In its alarmism, mass media ignores IPCC findings to deliberately spread climate misinformation
By Roger Pielke Jr., August 23, 2022, The Honest Broker
According to a poll conducted in late 2021, “Ninety-five percent of Americans believe the spread of misinformation is a problem.” As I have documented for more than a decade, public representations in the major media of the relationship of climate change and disasters is chock full of misinformation. What makes this issue fairly unique is the role played by journalists and some scientists in helping to spread that misinformation, while ignoring peer-reviewed science and consensus assessments.
Today’s post is organized into three sections: (1) What the most recent reports of the Intergovernmental Panel on Climate Change (IPCC) and U.S. National Climate Assessment (NCA) say about floods, (2) trends in the societal impacts of flooding, specifically damage, deaths and people affected, and (3) what the most recent literature says about flooding and its impacts into the future.
What the IPCC and U.S. NCA say about flooding
In summary there is low confidence in the human influence on the changes in high river flows on the global scale. In general, there is low confidence in attributing changes in the probability or magnitude of flood events to human influence because of a limited number of studies, differences in the results of these studies and large modelling uncertainties.
That means that the IPCC does not have confidence in overall trends in flooding. It also means that the IPCC similarly does not have confidence that the “probability or magnitude of flood events” can be attributed to climate change.
The IPCC could not be more clear.
Let’s contrast what the IPCC says with a few recent media reports:
- NPR: “How climate change drives inland floods” (shown also at the top of this post)
- The Washington Post: “both drought and flooding are closely tied to human-driven warming”
- New York Times: “When it comes to river floods, climate change is likely exacerbating the frequency and intensity of the extreme flood events”
The three articles have in common a common feature: each ignored the consensus conclusions of the most recent IPCC report. The New York Times article is particularly egregious in that the cited passage alleging increasing floods does not actually refer to historical observations, but instead to a study projecting future flooding under the infamous RCP8.5 scenario. Don’t get me started.
The IPCC — which deserves a lot of kudos for this — explicitly warnedagainst associating increases in extreme rainfall (even if attributed to human causes) with flooding caused by climate change:
Attributing changes in heavy precipitation to anthropogenic activities (Section 11.4.4) cannot be readily translated to attributing changes in floods to human activities, because precipitation is only one of the multiple factors, albeit an important one, that affect floods.
The lack of direct relationship between extreme precipitation and flooding is something that we were among the first to document empirically more than 20 years ago.
U.S. flooding not linked to human climate forcing
And there is more that may be surprising — In the United States, according to the U.S. NCA, it is not even appropriate to attribute an increase in extreme precipitation to climate change (emphasis added in the below).
The complex mix of processes complicates the formal attribution of observed flooding trends to anthropogenic climate change and suggests that additional scientific rigor is needed in flood attribution studies. As noted above, precipitation increases have been found to strongly influence changes in flood statistics. However, in U.S. regions, no formal attribution of precipitation changes to anthropogenic forcing has been made so far, so indirect attribution of flooding changes is not possible. Hence, no formal attribution of observed flooding changes to anthropogenic forcing has been claimed.
The casual attribution of heavy rains to climate change and then by extension any associated flooding to climate change is like catnip for the media (see here and here). However, such claims are not supported by consensus scientific assessments.
The bottom line from these recent consensus assessments is clear:
- Flooding has variously increased and decreased over different time periods in different places around the world (including the U.S.), but no overall trend has been detected.
- In the absence of an overall increase (or decrease) there is no trend to be explained, hence attribution of flooding to climate change has not be achieved.
Finally, despite evidence for increases (in some places) in extreme precipitation attributable to climate change, the IPCC is explicit that this cannot be extended to flooding. And in the U.S., the NCA is explicit that attribution to climate change of detected increases in extreme precipitation in some regions is “not possible.”
The original version of this article is available on The Honest Broker website.