Senior Meteorologist Stu Ostro of Weather.com explained that the extreme highs are related to very high pressure in the atmosphere just a few miles above the Earth’s surface. While there have always been extremes in weather, Ostro takes pains to point out the difference between our current extremes and what has happened in the past:

What’s changing now is the nature of those extremes, and also what’s important is the context.This time, the extreme drought, heat, and wildfires are occurring along with U.S. extremes this year in rainfall, snowfall, flooding, and tornadoes, and many other stunning temperature and precipitation extremes elsewhere in the world in recent years as well as, as I posted on my TWC Facebook “fan” page, record-shattering 500 millibar heights in high latitudes. And all of this is happening while there’s an alarming drop in the amount of Arctic sea ice.

The nature and context of the extremes is the difference between the 1930s and now.

In the southern U.S. states like Arizona and Texas have been experiencing extreme temperatures since before summer even officially started. Because the soil has been so dry, this has made the temperatures even hotter because no energy from the sun goes into evaporating the moisture. The intense drought has cause massive dust storms, also known as haboobs, in Arizona, with one that was nearly 50 miles wide swallowing Phoenix. Just north of this, states in the Central U.S. are experiencing the other extreme: high rainfall and flooding.

Numbers from the National Oceanic and Atmospheric Administration show that the Earth is 1.5 degrees warmer than it was in the 1970s, and the new average normals in 48 states have gone up. Heat has become the number one weather-related killer in the U.S. Heidi Cullen, a scientist at Climate Central and author of ‘The Weather of the Future: Heat Waves, Extreme Storms, and Other Scenes From a Climate-Changed Planet,’ explains what the “new normals” mean in a New York Times Op-Ed piece:

Drawing from methods used in epidemiology, a field of climate research called “detection and attribution” tests how human actions like burning fossil fuels affect climate and increase the odds of extreme weather events.Heat-trapping pollution at least doubled the likelihood of the infamous European heat wave that killed more than 30,000 people during the summer of 2003, according to a study in the journal Nature in 2004. And if we don’t ease our grip on the climate, summers like that one will likely happen every other year by 2040, the study warned. Human actions have warmed the climate on all seven continents, and as a result all weather is now occurring in an environment that bears humanity’s signature, with warmer air and seas and more moisture than there was just a few decades ago, resulting in more extreme weather.

The snapshots of climate history from NOAA can also provide a glimpse of what’s in store locally in the future. Using climate models, we can project what future Julys might look like. For example, by 2050, assuming we continue to pump heat-trapping pollution into our atmosphere at a rate similar to today’s, New Yorkers can expect the number of July days exceeding 90 degrees to double, and those exceeding 95 degrees to roughly triple. Sweltering days in excess of 100 degrees, rare now, will become a regular feature of the Big Apple’s climate in the 2050s.

In other words, get used to it. Because the days aren’t getting any cooler.

Via Treehugger and Weather.com

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