We are living through Earth’s hottest month on record, scientists say
Its not just a record-hot day or two , unprecedented heat waves or abnormally warm ocean waters : All indications are that this will be the hottest single month on Earth on record, and possibly in more than 100,000 years. Every day this month has set records for average global annual temperatures, and already, 17 days in July have been hotter than any others in more than 40 years of global observations, climate scientists said. Not even three weeks into the month, scientists declarations of an already assured monthly global record serve to punctuate what has been an onslaught of recent weather extremes. Record heat has been observed from Arizona to Rome to China. An unprecedented wildfire season continues in Canada . Flooding juiced by the fact that warmer air holds more moisture has devastated Vermont, northern India and South Korea. Were just really starting to see climate change kick in, said Nathan Lenssen, a postdoctoral researcher at the University of Colorado focused on historical temperature data. Seeing so many types of weather and climate extremes in a six-month period is pretty remarkable. While it is too soon for official records, all preliminary data points to this month being a watershed for the globe. National Oceanic and Atmospheric Administration data captured on a daily basis and presented in widely shared charts from the University of Maines Climate Reanalyzer have so far been largely validated by other analyses, including one from the Europes Copernicus Climate Change Service released earlier this month , said Zeke Hausfather, a climate scientist at Berkeley Earth and the tech company Stripe. Given the extreme global temperatures over the first half of July, it is virtually certain that July will set a record both as the warmest July and as the warmest month in absolute terms since global temperature records began in the mid-1800s, Hausfather wrote in an email to The Washington Post. July, the peak of the Northern Hemisphere summer, is the planets hottest month in any given year because the Northern Hemisphere contains more land than the Southern Hemisphere and because land heats up faster than oceans do. That means Northern Hemisphere temperatures have an outsize influence on planetary averages. At this point in the month, it would take truly dramatic cooling in the waning days of the month to offset the warmth observed over the past few weeks, said Michael Mann, the University of Pennsylvania climate scientist known for the hockey stick temperature plot that shows modern warming is unprecedented in at least 2,000 years. Such cooling is not expected to occur given the presence of an El Nino climate pattern that developed last month . El Nino is known to boost the planets temperature, as warmth stored within the Pacific Ocean pools at its surface along the equator, driving changes in weather patterns around the world and releasing more heat and humidity into the atmosphere. This spring and summer, ocean warmth has not been limited to the Pacific. Record warmth has also been observed in the North Atlantic, with bathwater-like warmth around Florida and abnormally mild conditions around the British Isles . Climate scientists say the ocean warmth is probably helping fuel what have been historic heat waves on land, even in many spots long used to summer extremes. 1 / 2 Temperatures reached a record 109 degrees in Rome and a record 126 degrees in China in recent days, while Arizona is enduring an unprecedented streak with nighttime temperatures in the 90s and daytime highs above 110 degrees. The average temperature at Phoenix Sky Harbor International Airport was 108 degrees Wednesday, 1.5 degrees above a record set in 1990. Flash floods, which scientists say global warming makes more likely, have also surged. The United States has experienced 11 flash flood emergencies, the most dire National Weather Service declaration for such an event, in the past 11 days, including one that dropped the most rainfall ever observed in Kentucky , with a 0.1 percent chance of happening, based on historical rainfall records. Dozens have been killed in flooding in South Korea and more than 100 have died in floodwaters in India . The last time such extremes may have been possible is thought to be about 6,500 years ago , during a period that, apart from the present, was Earths warmest in about 125,000 years. At that point, scientists say, temperatures averaged somewhere between 0.2 degrees Celsius and 1 degree Celsius (0.36 to 1.8 degrees Fahrenheit) warmer than they were from 1850 to 1900. Last month, global temperatures averaged 1.36 degrees Celsius (2.4 degrees Fahrenheit) over that preindustrial benchmark. Scientists and policymakers have urged nations to take actions that prevent warming from rising 1.5 degrees above preindustrial levels, but the planet is on pace to surpass that mark in the coming years . The heating trend is likely to fuel extreme weather throughout the next year as El Nino continues to strengthen, said Gavin Schmidt, director of the NASA Goddard Institute for Space Studies. El Nino will probably mean that 2024 will be even warmer than this year, which could itself set a record for highest average global temperatures, he said. On a teleconference with reporters Thursday, Schmidt said that because the El Nino is still developing, it cant take much blame for the recent surge of warming. The rising temperatures and the supercharging effect they have on weather are mostly related to human emissions of greenhouse gases, he said. Until we stop doing that, temperatures will keep on rising, Schmidt said. Our warming climate: In the Eastern U.S., the record-breaking heat wave is reaching is peaking. July was Earths hottest month , and heres where the worst, record-setting heat occurred . Use our tracker to see your citys extreme heat risk . Take a look at what extreme heat does to the human body . How to stay safe: Its better to prepare for extreme heat before youre in it. Heres our guide to bracing for a heat wave , tips for staying cool even if you dont have air conditioning , and what to know about animal safety during extreme heat . Traveling during a heat wave isnt ideal, but heres what to do if you are . Understanding the science: Sprawling zones of high pressure called heat domes fuel heat waves. Heres how they work . You can also read more about the link between weather disasters and climate change , and how leaders in the U.S. and Europe are responding to heat .