guest column :Achieford Mhondera
CLIMATE change is an environmental problem of potentially devastating proportions. It is evident that climate change has the potential to bring huge insecurity over food and water availability and also a cause of large-scale human displacement as in the case of Cyclone Idai in 2019.
Climate change can be a “threat multiplier” by bringing political, social and economic instability particularly in developing and most fragile states. An increasingly deteriorating environment and climate change is resulting in far more than stress on food and agricultural products, floods and droughts and water scarcity as it catalyses societal insecurity that may result in conflicts of different forms and magnitude. One area where climate change can amplify existing tensions or create new ones is in the area of shared river systems and fresh water supplies.
As the changes in climatic conditions can potentially alter water supplies and demand pattern, sharing of scarce water resources of shared rivers systems such as border marks and village boundaries will become the most likely security challenges in the near future.
Scientific evidence on climate change has been able to offer a basic understanding of how the hydrological cycle will change globally, but the predictions of water demand and supplies at the regional and basin level is still far from reaching a consensus.
However, it is a fact that the projected impacts of global climate change over fresh water and shared river systems may be huge and marked, but they will not take shape on the same scale in each and every geographical region.
Even within an international river basin such as the Nile, the Zambezi and Congo basins, the effects will vary depending on the location.
This ultimately enhances the uncertainties and anxieties over the water availability in the shared river systems.
Unfortunately, in face of all these, most water laws and policies are inadequate to meet the challenges posed by climate change or to additional consequences that appear to be inevitable.
Water-sharing arrangements between most countries which share international rivers such as Zimbabwe and Zambia as well as communities along rivers such as Save, Runde among others in most cases provide some mechanism to adjust to the run-off variability while agreeing on allocation of fixed quota of water.
In most cases, the regular water-sharing agreements tend to be based upon the assumption that any resulting shortages will be temporary, hence addressing the issue with temporary reallocation methods.
However, climate change does not only bring long-term increases or decreases to the average run-off of the river system, it can also influence the variability of those flows that require flexibility to be the part of the water- sharing framework to cope with emerging situations.
As climate change brings long-term changes to the volume and pattern of run-off in shared river systems, it is significant to examine the suitability of existing agreements to address this challenge. Changes which are related to climate change might require comprehensive adjustments in the ongoing water management structure of shared river systems.
There is no doubt that climate change poses extreme challenges to water resource management in shared river basins. This can be induced by extreme weather events, water shortages and changing sea levels.
While the significance of adjustment of flow variability in water sharing is crucial, many of the existing provisions within agreements are not adequate enough to meet scenarios that climate change models project.
They lack enforcement and are generally dependent upon ideal riparian behaviour in case of eventuality.
However, this approach may overcome run-off deficits in the short term, but climate change poses the risk of long-term flow reduction that would severely test existing provisions.
Undoubtedly, climate change is a major threat to humankind, which needs to be confronted by cooperative efforts, not by confrontational behaviour. This must also apply to water governance in shared river systems.