14 July 2017, Nature Communications, The unprecedented 2015/16 Tasman Sea marine heatwave. The Tasman Sea off southeast Australia exhibited its longest and most intense marine heatwave ever recorded in 2015/16. Here we report on several inter-related aspects of this event: observed characteristics, physical drivers, ecological impacts and the role of climate change. This marine heatwave lasted for 251 days reaching a maximum intensity of 2.9 °C above climatology. The anomalous warming is dominated by anomalous convergence of heat linked to the southward flowing East Australian Current. Ecosystem impacts range from new disease outbreaks in farmed shellfish, mortality of wild molluscs and out-of-range species observations. Global climate models indicate it is very likely to be that the occurrence of an extreme warming event of this duration or intensity in this region is respectively ≥330 times and ≥6.8 times as likely to be due to the influence of anthropogenic climate change. Climate projections indicate that event likelihoods will increase in the future, due to increasing anthropogenic influences. Read More here
Monthly Archives: July 2017
13 July 2017, The Conversation, Can property survive the great climate transition? As we become an increasingly urban species, urban resilience is emerging as a big deal. The idea is generating a lot of noise about how to develop or retrofit cities that can deal with the many challenges before us, or consume less energy in the transition to post-carbon economies. There is ample activity aimed at making this happen, including through designing and building ecocities, and calls such as that of the Transition Towns movement, which suggests substantial changes to our ways of life might be both necessary and inevitable. In all of this, very little has been said about the elephant in the urban living room – property. Property systems are the codification of our relationship to place and the way in which many of us make a claim to place, including a roof over our heads. If our cities are to become more resilient and sustainable, our systems of property need to come along for the ride. Static property rights will be tested Western systems of property law assume property is delineated and static: the property holder has invested (often substantial) financial resources to secure a claim to that neatly identified parcel of land and/or buildings. Further, the property owner expects to make a nice economic return on their parcel. Unfortunately, the future doesn’t look neatly delineated or static. Many researchers and practitioners tell us the future might not look like anything we’ve ever seen. Some say we are reaching a tipping point, after which the rules we have constructed will no longer apply or be of use. As some property is washed out to sea, much may become too hot to live in, and what remains may be subject to relentless and increasing waves of migration and instability. In the face of such calamity, how then might we – as a big, inclusive “we” – talk about and demonstrate our relationship to place? Will we be able to do that without seeing the emergence of metaphorical or actual fortresses? Read More here
13 July 2017, Climate Central, Greenhouse Gases Are Rapidly Changing the Atmosphere. Humanity’s grand experiment in the atmosphere continues, and a new report documents just how far it’s gone. On Tuesday, the National Oceanic and Atmospheric Administration released its annual index of 20 key greenhouse gases. It shows that their direct influence on the climate has risen 140 percent since 1750, with 40 percent of that rise coming in just the past 26 years. That increase is almost entirely due to human activities and has caused the planet to warm 1.8°F (1°C) above pre-industrial temperatures. The index takes greenhouse gas measurements from about 80 ships and observatories around the world — gathered in all their parts per million and parts per billion glory — and boils them down into a simple numerical index, which defines the rise from 1700-1990 as 100 percent or simply 1. This year’s number: 1.4. It’s a simple number that contains multitudes. For example, carbon dioxide’s influence on the climate has increased 54 percent overall since 1990. The four other major greenhouse gases in the index, which include nitrous oxide, methane and two types of chlorofluorocarbons, are responsible for 42 percent of the increase with 15 minor greenhouse gases accounting for the missing 4 percent. Carbon dioxide has risen rapidly in the atmosphere, with 2016 marking the second-largest annual increase ever observed at the Mauna Loa Observatory, the world’s main measuring station. This May, monthly carbon dioxide peaked at 409.65 parts per million. That’s a record high and a mark unseen in human history. If emissions continue on their current trend, the atmosphere will hit a state unseen in 50 million years. A bright spot in the report is the decline of chlorofluorocarbons’ warming influence on the planet. The chemicals were commonly used as refrigerants until the Montreal Protocol banned them in 1989. The treaty came about because they deplete the protective ozone layer, but phasing them out has also helped reduce their warming impact on the climate. Read More here
12 July 2017, New York Times, An iceberg the size of Delaware just broke away from Antarctica. A chunk of floating ice that weighs more than a trillion metric tons broke away from the Antarctic Peninsula, producing one of the largest icebergs ever recorded and providing a glimpse of how the Antarctic ice sheet might ultimately start to fall apart. A crack more than 120 miles long had developed over several years in a floating ice shelf called Larsen C, and scientists who have been monitoring it confirmed on Wednesday that the huge iceberg had finally broken free. There is no scientific consensus over whether global warming is to blame. But the landscape of the Antarctic Peninsula has been fundamentally changed, according to Project Midas, a research team from Swansea University and Aberystwyth University in Britain that had been monitoring the rift since 2014. “The remaining shelf will be at its smallest ever known size,” said Adrian Luckman, a lead researcher for Project Midas. “This is a big change. Maps will need to be redrawn.” Read More here