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Rising Sea Levels Pose Greatest Climate Change Threat
Sep 09, 2013

In the developed world, water conservation, flood control, sustainable agriculture and land-use planning are suggested as adaptation measures, as are improving resiliency to wind and flood events to reduce the financial and social risks and impacts associated with catastrophic events. This is especially important for developing countries, which is where more than 95 percent of weather-related fatalities occur.

“The debate on climate change and global warming has been intensely polarized. A great deal of this noise has clouded the very real and emerging issues that we as an industry and society need to address,” said Johnny Chan, PhD, director of the Guy Carpenter Asia-Pacific Climate Impact Centre. “In order to adapt to climate change and the changing risk landscape, it is necessary to cut through this noise and focus on objective decisions to mitigate both the financial and social risks associated with climate change.”

The evidence of global warming is undeniable and includes increasing air temperatures, increasing ocean water temperatures, tree ring characteristics, ice core characteristics and the retreat of ice caps, according to the Intergovernmental Panel on Climate Change (IPCC), a scientific body that reviews and assesses scientific evidence pertaining to the physics and impacts of climate change. While climate change has been documented with supporting evidence in past centuries, the rate of warming is believed to be unprecedented, IPCC added.

“Based on consistent and mounting scientific evidence, the IPCC has assessed that it is highly unlikely that recent warming trends can be explained away by natural variability alone,” said James Waller, PhD, research meteorologist for GC Analytics. “Estimates show that the mean temperature of the Earth could rise an additional two to four degrees Celsius by the end of the century. This may seem like a relatively small increase, but the impact of rising temperatures, even by a few degrees, could cause a shift in weather patterns, with considerable impact worldwide.”

The impact of weather-related hazards are dependent on the frequency and severity of CAT events, but also on vulnerability, population density, local infrastructure and the property values of affected areas, the report said, and so factors including per-capita gross domestic product, total insured value, population density and annualized property value must be accounted for, according to the report.

“With the exception of coastal flood, inland flood and drought, the blanket assumption that increasing financial losses are directly and completely caused by an increase in natural hazard frequency misrepresents the issues,” Guy Carpenter said.

Rising in sea levels, which are expected to increase coastal flood frequency and severity from tropical cyclones, extratropical cyclones and tsunami events, are the greatest threat posed by global warming, IPCC said, and a sea-level rise of more one to two feet by the end of the century can be expected. Increasing population density and urbanization in coastal areas has amplified the financial and societal impacts of such events, and the consequences of Cyclone Nilam in Eastern India and Superstorm Sandy in the United States are listed as examples of the threat. The impact of hurricanes is projected to become more severe under sea-level rise, IPCC said.

Changing weather patterns also increase the likelihood and impact of inland flood and drought, affecting agricultural, wildfire and water resources management. Global climate models indicate that the number of days between precipitation events will increase for areas including Southern Australia, Southeast Asia and India, Southern Europe, Central America and western North America by the end of the century. Others areas will experience diminished annual precipitation and could face water shortages. Drought increases wildfire hazards, and the report said the wildfire season in the western United States has increased by 78 days over the last three decades.