Climate change made Europe's July heat wave up to 3 degrees Celsius hotter, scientists say

Heat wave puts iconic landmark in jeopardy01:43

London (CNN)The scorching heat wave that broke records across Europe last month was made more likely, more intense and up to three degrees Celsius hotter by climate change, a study has found.

Scientists found that the event would have been a once-in-a-millennium occurrence without a changing climate, but was made up to 100 times more probable because of the process.

The UK, Germany, Belgium and the Netherlands all recorded their highest temperatures ever in the July heat wave, with the mercury topping 40 degrees in much of mainland Europe.

Without climate change, temperatures would have been between 1.5 and 3 degrees lower, according to the report from the World Weather Attribution group, an international alliance of meteorological researchers.

The group have analyzed every heat wave in Europe in the 21st century (in 2003, 2010, 2015, 2017, 2018, June 2019 and July 2019), and found that each one was made more likely because of climate change.

The report comes a day after the World Metereological Organization said July equaled -- and may have surpassed -- the hottest month in recorded history.

The July event was the second record-smashing heat wave in two months, with a similar one bringing 45.9 degree temperatures to France and causing wildfires in Spain in June.

Amid the sweltering heat, trains were canceled in a number of European countries due to risk of derailment.

A Eurostar train traveling from Belgium to London broke down on Wednesday, trapping passengers in 40 degrees Celsius heat, without air conditioning. Network Rail, which operates the UK's rail infrastructure, said that track temperatures in and around London were set to exceed 50 Celsius (122 degrees Fahrenheit), almost double the average summer rail temperature in the UK. Railway tracks expand in heat and are prone to buckling when temperatures rise.

Many European cities are not also designed to deal with such temperatures. Less than 5% of all European households have been air-conditioned, and public transport can grind to a halt in intense heat.

Scientists have long predicted that heat waves such as June and July's could become the new normal for Europe, driven by rising temperatures caused by greenhouse gas emissions.

A group of European scientists previously concluded that the June heat wave was made at least five times more likely because of climate change -- and perhaps 100 times more likely.

France's weather service also made the link, issuing a warning that without serious carbon dioxide reductions, heat waves could become more intense and frequent than in the past.

Meanwhile, a heatwave that started in the Sahara has rolled into Greenland this week -- where more records are under threat.

CNN's Isabelle Gerretsen and Jessie Yeung contributed reporting.

By Rob Picheta, CNN >>