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How climate change affects extreme weather around the world: Carbon Brief analysis

Carbon Brief is a UK-based website designed to “improve the understanding of climate change, both in terms of the science and the policy response”.  It is funded by the European Climate Foundation and is based in London. The article cited , and included, below received a highly-commended award for investigative journalism from the Royal Statistical Society.  Originally published in 2017, it is updated annually.



Mapped: How climate change affects extreme weather around the world

Scientists have published more than 230 peer-reviewed studies looking at weather events around the world, from Hurricane Katrina to Russia’s 2010 heatwave. The result is mounting evidence that human activity is raising the risk of some types of extreme weather, especially those linked to heat.

Carbon Brief’s analysis suggests 68% of all extreme weather events studied to date were made more likely or more severe by human-caused climate change. Heatwaves account for 43% such events, droughts make up 17% and heavy rainfall or floods account for 16%.

To track how the evidence on this fast-moving topic is stacking up, Carbon Brief has mapped – to the best of their knowledge – every extreme event attribution study from a peer-reviewed journal.

The map below shows 260 extreme weather events across the globe for which scientists have carried out attribution studies. The different symbols show the type of extreme weather; for example, a heatwave, flood or drought. The colours indicate whether the attribution study found a link to human-caused climate change (red), no link (blue) or was inconclusive (grey).

How to use our map of attribution studies.

Use the plus and minus buttons in the top-left corner, or double click anywhere, to zoom in on any part of the world. Click on a weather event to reveal more information, including a quote from the original paper to summarise the findings and a link to the online version.

The filter on the left allows users to select a specific type of weather event to look at or, for example, only those found to be influenced by climate change.

The software used to make the map currently only works with a Web Mercator projection (as used by virtually all major online map providers). It is worth noting that this – like all map projections – offers a somewhat distorted view of the world.

It is important to note that the weather events scientists have studied so far are not randomly chosen. They can be high-profile events, such as Hurricane Harvey, or simply the events that occurred nearest to scientific research centres. (More on this later.)

Guardsmen help evacuate Texans in need during Hurricane Harvey, Houston, Texas

Weather types

The 260 weather events in the map are covered by 234 individual scientific papers. Where a single study covers multiple events or different locations, these have been separated out.

Combining the evidence over the past 20 years, the literature is heavily dominated by studies of extreme heat (31%), rainfall or flooding (20%) and drought (18%). Together, these make up more than two-thirds of all published studies (68%). The full list is available in this Google sheet.

As the chart below shows, the number of events studied each year has grown rapidly over time; from eight in 2012 to 59 in 2018. Note that the studies typically follow a year or so after the event itself as the writing and peer-review process for journal papers can take many months.

The majority of studies included here have been published in the annual “Explaining extreme events” special issues of the Bulletin of the American Meteorological Society (BAMS). Each bumper volume typically contains around 20-30 peer-reviewed studies of events from the previous year. Other studies have been found through the Climate Signals database and online searches through journals.

Specific types of event can be displayed in the chart below by clicking on the category names at the top.

https://s3.eu-west-2.amazonaws.com/cbhighcharts2019/attribution/attribution-studies.html

Number of attribution studies by extreme weather event type and year. Note: the total number of events dipped in 2017 because the Bulletin of the American Meteorological Society special report for that year was published in early 2018 rather than late 2017.

Most of the categories of extreme weather are self-explanatory, but “storms” and “oceans” require a bit of explanation.

For ease of presentation, the “storms” category includes both tropical cyclones (i.e. hurricanes, typhoons) and extratropical storms. The “oceans” category encompasses studies looking at sea surface temperatures and storm surges, such as those generated by Typhoon Haiyan in the Philippines and Hurricane Sandy (pdf, p17) along the eastern US seaboard.

Thirsty people drinking from a public fountain set up for Paris Plage, during the summer heatwave, Paris, France.

There are also some new categories of events in this update, including “coral bleaching” and “ecosystem services”, reflecting the ongoing developments in attribution science.

For example, two studies focusing on 2016 found that El Niño and human-caused climate change combined to bring drought and poor harvests to southern Africa (pdf, p91), and that enhanced warming of sea surface temperatures increased the risk (pdf, p144) of coral bleaching on the Great Barrier Reef.

Such studies show that attribution studies are increasingly considering the impacts of extremes, rather than focusing purely on the weather event. One of the first of these “impact attribution” studies was published in 2016. It estimated that 506 of the 735 fatalities in Paris during the 2003 European heatwave were down to the fact that climate change had made the heat more intense than it would otherwise have been. The same was true for 64 of the 315 fatalities in London, the study said.

This shift towards impacts “is quite significant”, says Prof Peter Stott, who leads the climate monitoring and attribution team at the Met Office Hadley Centre and has been a co-editor of the BAMS reports since they began in 2012. He tells Carbon Brief:

“Impacts are hard to do because you have to establish a significant link between the meteorology and the impact in question. As editors, we’ve been trying to encourage more studies on impacts because it’s the impacts rather than the meteorology per se that tends to motivate these types of study – and if we only have the attribution on the meteorological event then we only have an indirect link to the relevant impact.”

Finally, some attribution research has also looked at the human influence on changes in general indicators of climate change, such as global average temperature or sea level rise. These have not been included in the attribution map as the focus here is on extremes.

Human influence

Turning to the results of the attribution studies that have been published so far, scientists found that human-caused climate change has altered the likelihood or severity of an extreme weather event in 78% of cases studied (68% made more severe or likely and 10% made less so).

In Carbon Brief’s first edition of this analysis in 2017, 68% of events were found to have a human impact (with 63% made more severe or likely and 6% less so).

Note that events are classified here as having an human impact if climate change is found to have influenced at least one aspect of that event. For example, a study of the 2011 East Africa drought found that climate change contributed to the failure of the “long rains” in early 2011, but that the lack of “short rains” in late 2010 was down to the climate phenomenon La Niña. This event is, thus, designated as having a human impact.

For the majority of events affected by climate change, the balance has shifted in the same direction. That is, rising temperatures made the event in question more severe or more likely to occur. These events are represented by the red in the chart below. Clicking on the red “slice” reveals that heatwaves account for 43% of such events, droughts for 17% and rainfall or flooding for 16%. Return to the original chart, and do the same with the other slices to see the proportion of different weather types in each category.

https://s3.eu-west-2.amazonaws.com/cbhighcharts2019/attribution/attribution-drilldown.html

In 11% of studied weather events, scientists found climate change had made the event less likely or less severe (pale orange in the chart above).

Unsurprisingly, this category includes blizzards and extreme cold snaps. However, it also features a few studies that suggest climate change has lessened the chances of heavy rainfall, and another that found rising temperatures have made agricultural drought in California less likely.

With thanks and acknowledgements to Carbon Brief.

The complete article can be found at

Mapped: How climate change affects extreme weather around the world

Later sections of the article contains sections on:

heatwaves

drought

heavy rain and flooding

 

 



 


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Wake-up Calls on Climate Change

One of the reviewers of my book described it as a Wake Up Call  and this phrase is being used more and more in relation to climate change, especially as people have experienced extremes of weather in the last two years.

Now, the Guardian has published an article about the things that their readers have described as Wake Up Calls:

https://www.theguardian.com/environment/2018/dec/21/the-heatwave-was-a-wake-up-call-readers-on-a-year-of-climate-change-anxiety?utm_term=RWRpdG9yaWFsX0dyZWVuTGlnaHQtMTgxMjIx&utm_source=esp&utm_medium=Email&utm_campaign=GreenLight&CMP=greenlight_email

They include the following:

  1. The 2018 heatwave.
  2. Wildfires in California.
  3. The IPCC report, saying we have 12 years.
  4. The launch of Extinction Rebellion.
  5. Extreme heatwaves harming the poorest people.
  6. The’Beast from the East’.
  7. ‘The changing political landscape prompted me’

 

wildfires


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The truth about heatwaves: 1

Summer 2018:

Here in the UK we have been experiencing an oppressive heatwave for the last 7 weeks, with temperatures reaching into the 30s and staying there for several days on end, with up to 36°C predicted for this week. Yet, back in April, we were rueing the fact that the winter seemed to be going on for ever and were fed up with rain, more rain and yet more rain.  And perhaps we should not have criticised so much rain, as it filled up the UK reservoirs, enabling the country to survive this long dry spell.

These extremes of weather are all part of a trend that we must expect to see more  and more, as climate change bites deep into our world. Unpredictable and more extreme weather patterns.

Yet, as bad as temperatures have been in the UK, we are not the only ones experiencing extreme weather events. It would appear that much of northern Europe has been experiencing similar high temperatures. A recent article in The Times, “A worrying trend of heatwaves” by Paul Simon (20th July 2018) gives further details.

Yes, records are not just being broken in the UK and Europe but across the world. At Quriyat on the coast of Oman the world’s hottest ever night on record was measured, with an overnight lowest temperature of 42.6°C on June 25.

The highest reliable temperature in Africa was recorded at 51.3°C in Algeria on July 5th. Many countries in Europe have also had their warmest average April and May on record, and Norway set a national high temperature record of 33.5°C  and Finland hit 33.4°C.  Temperatures in the Arctic circle have also reached 30°C.

heatwave

New Zealand, in the southern hemisphere, has its summer whilst we are in winter and, last December to January was the hottest summer ever recorded.

Other parts of the world, which are usually pretty sultry, are also suffering:

Taiwan: highest recorded temperature of 40.3°C on July 10;

United Arab Emirates: 51.4°C on July 10;

Pakistan: highest temperature for April recorded at 50.2°C.

Japan: highest ever recorded temperature of 41.1°C in Kumagaya, as the country struggles to recover from its worst flooding and landslide disasters for years.

Heatwaves are becoming more extreme and more frequent.

A recent piece on the Quartz website reiterates much of these findings:

https://qz.com/email/daily-brief/1342735/

Perhaps people (climate change deniers) can shrug their shoulders and explain it away as an interesting phenomenon but nothing significant.  But it would appear that, in addition to record daytime temperatures, there is also a significant change in night time temperatures too. Makkaur in Norway has had a record-breaking overnight temperature of 25.2°C on 18th July.  According to an article in the International Journal of Climatology (cited in The Times piece), temperatures during the night are increasing faster than those in the day, so there is little respite for anybody from the oppressive daytime heat.

Cities tend to suffer the most, as buildings retain the heat longer.

Farming in the UK is also being affected: livestock are now being fed winter feed, as summer grass has withered away; reservoirs for watering vegetables are running dry and crops such as spring barley and sugar beet are being hit.

Hospitals without air conditioning are becoming extremely hot, affecting nurses and patients alike (nurses are not allowed to carry water bottles).  In one Hampshire hospital, the extreme heat set off the fire alarm.


Another report from Unearthed describes how heat waves and record temperatures are occurring across the northern hemisphere.  In Quebec, Canada, 34 deaths have been attributed to a heat wave.  Record temperatures have been recorded too in Northern Siberia.


And, accompanying heat waves of course, there are very often wild fires or bush fires burning out of control – and probably adding to the overall effect of global warming. Damaging homes and property, as well as killing people and many of the endangered species that we care about.

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In the UK, as well as in other countries, there have been a series of wildfires, which have been difficult to bring under control. And today, as I write, we have heard about devastating fires in Greece, with homes destroyed, 60+ killed or missing and people fleeing into the sea to get away from the flames. Sweden has also experienced 50 forest fires burning in mid-July.

And last year, Portugal, Canada and Australia, among others, also experienced wild fires out of control.


See also, an earlier blog and heat waves and human survivability. This cites a Lancet article about how high temperatures can reach before people start dying – this depends on the level of humidity.


 

2nd August 2018

Today, I have received details of two articles, which both state that there is now no doubt that human-induced climate change is responsible for the current heat waves.

The first is from The Guardian, with the headline, “Extreme global weather is ‘the face of climate change’ says leading scientist.” It cites the comments by an eminent climate scientist, Prof Michael Mann, who “declares that the impacts of global warming are now ‘playing out in real-time’“.  See:

https://www.theguardian.com/environment/2018/jul/27/extreme-global-weather-climate-change-michael-mann?utm_source=esp&utm_medium=Email&utm_campaign=Green+Light+2016&utm_term=282539&subid=2617869&CMP=EMCENVEML1631

“Other senior scientists agree the link is clear. Serious climate change is “unfolding before our eyes”, said Prof Rowan Sutton, at the University of Reading. “No one should be in the slightest surprised that we are seeing very serious heatwaves and associated impacts in many parts of the world.”

The second article is from Media Lens today and is a compilation of articles from various places.  It is entitled “World on Fire: Climate Breakdown” and starts with the following paragraph:

“What will it take for society to make the deep-rooted changes required to prevent the terrifying and awesome threat of climate breakdown? This summer’s extreme weather events are simply a prelude to a rising tide of chaos that will be punctuated by cataclysmic individual events – floods, heatwaves, superstorms – of increasing severity and frequency. How long before people demand radical action from governments? Or, and this is what is really needed, how long until citizens remove corporate-captured governments from power and introduce genuine democracy?”

http://medialens.org/index.php?option=com_acymailing&ctrl=archive&task=view&mailid=498&key=3d627a0db9defa2572b31cb827097147&subid=9459-27247f5ad5910317f882bc7ac4e817e1&tmpl=component

The article gives details of the extreme temperatures recorded across the globe this summer but then gives an analysis of some of the things still being said by a climate-sceptic press, when reporting on the current heat wave: the Daily Mail; the Sun and even the BBC.  All are failing to properly acknowledge that it is caused by climate change.

The Media Lens writer does not mince any words.


 

 


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More extreme weather events caused by climate change?

The US state of Texas has experienced some terrifying extreme winds and unprecedented flooding as a result of Hurricane Harvey.  Photographs in the US press show homes destroyed, highways flooded and elderly people in an old people’s home sitting up to their waists in flood water.

Climate experts have been saying for a while that tornados, monsoons, tropical cyclones, hurricanes and flooding are becoming more extreme.  Climate change deniers are saying there is no evidence of a link between climate change and severe weather events but that these events are just due to natural variability.  However, I feel that the scientific evidence produced from studying 140 weather events around the world from Typhoon Haiyan in the Philippines to the California drought shows a clear link. The result is mounting evidence that human activity is raising the risk of some types of extreme weather, especially those linked to heat.

Carbon Brief has mapped all of these events:

https://www.carbonbrief.org/mapped-how-climate-change-affects-extreme-weather-around-the-world

and their analysis suggests that 63% of all extreme weather events studied were made more likely or more severe by human-caused climate change. Heatwaves account for nearly half of such events (46%), droughts make up 21% and heavy rainfall or floods account for 14%.

A recent article in The Guardian (28th August 2017) by Michael E. Mann, a distinguished professor of atmospheric science at Pennsylvania State University, has discussed whether Hurricane Harvey was caused by climate change. He concluded that climate change has worsened the impact of the Hurricane and other extreme weather events.  See:

https://www.theguardian.com/commentisfree/2017/aug/28/climate-change-hurricane-harvey-more-deadly?CMP=share_btn_tw

And where is Trump in all of this?

I wonder whether the current US devastation from Hurricanes Harvey and Irma will change Donald Trump’s mind about the reality of climate change. 

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Probably not, as he only seems to listen to the group of buddies he has gathered around him at the White House, most of whom have a vested interest in continuing to burn fossil fuels.  But will the swamped and bereaved residents of Houston and Florida allow him to continue on this blinkered course?

A recent report from the Union of Concerned Scientists has raised another problem arising from Hurricane Harvey: that more then 650 energy and industrial facilities may have been flooded as a result of the hurricane, with the Gulf Coast being home to many chemical industries as well, thus raising the risk of people living in the Houston area of being exposed to toxic chemicals.

http://blog.ucsusa.org/kristy-dahl/flooded-by-hurricane-harvey-new-map-shows-energy-industrial-and-superfund-sites

Meanwhile, Greenpeace have pointed out that the global media has focused on the disaster in Texas and ignored all the other tragic weather events taking place across the globe.  These include:

Flooding in South Asia:

In India, Nepal and Bangladesh 1200 people have also been recently killed by flooding, with 1.8 million children unable to go to school. The International Federation of Red Cross and Red Crescent Societies (IFRC) estimates more than 41 million people have been affected by monsoon rains and severe flooding as of June this year. Whilst the numbers are massive, the stories to come out of this disaster are just as tragic. Several people are reported to have died from falling into open manholes, a two-year-old has lost her life to a wall collapse and many are reported to be missing.

Sierra Leone:

Two weeks ago a mudslide hit Sierra Leone, killing at least 499 people.

image

Niger floods force thousands from their homes:

Serious flooding has led the authorities in Niger to order thousands of people to leave their homes in the capital Niamey. While many are sheltering in schools, others have nowhere to go. Already the torrential rains are reported to have killed at least 44 people in Niamey and other parts of the West African country since June, and has caused the destruction of hundreds of houses.

Storm Lidia

Tropical Storm Lidia hit the southern tip of Mexico’s Baja California peninsula with heavy rain and high winds on Thursday evening. While not projected to reach hurricane strength, authorities in the state of Baja California Sur suspended classes and flights until conditions were deemed safe.

Hurricane Irma:

This powerful hurricane rapidly intensified in the open Atlantic, posing a major threat to the Caribbean and potentially the United States. Initially labelled a tropical storm, Irma strengthened into a large Category 5 hurricane in a process known as “rapid intensification”.  This has caused extreme damage to many of the Caribbean islands, leaving thousands homeless.  Full news of the devastation is yet to emerge.

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Mark Lynas of CNN has written, “this is what climate change looks like”. See:

http://edition.cnn.com/2017/08/31/opinions/climate-change-harvey-lynas-opinion/index.html?utm_source=Weekly+climate+roundup&utm_campaign=7733095a5f-Climate+Roundup+16_06_2017&utm_medium=email&utm_term=0_81339309ed-7733095a5f-141770409

He goes on to say:

“It is not politically opportunistic to raise this issue now. Instead we have a moral duty not to accept the attempted conspiracy of silence imposed by powerful political and business interests opposed to any reduction in the use of fossil fuels. We owe this to the people of Texas as much to those of Bangladesh and India, and Niger — which was also struck by disastrous flooding this week.

Climate disasters demonstrate our collective humanity and interdependence. We have to help each other out — in the short term by saving lives and in the longer term by cutting greenhouse gases and enhancing resilience, especially in developing countries.”