Recently, a report in Nature Geoscience revealed that polar ice may be melting faster than previously thought, leading to a more significant rise in sea levels throughout the course of the century. We asked our Sustainability Roundtable to discuss the implications of the warming of the oceans and the subsequent rise in sea levels. What will these phenomena mean for the future development of Asian countries? Are there opportunities for regional cooperation in dealing with the consequences of these environmental changes?
Almost half of Asia's population lives within 100 kilometers of a coastal ecosystem. Japan, Taiwan, Philippines, Malaysia, Indonesia, Vietnam and numerous small island states are coastal societies; and sixty percent of China's population lives along its east coast. Seventeen of Asia's 20 largest cities are either coastal or sit on rivers impacted by ocean tides. Sea-level rise is a real risk for many low-lying Asian cities. Earlier this year, Shanghai's water supply was threatened as salt water reached further inland into major sources of drinking water; though this incident was primarily attributed to a severe drought that impacted freshwater river flows, rising sea-levels threaten to do the same to many coastal cities.
Asian leaders need not look toward future threats to justify major changes in coastal development and marine protection. Since time immemorial, people living in coastal regions have relied heavily on the abundant biological productivity and services that marine systems provide. However, because of rapid economic development in coastal areas, pollution and overfishing, the productivity and services that marine systems provide are declining. Warming oceans and ocean acidification, both caused by excessive carbon pollution, threaten to further disrupt already vulnerable marine ecosystems.
A recent government report declared that China's marine ecosystems face a "grave situtation," caused by over development, loss of wetlands, and excess pollution. According to China's national statistics 14 million tons of heavy metals were discharged into marine environments in 2009, and 57 percent of the country's intertidal wetlands were destroyed or lost their natural functions. Unfortunately, China's situation is not unique in Asia. Protecting marine wetlands are key to helping adapt to rising seas because they help filter water, control flooding, and provide a buffer zone for storm surges.
Coral reefs, the ocean's forests, are severely threatened by warming oceans and ocean acidification. Ocean acidification, caused by the increased absorption of carbon dioxide by the oceans, may have disastrous impacts on the ability of coral to grow and on the ocean's productivity. Warming oceans are already being blamed for an increase in giant jellyfish that disrupt fishing near Japan. Even more disturbing is that fact that warming oceans are known to reduce the number of phytoplankton, the bedrock of the marine food chain.
All of these factors threaten Asian economies and the livelihood of the hundreds of millions of Asians who make their living from marine-based services. Asian countries share many of the same challenges when it comes to protecting marine ecosystems and adapting to rising seas. The protection of marine wetlands and the preservation of intertidal zones are key to both maintaining the productivity of marine ecosystems and helping adapt to sea-level rise. Asian countries should focus on controlling land-based pollution that directly threatens marine ecosystems and increases the rate of sea-level rise. The health of Asia's seas are a regional issue and the risks of sea-level rise are shared. Regional cooperation and dialogue will be critical to accurately addressing the issues.