15 August 2016, Washington Post, What we can say about the Louisiana floods and climate change. Here we are again, with a flood event upending the lives of large numbers of Americans and making everybody wonder about the role of climate change. In this case, it’s the stunning, multiday flooding in southern Louisiana that hit after a low pressure system combined with record amounts of atmospheric water vapor, dumping more than two feet of rainfall over three days in some places. At least 11 people were killed, and thousands have had to leave their homes.On Monday, climate researchers and weather experts were in what’s by now a familiar posture — explaining that, no, this event wasn’t “caused” by climate change, but then again, it’s precisely the sort of event that you’d expect to see more of on a warming planet. “Climate change has already been shown to increase the amounts of rain falling in the most intense events across many parts of the world, and extreme rainfall events like this week’s Louisiana storm are expected [to] grow increasingly common in the coming years,” wrote the Weather Underground’s Bob Henson and Jeff Masters. [‘The worst situation I’ve ever been through.’ Six killed, thousands displaced during historic Louisiana flooding] “Louisiana is always at risk of floods, naturally, but climate change is exacerbating that risk, weighting the dice against us,” Katharine Hayhoe, a climate researcher at Texas Tech University, told The Washington Post. “How long will it be until we finally recognize that the dice are loaded?” The easiest link between climate change and extreme weather events involves heat waves, arecent study by the National Academy of Sciences found. This makes sense: A warming planet overall breaks warm-temperature records more frequently than cold-temperature records and sets the stage for lengthier, or stronger, bouts of extreme heat. Read More here
Category Archives: Impacts Observed & Projected
13 August 2016, Pacific Standard, America’s Latest 500-Year Rainstorm Is Underway Right Now in Louisiana. Observers are calling the record floods a “classic signal of climate change” — and high-resolution models predict another one to two feet of rain by Saturday evening. By mid-morning on Friday, more than a foot of rain had fallen near Kentwood, Louisiana, in just a 12-hour stretch — a downpour with an estimated likelihood of just once every 500 years, and roughly three months’ worth of rainfall during a typical hurricane season. It’s the latest in a string of exceptionally rare rainstorms that are stretching the definition of “extreme” weather. It’s exactly the sort of rainstorm that’s occurring more frequently as the planet warms. In response to the ongoing heavy rains, Louisiana Governor John Bel Edwards. declared a statewide state of emergency on Friday, and local governments aredistributing sandbags, conducting water rescues, and facilitating evacuations. The New Orleans Times-Picayune is maintaining a live blog of the latest developments. The Tickfaw River north of New Orleans soared 18 feet in about 12 hours to a new record crest on Friday morning, beating the water level of April 1983, and five feet higher than the high-water mark during Hurricane Isaac in 2012, the last hurricane to make landfall in Louisiana. Read More here
7 August 2016, The Guardian, Scientists warn world will miss key climate target. Grim backdrop to vital global emissions talks as new analysis shows 1.5C limit on warming is close to being broken. Leading climate scientists have warned that the Earth is perilously close to breaking through a 1.5C upper limit for global warming, only eight months after the target was set. The decision to try to limit warming to 1.5C, measured in relation to pre-industrial temperatures, was the headline outcome of the Paris climate negotiations last December. The talks were hailed as a major success by scientists and campaigners, who claimed that, by setting the target, desertification, heatwaves, widespread flooding and other global warming impacts could be avoided. However, figures – based on Met Office data – prepared by meteorologist Ed Hawkins of Reading University show that average global temperatures were already more than 1C above pre-industrial levels for every month except one over the past year and peaked at +1.38C in February and March. Keeping within the 1.5C limit will be extremely difficult, say scientists, given these rises. These alarming figures will form the backdrop to the Intergovernmental Panel on Climate Change talks in Geneva this month, when scientists will start to outline ways to implement the climate goals set in Paris. Dates for abandoning all coal-burning power stations and halting the use of combustion engines across the globe – possibly within 15 years – are likely to be set. Read More here
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