you can see, none of our competition entrants got the right answer. There were three people just above, and three more just below. We’ll put all six names into a hat to pick a winner. We’ll be in contact shortly.
If you’d like to enter the 2023 competition, now is your chance!
As always, the prize is a bottle of hooch of your choice, and a book from the GWPF or Net Zero Watch publication lists.
The Met Office reckons on a relatively sharp warming, suggesting HadCRUT5 will come in at between 1.08 and 1.32°C above pre-industrial (with a central estimate of 1.20°C). That’s 0.04°C above last year’s outturn, which doesn’t seem unreasonable, assuming we come out of the La Nina conditions that prevailed in 2022.
To enter, click here (opens a new site). Good luck!
The unusually mild weather at the turn of the year in Central Europe has strengthened the belief of many in Germany that CO2-induced global warming is in full swing. Globally – and this is the only thing that matters – temperatures are developing in a different direction.
If we take the average of the last years, the global temperature has been constant for 8 years and 4 months.
In December, the deviation of the global temperature from the 30-year average of the satellite-based measurements of the University of Alabama (UAH) dropped again, to 0.05 degrees Celsius. To be sure, there is a long-term temperature increase through 2015. But it has averaged only 0.13 degrees Celsius per decade since 1979.
Weakening North Atlantic Oscillation
But it gets even better: the latest scientific studies show for Europe that it will first go slightly downhill for 15-20 years.
Some climate science heavyweights recently caused a stir in the Nature journal “Climate and Atmospheric Science.” Katja Matthes, director of the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Johann Jungclaus of the Max Planck Institute for Meteorology in Hamburg and Nour-Eddine Omrani of the Norwegian Bjerknes Centre for climate research published a study showing that we are facing a weakening of the North Atlantic Oscillation, a cooling of the North Atlantic and a related global temperature development as between 1950 and 1970 (the authors say in their summary).
The graph shows the decline in North Atlantic temperatures by 2040, but because of the global warming trend, temperatures are not falling back to 1950-1970 levels, explains one of the authors, Eddine Omrani. The expected pause in warming gives us time, Omrani says, to work out technical, political and economic solutions before the next warming phase, which will take over again from about 2050.
Why is the coming cooling in Europe not being reported ?
No minimally informed person denies that climate changes. The climate has always changed. Since 1860 the predominant climate change has been warming, which is fortunate because if we had a winter like those of 1800-1850, we would be in for a shock. No one has been able to prove that global warming is primarily a consequence of our emissions. It is reasonable to assume that increased CO2 has contributed to warming since the mid-20th century when our CO2 emissions increased significantly, but no one knows how much they have contributed, no matter how much the Intergovernmental Panel on Climate Change (IPCC) insists that “humans are the dominant cause of observed global warming over recent decades.”(IPCC AR6, page 515).
There is no evidence for this statement. I know this because I have read thousands of scientific papers looking for it. And no, computer models are not evidence of anything but the programming skills of their authors. Models and their predictions are constantly changing and when our knowledge of climate changes, they must be redone.
The absolute lack of evidence contrasts sharply with the decision to cut our CO2 emissions to zero by completely changing our fossil fuel-based energy system and calling CO2 a pollutant—when it is as essential to life as oxygen. All this while most of the world doesn’t give a damn about emissions and many are only on board for the promised money.
December of 2022 finished the year with a global tropospheric temperature anomaly of +0.05 deg. C above the 1991-2020 average, which was down from the November value of +0.17 deg. C.
The average anomaly for the year was +0.174 deg. C, making 2022 the 7th warmest year of the 44+ year global satellite record, which started in late 1978. Continuing La Nina conditions in the Pacific Ocean have helped to reduce global-average temperatures for the last two years. The 10 warmest years were:
#1 2016 +0.389
#2 2020 +0.358
#3 1998 +0.347
#4 2019 +0.304
#5 2017 +0.267
#6 2010 +0.193
#7 2022 +0.174
#8 2021 +0.138
#9 2015 +0.138
#10 2018 +0.090
The linear warming trend since January, 1979 continues at +0.13 C/decade (+0.12 C/decade over the global-averaged oceans, and +0.18 C/decade over global-averaged land).
We all know that Santa’s workshop is somewhere in the Arctic, producing toys for the world’s children. Also north of the Arctic Circle is Professor Humlum’s office at the Unversity of Svalbaard wherein he toils each month to update a report on climate. The first chart in that report is the UAH temperature for the lower troposphere, copied following and annotated with lines showing the evident trends:
Figure 1: UAH global temperature anomaly
In the period from 1978 to 2015, the lower bound of the record is shown by the orange line. Then there was a period of a couple of years in which the temperature anomaly was in a narrow, steep uptrend channel. The temperature anomaly broke up from that channel due to the 2016 El Nino.
Since that 2016 El Nino, two parallel upper bounding lines have formed, in downtrend. The lower green one is formed by six points. The upper red line is formed from only two points – the minimum to make a line – but is notable in that it is parallel to the green line. So climate isn’t a randowm walk. There is some physical process that limits how far temperature excursions go.
The uptrend from the beginning of the satellite record in 1978 to 2015 was 0.4°C over 36 years. That equates to 0.000926°C per month. If we take that amount from each monthly temperature anomaly, cumulatively, we produce the following graph of the detrended monthly temperature anomaly distribution from 1978 to 2015:
The Earth’s climate has undergone some big changes, from global volcanism to planet-cooling ice ages and dramatic shifts in solar radiation. And yet life, for the last 3.7 billion years, has kept on beating.
Now, a study by MIT researchers in Science Advances confirms that the planet harbors a “stabilizing feedback” mechanism that acts over hundreds of thousands of years to pull the climate back from the brink, keeping global temperatures within a steady, habitable range.
Just how does it accomplish this? A likely mechanism is “silicate weathering” — a geological process by which the slow and steady weathering of silicate rocks involves chemical reactions that ultimately draw carbon dioxide out of the atmosphere and into ocean sediments, trapping the gas in rocks.
Scientists have long suspected that silicate weathering plays a major role in regulating the Earth’s carbon cycle. The mechanism of silicate weathering could provide a geologically constant force in keeping carbon dioxide — and global temperatures — in check. But there’s never been direct evidence for the continual operation of such a feedback, until now.
The new findings are based on a study of paleoclimate data that record changes in average global temperatures over the last 66 million years. The MIT team applied a mathematical analysis to see whether the data revealed any patterns characteristic of stabilizing phenomena that reined in global temperatures on a geologic timescale.
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Journal Reference:
Constantin W. Arnscheidt, Daniel H. Rothman. Presence or absence of stabilizing Earth system feedbacks on different time scales. Science Advances, 2022; 8 (46) DOI: 10.1126/sciadv.adc9241
Two new studies indicate there has been no modern warming in the last centuries in western (Urals) and eastern (Kolyma) Russian mountain ranges.
A new 27,000-year temperature reconstruction assesses it was ~2.5 to 4.8°C warmer than today from 8.9-5.2 ka BP in the Ural Mountains, or when CO2 is said to have hovered in the 265 ppm range.
Summer temperatures were also warmer during the Medieval Warm Period, or from 1.2-0.7 ka BP. After a post-Medieval cool-down fostering in the Little Ice Age, the reconstructed record suggests there has been no warming since 0.5 cal ka BP, or for the last several centuries.
The smoothed temperature record shown in the study indicates there was only one brief period in the last 10,000 years that was not warmer than today.
“The reconstructed TJuly [8.9-5.2 cal ka BP] are the highest recorded, reaching up to 4.8 °C higher than today’s air temperature. … Present day T July have persisted since 0.5 cal ka BP.”
A major survey into the accuracy of climate models has found that almost all the past temperature forecasts between 1980-2021 were excessive compared with accurate satellite measurements. The findings were recently published by Professor Nicola Scafetta, a physicist from the University of Naples. He attributes the inaccuracies to a limited understanding of Equilibrium Climate Sensitivity (ECS), the number of degrees centigrade the Earth’s temperature will rise with a doubling of carbon dioxide.
Scientists have spent decades trying to find an accurate ECS number, to no avail. Current estimates range from 0.5°C to around 6-7°C. Without knowing this vital figure, the so-called ‘settled’ science narrative around human-caused climate change remains a largely political invention, not a credible scientific proposition. Professor Scafetta has conducted extensive work into climate models and is a long-time critic of their results and forecasts. In a previous work, he said many of the climate models should be “dismissed and not used by policymakers”. Along with around 250 professors, he is a signatory to the World Climate Declaration which states there is no climate emergency and also notes climate models are “not remotely plausible as global tools”.
Scafetta’s latest work grouped 38 major climate models into low, medium and high ECS values, ranging between 1.8°C and 5.7°C. He found that models in the medium and high category “ran hot” in over 95% and 97% of cases respectively. The lower models were said to have done better when compared to global warming calculated for the period by the major surface datasets of 0.52-0.58°C. But the UAH satellite data showed warming up to 30% less during this period, suggesting even the low warming models produced “excessive warming” from 1980-2021.
According to Scafetta, these results are showed that the ECS figure could be as low as 1.2-2°C. Particular concern is expressed about surface temperature records that “appear to be severely affected by non-climatic warming biases”. Scafetta concludes that surface-based temperature records are likely to be affected by warming biases, such as the urban heat island effect due to expanding urban development, and subject to natural oscillations that are not reproduced by climate models. He concludes: “The global warming expected for the next few decades may be even more moderate than predicted by the low ECS-GCMs [Global Circulation Models], and could easily fall within a safe temperature range where climate adaptation policies will suffice.”
The New Pause, having paused a month ago, has now lengthened again: this time to exactly eight years. As always, the Pause is calculated as the longest period for which the least-squares linear-regression trend up to the most recent month for which the UAH global mean surface temperature anomaly is available is zero.
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The trend on the entire dataset during the 526 months from December 1978 to September 2022 is 0.95 C°, equivalent to only 1.34 C°/century. So slow a rate of warming is well within the natural variability of the climate, and is proving net-beneficial.
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The New Pause has grown to fully eight years in length at a most embarrassing point for true-believers: for the cost to the West of the economically suicidal policies that they have long advocated is now becoming all too painfully apparent, just as it is also ever more evident that the warming since 1990 is well below half the midrange prediction made by IPCC that year.
The so-called hiatus in global annual average temperature between 2002 – 2014, once controversial to some but now well-established in the peer-reviewed literature, ended in 2014 with the start of a series of record-breaking El Nino events that spiked global temperature with a subsequent fall-back. Now a new study into the effect of man-made aerosol pollution adds to likely reasons for the end of the hiatus, and may point to lower estimates for future global warming.
An international research team writing in the journal Atmospheric Chemistry and Physics, uses satellite data to show that concentrations of aerosol particles have decreased significantly since 2000. This is good news as cleaner air benefits health, but it also reduces particles’ which have a cooling effect on the terrestrial climate.
According to the Intergovernmental Panel on Climate Change (IPCC), by 2019 the global temperature had risen by 1.1 degrees Celsius compared to pre-industrial levels due to increasing greenhouse gasses from burning fossil fuels. At the same time the combustion of fossil fuels emit aerosols which cool our climate by reflecting sunlight and increasing the reflectivity of clouds.
Professor Johannes Quaas, a meteorologist at Leipzig University, and colleagues from Europe, China, and the US have published robust observational evidence of significant reduction of aerosol pollution and improved global air quality.
The so-called hiatus in global annual average temperature between 2002 – 2014, once controversial to some but now well-established in the peer-reviewed literature, ended in 2014 with the start of a series of record-breaking El Nino events that spiked global temperature with a subsequent fall-back. Now a new study into the effect of man-made aerosol pollution adds to likely reasons for the end of the hiatus, and may point to lower estimates for future global warming.
An international research team writing in the journal Atmospheric Chemistry and Physics, uses satellite data to show that concentrations of aerosol particles have decreased significantly since 2000. This is good news as cleaner air benefits health, but it also reduces particles’ which have a cooling effect on the terrestrial climate.
According to the Intergovernmental Panel on Climate Change (IPCC), by 2019 the global temperature had risen by 1.1 degrees Celsius compared to pre-industrial levels due to increasing greenhouse gasses from burning fossil fuels. At the same time the combustion of fossil fuels emit aerosols which cool our climate by reflecting sunlight and increasing the reflectivity of clouds.
Professor Johannes Quaas, a meteorologist at Leipzig University, and colleagues from Europe, China, and the US have published robust observational evidence of significant reduction of aerosol pollution and improved global air quality.
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When taken together with a couple of super-strong El Nino events which temporarily drove up global temperature (see graph below), the new findings suggest that the global warming hiatus — clearly evident prior to 2014 — may not have ended yet. If NASA’s satellite data are confirmed, it would suggest that much of the very moderate changes in global temperature this century may have been driven primarily by cleaner air and naturally-occurring El Ninos.
Global temperature changes 2000-2022. Source: Met Office/HadCRUT5…
New research continues to document non-warming and even “robust cooling” trends for entire regions of the Southern Hemisphere in recent decades.
Land surface temperature data compilations from the Southern Hemisphere (South America, Southwestern Andes, Tasmania, New Zealand, Australia) indicate that any warming during the 20th century occurred before 1980, with no obvious net warming since (Rezsöhazy et al., 2022).
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Sea surface temperature data from the Southeastern Indian Ocean, Tasman Sea, and Great Barrier Reef region indicate no net warming since 1982 (Chapman et al., 2022).
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A 2021 study reported a profound cooling trend for most of Antarctica in recent decades, with amplitudes of -2.8°C for East Antarctica and -1.68°C for West Antarctica during 1979-2018.
The Coupled Model Intercomparison Project (phase 6) (CMIP6) global circulation models (GCMs) predict equilibrium climate sensitivity (ECS) values ranging between 1.8 and 5.7 ∘∘C. To narrow this range, we group 38 GCMs into low, medium and high ECS subgroups and test their accuracy and precision in hindcasting the mean global surface warming observed from 1980–1990 to 2011–2021 in the ERA5-T2m, HadCRUT5, GISTEMP v4, and NOAAGlobTemp v5 global surface temperature records. We also compare the GCM hindcasts to the satellite-based UAH-MSU v6 lower troposphere global temperature record. We use 143 GCM ensemble averaged simulations under four slightly different forcing conditions, 688 GCM member simulations, and Monte Carlo modeling of the internal variability of the GCMs under three different model accuracy requirements. We found that the medium and high-ECS GCMs run too hot up to over 95% and 97% of cases, respectively. The low ECS GCM group agrees best with the warming values obtained from the surface temperature records, ranging between 0.52 and 0.58 ∘∘C. However, when comparing the observed and GCM hindcasted warming on land and ocean regions, the surface-based temperature records appear to exhibit a significant warming bias. Furthermore, if the satellite-based UAH-MSU-lt record is accurate, actual surface warming from 1980 to 2021 may have been around 0.40 ∘∘C (or less), that is up to about 30% less than what is reported by the surface-based temperature records. The latter situation implies that even the low-ECS models would have produced excessive warming from 1980 to 2021. These results suggest that the actual ECS may be relatively low, i.e. lower than 3 ∘∘C or even less than 2 ∘∘C if the 1980–2021 global surface temperature records contain spurious warming, as some alternative studies have already suggested. Therefore, the projected global climate warming over the next few decades could be moderate and probably not particularly alarming.
by P. Homewood, Sep 13, 022 in ClimateChange Dispatch
For weeks we have been told that this year’s warm summer is due to climate change.
The BBC’s Justin Rowlatt was quite clear: ‘We know what is behind this – greenhouse gas emissions caused by our burning of fossil fuels like coal and gas,’ a message amplified across the media and stoked by the Met Office, who delighted in their red warnings and public health alerts. [bold, links added]
It was not only the heat. The Met Office claimed that this summer’s drought is a harbinger of the future we could expect, ably assisted by fraudulently misleading images of ‘dried up reservoirs’ on BBC News.
As many of us suspected all along, the summer of 2022 was not a record breaker at all, as it was much hotter in 1976, as the Central England Temperature Series makes clear:
The Earth’s greenhouse effect is much larger than suggested so far. If surface radiation and the greenhouse effect set surface temperatures, our oceans would be boiling. Fortunately, they don’t. Water Earth has a strong water-vapor-based evaporative surface cooling mechanism that effectively sets and stabilizes surface temperatures at a much lower level than cooling by surface radiation emissions can do. Thanks to water vapor our temperature system is far more stable than admitted by the consensus, and thanks to water, water vapor, and clouds surface temperatures are favorable for present life.
Introduction
Early Earth consisted of hot molten lava covered by an extreme greenhouse atmosphere: hardly any surface radiation could reach space, if any. Nevertheless, its surface cooled. Upward convection brought sensible and latent heat from hot surfaces to elevations on the very edge of the atmosphere from where energy effectively could be radiated into space. Despite the near maximal greenhouse effect the surface of Early Earth cooled down and at a certain moment the first oceans developed. Those boiling oceans still resulted in a huge upward convective transport of energy, further cooling the surface. Until now, convective upward transport of energy plays the main role in surface cooling. Convection sets and regulates surface temperatures at actual level. Without evaporative-convective-cloud-cooling, our actual greenhouse atmosphere would theoretically result in a surface temperature of 202.3°C. On the real Earth the greenhouse effect warms the surface, but greenhouse warming does not set and control final surface temperatures. Earth’s H2O-based cooling system does.
Theoretical greenhouse effect
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Conclusions
The Earth’s greenhouse effect is huge, much higher than normally assumed. If cooled by ‘surface radiation only’ the surface of a theoretical planet would have had a surface temperature of 202.3°C. But the Earth’s surface temperatures are not set by the strength of Earth’s greenhouse effect. Additional H2O-based cooling systems keep the surface at a much lower temperature, balancing rising surface radiation uptake. At present, that balance is reached at a yearly average of 15 degrees Celsius.
Thanks to H2O-related surface cooling the Earth’s surface temperatures are bound to a narrow range, at a temperature level well suited for life on Earth. Due to its stability, life developed over many hundreds of millions of years.
Temperature regulates the cooling system; the cooling system regulates temperature.
The accuracy of the long-term global instrumental temperature record – especially the data obtained before the 1970s – wholly rests on the assumption that sailors obtained precisely reliable temperature measurements as they pulled wooden or canvas buckets out of the water from ships at random depths, locations, and times of day. They didn’t.
It has long been known that pulling a bucket out of the water from a ship is rooted in serious error, rendering the sea surface temperature (SST) data obtained nearly useless. Ashford (1948) summarized some of the more salient reliability problems with this method of measurement.
• The initial temperature of the bucket is generally different from that of the sea.
• The water in the bucket may change its temperature before the reading is taken owing to the processes of heat exchange and evaporation.
• The initial temperature of the thermometer is generally different from that of the sample.
• The thermometer is liable to scale errors.
• Owing to thermal lag, the thermometer may take an appreciable time to indicate the true temperature of the sample.
• If the thermometer is removed from the bucket when taking the reading, it may no longer indicate the true water temperature.
1. To support a claim that the Earth’s Climate System is “getting hotter” one has to have a long-term time series of measurements of heat in the climate system.
2. Current Global Mean Temperature data sets do not measure heat and thus can not supply evidence for #1.
3. The lack of such a time-series doesn’t mean that the Earth’s climate isn’t gaining energy (heat) – it simply means we don’t have any reliable measure of it.
4. Climate Science may have some evidence of long-term energy gain or what is commonly labelled “Earth’s Energy Budget” — energy in/energy out — but it doesn’t seem to be dominate in the ongoing climate controversy. The latest paper shows that we can still cannot directly measure instantaneous radiative forcing. “This fundamental metric has not been directly observed globally and previous estimates have come from models. In part, this is because current space-based instruments cannot distinguish the instantaneous radiative forcing from the climate’s radiative response.” It is possible that future satellite missions will be able to measure directly and accurately Earth’s incoming and outgoing energy.
Back in the days when data manipulation was still strictly forbidden, scientists reported the globe cooled significantly for decades even as CO₂ concentrations increased.
The global cooling amplitude was -0.5°C from 1960-1965, and 1976 was reported to be the coldest year of any year measured since 1958 (Angell and Korshover, 1978).
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Today these recorded 1960-1965 and 1958-1963 cooling trends have been fully erased and replaced with a slight warming or pause.
The linear warming trend since January, 1979 still stands at +0.13 C/decade (+0.11 C/decade over the global-averaged oceans, and +0.18 C/decade over global-averaged land).
Various regional LT departures from the 30-year (1991-2020) average for the last 19 months are:
The oceans swallowed my global warming? Desperate butt covering from alarmists who are facing increasingly embarrassing questions about the failure of the world to end.
by P. Homewood, July 23, 2022 in NotaLotofPeopleKnowThat
There has inevitably been a lot of apoplectic reporting about this week’s heatwave in Britain. Everybody from the BBC to the Met Office have been blaming it on climate change, with suitably scary colours to ram the message home:
Comparison of TV weather Maps from the BBC in summer 2012, left, and summer 2022 right. Source: BBC
Courtesy of Climate Realism
But so far I have not seen an objective analysis.
So let’s start with a few simple facts:
1) It was extremely hot for a couple of days this week.
2) The heat was the result of an extremely unlikely set of meteorological conditions – a perfect storm, if you like.
We know this because the Met Office told us so. On July 8th, they announced the possibility of a heatwave a week later. The weather model runs produced a wide band of possibilities, with most predicting similar temperatures to the weekend before, and some even forecasting no heatwave at all. At that stage on a couple of models out of the hundreds run predicted 40C temperatures, which were described by the BBC as “a very tiny possibility”.
by P. Homewood, July 19, 2022 in NotaLotofPeopleKnowThat
Meanwhile the jokers at the Met Office don’t seem to have realised that their temperature records begin at the depth of the Little Ice Age, or appear to have heard about Urban Heat Islands
It is mid July 2022. We are currently experiencing a significant – at the time of writing provisionally record-breaking – heatwave for the UK. Red weather warnings for extreme heat are in force for large parts of England and forecasts indicated a real possibility of temperatures reaching up to 40°C in some areas. Indeed, this temperature has already been exceeded. Whether or not records are broken, a key part of the work that we do at the Met Office is climate monitoring, an important aspect of which is the ability to put current weather into historical context. Climate monitoring serves many functions: It can effectively communicate the relative severity of an event; it can indicate how frequently such extremes are likely to occur; and it can monitor how the character or frequency of extremes are changing over time. In order to properly understand the risks from climate change, a key research question climate monitoring can help us to answer is, ‘What are the current weather and climate hazards, risks and impacts that should be expected in the UK and globally?’. To address this question, we must look to the past, and the scientific effort goes back further than you might think.
Making history
In 1663, Robert Hooke stood before the relatively newly formed Royal Society and proposed ‘A method for making the history of the weather’. Hooke and other notable scientists of the time were actively developing instruments capable of making meteorological measurements of wind, rain, air pressure, humidity and temperature. These were the early anemometers, rain gauges, barometers and thermometers of the time1. In his paper, Hooke recommended what should be measured and how it should be recorded, including ‘a scheme at one view representing to the eye the observations of the weather for a month’ and implored his colleagues to undertake such measurements. From a modern climatologist’s point of view, arguably one of the most important advances by Hooke was his recognition that if systematic and consistent measurements were made across the country, or even across the world, then an international perspective on the weather could be obtained, for the benefit of humankind.
For decades We have been told that we must not let global warming exceed two degrees Celsius above the “pre-industrial” global average temperature. Recently the IPCC lowered this limit to 1.5°C. In the latest IPCC report, called AR6, pre-industrial is defined as before 1750, but they use global temperatures from 1850-1900 as representative of the period because global average surface temperatures are not available for 1750.[1] The U.S., Europe, and much of Asia were industrialized by 1900, so their numbers are clearly not representative of the period of interest, unless temperatures remained constant from 1750 to 1900, which is unlikely.
Why the focus on 2°? In a 2014 comment in Nature, David Victor and Charles Kennel tell us that there is little scientific basis for the 2°C figure, but it was a simple focal point and it “sounded bold and perhaps feasible.” (Victor & Kennel, 2014). Then they admit the goal is “effectively unachievable.”
What is the “pre-industrial?” Did it have an ideal climate that we wish to return to? The year 1750 was in the coldest and most miserable part of the Little Ice Age (LIA). The LIA was the coldest period in the Holocene Epoch, or since the last glacial period ended about 12,000 years ago, at least in much of the Northern Hemisphere.
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La géologie, une science plus que passionnante … et diverse
Figure 1: UAH global temperature anomaly
