上海采取措施应对海平面上升

Zhang Zhenyu, of the Shanghai Flood Risk Information Center spokesperson, said the seawalls virtually encircle half of the city.

"These are all the sea walls we have built, including from Hangzhou Bay to up at the top at the border with Jiangsu province, including Chongming island, Hengsha island and Changxing island – those three islands – all have sea walls."

Over 520 kilometers of Shanghai's shoreline is lined with those sea walls, which could reduce the threat brought by rising sea levels to some extent.

Many experts have predicted that Shanghai is facing a serious danger of flooding with annual rainfall in the city 20 percent higher than the global average, causing sea levels expected to rise between 20 and 60 centimeters by 2050.

Apart from rising sea levels due to melting ice caps, increasing temperatures could also bring more extreme weather events such as typhoons and torrential storms.

Zhang Zhenyu said Shanghai itself is hit by an average of 2 to 3 typhoons annually, and the effects could be utterly severe if the torrential rains occur simultaneously with spring tides or Lake Tai floods.

But he also expressed confidence that the trend is still controllable.

"The sea levels here are rising, but although in recent years this trend has increased, it is still within the levels of being controlled. The controls we have in place already should be able to deal with the next 20, 50 – even 100 years of rising sea levels."

Apart from coastal protection, Shanghai also has a number of other river flood protection methods, such as a mechanical gate rising and falling once a day so as to regulate the water level in the Suzhou Creek which leads into the Huangpu River running through the center of Shanghai.

However, Shanghai doesn't only face rising water levels, but also has to deal with gradual sinking.

The city has sunk on average about 8 millimeters annually since the mid-1970s, but the trend has slowed to around 1 to 3 millimeters per year.

Shen Shuilong, a professor at Shanghai Jiaotong University, explained that the problem has come under control now thanks in part to government regulations that require strict outlines in the planning stages.

"Development is unavoidable, cities need to develop. But ground subsidence should be controllable if there is a plan in place for the protection of the ground and environment during planning and design stages."

For CRI, I'm Xie Cheng.