Another Global Heat Record In September; Disasters Pile Up, Too

Once again, more red than blue. September
globally was the warmest on record.

On a global basis, September was the world's hottest on record, according to the National Centers for Environmental Information.

If the above sentence seems familiar, it's because almost every month lately, we break a record for the hottest month, or score in the top two or three. 

Here's the official word from NCEI:

"The September 2020 global land and ocean surface temperature was the highest for September in the 141-year record at 1.75 F above the 20th century average of 59.0 F. This value surpassed the now second highest September temperature that took place in 2015 and 201 by 0.04 degrees."

The seven warmest Septembers on record have all occurred in the last seven years. The 10 warmest Septembers have happened since 2005. 

This was the 44th consecutive September and and 429th consecutive month of above normal global temperatures. That means if you're 35 years old or younger, you've never seen a month on a global basis that was cooler than average. 

The warmest places, relative to average, were Siberia, central and eastern Europe, western North America, central South America and Australia.

As always, a few areas were cooler than average, despite the global heat. But not by much. Greenland, parts of eastern North America, western Asia, the southern Indian Ocean and eastern Pacific Ocean, mostly near and off the west coast of South America.

That bit about the eastern Pacific is telling. It's a sign that a La Nina is under way.  La Ninas tend to cool the eastern Pacific and also suppress global temperatures a bit, too. That makes it rather remarkable that September broke the global heat record.

The opposite phenomenon, La Nino, features warmer than normal water in the eastern Pacific and tends to warm the world a bit. That's when you usually get monthly global heat records.

The past five years of repeated record global temperatures concern climate scientists James Hansen and Makiko Sato.

For the past 50 years or so, the world has warmed at a relatively steady clip of 0.18 degrees Celsius per decade. For the past five years or so, it's gone much faster than that rate.

The two scientists think that the abrupt change has something to do with atmospheric aerosols, which are tiny particles floating in the air. 

There are always such particles in the air, made up of a multitude of different types of material. Exactly what's going on with aerosols, and how that might be affecting climate trends, is not entirely clear. 

It might be that there's a decrease in the type of particles that block the sun and its heat. It's another topic scientists need to get a handle on.   

Serious damage in Louisiana from Hurricane Laura in 
August. It was one of 16 billion dollar disasters in
the United States so far this year. 

Meanwhile, expensive disasters continued to unfold during September. 

Jeff Masters, writing in Yale Climate Connections, says the United States this year has suffered 16 weather-related disasters costing $1 billion or more. 

That ties the record for the most in one year. It also doesn't include recent Hurricane Delta, which might also have cost $1 billion.  Plus, we have more than two months to go during which more big disasters might strike. 

The 16 disasters killed 188 people and caused a total of $46 billion in damage, Masters wrote.

There is an increasing trend in such disasters. A large part of it is that we're building more and bigger homes and businesses that are vulnerable to storms, wildfires and such.  Also, some of these disasters are getting more intense, and more capable of damage, in part because of climate change.