The Intergovernmental Panel on Climate Change has just issued a summary for policymakers of its report on "Climate Change Impacts, Adaptation and Vulnerability."

Going beyond the conclusions of its earlier report that human activities are contributing significantly to global climate change, the new report states: "There is high confidence that recent regional changes in temperature have had discernible impacts on many physical and biological systems." Of particular interest to Hawai'i are the conclusions that the panel's assessment makes with respect to islands.

The conclusions of the report should not come as a surprise to us here. As far back as 1989, the East-West Center hosted possibly the first Asia-Pacific conference on climate change. The distinguished participants included the current president of the climate-change panel and the first administrator of China's Environment Protection Agency. Many of the concerns voiced 18 years ago have been confirmed by the new panel reports. Work on strategies to reduce greenhouse gas emissions and assess the impacts of global climate change has continued at the East-West Center and at the University of Hawai'i.

It is clear that we have to plan for the likelihood that within the lifetime of today's college students, the sea level here will rise by about one foot. This has enormous implications for residents and for the state's No. 1 source of revenue, the tourism industry. To cite only a few examples, seawalls may have to be built to protect Waikiki and many hotel areas on the Neighbor Islands. Beach sand may have to be replenished more frequently where beaches may still exist. Systems for discharging treated waste into the ocean will have to be modified. New hotels will have to be built at elevations at least a few feet above the anticipated sea level.

But the effects on tourism are only the tip of the iceberg.

All of our islands now have major traffic arteries that are almost at sea level. On O'ahu, highways along the North Shore frequently have to be closed due to high surf. Fortunately, this lasts only a few hours. But if sea levels were to rise by a foot or so as the panel reports suggest they will, stretches of Kalaniana'ole and Kamehameha highways next to Sandy Beach, through Waimanalo, and at many other points would be permanently underwater. Considering how long it takes to even repair potholes in our roadways, it certainly is not too soon to initiate the planning process to address the challenge. Alternate routes may well have to be built to serve the communities that will be affected. There is no doubt the projects will be costly and hard on the taxpayers, but they will bring a smile to the construction industry.

Further, if the Honolulu rapid transit system is really to be built, we are fortunate to be in a position to incorporate global climate change considerations into its initial construction. The entire system should be designed to run at well above sea level. Stations along the route(s) will also have to be elevated.

Rising sea levels will not be the only aspects of climate change to impact us. The number of hurricanes, for example, may not increase, but it is likely their severity will be greater. We know from Kaua'i's experience with Hurricane Iniki how devastating storms can be. A hurricane of that magnitude will hopefully not hit us again soon, but we must be prepared for the eventuality that it will. We need to do this in any case, but global climate change requires us to address the planning and emergency response systems with greater urgency.

Due to space limitations, I will not address the multitude of implications for agriculture in Hawai'i, or the spread of nonnative species.

A warming of the ambient temperature will result in a greater demand for air conditioning. Some of it will be due to the increased temperature, but some will also be due to the fact that traditional homes in Hawai'i, which depend on the tradewinds to keep them cool, might no longer find such cooling adequate. A possible increase in the number of warmer days, or days without tradewinds, will only make matters worse.

The greater need for electricity provides us with an opportunity to push for much greater use of renewable energy such as solar and wind power. A carbon tax on fossil fuels, or something similar with a more saleable name, may well be enacted at the federal level during the next few years. This will result in renewable energy becoming much more competitive with fossil fuels in Hawai'i. Perhaps that will put us on the path to becoming the state which gets the largest share of its energy from nonpolluting energy sources ... a silver lining in the dark cloud of climate change.

Toufiq Siddiqi is an adjunct senior fellow at the East-West Center, and president of Global Environment and Energy in the 21st Century, a nonprofit organization based in Hawai'i. Siddiqi, also an affiliate graduate faculty member in the geography department at University of Hawai'i-Manoa, wrote this commentary for The Advertiser.