European summers have been getting longer and hotter. However, there\u2019s been a \u201chigh uncertainty\u201d about exactly how or why this is happening, says Dr Celia Martin-Puertas, a lead researcher from the Department of Geography at Royal Holloway.<\/p>\n
Now, new research<\/strong><\/a> reveals that today\u2019s heat patterns mimic those of 6,000 years ago, and could be a sign of even more hot days to come. <\/p>\n Looking to mud<\/strong><\/p>\n For the study, which was published in Nature Communications, Martin-Puertas and her team focused on an important record of climate history: mud. Sediments found at the bottom of Europeanlakes<\/strong><\/a> give a snapshot into how the seasons have changed over the past 10,000 years. <\/p>\n They assessed the \u201clatitudinal temperature gradient,\u201d or the temperature difference between the Arctic and the equator. This gradient is what guides the weather in Europe, driving winds from the Atlantic Ocean<\/strong><\/a> to the continent. <\/p>\n And as the Arctic warms up, the temperature difference between the Arctic and the equator decreases. As a result, air currents slow, thus intensifying and extending summer weather patterns like heatwaves<\/strong>.<\/a> The summer season itself would also last longer. <\/p>\n According to the study, for each 1 \u00b0C decrease in the latitude temperature gradient, the summer season would extend by about six days. This could add up to 42 extra summer days by 2100 if warming continues at the current rate. However, with the current trend of Arctic warming, Europe could see eight months of summer weather by the end of the century. <\/p>\n This mirrors conditions in Europe about 6,000 years ago, where the warm season lasted almost 200 days.<\/p>\n Why now?<\/strong><\/p>\n While the temperature gradient has always existed, greenhouse gas emissions<\/strong><\/a>accelerate the warming of the Arctic<\/strong><\/a>.<\/strong> The area is currently warming up to four times faster than the global average. <\/p>\n \u201cOur findings show this isn\u2019t just a modern phenomenon; it\u2019s a recurring feature of Earth\u2019s climate system,\u201d said Dr Laura Boyall, an author of the study and former PhD researcher in the Department of Geography at Royal Holloway. \u201cBut what\u2019s different now is the speed, cause and intensity of change.\u201d<\/p>\n The authors also note that other factors contribute to the changing summer<\/strong><\/a> patterns, such as human-caused positive and negative feedback loops.<\/p>\n How has Europe warmed in recent years?<\/strong><\/p>\n Europe is the world\u2019s fastest-warming continent. Cities in particular are hit hard by global warming thanks to the urban heat island effect<\/strong><\/a>, where heat is trapped by buildings and absorbed by asphalt and concrete. <\/p>\n