Record heat

It’s 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.
“We’re 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 Maine’s Climate Reanalyzer have so far “been largely validated” by other analyses, including one from the Europe’s 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 planet’s 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 Niño climate pattern that developed last month. El Niño is known to boost the planet’s 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. Link:Washington post