Impacts of Increased Climatic Variability

Introduction

There is ample evidence that climatic variability is increasing and this has profound implications on the global food supply. Water resources are most sensitive to these changes and conventional concepts of flood return frequency and drought forecasting need major rethinking. The anticipated changes in climatic variability are not only due to climate warming but are equally influenced by land use changes that have a pronounced impact on the hydrological cycle.

Evidence of Increased Variability

There is considerable evidence that extreme events are increasing. More attention has to focus on the sequences of climatic events such as heatwaves, followed by wildfire, followed by floods. Evidence for this are provided below by the 2021 event in British Columbia and a similar event in Australia and Mississippi in2022.  Also, the magnitude of extreme event is also increasing as show by examples from New Zealand and Australia in 2022/2023.

Since seven key countries produce more than half of the global export of key food items, increased climatic variability will have a profound impact on global food supplies. There is already significant evidence that an individual climatic event, or a major conflict in any one of these countries could have a global impact. This was documented in four examples that include the 2003 hot summer in France, the 2010 heat wave in Russia, the extended drought followed by two excessive floods in Australia, followed by the drought in Texas, an a extensive flood in Thailand and the conflict in the Ukraine. All of these countries are major food exporters and as will be shown later, these events create highly volatile conditions on global food supplies and prices.