As Europe and North America warm, bumblebees should be able to fly north to cooler climes, writes Tim Radford. But they're not: the bees' range is receding in the south, but staying put in the north, and scientists fear their shrinking habitat will put many species at risk of extinction.The humble bumblebee is feeling the squeeze from climate change.

Three kinds of whale, six varieties of seal, the walrus and the polar bear all have these five things in common: they are marine mammals; they depend on the Arctic for their survival as species; they are vulnerable; and biologists know surprisingly little about them. And since the Arctic is warming twice as fast as the rest of the planet, their future could become even more threatened as climate change increases habitat loss.

A global low-carbon energy economy is not only feasible – it could actually double electricity supply by 2050, while also reducing air and water pollution, according to new research. Even though photovoltaic power requires up to 40 times more copper than conventional power plants, and wind power uses up to 14 times more iron, the world wins on a switch to low-carbon energy. These positive findings are published in the Proceedings of the National Academy of Sciences by Edgar Hertwich and Thomas Gibon, of the Norwegian University of Science and Technology Department of Energy and Process Engineering.

Fracking is once again in trouble. Scientists have found that what gets pumped into hydrocarbon-rich rock as part of the hydraulic fracture technique to release gas and oil trapped in underground reservoirs may not be entirely healthy. Environmental engineer William Stringfellow and colleagues at Lawrence Berkeley National Laboratory and the University of the Pacific told the American Chemical Society meeting in San Francisco that they scoured databases and reports to compile a list of the chemicals commonly used in fracking.

Rising greenhouse gas levels are causing stronger winds over the Southern Ocean. It’s good news for Antarctica, writes Tim Radford, as the circumpolar winds are keeping its ice caps cold. But Australia is getting hotter and drier – and its problems will only increase. The answer to one of the enduring puzzles of global warming – the apparently sluggish response of the Antarctic continent to rising greenhouse gas levels – may have been settled by Australian scientists.

Scientists think the amount of methane emitted to the atmosphere from freshwater ecosystems will increase as the climate warms, reports Tim Radford. And that will trigger further warming. This highlights another mechanism by which the global carbon cycle may serve to accelerate rather than mitigate future climate change. British scientists have identified yet another twist to the threat of global warming. Any further rises in temperature are likely to accelerate the release of methane from rivers, lakes, deltas, bogs, swamps, marshlands and rice paddy fields.

It’s long been established that Arctic Ocean sea ice is on the retreat, writes Tim Radford. But it’s the pace of change that’s surprising scientists: latest studies show that the ice-free period is increasing by 5 days / decade. Ice in the Arctic continues to retreat. The season without ice is getting longer by an average of five days every 10 years.

Wildlife in Switzerland is seeking relief from warming temperatures by moving higher up the mountains, reports Tim Radford. Animals and plants are already today adapting to the rising temperatures at a surprising pace. Alpine ecosystems are on the rise. Between 2003 and 2010, plants have managed to scramble up another eight metres of mountain slope. On the way up, they were overtaken by butterflies, which collectively gained another 38 metres of higher ground. Alpine birds in turn fluttered an average of 42 metres higher.