Global & Disaster Medicine

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Global Drought

Drought Recovery Taking Longer

As global temperatures continue to rise, the prevailing wisdom in the climate science community is that droughts will grow more frequent and more extreme in the 21st century. Though temperatures were already rising in the 20th century, the global trend in drought length and severity was ambiguous, with no clear pattern. However, the impacts of droughts was less ambiguous, particularly in recent decades.

In a study published in August 2017 in the journal Nature, researchers from 17 institutions found that more of Earth’s land surface is now being affected by drought and ecosystems are taking longer to recover from dry spells. Recovery is particularly worse in the tropics and at high latitudes, two areas that are already pretty vulnerable to global change.

The map above is based on data from that study, which was led by Christopher Schwalm of Woods Hole Research Center. It depicts the average length of time that it took for vegetation to recover from droughts that occurred between 2000 and 2010. The darkest colors mark the areas with the longest drought recovery time. Land areas colored light gray were covered by ice or sand (deserts).

Up until now, most assessments of drought and recovery have focused on the hydrology; that is, has new rain and snowfall made up for the deficit of water in rivers, lakes, and soils? In this new study, researchers focused on the health and resilience of the trees and other plants because full reservoirs and streams do not necessarily mean that vegetation has recovered.

The research team combined observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, ground measurements, and computer models to assess changes in drought. In particular, they measured changes in gross primary productivity, or how well plants are consuming and storing carbon dioxide through photosynthesis. As the analysis showed, plants in many regions are taking longer to recover from drought, often because weather is more extreme (usually hotter) than in the past.

If the time between droughts grows shorter (as predicted) and the time to recover from them keeps growing longer, some ecosystems could reach a tipping point and change permanently. This could affect how much carbon dioxide is stored on land in trees and other vegetation (the land “carbon sink”). If less carbon is being captured and stored, then more of what humans produce would remain in the atmosphere, creating a feedback loop that amplifies the warming that leads to more drought.

“The most important implication of our study,” said Schwalm, “is that under business-as-usual emissions of greenhouse gases, the time between drought events will likely become shorter than the time needed for recovery.”

“Using the vantage point of space, we can see all of Earth’s forests and other ecosystems getting hit repeatedly and increasingly by droughts,” added co-author Josh Fisher of NASA’s Jet Propulsion Laboratory. “Some of these ecosystems recover, but, with increasing frequency, others do not.”

NASA Earth Observatory image by Jesse Allen, using data provided by Christopher Schwalm (WHRC). Story by Michael Carlowicz, with reporting from JPL and WHRC.


The Cost of Hurricanes

NY Times

Why Hurricanes Keep Getting Costlier

“….In 2016, the Congressional Budget Office estimated that hurricanes currently cause about $28 billion, on average, in annual damage nationwide. But those costs are projected to rise 40 percent between now and 2075, after adjusting for inflation.

Nearly half of that projected increase, the C.B.O. said, is because global warming and sea-level rise are expected to make hurricanes and storm surges more severe…..

But half of the expected rise in hurricane costs is the result of expected increases in coastal development. Today, according to the C.B.O., roughly 1.2 million Americans live in coastal areas at risk of “substantial damage” from hurricanes — defined as damage of at least 5 percent of average income. By 2075, that number is forecast to rise to 10 million.

https://nyti.ms/2xRygnq

https://nyti.ms/2xbfPNl

 

Population growth can also increase hurricane risks by adding newcomers who are unfamiliar with big storms or by clogging roads during evacuations…..”

“…..sea levels along Miami’s coasts have risen 3.3 inches since then [1992], and the city is already seeing an increase in “sunny-day flooding” during high tides. With sea levels higher, a hurricane that struck in a vulnerable place could conceivably produce far greater flooding….. “


Europe: Heatwave “Lucifer”


NASA: Sometime between July 10 and July 12, an iceberg about the size of Delaware split off from Antarctica’s Larsen C ice shelf.

Antarctic Ice Shelf Sheds Massive Iceberg

Sometime between July 10 and July 12, an iceberg about the size of Delaware split off from Antarctica’s Larsen C ice shelf. Now that nearly 5,800 square kilometers (2,200 square miles) of ice has broken away, the Larsen C shelf area has shrunk by approximately 10 percent.

Scientists have been tracking the stability of this ice shelf for several years. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured an image (above) of the new iceberg on July 12, 2017. The false-color view uses MODIS band 31, which measures infrared signals known as “brightness temperature.” This measurement is useful for distinguishing the relative warmth or coolness of a landscape. Dark blue depicts where the surface is the warmest—most notably between the new iceberg and the ice shelf, but also in areas of open ocean or where water is topped by thin sea ice. Lighter blue colors show intact or thicker ice (cooler surfaces).

acquired July 12, 2017 download large image (462 KB, JPEG, 1076×1004)
acquired July 12, 2017 download GeoTIFF file (1 MB, TIFF, 1076×1004)

The calving event was confirmed by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite. The day-night band (DNB) of VIIRS captured this image on July 12, 2017.

The final rupture was first reported by Project MIDAS, an Antarctic research project based in the United Kingdom. Adrian Luckman of Swansea University and MIDAS explains the significance of the calving event in a post here.

Larsen C, a floating platform of glacial ice on the east side of the Antarctic Peninsula, is the fourth-largest ice shelf on the coast of Antarctica. In 2014, a crack that had been slowly growing in the ice shelf for decades suddenly turned northward and accelerated, creating today’s iceberg.

“The interesting thing is what happens next…how the remaining ice shelf responds,” said Kelly Brunt, a glaciologist from NASA’s Goddard Space Flight Center and the University of Maryland. “Will the ice shelf weaken, or possibly collapse like its neighbors Larsen A and B? Will the glaciers behind the ice shelf accelerate and have a direct contribution to sea level rise? Or is this just a normal calving event?”

Scientists have monitored the progression of the rift over the past year using data from the European Space Agency’s Sentinel satellites (which can image with radar during the long Antarctic night) and thermal imagery from Landsat 8 and the MODIS instruments on NASA’s Terra and Aqua satellites.

In the coming months and years, researchers will monitor the response of Larsen C and the glaciers that flow into it with satellite imagery, airborne surveys, automated geophysical instruments on the ice, and field work.

“We don’t currently know what changed in 2014 that allowed this rift to push through the suture zone and propagate into the main body of the ice shelf,” said Dan McGrath, a glaciologist at Colorado State University who has been studying Larsen C since 2008.

McGrath said the growth of the crack is not directly linked to climate change. “The Antarctic Peninsula has been one of the fastest warming places on the planet throughout the latter half of the 20th century. This warming has driven really profound environmental changes, including the collapse of Larsen A and B,” McGrath said. “But with the rift on Larsen C, we haven’t made a direct connection with the warming climate. Still, there are definitely mechanisms by which this rift could be linked to climate change, most notably through warmer ocean waters eating away at the base of the shelf.”

The U.S. National Ice Center will monitor the trajectory of the new iceberg, which is likely to be named A-68. The currents around Antarctica generally dictate the path that the icebergs follow. In this case, the new berg is likely to follow a similar path to the icebergs produced by the collapse of Larsen B: north along the coast of the peninsula, then northeast into the South Atlantic.

NASA Earth Observatory images by Joshua Stevens, using MODIS and VIIRS data from LANCE/EOSDIS Rapid Response. Story by Maria-Jose Viñas, adapted for Earth Observatory by Kathryn Hansen.

Instrument(s):
Aqua – MODIS
Suomi NPP – VIIRS

A chunk of floating ice that weighs more than a trillion metric tons broke away from the Antarctic Peninsula


Danish Meteorological Institute: As of Thursday, temperatures in the area above 80 degrees north latitude were already more than 20 degrees warmer than the average temperature for this time of year and the most unusually warm region is right over the North Pole.

Washington Post

The View from the Top

 


CDC: Building Resilience Against Climate Effects (BRACE) Framework

CDC

BRACE Infographic

The Building Resilience Against Climate Effects (BRACE) framework is a five-step process that allows health officials to develop strategies and programs to help communities prepare for the health effects of climate change. Part of this effort involves incorporating complex atmospheric data and both short and long range climate projections into public health planning and response activities. Combining atmospheric data and projections with epidemiologic analysis allows health officials to more effectively anticipate, prepare for, and respond to a range of climate sensitive health impacts.

Five sequential steps comprise the BRACE framework:

Step 1: Anticipate Climate Impacts and Assessing Vulnerabilities
Identify the scope of climate impacts, associated potential health outcomes, and populations and locations vulnerable to these health impacts.

Climate Models and the Use of Climate Projections: A Brief Overview for Health Departments[PDF – 1.50 MB]

Assessing health vulnerability to climate change: A guide for health departments[PDF – 4.35 MB]

Step 2: Project the Disease Burden
Estimate or quantify the additional burden of health outcomes associated with climate change.

Step 3: Assess Public Health Interventions
Identify the most suitable health interventions for the identified health impacts of greatest concern.

Step 4: Develop and Implement a Climate and Health Adaptation Plan
Develop a written adaptation plan that is regularly updated. Disseminate and oversee implementation of the plan.

Step 5: Evaluate Impact and Improve Quality of Activities
Evaluate the process. Determine the value of information attained and activities undertaken.

More in-depth information about the BRACE framework can be found in the document titled Building Resilience against Climate Effects—A Novel Framework to Facilitate Climate Readiness in Public Health Agencies.


Madagascar: Eating cactus, rocks, and ashes to survive

NY Times

Madagascar

 


The Paris Agreement, which seeks to limit global warming to 2 degrees C (3.6 degrees F), thereby combatting climate change becomes international law today

NY Times

  • “….But scientists and policy makers say the agreement entering into force is just the first step of a much longer and complicated process of transitioning away from fossil fuels, which currently supply the bulk of the planet’s energy needs and also are the primary drivers of global warming….”
  • “….While the Paris agreement is legally binding, the emissions reductions that each country has committed to are not. Instead, the agreement seeks to create a transparent system that will allow the public to monitor how well each country is doing at meeting its goals in hopes that this will motivate them to transition more quickly to clean, renewable energy like wind, solar and hydropower….”
  • “….A report by the U.N. Environment Program released Thursday projects that annual emissions must be kept below 42 billion tons of CO2 (carbon dioxide) by 2030 for the world to have a chance to meet the goals set out in the Paris agreement. However, the agreement itself foresees emissions reaching 54 billion-56 billion tons in 2030, setting the world on a course to exceed the goal of limiting warming to 2 degrees Celsius (3.6 degrees Fahrenheit)…..”

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Effects of climate change on sea-level rise and hurricane activity on NYC: Water could surge some 9 feet in hurricanes occurring anywhere from 3 to 17 times more often than today

NYC-FutureFloodHazard_PNAS


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