Rising tensions with India and China over the European Union's "arrogant" law on carbon emissions could rob the region of the markets that can rescue it from economic malaise, airline leaders said on Thursday.

They also said they had prepared contingency plans for a possible exit of Greece from the euro, as part of the industry's extensive crisis management, and they were worried about a domino effect of more countries' being forced out of the currency bloc, with implications for all businesses.

Even as drought persists in parts of Kenya's arid north, intense rains are claiming lives in other parts of the country – flooding slums in the capital Nairobi, sweeping away hikers in the Rift Valley, and destroying crops.

Many Kenyans shake their heads in dismay at the increasingly extreme and volatile weather, which is costing money as well as lives in east Africa's economic powerhouse.

The United Nations chief, Ban Ki-moon, held out little hope on Thursday of an historic outcome at the Rio global development summit, now less than a month away, admitting negotiations had been "painfully slow".

The warning was the latest from United Nations officials and others involved in preparations that the summit, known as Rio+20, is unlikely to replicate the breakthrough achievements of the original environmental gathering in the city in 1992.

In the current issue of Science, researchers at the University of York report that the brown argus butterfly has spread its reach in England northward by about 50 miles over 20 years as a warmer climate allow its caterpillars to feed off wild geranium plants, which are widespread in the countryside.

“There was something unusual about the degree to which it was spreading its range,” said an author of the study, Jane K. Hill, a biologist at York. “It was turning up in places that were unexpected.”

The island nation of Kiribati is one of the countries most threatened by rising sea levels. However, many of the floods it has seen may be due to a mix of natural variability and human activities, complicating the picture of how rising sea levels are endangering Kiribati and other island nations.

Hopes are fading that climate talks in Qatar late this year will make even modest progress towards getting a new globally binding climate deal signed by 2015, as preliminary negotiations in Germany this week have left much work to be done.

The fear is that if work plans and agendas are not set by the end of this year at the latest it could have a knock-on effect, holding up the entire effort to avert potentially devastating global warming.

China spurred a jump in global carbon dioxide (CO2) emissions to their highest ever recorded level in 2011, offsetting falls in the United States and Europe, the International Energy Agency (IEA) said on Thursday.

CO2 emissions rose by 3.2 percent last year to 31.6 billion metric tons (34.83 billion tons), preliminary estimates from the Paris-based IEA showed.

China, the world's biggest emitter of CO2, made the largest contribution to the global rise, its emissions increasing by 9.3 percent, the body said, driven mainly by higher coal use.

Germany has asked for discussion on deeper EU carbon emissions cuts to be put on the agenda at a meeting of environment ministers in June, EU sources said.

If agreed, a more ambitious target could help to spur the European Union's carbon market, which has sunk to record lows.

Previous debate of bigger carbon cuts, however, has been difficult, with coal-reliant Poland objecting that they could damage its economy.

Bangladesh has become the partner of UN Secretary General Ban Ki Moon's initiative styled "Sustainable Energy for all".

UN chief's special envoy and senior adviser to the initiative Luis Gomes formally informed Bangladesh's inclusion to this initiative to the Environment and Forest Minister Dr Hasan Mahmud when he called on him at the latter's office here on Wednesday. In a written statement, Ban Ki Moon said, the main objective of the initiative is to protect the world from pollution, poverty and ensure economic development.

Climate researchers said Thursday the planet could warm by more than 3.5 degrees Celsius, boosting the risk of drought, flood and rising seas. The UN's target is a 2 C limit on warming from pre-industrial levels for manageable climate change. In a report, scientists said Earth's average global temperature rise could exceed the dangerous 3.5 C warming they had flagged only six months ago.