How to deny climate change using the IPCC report » Yale Climate Connections

The new Department of Energy secretary, Chris Wright, until recently was the CEO of Liberty Energy, the nation’s second-largest fracking firm. In 2024, the firm published a manifesto called “Bettering Human Lives,” in which Wright makes a provocative statement that would be reassuring – if only it were true:

“Another thing that we often hear about climate change is that it leads to a significant increase in extreme weather events with deadly consequences. This claim is false. Extensive reports from the Intergovernmental Panel on Climate Change (IPCC) actually show no increase in the frequency or intensity of hurricanes, tornadoes, floods, or weather-related droughts,” Wright wrote in a CEO letter introducing the report.

The IPCC is a U.N. body with the job of providing information about climate science to governments. Thousands of scientists volunteer to contribute to its reports, which are published every five to seven years.

Wright’s claim about what the IPCC says is effectively rebutted by atmospheric scientist Jim Kossin, one of the lead authors of the IPCC report, in the video below by Peter Sinclair, a former Yale Climate Connections contributor.

“We have high confidence that extreme precipitation events are increasing in intensity and frequency and that human actions are playing a substantial role,” Kossin says in the video. Even for drought, where the science is somewhat less certain, “We still have good confidence that drought extremes are increasing and that human actions are playing a role,” Kossin adds.

Understanding the limitations of the IPCC report

The IPCC report is considered the gold standard of climate change information because it is the result of a years-long assessment process by hundreds of the world’s top climate scientists, who subject it to a rigorous review. However, the IPCC report can be exploited by those with vested interests against acting on climate change. Here are four ways to do so:

1. Quote only from the Summary for Policymakers. This overarching summary, which generates the most attention, is not just a scientific document. It is also political, requiring unanimous line-by-line approval by all 195 nations involved, including petrostates such as Saudi Arabia and Russia. These nations have been accused of watering down the scientific content of the Summary for Policymakers for political reasons. Thus, if your goal is to mislead people, it’s best to ignore the main body of the report, which is unadulterated by a political review.
2. Ignore new research and quote from older IPCC findings. The IPCC report is published only every six years or so, and there is a cutoff period for how recently published research can be included. In a fast-moving field like climate change science, much of the IPCC report is out of date by the time it is published. So if there is new research showing a more definitive climate change effect, you can ignore it and quote from out-of-date science.
3. Use uncertainty to your advantage. The IPCC document is very conservative in its assessments, requiring a high level of consensus from multiple scientific papers before concluding a human-caused climate influence is involved. Since there is usually a fair degree of uncertainty in a finding, you can use that as an excuse to delay action.
4. Selectively cherry-pick the results. This is the technique that Wright uses. The IPCC report is long and complex, and it is possible to cherry-pick from it to support many different views. Thus, in a narrow sense, you can dip into the report to find statements supporting Wright’s contentions. For example, with respect to tropical cyclones (which include hurricanes), the latest IPCC report says: “data limitations inhibit clear detection of past trends on the global scale.” But the same document also has a statement contradicting Wright: “Human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heat waves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has strengthened.”

And in reality, here’s what the 2023 IPCC Synthesis Report Summary for Policymakers concludes:

“Climate change is a threat to human well-being and planetary health (very high confidence). There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all (very high confidence).”

What the 2021 IPCC Summary for Policymakers says about tropical cyclones

The 2023 IPCC Summary for Policymakers does not say much about tropical cyclones, a name for a category of storms that includes hurricanes and typhoons. It supports Wright’s assertion that tropical cyclones are not becoming more frequent but says they are getting more intense in some respects — in contradiction to his claim. Here is the Summary for Policymakers‘ main points:

1. The strongest storms are getting stronger. “It is likely that the global proportion of major (Category 3-5) tropical cyclone occurrence has increased over the last four decades.”
2. Typhoons are moving northward. “The latitude where tropical cyclones in the western North Pacific reach their peak intensity has shifted northward (very likely).
3. We can’t tell if the frequency of global tropical cyclones is changing. “There is low confidence in long-term (multi-decadal to centennial) trends in the frequency of all-category tropical cyclones.”
4. We know that tropical cyclones are dumping more rain, even though satellite records of the storms date back only a few decades. “Event attribution studies and physical understanding indicate that human-induced climate change increases heavy precipitation associated with tropical cyclones (high confidence), but data limitations inhibit clear detection of past trends on the global scale.” (Event attribution studies enable scientists to calculate the probability that climate change made a specific weather event more intense.)

There is more detail on tropical cyclones in Chapter 11 of the IPCC report, “Weather and Climate Extremes in a Changing Climate.” The chapter explains that the lack of confidence in seeing trends “should not be interpreted as implying that no physical (real) trends exist,” but rather that the historical record is not good enough to see the trends, particularly since natural variability is so high. Here are the additional main points on tropical cyclones:

1. Changes in tiny particles known as aerosols, which come primarily from air pollution, are very likely responsible for the recent increase in active hurricane seasons in the North Atlantic, North Pacific, and Arabian basins, but the role of human-emitted climate-warming gases is uncertain.
2. It is more likely than not that the slowdown of the translation speed – the movement of the center of the storm – of tropical cyclones over the U.S. is partially due to human-caused effects. This slowdown increases the damage potential of storms, since they can dump more rainfall and subject infrastructure to a longer period of high winds and storm surge.
3. The global frequency of rapid intensification events has increased over the past 40 years (and is likely partially due to human-caused effects). Rapid intensification means that a tropical cyclone suddenly strengthens significantly, which is dangerous because it leaves people with little time to prepare.
4. There is high confidence that human-caused climate change contributed to extreme rainfall amounts during 2017’s Hurricane Harvey and other intense tropical cyclones.

As for misleading claims about what we know about tornadoes, floods, and droughts, see these guides from our archives:

Bob Henson contributed to this post.