Why is sea ice so important?

After Norwegian scientists described profound changes in the Arctic as a "new era" for sea ice,BBC Weather's Tomasz Schafernaker reports for BBC Global on why it is so important.

New research from the British Antarctic Survey has revealed that both air temperature and warm ocean currents are contributing to the thinning of the Larsen C ice shelf in the Antarctic Peninsula. The team behind the study predict that the ice shelf could collapse within a century, with major consequences for global sea levels.

From BBC News-Weather

Arctic pollution rules 'not enough'

New guidelines have been passed to prevent pollution from ships in polar waters.

The Polar Code, passed at a meeting in London of the International Maritime Organization (IMO), ban ships from releasing oil, sewage, chemicals and waste into the sea.

The measures are set to come into force in 2017.

But environmentalists say the regulations do not go far enough.

WWF said a strong, legally binding Polar Code was particularly urgent in the Arctic, where new sea routes are expected to open up in coming decades.

IMO member states should "honour the original vision of the Polar Code, which saw environmental protection as a priority," said Rod Downie, WWF-UK's Polar Programme Manager.

"That means additional measures to reduce the risk of invasive marine species, more stringent requirements for oil spill response, banning the use and restricting carriage of heavy fuel oil by ships in the Arctic, reducing air emissions and black carbon, and addressing underwater noise," he said

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Ice retreat

The IMO is the United Nations agency with responsibility for the safety and security of shipping and the prevention of marine pollution by ships.

A spokesperson for the IMO said many of the things not specifically addressed in the Polar Code are addressed, or will be addressed, by other measures.

The Arctic is the fastest warming region of the planet.

If the polar ice retreats it could speed up the rise in global temperatures and change the world's weather patterns.

It could also open up a faster route for commercial cargo ships between Europe and Asia, and boost trade in ports in Arctic countries such as Russia, Norway and Canada.

From BBC Science/ Environment

Global carbon dioxide (CO2) concentrations have reached a new monthly record of 400 parts per million, according to scientists.

The milestone was announced by the US National Oceanic and Atmospheric Administration (Noaa).

They said it was the first month that the entire globe broke 400ppm, reaching levels that haven't been seen for about two million years.

Noaa's Pieter Tans said that reaching the mark was "a significant milestone".

Scientists announced that CO2 had passed the 400 ppm level for the first time in the Arctic in 2012, and then at Mauna Loa in Hawaii in 2013.

"It was only a matter of time that we would average 400 parts per million globally," said Mr Tans, lead scientist at Noaa's Global Greenhouse Gas Reference Network.

He added that CO2 has risen more than 120 parts per million since pre-industrial times.

"Half of that rise has occurred since 1980," he said.

Noaa collects its data on global carbon dioxide concentration on air samples taken from 40 sites around the world, including some remote islands.

From BBC Science/Environment