Extreme Temperatures
Physician Vladimir Paar suggests one would not need to cross the sea when travelling from Ireland or UK to Croatia via the rest of Europe.
"A majority of Europe will be under ice, including Germany, Poland, France, Austria, Slovakia and part of Slovenia", Paar said in an interview on Croatian news website Index.
Scientists have only begun assessments, with dive teams looking for "bleaching" that is a telltale indicator of temperature stress in sensitive corals, but initial reports are bleak. The impact could extend from Key Largo through the Dry Tortugas west of Key West, a vast expanse that covers some of the prettiest and healthiest reefs in North America.
Given the depth and duration of frigid weather, Meaghan Johnson, marine science coordinator for The Nature Conservancy, expected to see losses. But she was stunned by what she saw when diving a patch reef 2.5 miles off Harry Harris Park in Key Largo.
Star and brain corals, large species that can take hundreds of years to grow, were as white and lifeless as bones, frozen to death. There were also dead sea turtles, eels and parrotfish littering the bottom.

Sarah Truebe, a geosciences doctoral student at the University of Arizona, checks on an experiment that measures how fast cave formations grow in Arizona's Cave of the Bells.
The finding is the first to document that the abrupt changes in Ice Age climate known from Greenland also occurred in the southwestern U.S., said co-author Julia E. Cole of the University of Arizona in Tucson.
"It's a new picture of the climate in the Southwest during the last Ice Age," said Cole, a UA professor of geosciences. "When it was cold in Greenland, it was wet here, and when it was warm in Greenland, it was dry here."
"If you went around and looked at some of these fish, you would cry," said Capt. Scott Moore of Anna Maria.
The coldest water temperatures in Tampa Bay since 1989 took a heavy toll on the tropical snook, which died when the water stayed in the low 50s and upper 40s for 10 straight days.
The thumb-sized bird had survived two major snow storms, subfreezing temperatures and high winds by feeding on sugar water from a Harwich woman's back yard feeder.
Lela Larned, Wild Care's executive director, said the bird was "at the end of the line."
She says it appears to be getting better, but whether it survives remains uncertain.
Record high snowfall in central parts of the country early this month already broke a 73-year-old record. In Seoul on Wednesday, the mercury dropped to minus 15.3 degrees Celsius, challenging the lowest temperature in the capital city of -16.7 degrees, set on Jan. 22, 2004.
Southern parts of the peninsula are also struggling with "unprecedented" blizzards.
According to the Korea Meteorological Administration (KMA), Younggwang, a rural country in South Jeolla Province, was bombarded with 20.5 centimeters of snow, while other towns in the vicinity saw snowfall ranging from three to 10 centimeters.
The velvet swimming crabs are littering beaches around Thanet, along with smaller numbers of whelks, sponges and anemones.
It is the second year that icy temperatures have killed off the sea creatures in such large numbers.
Last year the Environment Agency set up an inquiry amid fears a mystery virus could be to blame.
Freezing fish, thousands of them, line the coast of South Florida from Key West to Fort Lauderdale.
"Cold water stress is causing all of these fish to die. We are seeing freshwater fish, saltwater fish, all turning up belly up," said Officer Jorge Pino of the Florida Fish and Wildlife Conservation Commission.
Pino ad the FWC patrol the state's waterways.
"The problem is the cold weather is altering the oxygen levels in the water, and that's causing the fish to die," he said.
Elderly locals told IRIN they had never seen cold this intense in Mali, a town in Guinea's Labé region.
"The vegetation looks as if it was burned in a fire," Hannibal Barry of the UN Office for the Coordination of Humanitarian Affairs (OCHA) told IRIN from Mali on 19 February during a joint evaluation by UN agencies, local authorities and NGOs.
Temperatures dropped to 1.4 degrees Celsius from 17 to 26 January, according to a preliminary report by the Food and Agriculture Organization (FAO) and World Food Programme (WFP).
The cold wiped out crops - mainly potatoes, tomatoes, peppers, onions and bananas - across five districts in Mali. It is not yet known how many hectares were destroyed, Mamadou Saliou III Diallo, head of agricultural operations at the Mali prefecture, told IRIN after visiting the affected areas.
William Patterson, from the University of Saskatchewan in Canada, and his colleagues have shown that switching off the North Atlantic circulation can force the Northern hemisphere into a mini 'ice age' in a matter of months. Previous work has indicated that this process would take tens of years.
Around 12,800 years ago the northern hemisphere was hit by a mini ice-age, known by scientists as the Younger Dryas, and nicknamed the 'Big Freeze', which lasted around 1300 years. Geological evidence shows that the Big Freeze was brought about by a sudden influx of freshwater, when the glacial Lake Agassiz in North America burst its banks and poured into the North Atlantic and Arctic Oceans. This vast pulse, a greater volume than all of North America's Great Lakes combined, diluted the North Atlantic conveyor belt and brought it to a halt.
Without the warming influence of this ocean circulation temperatures across the Northern hemisphere plummeted, ice sheets grew and human civilisation fell apart.