What's the time? I hope we're not too late

US comic, filmmaker and pessimist par excellence Woody Allen once said in a commencement address to new graduates: "More than any other time in history, mankind faces a crossroads. One path leads to despair and utter hopelessness; the other, to total extinction. Let us pray we have the wisdom to choose correctly."

Now, Allen has made a very successful career out of poking fun at wretchedness, but if you cut away the hyperbole, or at least tone it down a few thousand degrees, you could imagine this statement having relevance in any number of issues today.

For me, one in particular comes to mind－climate change.

In a column dealing with the subject a year or so ago, I wrote: "For years, we've been hearing about global warming, that future danger that can't be averted, only minimized. I've often wondered what climate change would be like when it finally arrives."

It looks like we're beginning to find out.

Take the tornadoes that tore through Kentucky, Tennessee and Missouri in the southern United States on Dec 10 and 11.

According to the US National Weather Service, "a historic long-track tornado entered western Kentucky from Tennessee shortly before 9 pm". It passed through a number of communities, cutting a swath of damage, as it headed northeast for 2 hours and 20 minutes. Reports followed of it killing 70 people in Kentucky, many of them in the town of Mayfield, where about 100 people were working overtime in a large factory that collapsed.

One woman in the factory later told CNN that she felt "a little gust of wind", then her ears started popping, the building started rocking and "boom, everything fell on us".

This past summer, southern Europe was gripped by a heat wave, leading to a belt of wildfires "that have torn through forests and homes, and destroyed vital infrastructure from Turkey to Spain", CNN reported.

But at roughly the same time, northern Europe had to contend with heavy rainfall that caused widespread flooding in the German states of Rhineland-Palatinate and North Rhine Westphalia. It spread into Luxembourg and with the Meuse river into Belgium and the Netherlands.

The effects of global warming are widespread, as the World Wildlife Fund explains in an online primer on glaciers and sea ice melting.

As a direct consequence of human-caused air pollution that began to have a significant impact during the industrial revolution, glaciers have been melting since the early 1900s. Their disappearance into the sea and the loss of polar ice shelves has accelerated to the point where: "Even if we significantly curb emissions in the coming decades, more than a third of the world's glaciers will melt before the year 2100. When it comes to sea ice, 95 percent of the oldest and thickest ice in the Arctic is already gone."

As polar ice melts, sea levels rise, which in turn causes land erosion and affects weather patterns. The white polar ice caps reflect energy from the sun back into space and their loss directly increases global warming. It's heading toward becoming a self-perpetuating cycle.

The ice shelf covering Greenland "is disappearing four times faster than in 2003" and if it were all to melt, "it would raise global sea levels by 20 feet" (6 meters), according to the World Wildlife primer.

It seems as though we've been talking for years about it being high time to reduce the air pollution our industries and large urban populations are causing before it is too late.

Hmm, what's the time right now? I hope it's not already too late.

Contact the writer at lydon@chinadaily.com.cn