You can find Part 1 here, Part 2 here and Part 3 here. Each part can be read independently, but I encourage you to start at the beginning, as each part builds on what came before.
It is known that climate change has intensified floods, storms and droughts in recent years, making them more common and severe. [emphasis, links added]
For example, a 2023 Pew Research Center poll found 84% of Americans believe climate change is making floods, storms, or droughts worse in their local communities.
It has become conventional wisdom today that climate change is the cause of the weather events we experience and see on social media. This is an obvious fact that requires little support.
As noted climate scientist Michael Mann explains, Detection of climate change is like “[turning] on television, [reading] newspaper or [looking] Step outside the window and look at what is becoming increasingly obvious to many.
Given these apparently undeniable realities, we might wonder why the Intergovernmental Panel on Climate Change (IPCC) spends so much time and effort assessing the science of detecting and attributing climate change. Well, at least to the IPCC, science still matters.
Given the widely popular beliefs and the media-friendly pundits willing to pander to them, many people are surprised, even shocked, to learn The IPCC reached the following conclusions on extreme events and climate change: Completely contradictory versus conventional wisdom and popular opinion.
According to the IPCC, The truth is, we can’t simply “look out the window” and observe climate change—even the hurricanes, floods, and droughts that fit the movie.
In fact, the current IPCC conclusion is: This century we will be unable to detect with high confidence changes beyond internal variation in most weather event statistics – This will still hold true even if the world follows the incredible RCP8.5 future predicted.
The gap between public and media opinion and scientific understanding of trends in extreme events is as wide as any I have encountered on any subject in the past 30 years.
The fact that this gap is encouraged and reinforced by many who claim climate expertise makes this issue truly unique among those where science meets policy and politics.
Let's look at the details.
In Part 3, I review the concept of “timing” of climate change signals. The IPCC explains in its latest assessment report (AR6):
In the context of human impacts on climate, the goal of emergencies research is to search for the occurrence of a signal that characterizes anthropogenic changes (defined as noise) relative to reference period climate change.
The IPCC further explains that “occurrence time” is closely related to the concept of “detecting” statistical changes in weather or climate variables, but not necessarily determining the cause of that change:
Related to the concept of emergence is the detection of change (Chapter 3). Change detection is defined as the process of demonstrating that some aspect of climate or a system affected by climate has changed in some defined statistical sense, typically using spatial aggregation methods that attempt to maximize the signal-to-noise ratio, such as “fingerprinting” (e.g. , Hegerl et al., 1996 ), but no reason for this change was provided. An identified change is detected in an observation if it is determined to have a small probability, e.g., <10% (Glossary), that it occurred by chance alone.
IPCC AR6 helpfully summarizes its conclusions on the timing of observed and predicted changes in 32 weather and climate variables, with high (90%) and medium (50%) confidence levels. The table below summarizes the IPCC's conclusions.
These conclusions represent the latest snapshot of the IPCC’s understanding of science and, like all areas of science, Assessment conclusions may change as new evidence and analysis emerge.
However, given the robustness of these findings in the context of the challenge of achieving high confidence in detecting changes, these findings are unlikely to change anytime soon.
Some key takeaways:
- You can’t look out the window and observe climate change;
- According to the IPCC, with the exception of indicators related to temperature changes, most indicators are unlikely to formally detect changes in extreme weather statistics beyond observed changes in the short term;
- Claims of hurricanes, floods and droughts are everywhere (and various other extreme cases) become more intense or frequent (regardless of the reason) These are false in the context of recorded variability;
- Many qualified experts and journalists deliberately promote misinformation related to extreme events;
- Many other experts and journalists knew better but said nothing.
Detection challenges are much greater at the scale of weather events that impact humans and ecosystems.
IPCC AR6 explains At regional and local scales, the detection and attribution of statistical trends in weather and climate variables is more difficult:
Attribution at subcontinental and regional scales is often more complex than at global scales due to various factors: a greater contribution from internal variability, increased similarity between responses to different external forcings, making it more difficult to distinguish their effects, global models The importance of some missing forcings in simulations at regional scales, and model biases related to the representation of small-scale phenomena.
The variables that the IPCC detects changing are mostly related to temperature – which will surprise many The IPCC does not claim to have high confidence in detecting precipitation changes in most regions:
The robustness of regional-scale attributions varies significantly between changes in temperature and precipitation. While the effects of anthropogenic forcing on long-term changes in regional temperature have been detected and attributed in almost all land areas, robust detection and attribution of human effects on regional precipitation changes have not yet been fully achieved in many land areas (Section 10.4.3). Although the contribution of anthropogenic forcing to long-term regional precipitation changes has been detected in some regions, reliable quantification of the contributions of different drivers remains elusive. The delayed appearance of anthropogenic precipitation fingerprints relative to temperature may be due to the opposing signals of fast and slow terrestrial precipitation forcing responses and time-varying SST variability patterns (Sections 8.2.1 and 10.4.3), stronger internal variability (Section 10.3.4.3) as well as the effects of greater observational uncertainty (Section 10.2) and model bias.
Climate science finds itself in a strange position. When it comes to extreme weather and climate, public opinion and political rhetoric has gone far beyond what data and research can support.
Climate experts face intense professional and social pressure to correct widespread misinformation about extreme weather. [weather] event.
When scientists offer corrections to this disagreement, they may be seen as downplaying the seriousness of climate change as a political issue, even if the corrections are scientifically accurate and consistent with consensus views.
This disagreement also creates a need for “research” to support false claims – Some scientists and officials have responded to these requests with flawed science and manufactured data — and get professional rewards for doing so.
at the same time, Climate experts also face significant professional and social pressure no Fixed common misinformation about extreme events.
I get it — a decade ago, when I testified before the House and Senate about the IPCC’s claims about extreme events (as I do in this series), I found myself in the crosshairs of the Obama administration, which led to led to a congressional investigation and ultimately led me to leave academia entirely.
So far, to its credit, IPCC Working Group 1 has stood firm against the pathological politicization of climate science.
This is not the case with IPCC Working Group II or the recent US National Climate Assessment. Can IPCC WG1 continue to hold up?
The Honest Broker is written by climate expert Roger Pielke Jr and is reader-supported. If you value what you read here, please consider subscribing and supporting the work.
Roger Pielke Jr. has been a professor at the University of Colorado since 2001. He holds degrees in mathematics, public policy, and political science, and is author of many books. (Amazon).
Read the break from The Honest Broker
