Britain has announced a tax on sugary drinks. Countries should go further and target foods that have large carbon footprints.

Original Source

A manipulative experiment in which a reef is alkalinized in situ shows that calcification rates are likely to be lower already than they were in pre-industrial times because of acidification.

Using a global coupled biogeochemistry–climate model and a chemistry and transport model reveals that China’s present-day global radiative forcing is about ten per cent of the current global total, made up of both warming and cooling contributions; if in the future China reduces the cooling forcings, global warming could accelerate.

Evidence from ecological studies, eddy flux towers and satellites shows that many tropical forests ‘green up’ during higher sunlight annual dry seasons, suggesting they are more limited by light than water. Morton et al. reported that satellite-observed dry-season green up in Amazon forests is an artefact of seasonal variations in sun-sensor geometry. However, here we argue that even after artefact correction, data from Morton et al. show statistically significant increases in canopy greenness during the dry season.

The terrestrial biosphere can release or absorb the greenhouse gases, carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), and therefore has an important role in regulating atmospheric composition and climate. Anthropogenic activities such as land-use change, agriculture and waste management have altered terrestrial biogenic greenhouse gas fluxes, and the resulting increases in methane and nitrous oxide emissions in particular can contribute to climate change.

Following a record winter in many ways, Arctic sea-ice cover seems poised to reach one of its smallest winter maxima ever. As of 28 February, ice covered 14.525 million square kilometres, or 938,000 square kilometres less than the 1981–2010 average. And researchers are using a new technique to capture crucial information about the thinning ice pack in near real time, to better forecast future changes.

Original Source

The contribution of the Greenland and West Antarctic ice sheets to sea level has increased in recent decades, largely owing to the thinning and retreat of outlet glaciers and ice streams. This dynamic loss is a serious concern, with some modelling studies suggesting that the collapse of a major ice sheet could be imminent or potentially underway in West Antarctica, but others predicting a more limited response.

New Delhi may be the world’s most polluted city, but it’s making an effort to relinquish that title. With pollution from particulate matter at potentially lethal levels early last December, city officials took a drastic step: they announced that they would temporarily restrict the use of private vehicles by allowing owners to drive only on alternate days, based on the sequence of their number plates.

Original Source

The identification of properties that contribute to the persistence and resilience of ecosystems despite climate change constitutes a research priority of global relevance. Here the researchers present a novel, empirical approach to assess the relative sensitivity of ecosystems to climate variability, one property of resilience that builds on theoretical modelling work recognizing that systems closer to critical thresholds respond more sensitively to external perturbations.

LIGO 'hears' space-time ripples produced by black-hole collision.

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