The Heavens Continue to Unleash Their Fury on South Asia — 24 Million Now Impacted by Flooding as Hato Approaches

The far heavier rains of a warming world have fallen hard over South Asia for nearly two months. In India and Nepal more than 18 million have been affected. But the floodwaters in these higher lands have combined into great torrents flooding downstream into Bangladesh. A country that is now witnessing its worst flood in 100 years as one-third of its low-lying land mass is covered by water.

(According to news reports, one-third of Bangladesh’s land mass is now covered by flood waters. August 19 satellite shot of Central Bangladesh shows raging rivers and flooded lowlands. Image source: NASA Worldview.)

The damage for such a poor country sitting at the forefront of a growing climate-change-based destruction from the recent extreme rain event has been tremendous. At least 115 people have died. Nearly six million have been impacted. The government has run out of medicine, water purification tablets, and temporary shelters for the hundreds of thousands of people displaced. More than 400,000 hectares of crops have been destroyed. Fully half a million homes have been damaged or lost. And there is not enough food or water to go around.

Fears of water-borne illness such as cholera are running high and calls for international aid in the flood-stricken state have grown more and more urgent. But the worst is not yet over as floodwaters from Nepal and India continue to swell Bangladesh’s multiple waterways over banks and into communities through central and southern parts of the country. And more rain may be on the way as another powerful storm system gathers.

(This is what happens if you keep burning fossil fuels. According to recent scientific reports, the global number of record-breaking rainfall events has increased dramatically during recent years. This increase has coincided with global temperatures exceeding the 1 C warmer than 1880s temperature threshold. Higher global temperatures amp up the hydrological cycle by squeezing more moisture out of land and ocean surfaces. A warmer atmosphere that’s more heavily loaded with moisture adds move convective energy to thunderstorms which tends to spike rainfall potentials for the strongest storms to higher levels. Image source: Increased Record-Breaking Precipitation Events Under Global Warming.)

In the Indian States of Bahir and Assam more than 430 people have lost their lives as schools have been buried under 8 feet of water, crops have been destroyed, roads have been washed out and power has been disrupted. As with Bangladesh, concern over contaminated water supplies has brought with it fears of water-borne illness as a gargantuan disaster relief effort gets underway.

Nepal has likewise seen its share of the pain and heartbreak. There, more than 140 people have perished in the floods as 40,000 families have been severely impacted.

(Hato, lower left, sets its sights on an already foundering South Asia on August 22nd. Image source: NASA Worldview.)

In total, more than 800 lives have been lost so far throughout these three countries. But the worst may be yet to come as, later this week, the remnants of Typhoon Hato will begin to affect the already-devastated region. Hato’s new injection of moisture and thunderstorms will bring back the potential for severe flooding over Nepal, India, and Bangladesh. Refilling rivers before they have a chance to subside and potentially generating yet one more major flood pulse for the lowlands.

(UPDATED)

Links:

Floods Claim More than 800 Lives Across India and Nepal

24 Million People Impacted by Flooding in India, Bangladesh and Nepal

NASA Worldview

Increased Record-Breaking Precipitation Events Under Global Warming

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Intensifying Equatorial Rains: 3.3 Million Afflicted by Flooding in India and Bangladesh as Hundreds Lose Lives to Landslides from Sierra Leone to Nepal

There’s something wrong with the rain these days. For many regions of the globe, when the rain does fall, it more and more often comes with an abnormally fierce intensity.

This increasing severity of heavy rainfall events is just one aspect of human-forced climate change through fossil fuel burning. For as the Earth warms, both the rate of evaporation and precipitation increases. And as atmospheric moisture loading and convection increase coordinate with rising temperatures, so do the potential peak intensities of the most powerful storms.

(Climate and extreme weather news August 13 through 15)

Sierra Leone — More than 300 Dead, 600 Missing After Deadly Mudslide

This past week, in Sierra Leone — already one of the wettest regions of the globe at this time of year — a very heavy rainfall event generated a severe mudslide that ripped a huge swath of devastation through Freetown. 3,000 people were immediately rendered homeless by the great rush of mud, rock, and soil. But more tragically in excess of 300 people are feared dead with 600 still missing.

This single event represents the deadliest natural disaster on record for Sierra Leone — which also suffered a flood that killed 103 people in 2009. According to news reports, the region in which this disaster occurred has experienced 20 inches more rain than usual over the 30 day period from July 15 through August 15. A total amount of rainfall in a single month period that’s now in the range of 50 inches. Clearly, the surrounding lands could not maintain integrity under the force of such a prolonged deluge. And unfortunately one of the succumbing hillsides let loose into a valley settlement.

(Heavy thunderstorms of Freetown on August 14th. Image source: NASA and Weather Underground.)

A statement by Weather Underground’s Bob Henson provides further climate context for this disaster:

The heaviest downpours in many parts of the globe have become heavier in recent decades, a trend attributed to human-produced climate change and expected to continue. A study led by Christopher Taylor (UK Centre for Ecology and Hydrology), published this spring in the journal Nature, finds that the Sahel’s most intense mesoscale convective systems (organized clusters of thunderstorms) have tripled in frequency since 1982. The recovery of Sahel rainfall since the 1980s only explains a small part of this trend, according to the study authors. They argue that Saharan warming is helping to intensify convection within the MCSs through increased wind shear and changes to the Saharan air layer. “The meridional gradient is projected to strengthen throughout the twenty-first century, suggesting that the Sahel will experience particularly marked increases in extreme rain,” the study concludes.

Pradesh and Nepal Landslides and Floods Kill Over 100 More

Severe rains also on August 14th unleashed a mudslide in Pradesh India that knocked two buses off a cliff — resulting in the tragic loss of 46 lives. The resulting landslide also injured 5 other passengers even as it buried numerous homes along its path.

Across the Bay of Bengal in Nepal flooding and landslides resulted in the loss of 62 lives as 30 districts reported severe conditions. There, rains displaced 1,500 families, destroyed 305 homes, and damaged more than 15,000 other dwellings. Dozens of Nepali roads have been blocked, a school has collapsed, and an airport has been forced to close as severe storms inundated the region.

In India and Bangladesh, 3.3 Million People are Affected by Flooding

In the Indian state of Assam, 84 people have lost their lives due to a massive flood that has now affected 2 million people across 29 districts. 2,734 villages have flooded and 183,584 people have been forced to relocate to one of 700 refugee camps. Meanwhile, across the state, some 3,830 water rescues have occurred. Dozens of roads and bridges have been washed out as rivers rise from moderate to unprecedented flood stages.

(Assam floods on August 14. Image source: Government of India and Floodlist.)

Finally, in Bangladesh, record rainfall has pushed rivers to some of the highest levels ever recorded. The result has been the forced displacement of 368,000 people to 970 temporary shelters as 1.3 million are afflicted by flooding. Tragically, 27 Bangladeshis have also lost their lives due to the extreme flooding. Rainfall rates of up to ten inches per day are contributing to the severe flooding even as water from floods further upstream in India and Nepal are flowing into Bangladesh river systems.

Conditions in Context — Very Severe Equatorial Rains

Overall, these various events may appear to occur separately. However, they are all associated with a very severe Equatorial rain pattern developing from Africa through Southeast Asia and stretching into the Atlantic inter-tropical-convergence zone during 2017. The apparently increased thunderstorm activity is now impacting everything from the intensity of monsoonal rains over Southeast Asia, the severity of storms in the Sahel of Africa, and the early formation of tropical cyclones off Cape Verde during August.

These heavy rainfall features are arguably linked to the climate-change based intensification of the hydrological cycle and, particularly, to the increasing intensity of Equatorial thunderstorms. The overall climate and weather trend for the larger region should thus be noted and these various related events should not be viewed in isolation.

Links:

Weather Underground

Floodlist

NASA

Climate and Extreme Weather News

Hat tip to Shawn Redmond

Hat tip to Suzanne

Hot Gulf of Mexico Hurls Rain Bombs at Florida and the U.S. Gulf Coast

Rain bomb. It’s a new kind of severe rainstorm that’s capable of overwhelming a city’s flood-handling capabilities in just an hour or two. Of generating 2-inch-plus per hour rainfall events in odd places and at unexpected times. A type of severe storm that’s been enabled by all the added heat and atmospheric moisture loading resulting from human-forced climate change.

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High Atmospheric Water Vapor NE Gulf

(High levels of atmospheric water vapor over the northeastern Gulf of Mexico is fueling the potential for severe, damaging and life-threatening rainfall events across the Gulf Coast this week even as numerous severe flood events occur across the globe. Image source: Earth Nullschool.)

Lately, due in large part to an atmosphere and ocean surface that’s about 1.2 degrees Celsius hotter than 1880s values and related added atmospheric moisture, the powerful, damaging, and life-threatening rain bombs have been going off hard and heavy across the globe. Last week, Ellicott City was hit, killing one and generating damage that will likely take years to repair. Yesterday, about 21 people lost their lives in a freak flood that dumped 20 inches of rain over part of Macedonia. In Sudan on Saturday, the Nile reached its highest levels in 100 years as thousands of homes were destroyed and more than 75 people lost their lives. In Karachi, Pakistan this weekend, 50 percent of the city is without power and ten people have lost their lives due to flooding. In India over the past two weeks, more than one million people have been displaced and 100 killed in devastating floods. And now, a very hot Gulf of Mexico appears to be hurling a number of similarly powerful storms at the U.S. Gulf Coast.

Severe Gulf Rainstorms Begin

There’s a hell of a lot of heat and moisture available to fuel storms over the Gulf of Mexico right now. And this region where ocean surfaces exceed 90 degrees Fahrenheit (running from 30 to 33 C, or 1 to 3 C above average) over a broad swath is just now starting to toss some extremely powerful rain bombs at nearby states.

Rain Bomb over Gulf of Mexico

(26 inches of rain fell over a portion of the Gulf of Mexico in one 24-hour period just west of northern Florida. Over the coming week, this moisture is expected to shift northward over Lousiana, Mississippi, and the Florida Panhandle. Image source: Jesse Ferrell at Accuweather.)

Strong convection is blowing up from the hot surface of these waters and exploding into thunderstorms. Already, big rain bombs are starting to fall out over the Gulf or streaming onto shore. As of yesterday, one of these systems produced more than 26 inches of rain in just one 12-hour period. That’s an average of about 2.2 inches of rainfall per hour for 12 hours running, an amount of water that would cause extremely severe flooding if it fell on a U.S. city.

Today, these rain bombs began roaring ashore over the Florida Panhandle. A series of such systems dumped 20 inches of rain near Dekle Beach, Florida even as powerful storms firing near Pinland and Perry dropped 16 inches.

20 Inches of Rain Dekle Beach

(Earlier today, 20 inches of rain fell near Dekle Beach, Florida even as totals near 16 inches fell between Pinland and Perry. Image source: Jesse Ferrell at Accuweather.)

To be clear, these are just thunderstorms associated with a very hot and moist weather pattern over the Gulf — but they’re producing rainfall amounts usually seen in strong tropical cyclones. Meanwhile, National Weather Service radar shows strong storms continuing to cycle into this region of Florida even as south Florida is hammered by heavy storms and intense squalls swirl over the western Panhandle, Alabama, and Mississippi.

More Severe Rain on the Way, but the Rain Bombs Themselves are Tough to Predict

Over the coming week, the potential for continued heavy storms is high. NOAA’s precipitation forecast model shows rainfall potentials for the region in the range of 5-10 inches for some locations over the coming week. It’s worth noting, however, that NOAA model runs have often not captured the full potential peak rainfall totals in some recent severe events. To this point, it’s also worth noting that forecasting rain bombs can be difficult, particularly so during recent years. Monitors like NOAA can track the underlying conditions, but it’s generally tough to see exactly where the big precipitation spike will occur until perhaps a few hours before the rain starts falling.

Part of this prediction difficulty is likely due to the fact that the added atmospheric moisture loading — 8 percent since the 1880s and 5 percent since the late 1970s — due to global warming has increased instability to the point where new, and less well understood, types of weather are being generated. These days, there are new kinds of thunderstorms ranging the globe, and there’s a lot we don’t understand about them.

Links:

Jesse Ferrell at Accuweather

NOAA Rainfall Prediction

Earth Nullschool

The Macedonia Flood

Four Major Floods Taking Place Right This Second

20 Inches of Rain in One Day

Hat tip to TodaysGuestIs

Hat tip to Andy in San Diego

 

Worst Flood in 200 Years — 1.2 Million People Displaced by Rising Waters in India

When you’re rolling with loaded climate dice the situation, as Indian disaster relief officials stated earlier today, is indeed grim.

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The Earth has been warmed by 1 degree Celsius over the past 135 years due to hundreds of billions of tons of fossil fuels burned. That’s a pace of warming more than 10 times faster than at the end of the last ice age. And with that one degree Celsius of global temperature increase, we get a 7 percent increase in the rate of evaporation and precipitation. Unfortunately, that heat-driven alteration in the hydrological cycle is not even. In some places, where the heat piles high into great atmospheric domes and ridges, we see excessive drought. In other places, the moisture finds a weak spot in the heat and then we see inundation. The ridiculous country-spanning floods that have now become all-too-common.

Komen Monsoon India August 4

(The remnants of tropical cylcone Komen combine with a monsoonal flow over India to produce severe storms over Central and Western India on August 4, 2015. Image source: LANCE-MODIS.)

Droughts and floods of a severity that we are not at all used to and that have greatly contributed to increasing extreme weather events worldwide. Events that over the past seven years displaced nearly 158 million souls. Sadly, that dread toll of displacement, loss of homes, and loss of lives continued this week in South Asia as a flood of Biblical scale devoured an enormous swath of land.

Drought, Heat Mass Casualties, then Flood

For this summer, the situation in India, Bangladesh and Myanmar has been one of drought and flood combined. Earlier this year, the arrival of monsoonal moisture was delayed by the influence of a powerful heat dome crouched over the region. In India, the high temperatures and humidity were so intense that tens of thousands were hospitalized and thousands lost their lives due to heat stroke. Official reports from the region indicated that a precipitation deficit of 10 to 30 percent or more was in the offing. But that was before the skies, super-charged with moisture through an unprecedented rate of evaporation, opened up.

Last week, a frail but rainfall dense tropical cyclone Komen slammed into the coast of Bangladesh. This storm combined with the heavy load of monsoonal moisture building over the region. These conjoined systems have since dumped from 300 to 1300 millimeters of rainfall (more than four feet of rain for some locations) over a broad region including Bangladesh, Myanmar, and the Bengali state of India. It’s a rainfall amount that measures not in inches and millimeters, but in feet and meters. And when you get that much rain there’s going to be some severe hell to pay.

Worst Flood in 200 Years, 13,000 Villages Under Water, 1.2 Million People Displaced

Heavy monsoonal rains are ‘normal’ for India during this time of year. And, as is typical with media outlets who seem mentally incapable of reporting on the impacts of human-caused climate change and related extreme weather these days, many are attempting to claim that the current epic rainfall in India is somehow part of a typical pattern. Nothing could be further from the truth. For by August 1 (two days before the Bengal rains began to shift westward) the day-on-day piling up of water had amounted to the worst flood experienced in all of 200 years of record keeping for the hardest hit regions.

It’s a media silence that pervaded in the earlier stages of this unfolding disaster. One in which only a trickle of reports hit the net or presses. A silence that led one minor local media outlet to issue this irate statement:

Chandra says media has completely ignored this flooding, including the state’s print media and television news channels. The media are mainly based in the state capital, Imphal. The state government is in total chaos and is completely unprepared to tackle the situation. No higher zone is left within the districts, and people are taking shelter in nearby hill stations.

In other words, the only solution for Bengalis during the first few days of this 200 year or worse flood event was to run to the hills.

manipur-flooding

(By Saturday, August 1, flood waters had already surged over river banks and inundated areas like Manipur. Now, more than 13,000 villages and in excess of 10 million people have been impacted. Image source: Blaze.)

Since that time, government and mainstream media response has been more widespread, even if most reports have not set the current extreme event in its proper climate change related extreme event context. Regardless of this widespread failure, yesterday, as reports rolled in that more than 11,000 villages had been buried by water in Bengal, the extreme nature of the situation began to settle in. Sparse news coverage indicated that at least a million people had been impacted and that flood refugees were beginning to pour into disaster shelters. By this morning, a more accurate assessment of the full scope of this disaster had been taken. Over 13,000 villages had been flooded out, more than 10 million persons had been impacted, and the official government count for persons huddling in disaster shelters had climbed to 1.2 million souls.

“Rivers in 13 districts are flowing over their danger marks. The situation is grim,” noted disaster management minister Javed Ahmad Khan to AFP.

Lives lost from the flooding have steadily and ominously increased to over 180. But with so many roads and bridges washed out. With so many villages still under water, it will take weeks before a full account is made of this year’s excessively severe flooding.

India rains

(Heavy rainfall is now focused over Central India with 125 mm [5 inches] or locally higher amounts centered east of Mumbai and southeast of Dehli. Image source: Monsoon of India.)

Severe rains have since shifted to central portions of India so the hard-hit Bengal region should be able to start picking up the pieces. Now it’s Central India that’s falling under the gun as monsoonal moisture is pumped up into towering thunderstorms by Komen’s circulation and southerly outflow.

Storm Heading Toward Mountains

Over the next few days, the most intense storms associated with Komen’s monsoonal interaction are expected to shift north and west, eventually stalling out over the mountainous regions of Northern India and Pakistan. Such a storm track risks increased rates of rainfall over high mountain glaciers. A weather situation that can dramatically increase  glacial ice loss and spike the potential for dangerous glacier outburst flood events.

Links:

At Least 180 Dead, A Million Displaced in India Due to Flooding

How Climate Change Wrecks the Jet Stream, Amps up the Hydrological Cycle to Generate Extreme Weather

LANCE-MODIS

Extreme Weather Related to Climate Change Displaced 158 Million People Over the Last 7 Years

Hothouse Rains Destroy 17,000 Homes in Myanmar

Heatwave Kills 2300 in India

Parts of India Experience Worst Flooding in 200 Years

Blaze

Monsoon of India

Sky News Monsoon Forecast

Hat Tip to Colorado Bob

Hothouse Rains Destroy More than 17,000 Homes in Myanmar — Bangladesh, India also Inundated

Heavy Rain Falls over Southeast Asia

(Widespread rain and thunderstorm activity visible in the August 3 LANCE-MODIS satellite shot of a region that has seen millions impacted by epic flooding occurring from July 30th through today. Image source: LANCE MODIS.)

August 3, 2015: A massive moisture blow off the world’s record hot oceans had to go somewhere. And, over the past few days, the tally has been extraordinary.

A weak but heavily moisture-laden tropical cyclone Komen slammed into the coast of Bangladesh on Thursday, July 30th. Since that time, the system has lingered over the region — dumping between 11 (286 mm) and 47 inches of rainfall (nearly 1200 mm) over that low-lying country, over Myanmar and over India. For sections of Myanmar that’s twice the rainfall amount the country typically sees in all of July but concentrated into a period of a just a few days. To many, the inundation came suddenly and without warning. According to an AP interview:

“There was no warning … we thought it was normal [seasonal flooding],” said Aye Myat Su, 30, from a monastery being used as a temporary shelter in the regional capital of Kalay. “But within a few hours, the whole house was under water. My husband had to get onto the roof as there was no way out.”

Aye Myat Su’s experience is not unique. For millions of people throughout a broad region have seen serious and devastating flood impacts. Due to the massive inundation, a huge swath of Myanmar is under water. There, more than 200,000 people there are thought to have been displaced or inundated by the floods. In the mountainous state of Hakha alone, landslides have destroyed over 700 homes.  All across the country, however, the wreckage has been extraordinary with more than 17,000 homes thought to have been destroyed as of Monday morning.

In the Bengal region of India more 10,000 villages have been impacted resulting in the displacement of 214,000 persons with more than 30,000 huddled in government disaster shelters. So far, 121 souls are reported to have lost their lives in the region. A death toll that is, sadly, likely to continue to climb. Debris and flood waters have also washed out hundreds of bridges, floated telephone poles out of the ground, destroyed public buildings and blocked many major roadways.

Due to what is a massive disruption of infrastructure — including widespread power outages — reports from some of the more heavily flooded regions remain sparse.

(Reports of damage, dislocation and loss of life mount after one of the worst floods in 200 years strikes Southeast Asia)

Government officials are scrambling to set up aid and relief flows to those displaced or who’ve seen their homes wiped out by the flooding. Myanmar’s president has declared a state of emergency and stated that his country would do its ‘utmost’ for flood victims of that stricken nation. But local officials have voiced doubts about towns’ and villages’ ability to recover without substantial outside assistance.

It’s a severe deluge that has covered a huge section of Southeast Asia and impacted the lives of millions. And for some regions, relief may come later rather than sooner. The moisture Komen delivered remains in place atop a seasonal monsoonal flow that will only provide more energy for storms. Heavy rains are thus expected to linger over many of the flooded regions in the coming days as powerful thunderstorms continue to develop in train or drift eastward over Thailand and Vietnam.

Links:

Floods, Landslide in Myanmar, Bangladesh Leave Dozens Dead

Over 100 Dead in India Floods

Death Toll Rises as Myanmar Faces Flood Emergency

Wicked Weather in Thailand

LANCE MODIS

Hat Tip to Leland Palmer

Wet Bulb at 33 C — Human Hothouse Kills Nearly 800 in Pakistan

Human-forced warming of the global climate system is pushing sea surface temperatures in some areas to a maximum of 33 C. Extreme ocean warming that is increasing the amount of latent heat the atmosphere can deliver to human bodies during heatwaves. And near a 33 C sea surface hot zone, the past few days have witnessed extreme heat and related tragic mass casualties in Sindh, Pakistan.

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For Pakistan, the heat and humidity has been deadly. Temperatures over Southeastern Pakistan hit 100 to 113 Fahrenheit (40 to 45 degrees Celsius) during recent days. Night time lows dipped only into the 80s and 90s (30s Celsius). Relative humidity throughout this period has remained above a brutal 50% even during the hottest hours of the day.

Wet bulb temperatures (the wet-bulb temperature is the temperature air has if it is cooled to saturation — 100% relative humidity — by evaporation) climbed into a dangerous range of 30 to 33 degrees Celsius. This greatly reduced the ability of evaporation at skin level to cool the bodies of human beings exposed to such oppressive temperatures. As a result, people working outdoors, the elderly, or those without access to climate-controlled environments fell under severe risk of heat related injuries.

The Hospital Morgue is Overflowing

According to reports from Al Jazzera, thousands of heat injuries and hundreds of deaths have occurred across the region since Saturday. Karachi’s largest hospital — Jinnah Postgraduate Medical Centre (JPMC) — has been flooded with over 5,000 patients suffering from heat injuries since the weekend. At some points, the hospital was receiving one heat injury patient per minute — a pace that nearly overwhelmed the facility. By earlier today, more than 380 of those patients had died.

Dr Seemin Jamali, a senior official at JPMC noted to Al Jazeera:

“The mortuary is overflowing, they are piling bodies one on top of the other. We are doing everything that is humanly possible here. Until [Tuesday] night, it was unbelievable. We were getting patients coming into the emergency ward every minute.”

Across Sindh, Pakistan the story was much the same with the total official heat death toll now standing at 775 and climbing as calls were raised for more government support for people impacted by the worst heat wave to hit Pakistan in at least 15 years.

Killing Heat and Unprecedented Rains

This extreme and deadly heat is a feature of a boundary zone between a hot, high-pressure air mass over the Persian Gulf region abutting against a very moist and El Nino-intensified monsoonal system over India. The result is a combination of high heat and high humidity — factors that, together, are very hard on the human body (wet bulb temperatures above 30 C are considered dangerous, while a blanket measure of 35 C [never reached yet on Earth] is considered rapidly deadly even in the shade).

During late May and early June, similar conditions resulted in hundreds of heat related deaths in India. When the heat finally abated, the subsequent influx of monsoonal moisture set off torrential downpours. In some places, rates of rainfall exceeded typical June monsoonal accumulations by nearly 50 percent with Mumbai already having received 32 inches of rainfall (normal June rainfall is 23 inches). With Mumbai showing daily rainfall accumulations of 1-3 inches, it is possible that June totals could be double that of a typical year.

A Ramping Oceanic Heat/Moisture Pump — Feature of a Record Warm World

The high heat, high humidity and related extreme rainfall events are all features of a warming world. At issue, primarily, is the impact of human forced global warming on the ocean system and how this heating then impacts the atmosphere — making it harder for humans to remain alive outdoors during the most extreme heating events even as it pushes a tendency for more and more extreme droughts and deluges.

This warming related heat and moisture flux is most visible out in the Pacific, where record global atmospheric and ocean heat is pushing maximum sea surface temperatures into the lower 30s (typically between 30 and 31 degrees Celsius). These high sea surface temperatures in a record warm world are now dumping an extreme amount of moisture into the atmosphere through an El Nino amplified evaporation rate. A subsequent amplification of the equatorial storm track due to extreme moisture loading has already seen extraordinary record rainfall events in places as widespread as India, China and the Central U.S.

image

(Sea surface temperatures climb to near 33 C in the Ocean region near Pakistan — supporting wet bulb temperatures [high heat and high humidity] that generate a heightened risk of heat injury and death. Image source: Earth Nullschool.)

Maximum global sea surface temperature is a good proxy measure for how much moisture the atmosphere can hold, a measure that also likely determines the maximum wet bulb temperature (implied latent heat) at any given point on the globe. And particularly, near Pakistan, we find ocean surface temperature readings in the range of 30 to 33 C running through the coastal zone of the Indian Ocean and on into the Persian Gulf. Readings that increased the amount of moisture the atmosphere could hold at high temperature, increased relative humidity readings as temperatures entered the 100s Fahrenheit (40s C), and forced wet bulb temperatures into deadly ranges which in turn reduced the ability of the human body to cool by evaporation at skin level.

This is how human-forced global warming kills with direct heat — by basically increasing latent heat to the point that evaporation can no longer cool the human body to a natural maintenance temperature of 98.6 (F) or 37 (C). And once wet bulb temperatures start hitting 35 C, then the heat casualty potential really starts to get bad — essentially rendering heat wave regions temporarily uninhabitable for human life outdoors. With maximum sea surface temperatures now running near 33 C, we’re probably just within about 2 C of hitting that deadly boundary.

The Pakistan and Indian heat deaths this year, though extraordinarily tragic and probably preventable without current level of human forced warming of the atmosphere, serve as a warning. Keep warming the globe through fossil fuel emissions and there are many far, far worse heatwaves to come.

Links:

Pakistan Heatwave Death Toll Edges Toward 800

Pakistan Heatwave Death Tool Rises to 750

Heavy Rain Soaks India as Monsoon Advances

Flash Floods Pelt China

Earth Nullschool

An Adaptability Limit To Climate Change Due to Heat Stress

Hat Tip to Colorado Bob

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