The El Nino weather phenomenon developing in the Pacific Ocean is building faster than previous El Ninos and may become the strongest of its kind this century, according to data from the US National Oceanic and Atmospheric Administration.
El Nino is characterised by rising surface water temperatures across millions of square miles of the equatorial Pacific Ocean. This event, which typically happens every three to seven years, has a knock-on effect on weather patterns right around the world.
It brings serious drought to some areas while delivering torrential rains to others. The previous strongest El Nino occurred 15 years ago, with damage estimated at $25 billion.
A new event is building, just three years after the last El Nino, but the temperature change is developing much more quickly than in previous severe visitations.
The 1982/83 El Nino - like others - reached its peak temperature change in just over a year, while this El Nino has almost reached these temperatures in six months, according to NOAA data.
Researchers cannot predict how an El Nino event will develop, but they can promise changed weather patterns, particularly in the tropics.
Western Europe could still experience catastrophic climate change due to another cause - subtle changes in the north Atlantic - according to two climatologists from the University of Berne, in Switzerland.
Drs Thomas Stocker and Andreas Schmitter base their theory on changes to a north Atlantic Ocean current called the thermohaline circulation, which could be brought about by global warming.
The thermohaline circulation is not driven by wind but by very small changes in the temperature and salinity of ocean waters which can modify water density. It can be affected by the volume of fresh, less dense water reaching the ocean from rain, snow-melt and rivers and also by changes in water temperature.
The circulation carries warm water which is passed on to the atmosphere off Europe, helping to keep it relatively mild. The researchers, who publish their findings this morning in the science journal, Nature, warn however that even minor climate change could slow or even halt the thermohaline circulation.
Climate change predictions involve increased rain over Northern Europe, but more fresh water means potential disruption to the circulation. This in turn would mean falling temperatures over Europe and damage to fisheries and farming.
In an accompanying article, Dr Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research in Germany said the effects of such a breakdown would be unpredictable but inevitably serious.
Changes in the thermohaline circulation in the past had caused cold spells lasting hundreds of years.
