Club Meetings at Mere are still cancelled due to the Coronavirus pandemic. A series of Zoom Meetings are arranged throughout the month.
14th January 2021 – Club Meeting – Speaker, Mr Keith Stevens, who gave a talk entitled ‘Climate Change? What Climate Change?’
Keith started his talk by stating that it was based upon four assumptions:
- The climate has changed in some way.
- It has changed for the worse.
- We are causing the change with our CO2
- People are dying because of climate change.
He looked at each of these in turn to see if they were true. This was measured in two ways. Firstly, by looking at the number of deaths which can be attributed to climate change and secondly, by looking at extra extreme weather events.
Weather can be defined as what is happening now, or immediate, whilst climate can be defined as looking at weather over a period of time, such as 30 years or more.
Keith then listed items of climatic conditions which could be regarded as killers, ranging from cyclones to flooding. He then went on to describe huge changes in climate over billions of years, defining the present time as part of an ice age, or an interglacial period, with polar ice temporarily retreating. He used a chart to show regular changes in climate every 100,000 years. This suggested that the earth would be warm for 10,000 years and then the next step must be downwards. The warm periods were much shorter than the colder periods. CO2 emissions also follow a similar rhythm, but there has been a huge increase in CO2 over the last 100 years, with the increase starting in the early 19th century.
Keith then used charts to show how the earth’s average temperature had risen by 0.6 oC between 1979 and 2020 and 0.8 oC between 1860 and 2020, although at the Poles, this was nearer 1.5 oC. However, between 1920 and 1940 there had been a temperature rise, but no corresponding increase in CO2, and between 1950 and 1970 the temperature remained fairly level but CO2 increased. The rise in sea level caused by global warming was 23 cm in 160 years. The melting freshwater from land-based glaciers could cause a cold spot in the North Atlantic which could slow the Gulf Stream, resulting in the Northern hemisphere getting colder.
Fatality figures attributed by the effects of climate show that cold weather kills 20 times more people than hot weather. Keith then produced figures showing annual worldwide fatalities from various climate conditions ranging from cyclones to wildfires. Looking at the statistics he produced for extreme weather conditions over the last 100 years, in areas such as hurricanes and flooding, fatalities have gone down, not up, following extreme weather events. Furthermore, record weather events are largely historical, with few record-breaking conditions over the last 10 years. In fact, at the moment, even typhoons and thunderstorms appear to be in decline. Monsoons occur as regularly as usual, and droughts lasting 10 or 20 years in California are nothing new. It is quite possible that Californian wildfires were caused more by bad forestry management than climate change.
Looking at agriculture, about 18m Km2 of the earth’s surface is used to grow crops and 34m Km2 is used for livestock. There has been a major increase in the efficiency of farming methods and the CO2 increase helps to give a higher crop yield. If the earth’s temperature were to fall by 2 oC, instead of rise, there would be a massive drop in food output.
Greenhouse gases help the earth’s atmosphere to maintain its temperature. The two most dominant gases are CO2 and water vapour. It is not known whether increases in CO2 have a linear or logarithmic effect on the earth’s atmospheric temperature. However, if CO2 was the driving force behind the earth’s temperature, the large spike in CO2 should cause an equivalent increase in temperature, but it has not. Water vapour has two hundred times more influence on the earth’s atmospheric temperature than CO2, which means that CO2 only accounts for just under 0.2 oC of the 0.8 oC increase in temperature.
Keith then showed a chart from Norwegian researchers which showed how temperature and CO2 levels had changed over an 11 thousand year period. A cyclic pattern was clearly visible, with CO2 levels mostly following the temperature. The mini-ice age in 1790 when the Thames froze was clearly visible on the chart, but there was no corelation between the recent steep rise in CO2 and the average temperature. In addition to this there are temperature oscillations in the Atlantic and the Pacific which follow a cycle of about 30 years.
He concluded by stating that CO2 will continue to rise, whether we like it or not. To date, the effects are barely measurable, and dominated by a natural rise in temperature. Man has mostly benefited from the rises in CO2 and temperature. Fewer people are dying as a result of climate change, and out of all of the environmental conditions, cold is the biggest killer. Keith’s penultimate slide ended with the statement ‘Climate change research is contrived to produce unjustified headline claims with the intention of keeping the so-called problem in the public eye, with future research grants being the objective’.
Keith then took questions from the audience.