In December 2019, the average temperature across Australia was about 2°C above what would be expected for the present-day, which is another 1.5°C above temperatures that were normal for December before humans started warming the climate. These extreme temperatures have contributed to the catastrophic bushfires which have devastated large areas.
But what may be considered ‘normal’ is constantly changing.
In a world which has warmed by 3°C – roughly the current global trajectory – what was extreme will be entirely normal.
The lower atmosphere is warming while the upper atmosphere is cooling – a clear fingerprint of the enhanced greenhouse effect from human emissions of carbon dioxide.
The simple explanation is that some of the infrared radiation emitted by the surface, which would have normally reached the upper atmosphere, is absorbed by greenhouse gases in the lower atmosphere. The upper atmosphere therefore receives less energy than before, and so cools. The very warm years (intense reds) in the upper atmosphere are the 1982-83 El Chichón and 1991-92 Pinatubo eruptions respectively.
On 21st June 2019, the #ShowYourStripes initiative was launched, providing ‘warming stripe’ graphics for virtually every country at showyourstripes.info.
The data was provided by Berkeley Earth and several national meteorological agencies, and the stripe graphics are available for 1901-2018 for most locations, but extended further backwards where the national data was easily available. The US States and UK regions have their own separate graphics, as do Stockholm, Oxford and Vienna – three of the longest continuous series in Europe.
With 2018 coming towards an end, the World Meteorological Organisation (WMO) released their provisional State of the Climate report. The WMO asked whether Climate Lab Book could provide some updated graphics, also reproduced here.
Following the ‘warming stripes‘ graphics for different locations around the world, this post focusses on the UK. The Met Office makes easily available long-running climate data from a small number of locations*. The visualisations below show the common changes in temperature and rainfall for the five longest climate monitoring stations in that set – Stornoway, Armagh, Durham, Sheffield & Oxford – which all have data for 1883-2017. Continue reading Climate stripes for the UK→
Climate change is a complex global issue, requiring simple communication about its effects at the local scale. This set of visualisations highlight how we have witnessed temperatures change across the globe over the past century or more. The colour of each stripe represents the temperature of a single year, ordered from the earliest available data at each location to now. All other superfluous information is removed so that the changes in temperature are seen simply and undeniably.