Hong Kong's climate change movements are gaining momentum with a growing number of young activists joining the ranks to make the government and the public more aware of protecting the environment.Gaby Lin reports from Hong Kong.

A thundering roar shattered the absolute stillness in no man's land, followed by others in rapid succession, as Natalie Chung Sum-yue - a young Hong Kong climate advocate - sat on an inflatable dinghy waiting to land on the world's southernmost continent - the virtually uninhabited Antarctica.

She was completely taken aback by what she saw - huge ice chunks breaking off from a massive iceberg, crashing into the water and whipping up tsunami-like waves.

"Was it an explosion or something like a gunshot?" Chung, 25, recalls of that shocking moment. "It was actually an enormous piece of ice tumbling into the water. And it was like every second, we heard these noises of ice cracking and colliding into each other."

The scene was just another wake-up call about climate change. Scientists in February found that the Antarctic sea ice had reached its lowest level since satellite records began 45 years ago.

If Antarctica continues to release massive amounts of water and further lift global sea levels, millions more people living in low-lying islands and coastal areas may face severe flooding as storm surges intensify. Hong Kong, as a subtropical harbor city constantly threatened by cyclones and typhoons, will not be immune from it.

Irked by the severity of climate change, Chung boarded a ship to Antarctica, hoping to seek some solutions to the problem. In February, she joined about 110 scientists, activists and policymakers from across the globe on a two-week-long expedition to the icy continent.