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human activity and the destruction of the planet


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The Truth about Heatwaves: 3

In three previous blogs, I have discussed heatwaves and their effects on land, over the oceans and their effects on human survivability.

In this (4th) blog, I am going to provide more data linking heatwaves in the UK with a spike in the number of deaths, especially in the elderly, the young and those with specific health issues – vulnerable groups.

After the 2018 heatwave, The Guardian, published an analysis of this, based on official statistics; it can be seen at: https://www.theguardian.com/society/2018/aug/03/deaths-rose-650-above-average-during-uk-heatwave-with-older-people-most-at-risk

The following includes extracts from The Guardian article:


Nearly 700 more deaths than average were recorded during the 15-day peak of the heatwave in June and July 2018 in England and Wales.

The height of the heatwave was from 25 June to 9 July, according to the Met Office, a run of 15 consecutive days with temperatures above 28C. The deaths registered during the weeks covering this period were 663 higher than the average for the same weeks over the previous five years, a Guardian analysis of data from the Office of National Statistics shows.

beachJuly 2018

ONS analysis for previous years indicate hundreds of additional deaths were associated with brief periods of heatwave conditions in July 2016 and June 2017. The full toll of the 2018 heatwave could reach 1,000, according to one prediction.

“While working in A&E this summer, I saw patients presenting with heatstroke and other conditions that were probably exacerbated by the hot weather, and this obviously places an additional strain on our already struggling health services,” she said.

Dehydration can lead to many issues, from dizziness and falls, to an increased risk of infections, heart attacks and strokes. The 2018 heatwave showed that hospitals and care homes must be made ready to cope with high temperatures.



Another article, published by the London School of Economics and Political Science last year, stated that people are dying of ignorance:

Hundreds are dying from ignorance of rising heatwave risks

The article states that many of these deaths could have been prevented if Government Departments and agencies had listened to the advice of experts and improved the shockingly poor flow of information to the public about the rising risk of heatwaves due to climate change.

There is evidence that many people perish each summer in the UK because they do not understand that the frequency of heatwave conditions are increasing.

The full death toll from summer 2018’s hot weather will not be known for a some time, but is likely to exceed 1000 based on what has happened in previous years.

It is a public health emergency about which nobody is talking. If more than 1000 people were killed in flooding, there would rightly be an outcry, particularly if many of the deaths could have been avoided.

Researchers at the London School of Hygiene and Tropical Medicine identified older people as being particularly vulnerable but also concluded that more people suffer in Greater London, South-East and East England. These are the hottest parts of the UK, and have been experiencing significant amounts of warming over the past few decades.

An assessment in 2014 found statistically significant increases in daily maximum, minimum and mean air temperatures between 1910 and 2011, with “the rate of change increasing from the north and west to the south and east”.

Public Health England published in 2015 an annual heatwave plan (PDF) and jointly operates, with the Met Office, the ‘Heat-Health Watch’ which issues warnings ahead of heatwave conditions occurring. However, the Met Office fails frequently to tell the public that climate change is increasing the risk of heatwaves in the UK.




Another report about the UK heatwave in 2019 had similar findings. It was from the Office for National Statistics (ONS):

https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/causesofdeath/articles/dosummerheatwavesleadtoanincreaseindeaths/2019-10-07

The number of deaths spiked on the hottest day of the summer, provisional official data shows.

There were 1,473 deaths on July 25 registered in England and Wales, rising from about 1,100-1,200 deaths per day around the same time, according to figures from the ONS.

July 25 saw temperatures reach 38.7C in Cambridge, breaking the record for the highest temperature ever recorded in the UK.

The ONS was looking at whether “killer heatwave” news headlines are backed up by the data in a release called ‘Do summer heatwaves lead to an increase in deaths?’

The stats body cautioned that the May to August 2019 data is “highly provisional” due to the amount of time it can take for deaths to be registered, meaning the recorded number of deaths per day is likely to increase as more deaths are registered.

HEALTH Heatwave

While comparisons with previous years cannot yet be made using the recent summer’s data, the statisticians compared the number of deaths per day in summer 2018 with the five-year average (2013-18).

The ONS said: “The comparatively high number of deaths occur mainly on days that are defined as heatwaves by Public Health England (PHE) in their deaths relating to heatwaves report.”

These spikes tended to be followed by periods of lower-than-average deaths, the ONS said.

The report went on: “This means that at a daily level, extreme heat seems to have an impact on the number of deaths, but across the summer period as a whole the number of deaths is similar to previous years.

“This could be because the most vulnerable people, for example, those with pre-existing respiratory or cerebrovascular diseases are more susceptible to death during heatwaves.”

Even when taking into account the heatwaves, the effects of winter on mortality are consistently greater than summer, the report added.



Another Public Health England (PHE) report analysed the number of deaths during the 2016 heatwave.  It found an excess of 908 deaths during the heatwave periods, when the Met Office had issued heatwave alerts.  See:

Public Health England, “PHE Heatwave Mortality Monitoring: Summer 2016”, June 2018. Available: https://assets.publishing.service.
gov.uk/government/uploads/system/uploads/attachment_data/file/714933/PHE_heatwave_mortality_monitoring_report_2016.pdf

The executive summary to the document is as follows:

Executive summary:

“Heatwaves are predicted to increase in frequency and intensity as a result of climate change. The health impacts of these events can be significant, particularly for vulnerable populations when excess mortality can occur. England experienced several heatwaves in the summer 2016. This report summarises the excess deaths observed throughout the heatwaves of summer 2016.

The summer of 2016 saw 3 Level 3 heatwave alerts issued by the Met Office. Excess
daily mortality was estimated using baseline death registration data from the Office for National Statistics (ONS). The first heatwave occurred from 18 July to 22 July 2016, where there were an estimated 612 excess deaths observed above baseline in the 65+ year olds. The second heatwave occurred between 22 August to 26 August 2016, where there were an estimated 296 excess deaths observed above baseline amongst 65+ year olds. The third and final heatwave of the summer 2016 occurred between 12 September and 17 September 2016, where there were no significant excess deaths observed. This resulted in a total estimate of 908 excess deaths over the summer 2016
period.”

The Conclusion to the report is as follows:

Conclusions
England observed 3 heatwave periods in 2016, with significant excess mortality impact in the >65 year olds decreasing in size and geographical extent with each heatwave across the summer. No significant impact was seen in the <65 year olds and the impact on mortality of 908 excess deaths was less than seen in 2006 (2,323 deaths) and 2003 (2,234 deaths). The UK has had a heatwave plan since 2004, the importance of which continues to be highlighted year on year.”



8th May 2020

Another Guardian report has reported on a new study, published by the Proceedings of the National Academy of Sciences (USA), in which they conclude that, within 50 years, one billion people will live in insufferable heat due to global warming.  This billion people will either be displaced or forced to endure insufferable heat for every additional 1 degree C rise in the global temperature.

The authors of the study were really shocked by the findings, as they had not expected the human species to be so vulnerable.  The Guardian article and the PNAS reference are as follows:

https://www.theguardian.com/environment/2020/may/05/one-billion-people-will-live-in-insufferable-heat-within-50-years-study?utm_term=RWRpdG9yaWFsX0dyZWVuTGlnaHQtMjAwNTA2&utm_source=esp&utm_medium=Email&CMP=greenlight_email&utm_campaign=GreenLight

https://www.pnas.org/content/early/2020/04/28/1910114117

 



An article, published on May 17th 2020 in The Conversation discusses the concept of climate sensitivity, which is defined as “the relationship between changes in carbon dioxide in the atmosphere and warming”.

They discuss the use of mathematical climate models to predict the amount of global warming in the future. If climate sensitivity is introduced to these models, there is a surprising and unexpected surge in temperatures in the future.  For example, they predict a rise of 7 degrees C in Australia by 2100, if emissions continue to rise unabated.

These higher temperature changes are not currently presented in the national climate projections, as they didn’t occur under the previous generation of models and emission scenarios.

Higher climate sensitivity means increases to heat extremes. It would mean we’ll see greater flow-on changes to other climate features, such as extreme rainfall, sea level rise, extreme heatwaves and more, reducing our ability to adapt. The two graphs below show temperature changes in the future in both high emission scenarios and a very low emissions scenario.

 

https://theconversation.com/just-how-hot-will-it-get-this-century-latest-climate-models-suggest-it-could-be-worse-than-we-thought-137281



There is also a report in the Washington Post about a heatwave in Siberia (May 2020).

https://www.msn.com/en-gb/news/environment/parts-of-siberia-are-hotter-than-washington-with-temperatures-nearly-40-degrees-above-average/ar-BB14tXLJ?ocid=spartandhp

The warmth in Siberia is already having repercussions on Arctic ecosystems, with unusually large Siberian wildfires already burning this year, snow cover plummeting unusually quickly and sea ice cover in areas such as the Kara Sea, which lies to the north of Central Siberia, at a record low for the date, having begun its seasonal melt more than a month earlier than is typical.

In recent years, scientists have raised growing concerns about the stability of Arctic permafrost, including stretches of permanently frozen soil located throughout Siberia. When the permafrost thaws, carbon dioxide and other planet-warming greenhouse gases that had been locked away for centuries is freed up, constituting an accelerant to global warming.

a close up of food: January to April temperature departures from average, showing the most significant temperature anomalies across Russia, including Siberia. (Berkeley Earth)

The temperature departures from average in Siberia this year are some of the highest of any area on Earth. Since January, the region has been running at least 3 degrees Celsius above the long-term average, according to a recent report from the National Oceanic and Atmospheric Administration.



 


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The effects of heat waves on human survivability

An article in the New Scientist (No.3161) by John Pickrell, entitled “Too hot to handle”, discusses the increasing trend of heatwaves throughout the world, as a result of climate change.

heatwave

Pickrell starts by discussing Australia, which had a heatwave in January 2017, with the hottest ever recorded temperatures in Sydney and Brisbane (Sydney had over 47 degrees). Large parts of the country had temperatures over 40 degrees C for weeks on end, as well as bush fires.  Many of the unique species of wildlife common to Australia had to be rescued from fires and heat, many of them suffering from heat exhaustion, burns, dehydration and stress.

koala

kangaroo

 

Temperatures of 50 degrees C are predicted by 2040 for Australia.

Pickrell then goes on to cite papers, which give statistics about fatalities during heatwaves, one from The Lancet which covered research by 26 institutions (including the World Health Organization).

The 2003 heatwave in France killed 70,000 people – but it would appear that the level of humidity is the crucial factor, as high levels of water in the atmosphere can reduce the body’s ability to cool down through sweating.  To sweat effectively, you must maintain your blood volume, so dehydration can cause heat stress, followed by heat stroke, multiple organ failure and possible death.  The elderly and children are at greater risk of heat stroke, as well as those on medication or with heart disease.

I came across another wordpress website, which gives a useful chart showing temperature against relative humidity and which combinations are lethal:

See: https://andthentheresphysics.wordpress.com/2017/06/24/heatwaves/

and below for the table (with acknowledgments):

nclimate_heatwaves

The black crosses in the chart above show temperature and relative humidity during events that were lethal. The blue line shows the likely boundary between lethal and non-lethal events, and the red line is a 95% probability threshold.


According to The Lancet, global warming has reduced the workforce in India by 418,000.


An interesting map of the world is given in the New Scientist article to show the probability of deadly heatwaves for three global warming scenarios: 1.5 degrees C; 2 degrees C and 4 degrees C.  This can be seen by clicking on the link below:

heatwaves data

It shows that, even with an increase in global temperature of 2 degrees, many parts of the world will become uninhabitable, through rising temperatures: North West Africa, much of the Middle East, parts of Central and South America, India, Pakistan and Bangladesh and much of Australia.  At four degrees the situation is dire throughout much of the tropical world.

The New Scientist article concludes with a list of advice on how to keep cool.


 Another academic article on a similar subject has been published in the Proceedings of the National Academy of Science USA by Sherwood and Huber in 2010 (Vol 107, (21), 9552-5) entitled “An adaptability limit to climate change due to heat stress.”  This article has been summarised in the Science & Technology section of the The Observer (10th Sept. 2017).  This article gives a chart showing which species die at particular degrees of warming above pre-industrial levels.  Amphibians will be the first to go (at 0.6 degrees+), followed by penguins, due to loss of food sources, as the krill populations dwindle. At 1.6 degrees+, the wooded tundra is lost, along with its inhabitants, moose, lynx and brown bears, followed by large African mammals, such as elephants, then rain forest dwellers (orangutans, jaguars, sloths) at 2.6 degrees+.  At a warming of 4 degrees, 70% of species would be extinct, coral reefs dead and deserts would expand across the world. The fate of humankind would be dominated by mass migration, on a scale even larger than we see today, with water resources extremely limited, as we would have to abandon most of the Earth or live underground.  The authors predict that, by 2050, temperatures will be in a range that nobody has experienced before.

It is interesting to note that the Australian town of Coober Pedy, a major site for opal mining, has already built an underground town, including hotels, for those times in the year when it is already too hot to live above ground.


2nd August 2018

Since this post was first written, time has now moved on into 2018 with heatwaves across much of the northern hemisphere (see other posts on this site for details).  Even climate sceptics are now beginning to accept that climate change is with us, with the extremes of weather which accompany it.

A piece this week in The Guardian by David Carrington deals with the issue of human survivability during heat waves.  I quote a short passage from him, in which he summarises scientific work on the issue:

The new analysis assesses the impact of climate change on the deadly combination of heat and humidity, which is measured as the “wet bulb” temperature (WBT). Once the WBT reaches 35C, the air is so hot and humid that the human body cannot cool itself by sweating and even fit people sitting in the shade die within six hours.

A WBT above 31C is classed by the US National Weather Service as “extreme danger”, with its warning stating: “If you don’t take precautions immediately, you may become seriously ill or even die.”

He then goes on to discuss which parts of the world are most at risk of high WBT temperatures.  This would appear to be the north China plain, with a population of 400 million people, most of them farmers.  The scientists who produced the data have predicted that by 2070 to 2100, this area of the world will become uninhabitable.  Other areas at risk are the Middle East, around the Gulf (particularly Dubai, Abu Dhabi, Doha and the coastal cities of Iran) and parts of South Asia (around the Indus and Ganges valleys).

For the full Guardian article, see:

https://www.theguardian.com/environment/2018/jul/31/chinas-most-populous-area-could-be-uninhabitable-by-end-of-century?utm_source=esp&utm_medium=Email&utm_campaign=Green+Light+2016&utm_term=282539&subid=2617869&CMP=EMCENVEML1631



July 2019

The UK has experienced another heatwave period this summer, with record temperatures being reached in a number of countries.  It was particularly humid in the UK, with weather forecasters predicting the humidity above 50%, a level which can prove fatal with temperatures above 25ºC, according to the graph shown above.

So its worth looking again at the relationship between WBT (wet bulb temperature) and death due to heat stress.  The following can be found in Wikipedia:

“Living organisms can survive only within a certain temperature range. When the ambient temperature is excessive, humans and many animals cool themselves below ambient by evaporative cooling (sweat in humans and horses, saliva and water in dogs and other mammals); this helps to prevent potentially fatal hyperthermia due to heat stress. The effectiveness of evaporative cooling depends upon humidity; wet-bulb temperature, or more complex calculated quantities such as Wet Bulb Globe Temperature (WBGT) which also takes account of solar radiation, give a useful indication of the degree of heat stress, and are used by several agencies as the basis for heat stress prevention guidelines.

A sustained wet-bulb temperature exceeding 35 °C (95 °F) is likely to be fatal even to fit and healthy people, unclothed in the shade next to a fan; at this temperature our bodies switch from shedding heat to the environment, to gaining heat from it. Thus 35 °C (95 °F) is the threshold beyond which the body is no longer able to adequately cool itself. A study by NOAA from 2013 concluded that heat stress will reduce labour capacity considerably under current emissions scenarios.

A 2010 study concluded that under a worst-case scenario for global warming with temperatures 12 °C (22 °F) higher than 2007, the wet-bulb temperature limit for humans could be exceeded around much of the world in future centuries. A 2015 study concluded that parts of the globe could become uninhabitable. An example of the threshold at which the human body is no longer able to cool itself and begins to overheat is a humidity level of 50% and a high heat of 46 °C (115 °F), as this would indicate a wet-bulb temperature of 35 °C (95 °F).”