FOR several hours last August, rain fell on the highest point of Greenland's ice sheet. It was the first time in recorded history that it rained instead of snowed in the island, which climatologists consider as a barometer for detecting changes in the Arctic icecap.

One climate expert describes the event as an "unprecedented shock to the system" and worries that "something is going on in the atmosphere that's taking us into uncharted territory."

The temperature must be just above or below zero degrees Celsius for rain to form as precipitation. That indicates that the Greenland ice sheet experienced a warming episode during that time.

Scientists were blindsided by the rain in Greenland. "So what else is out there?" one asked. "That's the real concern here. There could be some surprises that we're not anticipating at all."

Geophysicist John Moore took a bold leap by connecting the Greenland event to severe weather changes this year that triggered wildfires, droughts and searing temperatures in other parts of the world.

"Like a pan of water boiling on the stove, you turn the heat up and all sorts of chaotic circulations take place," according to Moore. "What happened in Greenland is evidence of this chaos."

Environment experts point to the Greenland rain event as unassailable evidence of the impact of climate change, in particular the effect of burning fossil fuels on global temperatures.

They believe that the buildup in the atmosphere of carbon dioxide and methane emissions from factories and vehicles is eating away at the world's ice sheets, and slowly turning them into meltwater. The frightening thing is that the pace of melting has been accelerating.

In the last decade, Greenland has lost more ice than it did in the previous century. If the melting continues at its present rate, tens of millions of people could face annual floods and displacement by 2030.

If the thawing trend continues until the end of the century, and Antarctica also starts to defrost, the number of affected people could rise to about half a billion, the experts predict.

Rising sea levels has long been on the list of the catastrophes that global warming could spawn.

Climate experts say sea levels have risen 8 to 9 inches since 1880. The biggest rise was recorded last year: 3.6 inches above 1993 levels.

That puts coastal communities around the world at risk. That also means more destructive storms as bigger surges drive seawater further inland.

Because of its long coastline, the Philippines is especially vulnerable to sea-level rise. In the Manila Bay area, for example, the increase is three to four times faster than the global average rate of 0.13 inches, opening the gates to massive flooding and coastal erosion.

There are, however, encouraging signs of a growing initiative to draw up strategies for sea-level rise awareness, mitigation and adaptation.

During a virtual meeting of the United Nations Open-ended Informal Consultative Process on Oceans and the Law of the Sea last June, the Philippine delegation highlighted the urgent need to address sea-level rise.

In October, a government panel of Filipino scientists included rising sea levels as among the top 10 hazards confronting the Philippines. The list was presented by the Philippine delegation to the climate summit in Glasgow.

The panel's action plan includes conducting climate and health impact assessments for provinces and cities, building a network of state colleges and universities to provide support to local governments and communities in facing climate-induced risks, and giving local governments more access to climate financing.

Our government can also find inspiration from several cities around the world that have adopted basic tactics in fighting sea-level rise, aside from reducing their carbon footprint. One is by putting up surge barriers and installing pumps and overflow chambers to keep the water out. Another is by restoring or expanding mangroves and wetlands to help reduce flooding.

Because these solutions are community-based, they can have a higher rate of success. What's needed is for everyone to be on the same page and be properly motivated.