Global Warming Effects Around the World


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Ocean flooding over sea wall

When the tide reaches its highest level during the full moon, it is not uncommon to see flooding as large waves crest the seawalls that protect the more populated areas of Guyana. Since parts of the country are already below sea level, further sea–level rise would cause even more flooding of homes, businesses, and agricultural areas, if flood protection measures are not improved. 1

Key Facts

Guyana is particularly vulnerable to sea–level rise stemming from climate change, plus regional shifts in the height of the sea. Close to 80 percent of Guyana's population lives in the low–lying coastal region. In fact, some of the historically habitable sections are already below sea level.2,3,4 By 2100, scientists project a global sea level rise of 2.6 feet (80 centimeters)—and as much as 6.6 feet (2 meters), depending largely on how much we continue to overload the atmosphere with carbon.5

  • Guyana's capital city of Georgetown relies on seawalls for protection. When flooding occurs after large waves top the seawalls or heavy rains, sluice gates open for drainage. However, these gravity-fed gates can do so only when the tide is low enough.
  • The coastal plain is home to almost all the country's agricultural production—critical for both food and export. The main crops are sugar and rice.6,7
  • Sea level along the Guyana coastline is rising faster than the global average,6 which will exacerbate future increases from further global warming.


With close to 80 percent of Guyana's population living in low–lying coastal regions, sea-level rise linked to global warming is dramatically increasing the likelihood that homes, businesses, hospitals, and schools will flood.2,3 Coastal portions of Guyana sit from 19.7 inches (0.5 meter) to 39.4 inches (1 meter) below sea level.4 The Ministry of Public Works already issues alerts during particularly high spring tides, so residents can take precautions against flooding.8

About 25 percent of the coast is now protected by seawalls, 60 percent by mangroves, and 15 percent by natural sandbanks.6 The seawalls have sluice gates that allow floodwaters from heavy rains and waves that crest the seawalls to drain. However, the gravity–controlled gates cannot open if the tide is not low enough. As sea level rises even more, the risk that the gates will not open also increases. Some locations already rely on pumped drainage, and more are likely to need it, raising the cost of protecting coastal development.6

Guyana's coastal plains are home to some three–quarters of the country's economic activities including almost all the country's agricultural production—critical for both food and export.4 The main crops are sugar and rice.7 Sea–level rise could devastate agricultural production if saltwater inundates fields and intrudes into the estuaries used to irrigate them.6 Saltwater from rising seas could also contaminate freshwater supplies used for drinking and other domestic and industrial activities, requiring costly treatment.6

Part of a Larger Pattern

Sea level has been rising globally since the end of the last ice age, but the rate of that rise has accelerated significantly. From 1993 to 2009, the annual rate rose to around 0.13 inch (3.4 millimeters)—nearly twice the twentieth–century average.9,10

Scientists attribute this recent acceleration to human–caused climate change. Oceans expand as they warm, and the Greenland and Antarctic ice sheets and mountain glaciers add water to the oceans as they shrink.5 After looking closely at the volume of water that could come from shrinking glaciers and ice sheets, scientists project a rise of 2.6 feet (80 centimeters) by 2100—or possibly as much as 6.6 feet (2 meters), depending on the pace of heat-trapping emissions and assumptions about ice sheet behavior.5

Besides global sea–level rise, several other factors influence regional sea levels, including sinking (subsidence) or rising (uplift) of the land, circulation of the atmosphere and the ocean, and the origin of meltwater. Scientists have found that the Guyana coast is subsiding owing to groundwater extraction, soil compaction, and drainage of wetlands. From 1951 to 1979, sea level off Guyana rose at a rate some six times the global average, (0.4 inch, or 10.2 millimeters per year), around 6 times the twentieth century average or 3 times the 1993 to 2009 annual average.6,10

What the Future Holds

Without improved sea and river defenses and drainage systems, the coastal plains of coastal Guyana face serious flooding—if not complete inundation—owing to higher sea levels possible under worst case scenarios.6 Such flooding would devastate most of the population and have consequences for a large percentage of the gross domestic product.4

The government recently projected that adaptation costs could exceed $1 billion (U.S.)—a fraction of the potential losses if nothing is done. This figure includes the costs of activities ranging from building and reinforcing levees and seawalls to flood–proofing health clinics.12 For context, $1 billion (U.S.) is equivalent to about 20 percent of Guyana's GDP in 2010.7

Because of increased flooding, the Ministry of Agriculture is already encouraging residents to relocate farther inland. In 2010, the ministry opened up new land to allow traditional coastal farmers to start moving their homes and farms inland.13

Coastal mangrove fringes are particularly at risk from sea–level rise. Mangroves naturally move slowly landward as sea level rises. However, because the Guyana coast is developed, the mangroves cannot do so, and slowly die off from being pinned in place as sea level rises. This exposes more of the coast to damage from saltwater inundation, storm surges, and reduces the nursery habitat for commercial fishing.14 Curbing the human activities that overload our atmosphere with carbon—the root cause of global sea–level rise—can go a long way toward slowing the pace of change, and creating more time for coastal communities to prepare for changes ahead.



  1. Photograph courtesy of Stabroek News. Online at Accessed August 31, 2011.
  2. Bureau of Statistics. 2007. 2002 population and housing census: National census report. Georgetown, Guyana. Online at Accessed February 9, 2011.
  3. 2006. The ten administrative regions. Online at Accessed February 9, 2011.
  4. Office of Climate Change, Office of the President of Guyana. 2010. Understanding of climate change, part 2. Georgetown, Guyana. Online at Accessed February 9, 2011.
  5. Pfeffer, W.T., et al. 2008. Kinematic constraints on glacier contributions to 21st–century sea–level rise. Science 321(1340) (doi): 10.1126/science.1159099.
  6. Guyana National Climate Committee. 2002. Guyana initial national communication in response to its commitments to the UNFCCC. Georgetown, Guyana. Online at Accessed February 9, 2011.
  7. Central Intelligence Agency. 2011. The world factbook. Online at Accessed on February 7, 2011.
  8. Stabroek News. 2010. Spring tide. Online at Accessed February 9, 2011.
  9. Bindoff, N.L., J. Willebrand, V. Artale, A. Cazenave, J. Gregory, S. Gulev, K. Hanawa, C. Le Quéré, S. Levitus, Y. Nojiri, C.K. Shum, L.D. Talley, and A. Unnikrishnan. 2007. Observations: Oceanic climate change and sea level. In: Climate change 2007: The physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H.L. Miller. Cambridge, UK, and New York, NY: Cambridge University Press.
  10. Nerem, R.S., D.P. Chambers, C. Choe, and G.T. Mitchum. 2010. Estimating mean sea level change from the TOPEX and Jason Altimeter Missions. Marine Geodesy 33(1). Online at Accessed February 9, 2011.
  11. Khan, M., and M. Sturm. 1995. Assessment of the vulnerability of coastal areas to sea–level rise: Case study Guyana. The Hague, the Netherlands: Ministry of Transport, Public Works and Water Management. Cited in Dalrymple, O. 2006. Sea–level rise implications for the coast of Guyana, Fourth International Latin American and Caribbean Conference for Engineering and Technology.
  12. Office of the President, Republic of Guyana. 2010. Low Carbon Development Strategy Transforming Guyana's Economy While Combating Climate Change. Online at Accessed February 9, 2011.
  13. Sutherland, G. 2010. 4,500 acres opened to flood–weary Essequibo farmers. Stabroek News. Online at Accessed February 9, 2011.
  14. Dalrymple, O. 2006. Sea–level rise implications for the coast of Guyana. Fourth International Latin American and Caribbean Conference for Engineering and Technology. Online at Accessed February 2, 2011.
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