A British aid charity is warning that by 2060 more than a billion people worldwide will live in cities at risk of catastrophic flooding as a result of climate change.

A study by Christian Aid says the US, China and India are among the countries most threatened.

It says the Indian cities of Kolkata and Mumbai will be most at risk.

The eight most vulnerable cities on the list are all in Asia, followed by Miami in the US.

The report urges governments to take action to reduce global warming and invest in disaster reduction programmes.

Dr Alison Doig, the report's author, told the BBC World Service that people living in large coastal cities were particularly at risk.

"I think it's cities like Kolkata, Dakar, the big mega-cities of the south and the emerging economies where the people are most vulnerable to exposure to sea-level rises and to higher rain events," she said.

"Flooding in these cities can cause massive damage, but can also threaten life."

Dr Doig warned that Florida was likely to suffer extensive flooding.

"The whole of Florida is totally vulnerable," she said.

"It is so low-lying, it is virtually swampland reclaimed. So significant climate change... raising water half to a full metre this century, will take out an awful lot of Florida and a significant amount of Miami."

Climate change constricts bumblebees' natural ranges

Across Europe and North America bumblebees have lost ground to climate change

New data on carbon shows that China's emissions per head of population have surpassed the EU for the first time. The researchers say that India is also forecast to beat Europe's CO2 output in 2019. Scientists say that global totals are increasing fast and will likely exceed the limit for dangerous climate change within 30 years. The world has already used up two thirds of the warming gases researchers calculate will breach 2 degrees C. The Global Carbon Project involves researchers from several different institutes around the world and it provides objective details on the scale of annual emissions. The latest data shows that a record 36 billion tonnes of carbon from all human sources were emitted in 2013. Top ten emitters 2013 - % of global total China - 29 USA - 15 EU - 10 India - 7.1 Russian Federation - 5.3 Japan - 3.7 Germany - 2.2 Republic of Korea - 1.8 Iran - 1.8 Saudi Arabia - 1.5 The biggest emitters were China, which produced 29% of the total, followed by the US at 15%, the EU at 10% and India at 7.1% But in an interesting development, China's emissions per head of population exceeding those of the European Union for the first time. While the per capita average for the world as a whole is 5 tonnes of carbon dioxide, China is now producing 7.2 tonnes per person, to the EU's 6.8 tonnes. The US is still far ahead on 16.5 tonnes per person. "We now see China's per capita emissions surpassing the EU," said Dr Robbie Andrew, from the Centre for International Climate and Environmental Research in Norway, who was involved in the research.

We may have to get used to winters where spells of weather go on for weeks - or even months.

New research suggests that the main system that helps determine the weather over Northern Europe and North America may be changing.

The study shows that the so-called jet stream has increasingly taken a longer, meandering path.

This has resulted in weather remaining the same for more prolonged periods.

The work was presented at the annual meeting of the American Association for the Advancement of Science (AAAS) in Chicago.

The observation could be as a result of the recent warming of the Arctic. Temperatures there have been rising two to three times faster than the rest of the globe.

According to Prof Jennifer Francis of Rutgers University in New Jersey: "This does seem to suggest that weather patterns are changing and people are noticing that the weather in their area is not what it used to be."

“We can expect more of the same and we can expect it to happen more frequently” Prof Jennifer Francis, Rutgers University

The meandering jet stream has accounted for the recent stormy weather over the UK and the bitter winter weather in the US Mid-West remaining longer than it otherwise would have.

"We can expect more of the same and we can expect it to happen more frequently," says Prof Francis

The jet stream, as its name suggests, is a high-speed air current in the atmosphere that brings with it the weather.

It is fuelled partly by the temperature differential between the Arctic and the mid-latitudes.