19 January 2016, Carbon Brief, Heat absorbed by oceans has doubled since 1997. The ocean is taking up twice as much heat now as it was just two decades ago, relative to pre-industrial times. According to new research, a third of that heat – and rising – is finding its way into the deep ocean below 700m, temporarily slowing warming at Earth’s surface. That the oceans are warming isn’t a surprise to scientists – it’s what we would expect from rising greenhouse gases. The more surprising part is the speed at which it is taking place. The new study, published today in Nature Climate Change, says as much heat entered the oceans in the last 18 years as in the previous 130 years. The new findings add to a growing body of research on the unseen impact of human activity on the oceans and the role they play in moderating the temperature we feel on Earth’s surface, say scientists not involved in the study. A brief history The oceans take up more than 90% of the heat trapped by greenhouse gases. It follows, then, that we would look to the oceans in seeking the fingerprint of human-caused climate change. Read more here
Yearly Archives: 2016
18 January 2016, The Conversation, Heading north: how the export boom is shaking up Australia’s gas market. You might have missed it, but last month something unusual happened in Australia’s eastern gas market. Gas in a major pipeline that normally flows from north to south started flowing in the opposite direction for the first time. This seemingly small change reflects big upheavals in Australia’s gas market as exports expand significantly. At Gladstone, Queensland, coal seam gas companies have invested around A$80 billion in equipment to chill gas to -160℃ and convert it to liquefied natural gas (LNG). This liquefied gas is then loaded onto ships and sold to overseas customers. Exports are well underway with over 80 70,000-tonne LNG cargoes loaded in 2015. As shown in the following chart, eventually three times as much gas will be exported from Queensland in the form of LNG each year as has historically been used in all of eastern Australia. Read More here
17 January 2016, Climate News Network, Grasses’ growing role for American cars. Second-generation biofuel made from natural grass species challenges ethanol derived from maize crops as the US seeks to reduce its fossil fuel use. In tomorrow’s world, it won’t be just the corn on the great American plains that is as high as an elephant’s eye. It will be the elephant grass as well. To deliver on US promises to reduce fossil fuel use, American motorists in future will drive on miscanthus − as elephant grass is also known – and prairie switchgrass. Researchers led by Evan DeLucia, professor of biology at the University of Illinois, report in a new journal, Nature Energy, that to exploit biofuels – which recycle carbon already in the atmosphere, and are therefore technically “carbon-neutral” – Americans will have to think again about how they manage the change away from fossil fuels. Right now, the US Environmental Protection Agency’s Renewable Fuel Standards foresee that by 2022 American motorists will start up their cars with 15 billion gallons (57 billion litres) of ethanol from corn. But this could be augmented by 16 billion gallons (60 billion litres) of biofuel derived from perennial grasses. Energy source The switch to the prairie’s native switchgrass (Panicum virgatum) andEurasian elephant grass (Miscanthus giganteus) will be necessary because there are problems with corn as a source of energy. One is that, in an increasingly hungry world, it reduces the overall levels of food available. The second is that corn requires annual planting, fertilising and harvesting. Perennial grasses simply grow, and can be mown once a year. So by turning over surplus land to swift-growing grasses, and at the same time reducing the levels of carbon dioxide released from cultivation, the US could meet its target of a 7% reduction in its annual transportation emissions by 2022. If farmers went on gradually to switch from corn to the grasses, the reduction could get as high as 12%. Read More here
16 January 2016, Climate News Network, Giant boost for south polar waters. Massive icebergs more than 18km long are feeding vital nutrients into the Southern Ocean and helping to increase its carbon storage capacity. British scientists have identified the monsters that fertilise the Southern Ocean and help remove carbon dioxide from the atmosphere. Giant icebergs drifting northwards could be responsible for storing up to a fifth of all the carbon that sinks into the south polar waters. Geographers at the University of Sheffield report in Nature Geoscience journal that they analysed 175 satellite images of ocean colour – an indicator ofphytoplankton activity. They learned that each huge iceberg, as it breaks off the ice shelf and begins to float away, also begins to cascade iron and other vital mineral nutrients in its melting waters. This is enough to stimulate ferocious plankton productivity for up to a month in its wake. The icebergs are not small − the researchers define “giant” as at least 18 kilometres in length − and nor can they be very frequent. Area of influence “We detected substantially enhanced chlorophyll levels, typically over a radius of at least four to 10 times the iceberg’s length,” says Grant Bigg, Professor in Earth Systems Science, who led the research. “The evidence suggests that carbon export increases by a factor of five to 10 over the area of influence, and up to a fifth of the Southern Ocean’s downward carbon flux originates with giant iceberg fertilisation. “If giant iceberg calving increases this century, as expected, this negative feedback on the carbon cycle may become more important than we previously thought.” The guess is that the Southern Ocean accounts for perhaps 10% of the ocean’s absorption of carbon dioxide from the atmosphere. Research such as this is part of the global process of understanding all theintricacies of the carbon cycle − in turn, an important part of modelling future climate change as a consequence of rising levels of greenhouse gas in the atmosphere, driven by human combustion of fossil fuels. Read More here