From IPCC report &quot;Climate Change 2013: The Physical Science Basis&quot; chapter 2:<p>&quot;In summary, there continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and&#x2F;or frequency of floods on a global scale.&quot; (2.6.2.2)<p>&quot;In summary, the current assessment concludes that there is not enough evidence at present to suggest more than low confidence in a global-scale observed trend in drought since the middle of the 20th century, owing to geographical inconsistencies in the trends.&quot; (2.6.2.3)<p>It&#x27;s <i>not</i> as simple as more energy -&gt; more chaotic weather -&gt; more severe floods and droughts. Unlike other parts of global warming, many changes in extereme events are hypothetical and unsettled. (For floods, we are not sure of <i>sign</i>!)