Skepticism, Science & Pseudoscience

There continues to be insufficient evidence and thus low confidence for consistent trends in the magnitude or frequency of floods on a global scale.

New results indicate that the AR4 conclusions regarding global increasing trends in hydrological droughts since the 1970s are no longer supported. Not enough evidence exists at present to suggest anything else than low confidence in observed large-scale trends in dryness (lack of rainfall), due to lack of direct observations, dependencies of inferred trends on the index choice and geographical inconsistencies in the trends.

Recent re-assessments of tropical cyclone data do not support the AR4 conclusions of an increase in the most intense tropical cyclones or an upward trend in the potential destructiveness of all storms since the 1970s. There is low confidence that any reported long-term changes are robust, after accounting for past changes in observing capabilities. However over the satellite era, increases in the intensity of the strongest storms in the Atlantic appear robust.

There is still insufficient evidence to determine whether robust global trends exist in small-scale severe weather events such as hail or tornadoes.