Heed the warnings of clouds and save lives

The heavens opened at the weekend but initially the situation was not as bad as the meteorologists had warned. But by Tuesday, the State Flood Control and Drought Relief Headquarters realized the severity of the situation and raised the emergency response to floods in Henan province to Level III.

Yet very few expected the volume of rain that the provincial capital Zhengzhou received on Tuesday, which prompted the flood control and drought relief authorities to raise the emergency response to Level II at 3 am on Tuesday, just seven hours after declaring a Level III emergency.

From Saturday to Tuesday, Zhengzhou received an unprecedented 624 millimeters of rain, almost the equivalent of its annual average of 640.8 mm, which indicates the intensity and fierceness of the downpour. And yet more rain is forecast across Henan in the next two days, although the central leadership has taken enough response measures, including sending more than 5,700 People's Liberation Army personnel to help with the search and rescue operations.

On Wednesday, Zhengzhou looked less like a modern Chinese city, as its streets had turned into overflowing streams which flushed everything in their wake including cars. The dams and reservoirs were overflowing, and the transport system come to a standstill, paralyzing normal life in the city. Unfortunately, a dozen or so neighboring cities had the same tragic experience.

As of Wednesday, Zhengzhou alone had reported 25 deaths and seven people missing. The worst tragedy took place in a subway, where 12 people died after the tunnel was flooded, though thanks to the tireless efforts of the rescue teams, more than 500 were pulled out to safety.

The meteorological department had warned of severe rainstorms before the deluge. But, as some reports suggest, people tended to ignore them, because initially the downpour was not as heavy as predicted.

We know from experience, irrespective of which part of the world we live in, that weather forecasts are not always accurate. As a result, we often take weathermen's warnings with a pinch of salt.

But given the advancements we have made in science and technology, why can't meteorologists forecast weather events accurately?

Perhaps because of clouds. Clouds have an enormous influence on Earth's energy balance, climate and weather. They help regulate the Earth's energy balance. While some clouds help cool the Earth by reflecting some of the sun's energy (or solar energy), other clouds contribute to warming by trapping some of the energy the Earth's surface and lower atmosphere emit (called thermal energy), and thus regulate the Earth's average temperature.

On the other hand, weather plays a key role in accurately forecasting natural calamities such as heavy downpours, hurricanes and tornadoes. But weather variations can occur suddenly and inexplicably, depending on the ever-changing distribution and density of clouds.

Clouds also help spread the sun's energy evenly over the Earth's surface, and storms, moving across the planet, transport energy from warm areas near the equator to cold areas near the poles. Even a small change in the density or location of clouds could change the climate, and weather, more than the anticipated changes caused by greenhouse gases, human-produced aerosols or other factors associated with global warming.

It is the unpredictable movement of clouds that at time makes it difficult for meteorologists and other scientists to create accurate, realistic computer simulations of the clouds and the Earth's currents. The result: forecasts of severe weather events are not always entirely accurate.

Regrettably, global warming is making the movement of clouds and storms across the world increasingly unpredictable. And the more greenhouse gases we emit, the more unpredictable the weather patterns will become.

In such a scenario, people and local governments need to be made aware of the dangers of ignoring weather warnings, because more often than not it is seen that meteorological warnings are real, even if at times they might be inaccurate by a day or about the severity of the weather event.

All the people are heart broken for the tragedies and wish the floods will fade as soon as possible. Meanwhile, people and local governmets should learn from the tragedies to prevent similar cases in the future by heeding the meteorological warnings and taking concrete measures in advance.

The author is a senior editor with China Daily.

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