Time for another trip to Skeptical Science... Archived Message
Posted by Ian M on July 18, 2022, 3:57 pm, in reply to "Re: Eamonn Holmes on GB News: People will be 'disappointed if this record in temperatures isn't broken'"
Global warming is increasing the risk of heatwaves
What the science says...
Global warming is increasing the frequency, duration and intensity of heatwaves.
Heatwaves have happened before
"Australia has always had extreme heat, droughts, bushfire and flooding rains... Whatever is the extent of global warming and any human contribution to climate change, exaggerating the 2013 heatwave is just another green lie which will blow up in all our faces." (Miranda Devine)
Global warming is causing more frequent heatwaves. Record-breaking temperatures are already happening five times more often than they would without any human-caused global warming. This means that there is an 80% chance that any monthly heat record today is due to human-caused global warming.
Figure 1: Likelihood of heat records compared to those expected in a world without global warming.
What will heatwaves be like in the future? If we continue to rely heavily on fossil fuels, extreme heatwaves will become the norm across most of the world by the late 21st century. However, if we take major steps to reduce human greenhouse gas emissions, the number of extreme heatwaves will stabilize after 2040. Either way, we will see more heatwaves, but how much more depends on us.
However, the growing risk from heatwaves is ignored by some who argue that heatwaves have happened in the past, hence current heatwaves must be natural. This line of argument is logically flawed, using a logical fallacy called a non sequitur (Latin for 'it does not follow'). This is a fallacy where your starting statement does not lead to your conclusion. For example, this is like arguing that people have died of cancer long before cigarettes were invented, hence smoking can't cause cancer.
The longer we continue to rely on fossil fuels and the higher our greenhouse gas emissions, the more extreme heat we'll lock in. If we manage to take serious action to reduce our greenhouse gas emissions, we can limit global warming to a level where extreme heat events will become more commonplace, but we can manage to adapt to.
Basic rebuttal written by John Cook
Update July 2015:
Here is a related lecture-video from Denial101x - Making Sense of Climate Science Denial
Heathrow had 16 consecutive days over 30 °C (86 °F) from 23 June to 8 July and for 15 consecutive days from 23 June to 7 July temperatures reached 32.2 °C (90 °F) somewhere in England. Furthermore, five days saw temperatures exceed 35 °C (95 °F). On 28 June, temperatures reached 35.6 °C (96.1 °F) in Southampton, the highest June temperature recorded in the UK. The hottest day of all was 3 July, with temperatures reaching 35.9 °C (96.6 °F) in Cheltenham.
The great drought was due to a very long dry period. The summer and autumn of 1975 were very dry, and the winter of 1975–76 was exceptionally dry, as was the spring of 1976; indeed, some months during this period had no rain at all in some areas (citation needed).
The drought was at its most severe in August 1976 and in response Parliament passed the Drought Act 1976 to ration water. Parts of the south west went 45 days without any rain in July and August. As the hot and dry weather continued, devastating heath and forest fires broke out in parts of Southern England. 50,000 trees were destroyed at Hurn Forest in Dorset. Crops were badly hit, with £500 million worth of crops failing. Food prices subsequently increased by 12%.
In the last week of August 1976, days after Denis Howell was appointed 'Minister for Drought', severe thunderstorms brought rain to some places for the first time in weeks. September and October 1976 were both very wet months, bringing to an end the great drought of 1975–1976.
In the Central England Temperature series, 1976 is the hottest summer for more than 350 years. The average temperature over the whole summer (June, July, August) was 17.77 °C (63.99 °F), compared to the average for the unusually warm years between 2001–2008 of 16.30 °C (61.34 °F).
The summer was so hot that it is embedded in the national psyche, with subsequent heatwaves in 1995, 1997, 2003, 2006, 2018, 2020 and 2022, all using 1976 as a benchmark.
Something odd about all those later heatwaves clustered in such a short space of time, can't quite put my finger on why...
Amazing how people can grasp at any shoddy piece of reasoning to avoid a conclusion they don't like. They'll be coming out with the same tired old bullshit when temps hit 50, I'm sure.