“The whole aim of practical politics is to keep the populace alarmed (and hence clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary” H L Mencken
The introduction to the Conference of Parties (COP 26) in Glasgow in November 2021 is headed in bold letters: “CLIMATE CHANGE IS THE GREATEST RISK FACING US ALL”. It goes on to note “Despite the opportunities we are not acting fast enough. To avert this crisis, countries need to join forces urgently” and furthermore they see the event as “…to be the world’s last best chance to get runaway climate change under control“.
The following figure should now be familiar to anyone following the debate on climate change. It is taken from section A1 of the Sixth Assessment Report of the The Intergovernmental Panel on Climate Change (IPCC) which section states that:
“It is unequivocal that human influence has warmed the atmosphere, ocean and land.
Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere
A legally binding international treaty on climate change was adopted by 196 Parties at COP 21 in Paris, on 12 December 2015 and entered into force on 4 November 2016. The so-called Paris Agreement‘s goal was to limit global warming to well below 2, preferably to 1.5 degrees Celsius, compared to pre-industrial levels.
The next webpage considers what methods were used to measure or determine these temperatures and highlights areas of controversy surrounding the presentation of temperature data.
A glossary of terms associated with the topic of climate change appears below.
GLOSSARY – a selection with sources cited.
Anthropogenic greenhouse gases: Greenhouse gases generated by human activity rather than natural processes or by forcings. The main sources are burning fossil fuels, agriculture, forestry and land use, cement manufacture and aerosols – BGS
Climate: Climate is usually defined as the average weather, or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities (such as temperature, rainfall, cloudiness, sunshine, and wind speeds) over a period of time ranging from months to thousands or millions of years. The classical period for averaging these variables is 30 years, as defined by the World Meteorological Organization – adapted from IPCC Glossary
Climate Change: A change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings (i.e. ‘influences’) such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use – IPCC Glossary
Greenhouse Gases: A greenhouse gas is called that because it absorbs infrared radiation from the Sun in the form of heat, which is circulated in the atmosphere and eventually lost to space. In descending order, the gases that contribute most to the Earth’s greenhouse effect are: water vapour (H2O), carbon dioxide (CO2), nitrous oxide(N2O), methane (CH4) and ozone (O3). Without the natural greenhouse effect, the heat emitted by the Earth would simply pass outwards from the Earth’s surface into space and the Earth would have an average temperature of about -20°C – BGS . See also anthropogenic greenhouse gases.