2 August 2016, Carbon Brief, Scientists confirm multiple climate records broken in 2015. Last year saw records in the Earth’s climate system continue to tumble, says the latest State of the Climate report from the US National Oceanic and Atmospheric Administration (NOAA). The 300-page report, now in its 26th year, is an annual assessment of the world’s climate, scrutinising the Earth’s land, oceans, ice and atmosphere. It is compiled by more than 450 scientists from 62 countries. Carbon Brief takes a look at how rising greenhouse gas emissions, with the help of a strong El Niño event, made 2015 into a record-breaker. Greenhouse gases Last year was record-breaking for concentrations of all three of the main long-lived greenhouse gases that contribute to climate change: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). At the Mauna Loa Observatory, where scientists have been monitoring CO2 since the 1950s, the average concentration for the year as a whole surpassed 400 parts per million (ppm) for the first time. At 400.8ppm, CO2 levels in the atmosphere were 3.1ppm greater than 2014 – the largest annual increase of the 58-year record. In addition, March 2015 was the first time average CO2 concentration across the globe has been more than 400ppm for an entire month. Global annual average CO2 levels for 2015 finished just shy of the 400ppm milestone, at 399.4 ppm. You can see this in the chart below, one of several graphics produced alongside the report. Meanwhile, levels of both methane and nitrous oxides reached new record highs in 2015, at 1834.0 parts per billion (ppb) and 328.2ppb, respectively. Read More here
Category Archives: The Science
1 August 2016, Carbon Brief, Guest post: An Antarctic voyage in search of blue carbon. A guest article from Dr David Barnes, a marine benthic ecologist at the British Antarctic Survey, and colleagues Chester Sands, Narissa Bax, Rachel Downey, Christoph Held, Oliver Hogg, Kirill Minin, Camille Moreau, Bernabé Moreno and Maria Lund Paulsen from the Antarctic Seabed Carbon Capture Change project. As global temperatures rise, the response from different parts of the climate system can amplify or dampen the pace of warming. These are known as feedback loops. Melting sea ice, for example, tends to cause a positive feedback loop. The loss of sea ice means that energy from the sun that would have been reflected away by the bright white ice is instead absorbed by the darker ocean. This causes further warming, which in turn causes more sea ice loss, and so on. Negative feedback loops, on the other hand, work to reduce further warming. Blue carbon is one such example. Blue carbon is the term given to carbon stored in coastal or marine ecosystems. It typically refers to salt marshes, mangroves, and seagrass beds, which capture CO2 from the atmosphere and store it in their leaves, stems and in the soil. A less well-known – but no less important – contribution to blue carbon comes from tiny organisms that live on the seabed. These creatures, known as zoobenthos, take up carbon from the plankton they eat and the CO2 in seawater they use to build their skeletons. When the zoobenthos die, their bodies are eventually buried in the sediment of the seabed, sequestering carbon in the process. Our initial research suggests that coastal areas of the Arctic and Antarctic are absorbing and storing more blue carbon as the climate warms. This boost to carbon storage could form one of the biggest negative feedback loops against climate change on Earth. Read More here
16 July 2016, Climate News network, Cyclones set to get fiercer as world warms. New analysis of cyclone data and computer climate modelling indicates that global warming is likely to intensify the destructive power of tropical storms. Powerful tropical storms − known variously as cyclones, typhoons and hurricanes − bring death and destruction to huge swathes of the Earth’s surface. And new research suggests that they are likely to become even stronger. Storms such as the super-typhoon Nepartak that scoured Taiwan earlier this month with winds of 150 miles per hour and then flooded parts of China, are expected to grow even fiercer as the planet warms. That trend is not clear yet, but scientists in the US say it soon will be. Ironically, one of the main reasons why these storms will gain in power is theeffort in many countries to reduce air pollution. Damaging as it is in stunting and shortening lives, the one arguable benefit of filthy air is its ability to dampen the effects of greenhouse gases (GHGs) on cyclones and their like. Over the last century, tiny airborne particles called aerosols, which cool the climate by absorbing and reflecting sunlight, have largely cancelled out the effects of GHG emissions on tropical storm intensity, according to a new scientific review paper published in Science journal. Read More here
11 July 2016, Carbon Brief, Shifting global cloud patterns could amplify warming, study says. A new study sheds light on one of the biggest uncertainties in predicting future changes to Earth’s climate: clouds. Clouds both warm the planet by insulating the Earth’s surface like a blanket, while simultaneously cooling it by reflecting away energy from the sun. Climate models predict that as the Earth warms in response to greenhouse gases, clouds will shift towards the poles and sit higher in the sky, further speeding up warming. But clouds are tricky to measure and until now, scientists haven’t been able to find direct evidence that these changes were actually happening in the real world. The new study published in Nature uses satellite data to identify how cloud patterns have changed in recent decades, confirming the pace of warming predicted by climate models. Satellite data Scientists use weather satellites to measure the extent, height and thickness of clouds. But these measurements suffer from several issues that can limit how useful they are for detecting long-term changes in cloudiness. Small discrepancies in the data are caused by satellite sensors degrading over time and being replaced by new, more precise instruments. Another issue is the gradual change in the orbit of satellites themselves, says the study’s lead author, Prof Joel Norris, professor of climate and atmospheric sciences at the Scripps Institution of Oceanography in San Diego. He explains to Carbon Brief: Read More here