3 August 2015, The Conversation, The scariest part of climate change isn’t what we know, but what we don’t. We know a lot about what climate change will do, but ‘when’ is a tougher question. “It’s tough to make predictions, especially about the future”: so goes a Danish proverb attributed variously to baseball coach Yogi Berra and physicist Niels Bohr. Yet some things are so important — such as projecting the future impacts of climate change on the environment — that we obviously must try. An Australian study published last week predicts that some rainforest plants could see their ranges reduced 95% by 2080. How can we make sense of that given the plethora of climate predictions? In a 2002 press briefing, Donald Rumsfeld, President George W. Bush’s Secretary of Defence, distinguished among different kinds of uncertainty: things we know, things we know we don’t know, and things we don’t know we don’t know. Though derided at the time for playing word games, Rumsfeld was actually making a good point: it’s vital to be clear about what we’re unclear about. So here’s my attempt to summarise what we think we know, don’t know, and things that could surprise us about climate change and the environment. Read More here
hmcadmin
2 August 2015, Climate News Network, Global temperatures have risen by 1°C in the past 150 years, and one scientist says doubling that level could unleash catastrophic sea level rise this century. The world is now halfway towards the internationally-agreed safety limit of a maximum 2°C rise in global average temperatures, researchers say. That limit seeks to prevent the global warming caused by the burning of fossil fuels exceeding 2°C above the pre-industrial global temperature. The UN’s Paris climate summit later this year aims to ensure that it is not breached. It appears that the human race has taken roughly 250 years to stoke global warming by 1°C. On present trends, we look likely to add the next 1°C far more quickly – across much of the world, many climate scientists believe, by the middle of this century. The research is published in the journal New Scientist, which commissioned it. As so often with climate projections, it needs qualifying and teasing apart. Some scientists, for example, warn that there’s uncertainty about just what the pre-industrial global temperature was. The New Scientist research is careful to be specific: it says global surface temperature is now passing 1°C of warming “relative to the second half of the 19th century”. Farewell, hiatus. And one of the four main trackers of temperature thinks that milestone will be passed only if there is a strong El Niño, the cyclic Pacific weather phenomenon that periodically brings widespread chaos in its wake. However, the research looks likely finally to lay to rest the argument that global warming is slowing and stuttering to a virtual halt, the so-called hiatus theory. Kevin Trenberth, of the USNational Center for Atmospheric Research in Boulder, Colorado, told New Scientist: “There’s a good chance the hiatus is over.” Read More here
2 August, The Guardian, The truth about the people and numbers in loud and furious migration debate. David Cameron referred to a ‘swarm’ from Calais. But migration is happening across the globe, and the motives are more complex than stereotypes suggest. ‘You have got a swarm of people coming across the Mediterranean seeking a better life, wanting to come to Britain because Britain has got jobs,” David Cameron said last week. Leaving the language aside, there is some truth in this. But it also misses out a lot. This is not a British problem. It is a European problem and a North African one and a Middle Eastern one. It is not going to be solved by a few miles of barbed-wire fencing or, as the prime minister emerged from Friday’s “emergency meeting” to say, “more dogs”. Why do all the people coming across the Mediterranean want to come to Britain? Read More here
1 August 2015, Climate Network News, Wildfire threat spreads across warming world. As climate change warms the world vegetation dries, rainfall patterns waver and the threat of wildfire spreads. Wildfire – nature’s way of turning fallen vegetation into the next season’s nutrients – is a growing hazard. In the last 35 years, the wildfire season has grown longer by a fifth, and wildfire is now a threat to one fourth of all the plant-covered land on the planet. US researchers report in Nature Communications that since 1970 the number of days without rain has increased by well over one day every decade. William Jolly of the US Forest Service in Missoula, Montana and colleagues say they examined the fire season worldwide for the study period, taking into consideration all the factors that are used to calculate fire hazard: wind, humidity and temperature, as well as rainfall levels. They found that the combined changes in the surface weather have meant that the fire season has increased so far by 18.7%. Worldwide, wildfires sear, scorch or incinerate about 350 million hectares of ground cover every year. Changes in the rainfall patterns were a factor, with the number of rain-free days increasing by 1.31 days per decade. The season of smoke and cinders and smouldering stumps had been extended almost everywhere. Read More here