Cars are parked on an overpass on a flooded street in Bangkok, Thailand. Projections on the rise of sea levels show Bangkok could be at risk of inundation in 100 years. (Associated Press file photos)

From Bangkok to Miami, cities and coastal areas across the globe are already building or planning defenses to protect millions of people and key infrastructure from more powerful storm surges and other effects of global warming. • Some are planning cities that will simply adapt to more water. • But climate-proofing a city or coastline is expensive, as shown by New York Mayor Michael Bloomberg’s $20 billion plan to build floodwalls, levees and other defenses against rising seas. • The most vulnerable places are those with the fewest resources to build such defenses, secure their water supplies or move people to higher ground. How to pay for such measures is a burning issue in U.N. climate talks, which just wrapped up a

FILE – In this Wednesday, March 28, 2012 file photo, amphibious homes float on the harbor in the IJburg neighborhood in Amsterdam. IJburg is a new district in the eastern part of town completely surrounded by water. The Netherlands, a third of which lies below sea level, has been managing water since the Middle Ages. (AP | Margriet Faber)

session in the German city of Bonn. • A sampling of cities around the world and what they are doing to prepare for the climatic forces that scientists say are being unleashed by global warming:ROTTERDAM, Netherlands

In a country where two-thirds of the population lives below sea level, the battle against the sea has been a matter of life and death for centuries.

The focus in the 20th century was on a spectacular series of sea defenses, including massive steel and concrete barriers that can be quickly moved to protect against storm surges. But current techniques embrace a philosophy of “living with water.”

Thousands of waterways are being connected so the country can act as a sponge and absorb influxes of water. Some areas have been designated as flood zones. Houses that can float have been a building sensation.

VENICE, Italy

Sea-level rise is a concern for this flood-prone city. It’s in the process of realizing an expensive and oft-delayed system of underwater barriers that would be raised in the event of flooding over 43 inches.

Venice, a system of islands built into a shallow lagoon, is extremely vulnerable to rising seas because the sea floor is also sinking. Plans for the new

FILE – A tourist sits outside a cafe in a flooded St. Mark square as high tides reached 1.05 meters above sea level, partly flooding the city of Venice, Italy on Monday, Oct. 15, 2012. The Lagoon City, a system of islands built into a river delta, is extremely vulnerable to rising sea levels. At the same time it is experiencing a lowering of the sea floor. The constant flooding puts the city’s considerable architectural treasures at risk. (AP | Luigi Costantini)

so-called Moses barriers will cost more than 4 billion euro. The first of these have been moved into place in recent days. Many Venetians remain skeptical of the project due to the high costs and concerns over environmental risks.MIAMI

Southern Florida is one of those places that show up as partially under water in many sea-level projections for this century. So it’s no surprise local leaders are seeking ways to adapt. Four counties of South Florida, including Miami-Dade, have collaborated on a plan to respond to climate change. Their overarching goal: keeping fresh water inland and saltwater away.

Before writing the plan, the counties reviewed regional sea-level data and projected a rise of 9 to 24 inches in the next 50

FILE – In this Saturday, Oct. 8, 2005 file photo, boats sail in Miami’s Biscayne Bay at the start of the annual Columbus Day Regatta. Southern Florida is one of the places that shows up as partially under water in many sea level projections for the 21st century. (AP | Lynne Sladky)

years along a coastline that already has documented a rise of 9 inches over the past 100 years.BANGLADESH

Bangladesh is one of Asia’s poorest countries and one that faces extreme risks from rising sea levels. Its capital, Dhaka, is at the top of a list of world cities deemed most vulnerable to climate change, according to risk analysis company Maplecroft.

The World Bank says a sea-level rise of 5 inches would affect 20 million people along the 440-mile coast. Many of these people would be homeless.

Bangladesh is implementing two major projects worth $470 million that involve growing forests on the coastal belt and building more multistory shelters to house people after cyclones and tidal surges.

BANGKOK,

FILE – In this Sunday, May 31, 2009 file photo, floodwaters flow to a lower area as villagers rebuild an embankment at Protap Nagar in Shatkhira, Bangladesh, about 176 kilometers (109 miles) southwest of Dhaka after Cyclone Aila. The low-lying delta nation of 153 million people is one of Asia’s poorest countries, and one that faces extreme risks from rising sea levels. (AP | Pavel Rahman)

ThailandSea-level rise projections show Bangkok could be at risk of inundation in 100 years unless preventive measures are taken. But when the capital and its outskirts were affected in 2011 by the worst flooding in half a century, the immediate trigger was water runoff from the north, where dams failed to hold very heavy rains.

The government recently announced winning bids totaling $9.38 million by Chinese, South Korean and Thai firms to run the flood and water management schemes, including the construction of reservoirs, floodways and barriers.

Solutions to the problem of rising seas are still being studied.

“Construction alone is not sustainable,” said Seree Supratid, director of a climate and disaster center at Rangsit University. “People have to adapt to nature.”