Weather and Climate Revisited

I have been a persistent critic of the Hochul Administration’s consistent linking of any extreme weather event to climate change as rationale for the Climate Leadership & Community Protection Act (Climate Act).  In my articles responding to the claims I explain that according to the National Oceanic and Atmospheric Administration’s National Ocean Service “Weather reflects short-term conditions of the atmosphere while climate is the average daily weather for an extended period of time at a certain location.”  The referenced article goes on to explain “Climate is what you expect, weather is what you get.”  This post is in respond to a friend who says that he has “grappled with this statement in the past, but still don’t fully understand it”

I have followed the Climate Act since it was first proposed, submitted comments on the Climate Act implementation plan, and have written over 400 articles about New York’s net-zero transition. The opinions expressed in this post do not reflect the position of any of my previous employers or any other organization I have been associated with, these comments are mine alone.

Overview

The Climate Act established a New York “Net Zero” target (85% reduction in GHG emissions and 15% offset of emissions) by 2050.  It includes an interim 2030 reduction target of a 40% reduction by 2030 and a requirement that all electricity generated be “zero-emissions” by 2040. The Climate Action Council (CAC) is responsible for preparing the Scoping Plan that outlines how to “achieve the State’s bold clean energy and climate agenda.”  In brief, that plan is to electrify everything possible using zero-emissions electricity. The Integration Analysis prepared by the New York State Energy Research and Development Authority (NYSERDA) and its consultants quantifies the impact of the electrification strategies.  That material was used to develop the Draft Scoping Plan outline of strategies.  After a year-long review, the Scoping Plan was finalized at the end of 2022.  In 2023 the Scoping Plan recommendations were supposed to be implemented through regulation, PSC orders, and legislation.  Not surprisingly, the aspirational schedule of the Climate Act has proven to be more difficult to implement than planned and many aspects of the transition are falling behind.  In order to keep the public’s support for the transition the Hochul Administration links recent extreme weather events to climate change.

Weather vs. Climate

The link between extreme weather and climate is commonly made by the mass media egged on by climate activists.  In response I have a page devoted to rebuttals to these claims.  I also have another page addressing climate change attribution.  I have noted that the standard climatological average is 30 years.  In order to think about a change in today’s climate averages you really should compare the current 30 years against the previous 30 years.  In order to get a trend, you need to look at as much data as possible.  On the face of it that might seem easy but the reality is that the conditions for a representative trend are difficult to achieve.  Ideally you need to use the same instruments, the same methodology, and keep the conditions around the observing location the same.

My reader friend still doesn’t understand why I am so dismissive of these claims. He wrote:

Perhaps there is a different way for you to say it that I will understand.    It seems reasonable to conclude that an individual weather event can be plausibly linked to a changing climate, if the question can be asked: “But for ____  ______,   would this have happened?”  

I think that laypeople have heard the narrative that climate change is affecting weather today so often that it “seems reasonable that an individual weather event can be plausibly linked to a changing climate”.   When I did a search on the term “what conditions can impact the weather” all that came up were articles arguing that there is a link.  This story is everywhere so the presumption that there is a plausible link is logical.  I show why that is wrong below.

My Response

I have given some thought to his perception relative to mine.  For the record, I have a BS and a MS in meteorology, have been working in the field for 50 years, but have limited forecasting experience because my emphasis has been air pollution meteorology.  I think that as a result of my background I know what is involved with weather forecasting and when I weigh all the parameters affecting a weather event relative to the limited effects associated global warming, I dismiss claims that climate change can cause any weather events.  There might be a tweak in the observed observations but that is all.

Let me explain by considering what is involved with a weather forecast.  Weather.US lists results from different weather forecast models.  This link provides a response to the question what are weather forecast models?:

Numerical Weather Prediction

Weather models, known formally as “Numerical Weather Prediction” are at the core of modern weather forecasts. All the forecast information you see at weather.us is powered by weather models, do what are they and how do they work?

Weather models are simulations of the future state of the atmosphere out through time. Millions of observations are used as initial conditions in trillions of calculations, producing a three dimensional picture of what the atmosphere might look like at some time in the future. Massive computers are used to do these calculations at incredibly fast speeds to enable simulations to cover the entire globe, and extend up to two weeks into the future.

Global vs Regional models

There are two general types of weather models, global models and regional models. Global models produce forecast output for the whole globe, generally extending a week or two into the future. Because these models cover a wider area, and a longer timespan, they’re generally run at a lower resolution, both spatially (fewer forecast points per given area) and temporally (fewer time points get a forecast).

Regional models on the other hand have much higher resolutions, but only cover some part (region) of the globe, and only provide forecasts a couple days out in time. The advantage with these models is that their higher resolution lets them “see” features that the global models miss, most notably including thunderstorms.

Why are there so many models and how are they different?

Many different national weather centers have supercomputers that run weather models. Each of these is slightly different, using different equations to solve for various physical processes that shape our weather patterns. Many of them also have slightly different resolutions, and use slightly different combinations of initial data sources.

These slight differences multiply out through time because the atmosphere is a chaotic system. This also means any errors that the models make in the near term become exponentially larger with time. This is why the forecast for a week from now is far less accurate than the forecast for tomorrow.

Weather modelling centers attempt to control for the influence of chaos by running ensemble systems that each use slightly different initial conditions. Each ensemble “member” then produces a forecast as if its set of initial conditions were correct. This provides some way of quantifying how likely a given forecast outcome is, helping to show forecast uncertainty.

My education and background included an emphasis on measuring parameters that affect weather forecasts.  The discussion above notes that models start with initial conditions that are based on these meteorological variables.  The World Meteorological Organization Measurement of Meteorological Variables report describes measuring techniques for the following parameters that all affect weather forecasts:

• Present weather
• Past weather
• Wind direction and speed
• Cloud amount
• Cloud type
• Cloud-base height
• Visibility
• Temperature
• Relative humidity
• Atmospheric pressure
• Precipitation
• Snow cover
• Sunshine and/ or solar radiation
• Soil temperature
• Evaporation

Keep in mind that the initial conditions must not only include the surface observations but also observations of wind, temperature, and humidity in layers above ground.  As noted above, there are many different types of forecasts and the use of these parameters is determined by the type of forecast.  For example, if I was forecasting the impacts of air pollution within 50 miles of a source, I would not be concerned about soil temperature and evaporation. 

In this response I am addressing whether individual extreme weather events (less than a week) can be linked to climate change associated with the greenhouse gas (GHG) effect.  Increased GHGs reduces long-wave radiation (earth surface temperature) creating warming.  No weather forecast model incorporates long-wave radiation measurements because the variation is so small over a week.  Claims that climate change is affecting weather events associated with the GHG effect presume that there is warming that affects the events. 

Given all the parameters that affect weather forecasts I do not think that a tweak in temperature can be linked to the cause of a specific event for two reasons.  The first is that the temperature effect associated with the greenhouse effect is only of many parameters associated with weather events and I don’t think it has a high impact on extreme events.  The second reason is related to the discussion above about the chaotic atmosphere.  It states that “Weather modelling centers attempt to control for the influence of chaos by running ensemble systems that each use slightly different initial conditions.”   The change in atmospheric radiation due to GHG emissions is smaller than the initial conditions variation.

Given my lack of forecasting experience it is appropriate to consider another source.  Presumably climate change would have the greatest impact on heat wave.  Dr. Cliff Mass describes the effect of global warming on the Pacific Northwest Heatwave of 2021.  His synopsis:

Society needs accurate information in order to make crucial environmental decisions. Unfortunately, there has been a substantial amount of miscommunication and unscientific handwaving about the recent Northwest heatwave, and this blog post uses rigorous science to set the record straight. First, the specific ingredients that led to the heatwave are discussed, including a high-amplitude ridge of high pressure and an approaching low-pressure area that “supercharged” the warming. Second, it is shown that global warming only contributed a small about (1-2F) of the 30-40F heatwave and that proposed global warming amplification mechanisms (e.g., droughts, enhanced ridging/high pressure) cannot explain the severe heat event. It is shown that high-resolution climate models do not produce more extreme high temperatures under the modest global warming of the past several decades and that global warming may even work against extreme warming in our region. Importantly, this blog demonstrates that there is no trend towards more high-temperature records. Finally, the communication of exaggerated and unfounded claims by the media, some politicians, and several activists are discussed.

Conclusion

The premise that it seems reasonable in the statement “It seems reasonable to conclude that an individual weather event can be plausibly linked to a changing climate, if the question can be asked: ‘But for ____  ______,   would this have happened?’  “ is flawed.  The greenhouse effect is only one of many parameters affecting weather and the change in atmospheric radiation due to GHG emissions is smaller than the initial conditions variation used to address chaotic atmospheric conditions means that there is no provable link.  The suggestion that climate change causes unusual weather events ultimately is an unfalsifiable hypothesis because no test can ever show that it is not real because it cannot be detected.