Atlantic region faces turbulent climate, warns study

CLIMATE change may affect east Asia differently from north Atlantic countries, according to a study published yesterday.

The extreme effects of climate change on the world — depicted in the Hollywood movie The Day After Tomorrow — may not be quite true.

In particular, the scene from the film depicting huge ice balls falling on Tokyo, causing death and destruction, is very unlikely.

Research suggests that temperatures are unlikely to change as drastically in east Asia as they could do in countries bordering the north Atlantic.

Scientists studied the period from 16,000 to 10,000 years ago as they believe that climate change patterns experienced then are similar to those we are experiencing today. This is because then, as now, temperatures were gradually increasing from cold to warm.

Around 12,000 years ago, the world experienced a huge surge in cold temperatures — known as the Younger Dryas cold reversal event — which lasted around 1,000 years.

Warming caused ice from the Polar Cap to melt into the sea and destabilise the Gulf Stream, leading to a drastic drop in temperatures. The Gulf carries warm water from the tropics to the north Atlantic and raises air temperatures.

Some scientists expect that current global warming will trigger a repeat of this cold surge in years to come. The study, led by Newcastle University, is published in the July issue of Geology, the journal of the Geological Society of America.

However, the researchers suggest this scenario may not be experienced across the globe. For the study, researchers analysed fossilised pollen samples in the sediment taken from the bottom of Lake Suigetsu in Japan.

Pollen samples can indicate the changes in the type of vegetation over time, which in turn indicates changes in the climate.

By comparing information from this material with statistics from today, the researchers were able to determine the change in temperature and precipitation over time for the period from 16,000 years ago to 10,000 years ago.

The statistics reflected a cold surge at around 12,000 years but temperatures only fluctuated slightly — an estimated 5C decrease in winter and no more than 3C decrease in summer.

It is believed the north Atlantic experienced a 7C to 10C decrease in temperatures during the same event.

These results suggest east Asia reacted differently to global warming 12,000 years ago. If the pattern is repeated as researchers expect it to, the same effect is likely the next time a cold surge happens. The researchers suggest this is because the Asian monsoon front largely acts as a barrier from theeffect of north Atlantic cooling, so temperature predictions will apply to Japan and other lands east of the monsoon barrier.

Dr Takeshi Nakagawa, a paleoclimatologist at Newcastle University, said: “The research suggests Asia will not be as severely affected by the destabilising of the Gulf stream as countries bordering the northern Atlantic.

“This research provides another key to understanding how the climate system works as a whole, which should be useful in international deliberations on tackling global warming.”