The weakening sun was not the determinant factor for the Little Ice Age. Strong volcanic eruptions in particular, but also a smaller amount of greenhouse gases in the atmosphere were important factors during this period of cooler climate in the 16th and 17th century, a new study shows. This implies that low solar activity, which is expected by some researchers for the coming decades, cannot considerably slow down global warming caused by humankind’s greenhouse gas emissions.

The environmental restoration of Ogoniland could prove to be the world's most wide-ranging and long term oil clean-up exercise ever undertaken if contaminated drinking water, land, creeks and important ecosystems such as mangroves are to be brought back to full, productive health. A major new independent scientific assessment, carried out by the United Nations Environment Programme (UNEP), shows that pollution from over 50 years of oil operations in the region has penetrated further and deeper than many may have supposed.

When politicians fail, should technicians take over? Can one capture carbon dioxide and store it underground? Should we do it? A new paperback contains all possible arguments regarding this main question of climate change and climate policy – and helps finding the right answer. By Udo E. Simonis

The West Antarctic ice sheet is a potential tipping element of the climate system that might have partially tipped already. According to a study now published in Climatic Change, experts can not rule out that ice masses in the Amundsen Sea sector of Antarctica have already begun to destabilize. This is one of the results of a new assessment of the current state of six potentially unstable regions in the climate system with large direct impacts on Europe. The likelihood of climatic transitions of these elements generally increases as global mean temperature increases due to greenhouse gases emitted by human activity.

Large areas of the globe are likely to warm up so quickly that by the middle of this century even the coolest summers will be hotter than the hottest summers of the past 50 years. By Donna Hesterman

Multiple Benefits Include Improved Air Quality and Human Health, Higher Crop Yields, Reduced Rate of Climate Change in the Near-Term and a Chance to Slow Serious Melting of the Arctic. New UNEP-WMO Assessment Complements Urgent Action Needed to Cut CO2 Emissions Under UN Climate Treaty.

The much debated date for phasing out nuclear power in Germany has little impact on consumer prices of electricity, according to scientists. An exit before 2020, however, could push up emissions of the greenhouse gas CO2 in the short term. Yet security of supply is the crucial point. This security can only be guaranteed if both renewable energies and fossil power generation along with power grids are scaled up, shows a study which for the first time presents a comprehensive calculation of the effects. Deploying power plants fired by gas instead of coal could, at an equal price, lead to less emissions and more competition.

“Through their consumption most industrialised countries contributed more to emission increases in developing countries than they cut emissions at home”, said Jan Minx. In 2008, emission increases in developing countries from industrialised countries’ consumption exceeded the emission savings made in industrialised nations by five times.

This cover letter is provided to explain the reasoning and concerns that were conveyed in a letter which I sent to Secretary of Agriculture, Thomas Vilsack on January 17, 2011 (Attachment 1). The letter was not intended for public distribution; however, the letter was 'leaked' and subsequently posted on the internet from which it soon became public knowledge world-wide.

Depletion of the ozone layer- the shield that protects life on Earth from harmful levels of ultraviolet rays - has reached an unprecedented level over the Arctic this spring because of the continuing presence of ozone-depleting substances in the atmosphere and a very cold winter in the stratosphere. The stratosphere is the second major layer of the Earth’s atmosphere, just above the troposphere. The record loss is despite an international agreement which has been very successful in cutting production and consumption of ozone destroying chemicals. Because of the long atmospheric lifetimes of these compounds it will take several decades before their concentrations are back down to pre-1980 levels, the target agreed in the Montreal Protocol on Substances that Deplete the Ozone Layer.