Tag Archives: IPCC

Merseyside Totemy

The recent extreme weather is perhaps leading more people to appreciate the changes in our climate are real and likely to have a serious impact on our way of life [see ‘Climate change and tides in Liverpool‘ on May 11th, 2016].  However, I suspect that most people do not appreciate the likely catastrophic effect of global warming.  For example, during the 20th century, the average rise is sea level was 1.7 mm per year; however, since the early 1990s it has been rising at 3 mm per year, and sea levels are currently rising at about 4mm per year according to the Intergovernmental Panel on Climate Change.  It is difficult to translate  statistics of this type into a meaningful format – the graph below helps in recognising the trends but does not convey anything about the impact.  However, I am impressed by a new art installation on the Liverpool waterfront by Alicja Biala called ‘Merseyside Totemy’ which illustrates the percentage of each of three high-risk local areas that will be underwater by 2080 if current trends continue: Birkenhead (centre of photograph), Formby (left) and Liverpool City Centre (right behind tree) [see www.biennial.com/collaborations/alicjabiala].  Perhaps using data for 30 years time rather than 60 years would have focussed people’s attention on the need to make changes to alleviate the impact.

Figure 1 from

Figure 1. Time series of global mean sea level (deviation from the 1980-1999 mean) in the past and as projected for the future. For the period before 1870, global measurements of sea level are not available. The grey shading shows the uncertainty in the estimated long-term rate of sea level change. The red line is a reconstruction of global mean sea level from tide gauges, and the red shading denotes the range of variations from a smooth curve. The green line shows global mean sea level observed from satellite altimetry. The blue shading represents the range of model projections for the SRES A1B scenario for the 21st century, relative to the 1980 to 1999 mean, and has been calculated independently from the observations. Beyond 2100, the projections are increasingly dependent on the emissions scenario. Over many centuries or millennia, sea level could rise by several metres. From https://archive.ipcc.ch/publications_and_data/ar4/wg1/en/faq-5-1-figure-1.html

Inconvenient facts

The latest UN Climate Change Conference in Madrid, which is holding its closing session as I am writing this post, does not appear to have reached any significant conclusions.  Unsurprisingly, vested interests have dominated and there is little agreement on a plan of action to slow down climate change or to mitigate its impact. However, perhaps there is progress because two recent polls imply that 75% of Americans believe humans cause climate change and roughly half say that urgent action is needed.  This is important because the USA has made the largest cumulative contribution to greenhouse gas emissions with 25% of total emissions, followed by the EU-28 at 22% and China at 13%, according to the Our World in Data website.  However, the need for urgent action is being undermined by suggestions that we cannot afford it, or that we will have better technology in the future that will make it easier to act.  However, much of the engineering technology that is needed to remove fossil fuels from our economy is already available.   Of course, the technology will be improved in the future but that is always true because we are continually making technological advances.  We could replace fossil fuels as the energy source for all of our electricity, buildings and heating (31%) and for most of our industry (21%) and transportation (14%) using the technology that is available today and this could eliminate about two-thirds of current global greenhouse gas emissions. The numbers in parentheses are the percentage contributions to global greenhouse gas emissions according to the IPCC. Of course, it would require a massive programme of infrastructure investment; however, if we are serious then the subsidies paid to the oil and gas industry could be redirected toward decarbonising our economies.  According to the IMF, that is approximately $5.2 trillion per year in subsidies, which is about the GDP of Japan.  The science of climate change is well-understood (see for example ‘What happens to emitted carbon‘ and ‘Carbon emissions and surface warming‘) and widely recognised; the engineering technology to mitigate both climate change and its impacts is largely understood and implementation-ready; however, most urgently, we need well-informed public debate about the economic changes required to decarbonise our society.

Sources:

Mark Maslin, The five corrupt pillars of climate change denial, The Conversation, November 28th, 2019.

United Nations Blog, The drive to a conclusion, December 13th, 2019.

Sandra Laville, Top oil firms spending millions lobbying to block climate change policies, says report, The Guardian, March 22nd 2019.

Footnote: The videos ‘What happens to emitted carbon‘ and ‘Carbon emissions and surface warming‘ are part of a series produced by my colleague, Professor Ric Williams at the University of Liverpool.  He has produced a third one: ‘Paris or Bust‘.