The World’s Coastlines: Rapid Change and Growing Risk
The world’s coastal zones are changing rapidly — and their rate of change is predicted to increase from coastal development and climate change, both of which will dramatically increase risks of catastrophic damage to coastal communities.
In 2011, insured losses from natural disasters (especially coastal and riverine hazards) reached an all-time high, and impacts will continue to worsen with continued climate change. In fact, the top 15 nations most at risk to natural hazards such as floods, fires and earthquakes are all coastal, tropical and developing countries (World Risk Report 2012). Erosion, inundation and extreme weather events already affect hundreds of millions of vulnerable people, important infrastructure, tourism, and trade — with significant losses to national economies and major impacts on human suffering.
And ecosystem degradation raises these risks by further exposing communities and assets to more waves, winds and water. Coastal and marine habitats — particularly coral reefs and wetlands — are at the front line of many of these changes, and are increasingly lost and degraded. Global losses of coastal habitats are as high as 85% for oyster reefs, 30-50% for wetlands, and approximately 30% for coral reefs. Often, the loss of these habitats is greatest around population centers — maximizing the loss of benefits to people.
Billions of dollars — from international agencies as well as national and local governments — are moving to reduce risks from coastal hazards and climate change, creating both threats and opportunities for natural systems. But most these funds are destined for the creation of “grey infrastructure” such as seawalls, which will further degrade coastal ecosystems, and may not be cost effective for risk reduction when compared to more natural and hybrid alternatives.
Because of the wave of global science following Hurricane Katrina and the 2004 Indian Ocean tsunami, decision-makers now recognize that coastal habitats have some role to play in risk reduction. Those decision-makers are rightly asking:
- How cost-effective are natural ecosystems for coastal defense?
- Where and how should we restore these natural defenses?
- How do we create incentives to reduce risks by conserving coastal habitats?
Read about this Inquiry