World Meteorological Day coincided with a cold that swept a large part of China yesterday and caused many to hesitate about what to wear before leaving their homes for work.

Normal as such weather is in spring, this year we have also experienced the highest spring temperature northern China has ever had.

Today we are experiencing the severest droughts, the hottest days or the worst snowstorms in history.

And we have enough reason to believe that these records will soon be broken. It seems we can barely find any reason to be optimistic about the future when it comes to the weather.

Weather, climate and the air we breathe, the theme of World Meteorological Day this year, reminds us of the close relationship between them.

Back a century or so ago when our understanding of nature was so limited, we would curse the Gods when a lack of rain parched our crops and, likewise, when too much ruined the harvest.

It is ironic that our understanding of climate change is facilitated by the development of science and technology, which has simultaneously seen us discharge greenhouse gas emissions.

The discovery of the Antarctic ozone hole and its growth have helped us realize the impact of human activities on atmospheric changes, as have findings on both poles' melting glaciers, sea ice and permafrost.

We are also told that 10 percent of the glaciers in the country's Qinghai-Tibet plateau have disappeared in the past three decades and that the total area of glaciers will shrink to 72 percent of their current size by 2050.

Research indicates that the earth's global surface temperature increased by approximately 0.6 C in the past century. Scientists estimate that the globe's average surface temperatures will rise by 1.4 to 5.8 C in the next 100 years.

With nobody but ourselves to blame for increasingly frequent extreme weather conditions, it is high time we did something to reduce the greenhouse emissions we discharge.

The convening of the United Nations' conference on climate change at the end of last year was a sign that increasing numbers of countries and politicians have come to realize that climate change is something that nations must jointly deal with.

We cannot afford to wait until it is too late - when the rising seas have submerged continents and the disappearance of glaciers has dried up our rivers.

This annual day should be a reminder to all that we have an impact on world weather, and that global warming is a matter of life and death.

(China Daily March 24, 2009)