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hurricanes

August climate impacts stories: Hurricane Harvey, other climate change fueled-floods, and more

August 30th: Harvey reminds us that we should treat climate change as we treat other public health threats. That’s the argument in this New York Times op-ed: Harvey, the storm that humans helped cause.

Holthaus-harveyAugust 29th: The most sobering hot-take on Harvey is by Eric Holthaus: Harvey is what climate change looks like.

August 27: Michael Mann offered a clear explanation of the climate change-Hurricane Harvey connection.

Climate change boosts hurricanes through higher and hotter seas say @KHayhoe @AndrewDessler: The relationship between hurricanes and climate change.

August 26: Rapid hurricane intensification, like we’ve seen with Harvey, is consistent with climate change, writes Chris Mooney.

August 25: First tanker crosses Arctic from Europe to Asia-without icebreaker help. Fleet of 15 coming soon.

August 24:Alaska’s permafrost is thawing, and that has huge implications, locally, regionally, and globally. (My colleagues Beth Herndon and Lauren Kinsman-Costello are studying how permafrost melt, wetlands, carbon, and phosphorus interact in the Alaskan tundra.

2017WarmNights_cleveland_en_title_lgAugust 23: As the number of warm nights is increasing, it makes it harder to recover from heat waves.

August 22: Britain’s seabird colonies face catastrophe as warming waters disrupt their food supply. But we don’t know exactly how big problem is because the UK government won’t fund a new seabird census. The last one was done in 2000.

August 20: High Ground Is Hot Property as Sea Level Rises: Climate Gentrification in Miami.

August 19: Climate gloom and doom? Bring it on. But we need stories about taking action, too. (via @ClimateCuddles)

August 16:Humid heat waves that can kill healthy people in hours will affect millions in South Asia in decades.

August 15:

August 14th: 91 volcanoes discovered under the West Antarctic Ice Sheet!!!! This is so exciting on multiple levels, from the pure geo-nerdery to the potential climate change impacts. Geeking out. (Read Andrew Freedman’s article for all of the details, but its possible that (1) geothermal heating associated with the volcanoes will contribute to melting and destablization; (2) melting the ice sheet could enhance volcanic activity as the pressure is released; and (3) the volcanoes will help anchor the ice sheet in place and reduce the possibility of catastrophic collapse. These are not mutually exclusive possibilities.)

 

August 13th: Flooding in Miami now happens every spring tide. Rainfall & storm surges don’t help out either. I liked the headline in the Washington Post: “Flooding in Miami is no longer news – but it is certainly newsworthy.”

August 12th: Sometimes you just have to laugh, so you don’t cry. Talking about climate politics, with humor. Thanks, Stephen Colbert.

 

August 11th: Climate change fueled a mega-rainstorm that flooded Louisiana 1 year ago, and the vulnerable people caught in the flood are still picking up the pieces. Special and important reporting by Climate Central.

August 10th: A new paper in Science shows that European floods have shifted in timing, up to 2 weeks earlier per year, since 1950. What’s particularly intriguing about the study is that the timing shifts haven’t just occurred in snowy regions, but also in places where rainfall is causing water tables to rise and soils to become more saturated earlier in the spring.

August 9th: Erratic weather affects subsistence rice farmers in Madagascar, further proof that some of the worst climate change impacts will be felt by those least responsible for causing it.

August 7th: Peru’s glaciers have made it a laboratory for adapting to climate change. It’s not going well. This is a really nice feature story from the Washington Post.

August 5th: A new report says that extreme heat & weather could kill 50x more people per yr in Europe by 2100 than today. That may be overestimate, but a more reasonable number in the report is that 2 out of every 3 Europeans will be affected by weather disasters (per year?) compared to 1 in 20 today. Heat waves will account for 99% of all the excess deaths predicted, and it’s awfully hard to relocate away from a heat wave.

August 4th: If you are not yet listening to smart & human commentary on climate change, what’s stopping you?

 

August 2nd: A visualization that condenses space and time to tell a powerful story about the local and global impacts of climate change through the 20th century and beyond.

 

In slow-moving hurricanes, the danger comes from all the water

Cross-posted at Highly Allochthonous When Hurricane Isaac passed over New Orleans as a Category 1 storm on the seventh anniversary of the disastrous Hurricane Katrina, everyone in the US let out a big sigh of relief. A category 1 storm, the lowest level of hurricane intensity on the Saffir-Simpson scale, meant sustained winds in the 74-95 mile per hour (119-153 km/hr) range, which are described as “very dangerous winds [that] will produce some damage.” There were few, if any, mandatory evacuation orders in Louisiana, and the media interviewed people saying that they heard Isaac would be a Category 1 storm so they “didn’t think it would be that bad.” Those people opted to stay in their homes Louisiana’s Plaquemines Parish, along the Mississippi River near New Orleans. Indeed, as the early reports from Louisiana came out, it sounded as if the storm had been relatively low in drama.

Hurricane swirl as Isaac makes landfall in Lousiana contrasts with the bright city lights in the southeastern US

This will be the iconic image of Hurricane Isaac. NASA/NOAA/DoD VIIRS image of the hurricanes clouds superimposed on the city lights on the southeastern US. All those clouds are full of water. Image source: http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=79023

Only later did reports start to trickle out of levees overtopped, and people stranded on rooftops and in attics, being rescued by neighbors with boats. The flooding this time wasn’t in New Orleans itself, but in nearby Plaquemines Parish, where levee upgrades weren’t scheduled to be completed for a few more years. At least one levee overtopped, flooding the town of Braithwaite and surrounding areas where about 1700 people live, with up to 4.3 m (14 ft) of water. That water ended up trapped between the federal, main Mississippi River levee and more locally managed back levees. State officials have now breached those back levees to more quickly drain the water out of the town, rather than slowly pump the area dry. But several people died inside their flooded homes.

Aerial view of flooding in Louisiana Parish

US Coast Guard photo of floodwaters in Plaquemines Parish, Louisiana

It’s not clear to me from the news reports whether the levee overtopped from a wind- and pressure-driven storm surge or whether it overtopped from the sheer amount of rain that fell on the area, but in either case the slow-moving nature of Hurricane Isaac turned out to make the meager Category 1 hurricane into something much more horrific for some Lousiana communities. A reporter on the scene in Braithwaite described the eyewall, with the most intense winds and rain, stalling out in the area, but throughout its life Isaac was a fairly slow moving tropical cyclone. As it moved across Louisiana, its center was moving north about 9 miles per hour (14.5 km/hr). Typical hurricanes move about 15-20 mph (24-32 km/hr), and some can move up to 60 mph (96.5 km/hr).

The problem with a slow-moving hurricane is that vast amount of precipitation can occur in the affected areas. In some parts of Louisiana, Alabama, Mississippi, and Florida more than 15 inches (380 mm) of rain have fallen in the last week. In New Orleans, the Hydrometeorological Prediction Center reports that 20.08 inches (510 mm). In the image below, you can also see the northward progression of the storm since making landfall.

Colorful image of rain in Louisiana, Florida, Arkansas and Missouri as a result of Isaac.

NOAA's Advanced Hydrologic Prediction Service (AHPS) map of rainfall accumulations for the week leading up to September 1, 2012.

All that water can lead to levee over-topping, like in Plaquemines Parish, and the risk of dam failures. Evacuations were ordered along the Tangipahoa River, which drains into Lake Pontchartrain, because of fears that Percy Quin Dam would fail. More than 50,000 people have been evacuated as the risk of dam failure or the need to intentionally breach the dam is still being evaluated. And, of course, while media attention (and this blog post, guilty as charged) focuses on the dramatic stories, there are many other areas in the Gulf Coast where flooding is on-going. Even as far north as Kansas City and southern Illinois, flood warnings are in effect.

Isaac is a good reminder why the primary cause of death in the US from tropical cyclones is from freshwater flooding. And it suggests that the single-minded focus on hurricane windspeeds may distract us from taking the flooding threat as seriously as we should. Those people who decided to stay in Plaquemines Parish because the Category 1 hurricane wouldn’t be that bad? When the interview was conducted, they were expressing their regret. The president-elect of the American Meteorological Society, J. Marshall Shepherd, wrote a blog post about the Lessons from Isaac, in which he suggested: “Is it time to consider an augmentation of the Saffir Simpson scale to capture the rainfall-flood threat? It is a difficult science problem, but probably one worth investigating. I also argue that our media colleagues must consider their coverage strategy and category “anticipation” or hype carefully.”