The latest report on Renewables from the Committee on Climate Change (CCC) offers lukewarm support for electricity generation from tidal streams. The UK has some of the fiercest tidal currents in the world, but the CCC says the tidal turbines will deliver energy at a higher cost than PV in 2040. The assumptions behind this pessimism are questioned in this article.
The World Health Assembly is due to address water and sanitation for the first time in its history at its meeting this week. Water Aid is calling on leaders to provide safe water and sanitation to transform the lives of people in countries like Uganda, where the lack of access to these basic services is a major cause of disease
Acidity is measured by its pH (power of hydrogen) value. Fresh water has a pH reading of 7. Readings below that are considered to be acidic. Those above 7 are alkaline. Surface sea water had a reading of 8.2 a century ago.
As the world's climate warms, will the Pacific Ocean make matters worse by dumping extra heat into the atmosphere? Ancient fossils and the latest modelling both suggest such fears may be unfounded. But there is a downside: extreme weather caused by the Pacific's shifting waters might become more common.
Better forecasting of where the wind is blowing could allow British fossil fuel power stations to be switched off and counter critics' claims that wind power is too intermittent.
The head of the UN's Population Fund, Babatunde Osotimehin, talks to Annie Kelly about the key issues driving the debate around population and food security
If you want to see global warming's signature, look to the Arctic. Up north, the air is warming and the ice is melting. As all of that reflective ice goes away, the Arctic Ocean is soaking up more sunlight, further enhancing warming. Melting Arctic ice is also contributing significantly to sea level rise.
Europe's forests can play a key role in helping mitigate the impact of climate change, a report described as the most comprehensive of its kind concludes.
Global warming could be slowed down if governments cleaned up what's known as black carbon from industry and cooking fires, 50 of the world's leading atmospheric scientists said on Tuesday.
What a difference a year makes. In February 2010, climate sceptics were crowing about apparent admissions from Phil Jones at the Climate Research Unit (CRU) in Norwich, UK, that warming trends over the period 1995 to 2009 were "not statistically significant"
Nearly half of the UK's top companies do not have targets on greenhouse gas emissions, despite years of legislation and campaigning on the issue, a study by the Carbon Trust has found.
On the eve of climate talks that began last week, the UN's climate chief, Christiana Figueres, told the Guardian: "We are putting ourselves in a scenario where we will have to develop more powerful technologies to capture emissions out of the atmosphere."