Day: February 10, 2024

Proof that the Spencer & Christy Method of Plotting Temperature Time Series is Best

The goal here is to plot multiple temperature time series on a single graph in such a way the their different rates of long-term warming (usually measured by linear warming trends) are best reflected by their placement on the graph, without hiding those differences.

From Roy Spencer, PhD.

February 9th, 2024 by Roy W. Spencer, Ph. D.

Since the blogosphere continues to amplify Gavin Schmidt’s claim that the way John Christy and I plot temperature time series data is some form of “trickery”, I have come up with a way to demonstrate its superiority. Following a suggestion by Heritage Foundation chief statistician Kevin Dayaratna, I will do this using only climate model data, and not comparing the models to observations. That way, no one can claim I am displaying the data in such a way to make the models “look bad”.

The goal here is to plot multiple temperature time series on a single graph in such a way the their different rates of long-term warming (usually measured by linear warming trends) are best reflected by their placement on the graph, without hiding those differences.

A. Raw Temperatures

Let’s start with 32 CMIP6 climate model projections of global annual average surface air temperature for the period 1979 through 2100 (Plot A) and for which we have equilibrium climate sensitivity (ECS) estimates (I’ve omitted 2 of the 3 Canadian model simulations, which produce the most warming and are virtually the same).

Here, I am using the raw temperatures out of the models (not anomalies). As can be seen in Plot A, there are rather large biases between models which tend to obscure which models warm the most and which warm the least.

B. Temperature Anomalies Relative to the Full Period (1979-2100)

Next, if we plot the departures of each model’s temperature from the full-period (1979-2100) average, we see in Plot B that the discrepancies between models warming rates are divided between the first and second half of the record, with the warmest models by 2100 having the coolest temperature anomalies in 1979, and the coolest models in 2100 having the warmest temperatures in 1979. Clearly, this isn’t much of an improvement, especially if one wants to compare the models early in the record… right?

C. Temperature Anomalies Relative to the First 30 Years

The first level of real improvement we get is by plotting the temperatures relative to the average of the first part of the record, in this case I will use 1979-2008 (Plot C). This appears to be the method favored by Gavin Schmidt, and just looking at the graph might lead one to believe this is sufficient. (As we shall see, though, there is a way to quantify how well these plots convey information about the various models’ rates of warming.)

D. Temperature Departures from 1979

For purposes of demonstration (and since someone will ask anyway), let’s look at the graph when the model data are plotted as departures from the 1st year, 1979 (Plot D). This also looks pretty good, but if you think about it the trouble one could run into is that in one model there might be a warm El Nino going on in 1979, while in another model a cool La Nina might be occurring. Using just the first year (1979) as a “baseline” will then produce small model-dependent biases in all post-1979 years seen in Plot D. Nevertheless, Plots C and D “look” pretty good, right? Well, as I will soon show, there is a way to “score” them.

E. Temperature Departures from Linear Trends (relative to the trend Y-intercepts in 1979)

Finally, I show the method John Christy and I have been using for quite a few years now, which is to align the time series such that their linear trends all intersect in the first year, here 1979 (Plot E). I’ve previously discussed why this ‘seems’ the most logical method, but clearly not everyone is convinced.

Admittedly, Plots C, D, and E all look quite similar… so how to know which (if any) is best?

How the Models’ Temperature Metrics Compare to their Equilibrium Climate Sensitivities

What we want is a method of graphing where the model differences in long-term warming rates show up as early as possible in the record. For example, imagine you are looking at a specific year, say 1990… we want a way to display the model temperature differences in that year that have some relationship to the models’ long-term rates of warming.

Of course, each model already has a metric of how much warming it produces, through their diagnosed equilibrium (or effective) climate sensitivities, ECS. So, all we have to do is, in each separate year, correlate the model temperature metrics in Plots A, B, C, D, and E with the models’ ECS values (see plot, below).

When we do this ‘scoring’ we find that our method of plotting the data clearly has the highest correlations between temperature and ECS early in the record.

I hope this is sufficient evidence of the superiority of our way of plotting different time series when the intent is to reveal differences in long-term trends, rather than hide those differences.

The world’s top carmaker got mocked for rejecting EV hype—not anymore. ‘I want to congratulate Toyota’ 

“I want to congratulate Toyota, which was attacked for saying it was never going to go all-electric and it was going to continue to make the cars people wanted to buy,” said Diana Furchtgott-Roth, director of the Center for Energy, Climate, and Environment at the Heritage Foundation, on Fox Business.

CEO Akio Toyoda

Toyota was skeptical of electric vehicles back when that wasn’t fashionable. In October 2022, for instance, then-CEO Akio Toyoda said that EVs “are just going to take longer than the media would like us to believe.”

As other big carmakers made bold proclamations about when they go all electric, Toyota refused to play along, vowing instead to keep offering a wide array of power trains and letting consumers decide for themselves. The Fortune has the story.

“That’s our strategy and we’re sticking to it,” he insisted, vowing to focus on hybrids, which this carmaker pioneered with the release of the Prius in Japan in 1997, and three years later in the U.S. Since then, the Japanese giant has steadily increased its hybrid offerings.

Toyota’s stance was not a good look at the time—and it didn’t go over well. 

“Toyota is not correctly responding to calls from the market to take a lead in electric vehicles,” Satoru Aoyama, senior director at Fitch Ratings, told the Financial Times, warning the carmaker could “lose investor confidence.” 

Environmentalists were none too pleased, either. “The fact is: a hybrid today is not green technology,” blogged Katherine Garcia, director of the Sierra Club’s Clean Transportation For All campaign.

“The Prius hybrid runs on a pollution-emitting combustion engine found in any gas-powered car…Rather than invest in EVs, though, Toyota is putting corporate profits and the status quo over tackling the climate crisis.”

The pressure grew so intense that, partly in response, Toyoda—the grandson of the company’s founder—left his CEO role to become chairman. 

“Because of my strong passion for cars, I am an old-fashioned person in regards to digitalization, electric vehicles, and connected cars. I cannot go beyond being a car guy, and that is my limitation,” he said. “The new team can do what I can’t do.” 

‘A strength of Toyota’

But it turns out he was onto something. This week, the carmaker raised its operating profit guidance by nearly 9% for the fiscal year ending March 31, crediting higher sales of hybrid vehicles across all its major markets. 

That contrasted with EV leader Tesla, which despite repeated price cuts to boost demand warned that this year’s sales growth might be “notably lower” than last year’s. Meanwhile there are increasing signs from carmakers and markets around the world that sales growth for electric vehicles is slowing. 

With hybrids alone, Toyota sold roughly 3.4 million vehicles globally last year, up from 2.6 million in 2022. Tesla, by contrast, sold 1.8 million vehicles, all of them electric. In total, Toyota sold 11.2 million vehicles, allowing it to retain its crown as the top-selling carmaker for the fourth consecutive year.

EV sales in the U.S. grew an impressive 51% last year, according to Edmunds, but hybrid sales did even better, jumping 63%. 

“We think the market is now rethinking the potential of hybrid products, which are a strength of Toyota,” Goldman Sachs analysts wrote in a recent research note.

“I want to congratulate Toyota, which was attacked for saying it was never going to go all-electric and it was going to continue to make the cars people wanted to buy,” said Diana Furchtgott-Roth, director of the Center for Energy, Climate, and Environment at the Heritage Foundation, on Fox Business.

Read the full story here.

Jury finds in favor of Michael Mann in defamation lawsuit against Mark Steyn, Rand Simberg

The jury deliberated for close to a full day before reaching its decision.

The Trial of George Jacobs, 5th August 1692, 1855 (oil on canvas)

From Climate Depot

By Marc Morano

https://tnc.news/2024/02/08/mann-defamation-lawsuit-steyn-simberg2


By Andrew Lawton

A Washington, D.C. jury has found that conservative writers Mark Steyn and Rand Simberg defamed climate scientist Michael Mann.

The jury deliberated for close to a full day before reaching its decision.

At issue were two blog posts, one by Steyn and one by Simberg, comparing the investigation into alleged academic misconduct by Mann, then a Penn State professor, to Penn State’s handling of Jerry Sandusky, the school’s former head of athletics who raped and molested children.

“If an institution is prepared to cover up systemic statutory rape of minors, what won’t it cover up?” Steyn wrote in his post, which quoted Simberg’s.

The jury awarded Mann $1 in compensatory damages from each plaintiff. It also awarded $1,000 in punitive damages from Simberg and $1 million from Steyn.

The jury found that the statements at issue were defamatory and published with reckless disregard for the truth. They also found that Mann suffered actual injury from the statements’ publication.

Mann sued Steyn and Simberg, along with their respective publishers National Review and the Competitive Enterprise Group in 2012, claiming the posts damaged his reputation as a climate scientist.

In a trial that stretched on for three-and-a-half weeks, Mann claimed he felt like a pariah in his community, noting he once received a dirty look from someone in a grocery store. He said he lost significant grant funding after the blog posts were published, but was not able to produce any evidence linking this to the posts.



Steyn and Simberg argued that Mann’s stature, earnings and reputation have only improved since 2012, meaning that even if he had been defamed, he had suffered no damages, which the plaintiff in a defamation suit must prove.

How Toyota accelerated past the electric car slowdown

Carmaker blazing its own trail as rivals miss out on hybrid gold rush.

Carmaker blazing its own trail as rivals miss out on hybrid gold rush.

Speaking to Toyota employees last month, Akio Toyoda sounded slightly bruised.

The chairman of the world’s biggest car maker described how he had been “beaten up” by critics for refusing to bet all his company’s chips on electric vehicles (EVs).

Instead, he has doggedly championed a so-called multi-pathway approach that spans EVs, hybrids and even hydrogen-powered cars. The Telegraph has the story.

The decision has infuriated climate activists who once praised Toyota for its eco-friendly Prius hatchback, while even industry insiders have wondered whether the company is making a strategic blunder.

“It’s really hard to fight alone,” Toyoda said to staff, according to a translation of his January remarks.

But now the industrialist’s rivals are looking on in envy, as a slowdown in EV sales has left his company in pole position to capitalise on a surge in demand for hybrids.

Toyota sold 10.3 million cars in 2023, an increase of 7.7pc compared to a year earlier.

The total included a combined 3.5 million hybrids and plug-in hybrids – a year-on-year increase of 32pc – but only 104,000 EVs.

For the year to the end of March, the Japanese giant is now forecasting profits of 4.5 trillion yen (£24bn), up from 2.5 trillion yen previously.

Yoichi Miyazaki, executive vice president at Toyota, said hybrids were even selling strongly in China – the world’s biggest market and producer of EVs.

“As a realistic solution, hybrids are still favoured by our customers,” he told reporters.

Meanwhile, rival manufacturers that have driven further ahead with EVs are now pumping the brakes, with Ford, Volkswagen and General Motors among those scaling back production.

After successfully targeting early adopters, they are finding the mass market much tougher to crack – with many consumers still put off by high prices and worries about charging infrastructure.

“EVs have soaked up all of the early adopter and wealthy demand,” explains Andrew Bergbaum, an automotive expert at consultancy AlixPartners.

“But the costs still haven’t come down to the point where they’ve reached the mass market prices you see with internal combustion engine (ICE) cars.

“Hybrids are also considerably cheaper [than EVs], because the batteries in them are so much smaller.

“Once you couple that with range anxiety and concerns about EV resale values, it’s a fairly understandable market phenomenon.”

Read the full story here.

Men at War, Part 6 – American V Russian Temperature Reconstructions

Looking at the research papers* I have on file by Russians, and being reminded of the American temperature reconstruction from the Michael Mann versus Mark Steyn court case,  well they are very different.

From Jennifer Marohasy

By jennifer

I have been remembering Russian historical temperature reconstructions based on tree ring data, as I have listened along to the Climate Change on Trial podcast series by investigative journalist Ann McElhinney.

Looking at the research papers* I have on file by Russians, and being reminded of the American temperature reconstruction from the Michael Mann versus Mark Steyn court case,  well they are very different.

The Russian temperature reconstructions based on tree ring data generally show the cooling so evident in the instrumental record (unhomogenized/raw) for the Arctic region from 1940 through to 1975.  Of course, the Russian reconstructions also include the Medieval Warm period (10th to 12th centuries).

The Americans flatten the early part of the 1,000 years long record, obliterating the Medieval Warm period, and then they use ‘Mike’s trick’ that is to graft some remodelled (homogenised) instrumental temperature data onto the end of the proxy temperature series to get a big uptick.   Thus, creating what has become known as the ‘hockey stick’.

Mark Steyn has repeatedly suggested that all of this is rather fraudulent.   I agree.

For his troubles, Steyn was awarded punitive damages of US$1 million in the Washington DC Superior Court just yesterday.  To understand the context, consider listening along from the beginning, with the Climate Change on Trial podcast series by investigative journalist, and dear friend, Ann McElhinney.

What the Americans, including Mann, have done with the tree ring data, is much the same as the Australian Bureau of Meteorology’s homogenisation of the instrumental temperature.  This mostly involves cooling the past, so the present appears warmer.   I’ve written so much about this, and I will be writing some more.  For context, consider my ‘Hyping Maximum Temperature’ series, that I could perhaps turn into a podcast series (Part 1 to Part 7).

Homogenisation of the Australian data that only begins in 1910, mostly obliterates the very warm decades at the beginning of the twentieth century and in the process does away with the cooling trend in the first half of the twentieth century, from about 1920 through to 1950.   Considering the instrumental temperature series overall from 1910, and before they are remodelled , it is about as hot now as it was back in say 1914.  Heatwaves were worse in 1896 (there are records back to 1850, unhomogenized), and summers were hotter in the late 1930s (considering the data before it is remodelled).   Considering the annual averages, well, unhomogenized mean temperatures show cooling to about 1950 and then warming after this.

A problem with the last thirty years of temperature data is that it has been measured from automatic weather stations using platinum resistance probes that can be calibrated to show however many degrees hotter or cooler than a mercury thermometer might be considered convenient.

To be clear, that are at least three problems with the official Australian temperature series, 1. they are truncated (only beginning in 1910), 2. they are homogenised (cooling the data from mercury thermometers), and 3. they are unreliable at least from 1996 with the transition to a different method of measurement (platinum resistance probes in automatic weather stations).

It is the case that the Americans also remodelled (homogenize) their instrumental temperature data, as well as the proxy temperature data from tree rings, to also fit a particular and convenient narrative.

This is important to the West, or at least our financial institutions that are heavily invested in the energy transition.  This energy transition, is, of course, prefaced on the assumption that temperatures continued to rise through most of the twentieth century and that they are now unprecedented.  This is achieved for the official record through a combination of homogenisation (remodelling) and change of measurement system (from mercury thermometer to platinum resistance probes).

__________

* The chart featured at the top of this post is from a paper by O.V. Sidorova et al. from the V.N. Sukachev Institute of Forestry in Russia.  It was presented at the Dendro symposium in Switzerland from April 21st to 23rd  in 2005.

The chart shows key features of the American hockey stick (without complete shaft) and contrasts this with a Russian proxy temperature reconstruction.

It is the case that the Russians have longer historical reconstructions based on tree ring data and continue to collect and analyse tree ring data.

The Americans have more-or-less stopped this work with tree rings, and so their reconstructions based on proxy data end in about 1965, after which they conveniently graft instrumental temperature series measured using platinum resistant probes.

I must say, at the moment, it is quite apparent that the Russians, and also the Chinese, are going much better science than anyone much in the West, at least in the areas of interest to me including rainfall forecasting and historical temperature reconstructions.    It is perhaps also worth noting that reliable rainfall forecasts need accurate historical temperature reconstructions.

Mann vs. Steyn: A Disgrace to the Profession – Climate Change Roundtable #97

On episode 97 of Climate Change Roundtable, The Heartland Institute’s Anthony Watts, H. Sterling Burnett, Linnea Lueken, and Jim Lakely break down what happened in the trial, how this criminally unjust jury decision came to be, and what this means for the First Amendment rights of anyone who questions alarmist dogma in public.

The Climate Trial of the Century is over, and the result is an absolutely travesty of justice. A D.C. jury ruled yesterday that Mark Steyn must pay $1 in compensatory damages and an absurd $1 million in punitive damages to climate media star Michael Mann for his claimed defamation. His co-defendant, Rand Simberg, was socked with paying $1 in compensatory damages, but only $1,000 in punitive damages.

We followed the trial every day for nearly four weeks, and we can tell you that it was a disgrace to the professions in our legal system, the “profession” of juries to administer justice, and the professions in alarmist climate science. In short, the whole thing was a disgrace.

On episode 97 of Climate Change Roundtable, The Heartland Institute’s Anthony Watts, H. Sterling Burnett, Linnea Lueken, and Jim Lakely break down what happened in the trial, how this criminally unjust jury decision came to be, and what this means for the First Amendment rights of anyone who questions alarmist dogma in public.

Activists just can’t stop using emotional blackmail to sell the climate change narrative

Even though a big deal was made earlier this year about climate activists not using polar bears anymore to try and sell the climate change emergency narrative, they just can’t seem to help themselves.

From polarbearscience

Even though a big deal was made earlier this year about climate activists not using polar bears anymore to try and sell the climate change emergency narrative, they just can’t seem to help themselves.

So it’s not at all surprising that yet another amateur climate activist has resorted to using the emotional ploy of a photo of a polar bear on sea ice to win the 2023 Wildlife Photo of the Year People’s Choice Award sponsored by the Natural History Museum London (UK).

Said Museum director Dr Douglas Gurr of the photo taken by British amateur photographer Nima Sarikhani: “

His thought-provoking image is a stark reminder of the integral bond between an animal and its habitat and serves as a visual representation of the detrimental impacts of climate warming and habitat loss.“

Yet, the photo itself doesn’t show an animal beaten down by a struggle to survive but rather a fat polar bear so confident in its environment that it is relaxed enough to take a nap. It’s the photographer and his climate-anxious audience that perceives this to be a precarious situation, not the polar bear. The bear is fine.

The Barents Sea subpopulation, to which this particular polar bear belongs, is currently thriving. Barents Sea polar bears are not slowly starving to death but successfully making their way through the challenges of Arctic life as all polar bears must do.

The photographer who took the polar bear photo was quoted in the museum press release as saying:

‘Whilst climate change is the biggest challenge we face, I hope that this photograph also inspires hope. There is still time to fix the mess we have caused.’

I have no idea what “mess” he’s referring to. Like the photo he took, visions of climate change disaster are an illusion perpetuated by the media and misinformed educators like the Natural History Museum. Summer sea ice hasn’t declined in 17 years and the polar bear catastrophe we were promised never happened. In case you missed it, I wrote a book about that.

Polar bears across the Arctic are thriving.

As I mentioned to Tom Nelson in my interview with him last month, the work I have done exposing the failed polar bear narrative over the last 11 years has been incredibly useful in helping the public apply critical thinking to other, more complex issues, including Covid containment measures and the WEF climate change agenda. That’s the value of good science communication: it’s beneficial in more than one specific context.

If the public can see that polar bear specialists have been hiding data from the public and misrepresenting research results in order to maintain their support of human-caused climate change, how much other “supporting evidence” for the climate change agenda is just as scientifically suspect?

Do yourself a favour and keep thinking critically about everything. That’s what will save us all.

Climate change row as British scientists claim ‘Day After Tomorrow’ modelling is wrong

Prediction by Dutch team that vital Atlantic system could reach a tipping point and trigger new ice age has been ‘forced’, say experts.
“Models are not reality. The real system may be more, or less, prone to collapse than this model suggests.”

Prediction by Dutch team that vital Atlantic system could reach a tipping point and trigger new ice age has been ‘forced’, say experts.

Aclimate model predicting a devastating ‘Day After Tomorrow’ collapse of ocean systems has been criticised for relying on ‘entirely unrealistic’ scenarios.

A Dutch team from Utrecht University published work in the journal of Science Advances this week suggesting that the Atlantic Meridional Overturning Circulation (AMOC) could reach a tipping point, triggering a new ice age. The Telegraph has the story.

The AMOC transports heat and salt throughout the world’s oceans and helps regulate the global climate, driving the Gulf Stream that keeps Britain warmer than it should be for its northerly latitude.

In the apocalyptic science fiction film The Day After Tomorrow, the ocean system is disrupted by climate change, plunging the northern hemisphere into a permanent winter.

Although ice-core data suggests the AMOC can switch off, recent sophisticated modelling has not been able to reproduce the effect, leading many scientists to think a collapse is unlikely to happen.

The new study claims to have shown that AMOC is “on route to tipping”, a prospect that the authors say is “bad news for the climate system and humanity”.

However British scientists warned that the outcome had been “forced” by using unlikely variables, such as assuming large influxes of freshwater into the Atlantic.

Prof Jonathan Bamber, director of the Bristol Glaciology Centre at Bristol University, said: “They did this by imposing a huge freshwater forcing to the North Atlantic that is entirely unrealistic for even the most extreme warming scenario over the next century.

“Their freshwater forcing applied to the North Atlantic is equivalent to six cm/year of sea level rise by the end of the experiment, which is more than seen during the collapse of the ice sheet that covered North America during the last glaciation.”

The UN’s Intergovernmental Panel on Climate Change has said that the AMOC is unlikely to collapse this century, and many scientists do not believe it will fail even if the climate continues to warm.

Observational data for the ocean system only goes back to 2004, making it difficult to predict, and because it spans the globe, most models cannot account for all the nuances and influences.

Commenting on the new research, Prof Andrew Watson, of Exeter University, said “They say it suggests that ‘the present day AMOC is on route to tipping’.

‘Push it quite hard’

“This sounds alarming, but it’s important to note that this is not the same as saying collapse is going to happen imminently. They have to run their model for a long time (1,700 years) and push it quite hard to make the collapse happen.

“Models are not reality. The real system may be more, or less, prone to collapse than this model suggests.”

Read the full story here.

Ford EV Crisis: “Our Gen 2 vehicles won’t launch unless we can … profit”

Death of the EV revolution?

From Watts Up With That?

Death of the EV revolution?

Ford pulls the plug on EV strategy as losses pile up

‘Our Gen 2 vehicles won’t launch unless we can get to a profit’

Brandon Vigliarolo 
Wed 7 Feb 2024  // 18:30 UTC 

The reality of electric vehicle prices has finally caught up with the venerable US automaker Ford, which said yesterday that it’s rethinking its loss-making EV strategy.

The news came during Ford’s Q4 2023 earnings call yesterday, and included revelations that the Detroit-based biz was also reassessing its EV battery strategy, a decision that comes as no surprise in the wake of delays announced last year. 

“We delayed our second joint venture battery plant in Kentucky. We reduced the size of our new lithium iron phosphate plant in Michigan, and we did not proceed with our JV battery plant in Turkey,” Ford CFO, John Lawler, said on the call.

“We are further adjusting installed capacity to match demand, reassessing vertical integration in new battery chemistries, adjusting Gen 2 products and potentially their launch timing to ensure they meet our criteria for profitability.” 

…

“Our Gen 2 vehicles won’t launch unless we can get to a profit and a return on that capital that we’re investing there at the pricing environment that we now understand is reality,” Lawler said. “We know that we have to have this electric vehicle business stand on its own and be profitable because we know that there are competitors out there.” 

…Read more: https://www.theregister.com/2024/02/07/ford_ev_strategy/

Given the lack of consumer interest in EVs, is this actually a demand to the Biden Administration to provide more taxpayer cash, or does it represent a genuine change in corporate direction?

Does the Biden Administration have any more borrowed cash to provide?

I guess time will tell.

Climate Change Is Not Behind Lake Mead’s Decline, Overuse and Poor Management Are

With an atmospheric river dumping trillions of gallons precipitation on California and other western states, some news outlets have asked how the precipitation might affect Lake Mead, suggesting that the rainfall will do little for the lake or the Colorado River basin which feeds it because it’s drying out due to climate change.


By H. Sterling Burnett

With an atmospheric river dumping trillions of gallons precipitation on California and other western states, some news outlets have asked how the precipitation might affect Lake Mead, suggesting that the rainfall will do little for the lake or the Colorado River basin which feeds it because it’s drying out due to climate change. Although it is true that the current storm will likely do little to reverse Lake Mead’s decline in the long-term, the reason for its decline is not climate change, but instead, overuse and poor management of the reservoir.

A number of mainstream media outlets ran stories in recent days remarking on the fact that the recent atmospheric river event is dumping more water in a few days than Lake Mead, America’s largest reservoir by volume, can hold at full capacity. On February 7, for example, Newsweek, ran two stories on the heavy rains, “Bomb Cyclone To Dump More Water Than in Lake Mead on California,” and “Atmospheric Rivers Won’t Refill Lakes Mead and Powell, says expert.”

These two stories were largely straight forward reporting, the kind of honest journalism Americans used to expect from the media outlets. Newsweek did not attribute the present atmospheric river or Lake’s Mead or Powell present water levels to climate change.

Also, Lake Mead’s water levels are dominated, not by a single rainfall event, affecting areas primarily downstream of the reservoir, but by seasonal snowpack across the course of the winter which, when it melts over time, flows into the lake, its feeder streams, and Lake Powell above it, which is the primary source of stream flow feeding Lake Mead. Last season’s record snowfall on mountains of the Colorado River Basin boosted lake levels.

Courthouse News and the Missoula Current each ran stories covering a trial in which climate activists are suing U.S. Department of the Interior for setting a management plan that fails to account for the impacts of climate change, which they claim is causing lake and river levels to fall.

As detailed at Climate Realism, here, here, here, and here, for example, this is not the first time climate activists, often with the support of the mainstream media, have falsely claimed climate change has caused a precipitation decline in the Western United States, which they blame for recent declines in Lake Mead, the Great Salt Lake, and Lake Tahoe. Mismanagement is part of the story of the decline in some Western rivers, reservoirs, and lakes, but there is no evidence long-term climate change is contributing to the decline. Myriad other factors are, though.

As Newsweek reports, Lake Mead did reach its lowest measured water levels since filling in history in 2022, but it had similar low-level seasons in from 1955-1957 and again in 1964 and 1965, nearly 70 and 60 years of global warming ago, respectively, when temperatures were cooler.

The U.S. Drought Monitor reports that under 35 percent of the Colorado river basin, touching on seven states and parts of northern Mexico, is currently suffering any drought, and only approximately 3 percent of the area is suffering extreme or exceptional drought. A review of the history shows that record lake levels were recorded between 1965 and 1983, with Lake Mead remaining consistently above average through 2002, a representing a 37-year period of sustained above average water levels, even as temperatures were rising. As is noted in Climate at a Glance: Water Levels – Lake Mead, after 37 years of abundance, some decline was bound to eventually occur.

Since then, the Colorado River Basin has on average experienced below average precipitation, but it is in the arid West so that is to be expected. The U.S. drought monitor shows some years with severe, widespread drought for extended periods of time, and some years in which less than 10 percent of the basin was experiencing any drought at all. Regardless there is no clear trend of droughts of increasing intensity that would suggest climate change was causing a sustained decline in precipitation across the basin.

Since climate change can’t be shown to be contributing to Lake Mead’s decline, we must examine other factors which might, and there are many. The National Park Service (NPS) discusses two factors contributing to Lake Mead’s decline that are entirely ignored by climate alarmists: sedimentation and evaporation. Concerning evaporation, the NPS writes, “[e]vaporation in the area is extremely high and represents a significant water loss [equaling] … almost 10% of the average annual inflow.”

In addition, the NPS cites research which suggests that by 1970 the build up of sediment behind the Hoover Dam had already robbed Lake Mead of approximately 12 percent of its volume. Some of that sediment has likely compacted since then, but over the 54 years since that study study was done sediment has continued to flow into Lake Mead and accumulated, so its volume had undoubtedly shrunk even more. Sustained dredging operations would both increase Lake Mead’s volume and provide valuable, fertile soil for those who might want it.

The most important single factor in Lake Mead’s decline, however, is the tremendous growth in population for the region. Arizona and Nevada are two of the fastest growing states in the United States. The number of agricultural, urban, and industrial users of water from Lake Mead and its feeder rivers has grown tremendously in the past 30 years. More people farming in, living in and building homes, golf courses, businesses, in Arizona, California, Nevada, and Mexico, means more demand for water from Lake Mead, whether or not precipitation in the basin has declined. Since 1993:

  • Arizona’s population increased by approximately 3.44 million people;
  • Nevada has added about 1.81 million people;
  • And, California saw its population grow by about 7.82 million people.

Ever more people drawing water from the limited and variable resource that is Lake Mead, would naturally result in declining lake levels, unless the stream flow into it were dramatically increased. The latter is precluded by the fact that other states that draw water from the Colorado River, and other tributary rivers in the Colorado River Basin, have also experienced dramatic population growth, meaning there is less water flowing into Lake Mead simply because more people are taking more water out of its tributaries for more uses upstream. The largest source of water for Lake Mead is outflow from Lake Powell, yet Lake Powell is also oversubscribed and has the same problems with sedimentation and evaporation that Lake Mead does, limiting the water sent downstream to Lake Mead. Less flow in, more water withdrawn is a recipe for declining water levels.

And that’s not even counting the increase in water demand from Mexico.

Both California and the Federal government basically acknowledged in December 2023 that over withdrawal is the prime cause of Lake Mead’s declining fortunes. As reported by Fox News, “water districts representing California farmers and other major water users in the state agreed to significant cuts in exchange for hundreds of millions of dollars from the federal government.” The government estimates that this agreement by itself will result in Lake Mead rising at least 10 feet. Similar agreements with Arizona, Nevada, and Mexico would be expected to increase Lake Mead’s volume even more.

In short, myriad factors have resulted in Lake Mead’s substantial water loss. Climate Change is not among them.

The post Climate Change Is Not Behind Lake Mead’s Decline, Overuse and Poor Management Are appeared first on ClimateRealism.