Daily Archives: November 7, 2019

Sea Level Rise & Food Security

Today, nearly a third of the global population is food insecure.

The United Nations defines the four pillars of food security as:

  1. The availability of sufficient quantities of food of appropriate quality, supplied by domestic production or imports
  2. Access by individuals to adequate resources for acquiring appropriate foods for a nutritious diet
  3. Utilization of food through adequate diet, clean water, sanitation, and health care to reach a state of nutritional well-being where all physiological needs are met
  4. Stability, because to be food secure, a population, household or individual must have access to adequate food at all times

350 year old Cornfield in the Chesapeake Bay submerged in salt water like never before. South Florida, North and South Carolina, and Louisiana have each reported that SLR has threatened wetlands in low lying areas and that SLR has disturbed groundwater and vegetation dynamics.

Climate change threatens each pillar of food security. Without immediate climate action, global food insecurity is only going to worsen. Food security, especially in low lying coastal areas and small islands, is intrinsically tied to climate change and sea level rise (SLR). Sea level rise serves as a threat amplifier, especially in regions of the world with dense coastal populations and heavy reliance on coastal agricultural infrastructure.

Global average SLR is the most confidently predicted climate change threat. Mainstream media tends to center its coverage and reporting on the impact of SLR on coastal inundation and extreme weather events. This is fair: entire communities face the threat of hurricanes, tidal waves, and erosion, and are rapidly being forced to consider their options to protect their resources, adapt to the threat, or retreat from the coast. By 2100, our world will watch many communities, even nations, disappear entirely. However, climate change and SLR threaten our world in another, systemic fashion: food security.

As the impacts associated with SLR worsen (e.g., erosion, land loss, flooding, salinization, extreme weather events, cascading impacts), and as patterns of tropical and extratropical cyclones, rising air and sea temperatures, and changing rainfall patterns continue, the stability of our food systems will crumble. Coastal communities who are highly vulnerable to SLR will see the greatest change in agricultural patterns— mainly, salt-water intrusion and increased soil salinity, coupled with floods and waterlogging from increased intensity and frequency of extreme weather events. Small farming communities in warming coastal regions will feel the greatest strain on food security.


Caption: The global impact of climate change on crop productivity will be significant. This simulation demonstrates the change in yield of 11 crops by 2050 averaged across green house gas emissions scenarios.

According to the FAO, the Asia-Pacific region is especially vulnerable to impacts of SLR and severe weather events on food security—today the Asia Pacific region houses more than half of the world’s undernourished people (about half-a-billion). Studies project that Bangladesh will experience a 15.6% reduction in rice yield as a result of increased soil salinity in coastal areas. Vietnam has also reported a decrease in agricultural production stemming from the impact of strong storm surge, rising temperature, and variability in rainfall pattern.


“Due to sea-level rise, salt water can intrude 30 to 40 kilometers inland, followed by high water levels in the riverbeds and increased sedimentation in canals and flooded plains”

Speaking specifically to small island nations, climate change and SLR will have an especially dire impact on local food security. Communities that rely on seafood as a primary source of protein will see adverse impacts as a result of sea warming and acidification. These changes impact the migratory and mating patterns of fish, threatening the viability of fisheries that communities have long depended on. Moreover, the most recent IPCC report on the Ocean and Cryosphere in a Changing Climate predicts a significant reduction in the biomass of marine animals across the food web, as well as a reduction in maximum catch size potential of fisheries. The IPCC predicts that the decrease in seafood availability will have significant impact on Small Island Developing states.

SLR also poses the threat of saltwater incursion into existing agricultural lands in small islands and coastal communities. Changes in precipitation patterns combined with sea level rise will impact soil salinization and agricultural production, which will result in diminished food and water security. Wetlands are complex, eco-hydrological environments where ground and surface water interact with climate, tidal influence, topography and vegetation. SLR interrupts this relationship, resulting in abnormal soil salinity and vegetation shifts. Overall, studies have found that crop productivity is expected to decrease in low latitude and tropic regions with local land and sea temperature increases.


In Southeast Asia, the issue of food security is crucial. The region expects the middle class to grow by 60 million people in just five years. Beyond Southeast Asia, to feed the growing population of the world, global food calorie yield will have to increase 50 % by 2030.

Combined, the impact of climate change and SLR on fishery viability and agricultural production will have dire social, economic, and ecological impacts on coastal and small island communities. Communities will face adverse impacts on nutritional health, small farm income, state sovereignty, ecosystem health, land tenure, food price and market stability, and fresh-water competition. Communities depending on small scale coastal agriculture will be forced to import food, at high cost. Overall, decreases in agricultural and fishery production will affect income, livelihood and food security of marine-resource dependent communities. The IPCC concluded that long-term loss and degradation of marine ecosystems compromises the ocean’s role in cultural, recreational, and intrinsic values important for human identity and well-being. These findings regarding food security only serve to increase the urgency with which the world must tackle carbon and GHG emissions, and pour funding into efforts to adapt to the impacts of climate change and SLR.