By Ranjan Panda*
The much awaited Fifth Assessment Report of Intergovernmental Panel on Climate Change (IPCC) is out with a host of warnings about climate’s vagaries we are going to face in the coming years. It was released in Yokohama of Japan on Monday, March 31, 2014.
Called ‘Climate Change 2014: Impacts, Adaptation, and Vulnerability, this report, prepared by the Working Group II of the IPCC lists in great detail the impacts of climate change that have already occurred and the future risks from climate change. It also talks about measures needed to reduce these risks. Here, in this piece, we are giving a general description of the likely impacts mostly on water resources and food security due to climate change as dealt by the said report.
Climate change in the 21st century is projected to reduce renewable surface water and groundwater resources significantly in most dry subtropical regions, intensifying competition for water among sectors, says the report. In areas which are known as dry regions, the frequency of drought is likely to increase by the end of the 21st century. In contrast, water resources are projected to increase at high latitudes.
Drinking water quantity and quality to be badly affected –
Drinking water supplies the world over would be affected badly as climate change would reduce the quality of raw water and conventional treatment methods are most likely to fail due to interacting factors such as increased temperature; increased sediment, nutrient and pollutant loadings from heavy rainfall; increased concentration of pollutants during droughts and disruption of treatment facilities during floods.
Species at risk –
A large number of both terrestrial and freshwater species face increased extinction risk due to the projected climate change during and beyond the 21st century. This is especially as climate change interacts with other stressors, such as habitat modification, over-exploitation, pollution, and invasive species. Many species, the report says, will be unable to track suitable climates under mid- and high-range rates of climate change during the 21st century. While some species will adapt to new climates, those that cannot adapt sufficiently fast will decrease in abundance or go extinct in part or all of their ranges.
Ecosystems at threat –
According to the report, within this century, the magnitude and rate of climate change associated with medium-to high-emission scenarios pose high risk of abrupt and irreversible regional-scale change in the composition, structure, and function of terrestrial and freshwater ecosystems, including wetlands. Examples that could lead to substantial impact on climate are the boreal-tundra Arctic system and the Amazon forest. Carbon stored in the terrestrial biosphere (e.g., in peatlands, permafrost, and forests) is susceptible to loss to the atmosphere as a result of climate change, deforestation, and ecosystem degradation. Increased tree mortality and associated forest dieback is projected to occur in many regions over the 21st century, due to increased temperatures and drought. . Forest dieback poses risks for carbon storage, biodiversity, wood production, water quality, amenity, and economic activity.
Watch the Sea, it’s going to bring many woes –
Due to sea-level rise projected throughout the 21st century and beyond, coastal systems and low-lying areas will increasingly experience adverse impacts such as submergence, coastal flooding, and coastal erosion. This is almost certain. The population and assets projected to be exposed to coastal risks as well as human pressures on coastal ecosystems will increase significantly in the coming decades due to population growth, economic development and urbanization. The relative costs of coastal adaptation vary strongly among and within regions and countries for the 21st century. Some low-lying developing countries and small island states are expected to face very high impacts that, in some cases, could have associated damage and adaptation costs of several percentage points of GDP.
Marine-species redistribution and marine-biodiversity reduction in sensitive regions will challenge the sustained provision of fisheries productivity and other ecosystem services. Species richness and fisheries catch potential are projected to increase, on average, at mid and high latitudes and decrease at tropical latitudes.
The progressive expansion of oxygen minimum zones and anoxic “dead zones” is projected to further constrain fish habitat. Climate change adds to the threats of over-fishing and other non-climatic stressors, thus complicating marine management regimes. Ocean acidification will also pose severe problems for both fisheries and livelihoods.
Impact on food security and food production systems –
For the major crops (wheat, rice, and maize) in tropical and temperate regions, climate change without adaptation is projected to negatively impact production for local temperature increases of 2°C or more above late-20th-century levels, although individual locations may benefit. Projected impacts vary across crops and regions and adaptation scenarios, with about 10% of projections for the period 2030-2049 showing yield gains of more than 10%, and about 10% of projections showing yield losses of more than 25%, compared to the late 20th century. After 2050, the risk of more severe yield impacts increases, and depends on the level of warming.
Climate change is projected to progressively increase inter-annual variability of crop yields in many regions. These projected impacts will occur in the context of rapidly rising crop demand. All aspects of food security are potentially affected by climate change, including food access, utilization, and price stability (high confidence). Redistribution of marine fisheries catch potential toward higher latitudes poses risk of reduced supplies, income, and employment in tropical countries, with potential implications for food security. Global temperature increases of ~4°C or more above late-20th-century levels, combined with increasing food demand, would pose large risks to food security globally and regionally. Risks to food security are generally greater in low-latitude areas.
The Odisha connection –
Even though we have written this article by way of general description without touching on any specifics of the negative impacts climate change will have on India or Odisha, the trends show that Odisha will continue to be a hot bed of such impacts. A general assessment of the report tells us that droughts and desertification, water scarcity, reduced fish diversity and production, food insecurity, degradation in water quality, cost of adapting to sea level rise and other disasters, etc. will increase further making the state further vulnerable. Odisha has to reinvent its design of development and reduce mining, deforestation and craze for coal fired power plants to prevent such a possibility.
* Ranjan Panda is the Convenor, Water Initiatives Odisha, INDIA Mahanadi River Waterkeeper (Member, Waterkeeper Alliance, New York