People around the world are faced with the challenge of adapting to changing climatic conditions, but what happens when small changes are not enough or are not even possible? Nick Brooks, Director of Garama 3C Ltd makes the case for transformational adaptation.
Most of today’s adaptation interventions involve incremental approaches intended to protect and sustain existing systems and practices, rather than transformational adaptation that seeks to replacing failing systems with new ones that are better suited to emerging or expected climatic conditions. Indeed, many do not even go as far as incremental adaptation, instead addressing the so-called ‘adaptation deficit’, or the gap between current practice and what is sustainable under existing conditions.
A key question for adaptation in the 21st century is where, and when, the limits to incremental approaches might be encountered.A key question for adaptation in the 21st century is where, and when, the limits to incremental approaches might be encountered. This might occur as a result of the local manifestations of climate change being so severe and/or rapid that societies simply cannot adapt, or as a result of relatively small changes meaning that systems or activities that are already marginal are no longer viable.
One type of change that might require transformational adaptation is a transition to hyper-aridity, as occurred throughout the northern hemisphere sub-tropics during the last global climatic reorganisation between about 6,000 and 5,000 years ago. Such a transition might already be underway in the US Southwest, and is suggested – at least as a possibility – by climate projections for parts of North Africa and the eastern Mediterranean, and parts of southern Africa.
According to the United Nations Statistics Division, Tunisia, Israel and Jordan already use 70%, 80% and 92% respectively of their annual total renewable surface water resources every year, through runoff capture and abstraction from non-renewable aquifers.
Projected changes in temperature and rainfall mean that total renewable surface water availability may decline below current usage in the latter half of the 21st century. Clearly, current water management regimes and agricultural systems would not work under such a scenario, and different economic and production models would be required in the event of such a transition.
a 2005 study raises the possibility of a shift to hyper-aridity in the Greater Kalahari regionIn southern Africa, climate projections indicate severe drying in the far south west, while a 2005 study by researchers at the University of Oxford raises the possibility of a shift to hyper-aridity in the Greater Kalahari region, as fossil dunes that are currently stable become mobile due to changes in rainfall and wind regimes and the disappearance of vegetation. Such a transition would place the viability of existing agricultural and livestock systems in doubt, potentially requiring a shift to new activities and/or the abandonment of certain areas. Aridity is likely to intensify in many other parts of the world, including parts of southern Europe, Australia and central Asia.
the combination of temperature and humidity in the region around the Arabian Gulf is likely to approach or exceed the limits of human survivability within the 21st centuryIncreases in aridity will be driven as much by changes in temperature and evapotranspiration as by changes in rainfall. However, aridity is not the only impact of higher temperatures. A recent paper in the journal Nature Climate Change concluded that the combination of temperature and humidity in the region around the Arabian/Persian Gulf is likely to approach or exceed the limits of human survivability within the 21st century, making it physically impossible for people to live there in the hottest months.
The other obvious context in which transformational adaptation might be required is sea-level rise, which will increase disaster risk, potentially to the point at which the costs of defences or reconstruction becomes unfeasible, leading to the abandonment of coastal areas. Ultimately, sea-level rise will simply wipe out some coastal areas, as they disappear under rising waters. The intrusion of salt water into coastal aquifers due to sea-level rise and subsidence resulting from the abstraction of groundwater will lead to changes in coastal ecosystems and challenge coastal agriculture.
A combination of rising temperatures and declining rainfall may make certain crops unviableA combination of rising temperatures and declining rainfall may make certain crops unviable. A recent study identified areas in which nine existing sub-Saharan Africa crops might become unviable due to climate change under current management regimes, starting in the 2020s for the most at-risk crops. This study suggested replacing existing crops with alternative crops as a ‘transformational adaptation’ measure that was feasible in most (but not all) contexts.
smallholders deploy a host of measures to produce crops in highly marginal environments that might be technically ‘unviable’ by the criteria used in modelling studiesThe above examples suggest the existence of thresholds of change beyond which existing systems and practices are existentially challenged. Climate vulnerability and risk assessments (VRAs) need to start considering what these thresholds might be, and where and when they might be breached. However, such thresholds are not fixed, and might be ‘pushed back’ by incremental adaptation measures, meaning that transformational adaptation can be delayed or avoided. Modelling studies might also be overly simplistic in their representations of what is viable and what is not, particularly when it comes to agriculture. For example, smallholders deploy a host of measures to produce crops in highly marginal environments that might be technically ‘unviable’ by the criteria used in modelling studies.
Transformational adaptation as defined above (i.e. abandoning or replacing existing systems on the grounds that they are not viable under climate change) may be hugely challenging, and in many cases will face huge obstacles, including the likely creation of winners and losers. It is not a panacea, and should not be proposed as a universal solution. Nonetheless, it should be on the radar of planners and decision-makers, and should be explicitly considered in VRAs and the design of adaptation strategies.
Transformational adaptation may not be needed everywhere, but in some places it will be absolutely essential to our survival.Climate projections suggest a global average surface warming of around 4°C by the end of the century, relative to the pre-industrial average. This warming is very similar in magnitude to the warming that occurred between the end of the last ice age, some 21,000 years ago, and the beginning of the current interglacial period around 10,000 years ago. But it is happening some hundred times faster. The world of the past 10,000 years has looked very different to that of the last glacial period. It is inconceivable that a similar warming, over a much (indeed, ridiculously) shorter period, will not reshape the face of the Earth in ways that we have only just begun to comprehend. Transformational adaptation may not be needed everywhere, but in some places it will be absolutely essential to our survival.
A longer version of this article can be found on the Garama website. Nick Brooks can be contacted at nb@garama.co.uk
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