The 10 European cities whose temperatures have been most influenced by climate change over the last year include four in Spain

The 10 European cities whose temperatures have been most influenced by climate change over the last 12 months include four in Spain: Madrid, Barcelona, Valencia and Zaragoza.

The extent to which climate change affects daily temperatures around the world can now be measured in real time thanks to a new online tool launched by Climate Central. The tool applies a new five-point scale called the Climate Shift Index (CSI) to establish the degree to which climate change has influenced local daily average temperatures. By way of example, a CSI level of three means that a day’s temperature was made at least three times more likely than it would have been without the impact of anthropogenic climate change. The highest CSI level is five.

Based on the CSI, Climate Central has today published ‘365 Days on a Warming Planet’, a report that reveals the impact of human-driven climate change on average temperatures for each day from 1 October 2021 to 30 September 2022 in more than a thousand cities across the planet. Using the information in question, Climate Central has also produced a ranked list of the cities most affected over the last year for each continent.

The report ‘365 Days on a Warming Planet’ reveals the impact of human-driven climate change on daily average temperatures in more than a thousand cities.

A high-CSI day is a day with a CSI level of three or above. The report shows that Madrid was the European city with the third greatest number of such days (66) between the aforementioned dates, behind only Valletta (Malta) and Longyearbyen (Norway). Valencia (59 high-CSI days), Zaragoza (58) and Barcelona (53) are in the next three positions in the same list.

The report also reflects the extent of human exposure, calculated by multiplying each city’s population by its total number of high-CSI days. Using that criterion, Madrid was the European city with the highest human exposure score, with Barcelona, Valencia and Zaragoza ranking fourth, seventh and eighth respectively. Madrid is actually the only European city to feature among the 121 cities of the world with the highest human exposure levels in the period studied.

Corina Basnou is a CREAF researcher who has worked extensively on sustainability in cities. Her reaction to the data in the report was as follows:

“It is essential that the councils and inhabitants of cities be aware of the need to adapt them to climate change and understand the value of nature-based solutions to that end. Such solutions involve changing the ‘skin’ of cities from grey to green, by increasing the amount of urban vegetation like parks, trees in streets, gardens and green walls, which bring temperatures down and regulate the flow of air and water. Another example, in cities with rivers, is riverbank woodland, which reduces the effects of flooding in the event of heavy rainfall. All those measures, if well planned, can help improve energy efficiency, the regulation of urban microclimates or heat islands, biodiversity conservation, and the interconnection of urban and peri-urban green areas.”

CORINA BASNOU, CREAF researcher

Joan Pino, CREAF’s director, who is also an expert on urban sustainability, added the following:

“For example, planting more trees and vegetation could reduce temperatures by five to 10°C, depending on the situation and the type of plants chosen. The most important thing is to carefully plan what species to plant, taking into account the shadow they provide and the amount of water they need. For instance, planting lots of deciduous trees from subtropical climate zones would be a good option because they provide a great deal of shade and consume less water than other central European species.”

JOAN PINO, CREAF’s director.

On a global scale, ‘365 Days on a Warming Planet’ highlights that 7.6 billion people (96% of the world’s population) experienced temperatures affected by human-driven climate change in the last 12 months. The report also states that people living close to the equator and on small islands have been particularly affected. Over the period analysed, the impact of anthropogenic climate change on temperatures was at its greatest in Mexico, Brazil, western and eastern Africa, the Arabian Peninsula and the Malay Archipelago.

Lastly, the report notes that, when urban population size is accounted for, total human exposure to daily temperatures altered by climate change in the period studied was highest in Lagos (Nigeria), Mexico City (Mexico) and Singapore.

Source of information: Climate Central