Climate change is highly likely to contribute to increases in the likelihood and/or intensity of high impact weather events such as droughts, hurricanes and heatwaves in certain parts of the world. Where these places are relied on by humans as places to live, for agriculture or resource production, a higher occurence of extreme events may have significant economic and social impacts.
As is described more here, climate can be defined as the average weather over long periods of time. Whilst weather over long periods therefore defines climate (and any changes to climate), changes to the climate can also impact short-term weather. In particular, local changes to sea and land temperatures have been shown to increase the probability of extreme weather events occuring in those locations; or increase the impact of extreme weather events when they do occur. Attributing the occurrence or intensity of specific weather events to climate change requires a detailed analysis of how extreme weather events are changing and an understanding the science of what is driving any changes. This allows scientists to determine whether there is any 'climate change signal' behind the occurrence and/or magnitude of an event.
In general, higher temperatures mean more energy in the atmospheric, land and ocean systems; and more energy means large-scale releases or transformation of this energy through extreme weather events occurs more often and has a higher impact when it does occur. By way of an example, hurricanes occur in specific latitudes where sea temperatures are within a particular range. Changes to sea temperatures as a result of climate change has the potential to change the distribution of sea temperatures such that: (i) the likelihood of a hurricane occurring (as a function of the environmental pre-requisites); and/or (ii) the likelihood of humans impacting humans (based on the location of their occurence); and/or (iii) the magnitude of hurricanes that do occur; increases as a result.
There are many sources of data on extreme weather events. However, one industry that is directly impacted by natural hazards is insurance, and an analysis of losses (i.e. insurance claims) resulting from natural hazards allow us to understand the changes in the magnitude and frequency of such events. For example MunichRe, an insurer, observes:
More information can be found at: World Weather Attribution and MunichRe's climate change and its consequences.
