Climate Denial Crock of the Week

UPI:

The coasts of the southeastern United States and the Gulf of Mexico are seeing record sea-level rise caused by man-made climate change and a peak in natural weather variability, according to a new study out Monday.

Researchers at New Orleans’ Tulane University warn that the annual sea rise of half an inch detected over the past 12 years was further proof of the “urgency of the climate crisis for the Gulf region” and called for a major, sustainable effort to combat it.

The coasts of the southeastern United States and the Gulf of Mexico are seeing record sea-level rise caused by man-made climate change and a peak in natural weather variability, according to a new study out Monday.

Researchers at New Orleans’ Tulane University warn that the annual sea rise of half an inch detected over the past 12 years was further proof of the “urgency of the climate crisis for the Gulf region” and called for a major, sustainable effort to combat it.

“Instead, we found that the acceleration is a widespread signal that extends from the coasts of the Gulf of Mexico up to Cape Hatteras in North Carolina and into the North Atlantic Ocean and Caribbean Seas, which is indicative for changes in the ocean’s density and circulation.”

The team was able to isolate the different elements contributing to the speeding up of the rate at which sea levels were rising by dissecting field and satellite measurements dating back to 1900.

They discovered that changing wind patterns and ongoing warming are responsible for the expansion of this circulating ocean system, known as the Subtropical Gyre, since 2010. As gyres expand they occupy more space which causes the sea level to rise.
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Monday’s study follows a report published Wednesday in the journal Nature raising new fears about the speed at which the ice sheets are likely to retreat in the future, with implications for rising sea levels.

Researchers from three British universities and the Geological Survey of Norway said they had confirmation that an ice sheet covering Eurasia during the last ice age retreated at a rate many times what they believed was possible, based on satellite measurements of Artic and Antarctic glaciers taken over the past 50 years.

Phys.org:

Changes in air patterns as the world warms will likely push more and nastier hurricanes up against the United States’ east and Gulf coasts, especially in Florida, a new study said.

It’s all about projected changes in steering currents, said study lead author Karthik Balaguru, a Pacific Northwest National Laboratory climate scientist.

“Along every coast they’re kind of pushing the storms closer to the U.S.,” Balaguru said. The steering currents move from south to north along the Gulf of Mexico; on the East Coast, the normal west-to-east steering is lessened considerably and can be more east-to-west, he said.

Overall, in a worst-case warming scenario, the number of times a storm hits parts of the U.S. coast in general will probably increase by one-third by the end of the century, the study said, based on sophisticated climate and hurricane simulations, including a system researchers developed.

The central and southern Florida Peninsula, which juts out in the Atlantic, is projected to get even more of an increase in hurricanes hitting the coast, the study said.

Climate scientists disagree on how useful it is to focus on the worst-case scenario as the new study does because many calculations show the world has slowed its increase in carbon pollution. Balaguru said because his study looks more at steering changes than strength, the levels of warming aren’t as big a factor.

The study projects changes in air currents traced to warming in the equatorial eastern Pacific Ocean, just off the coast of South America. Climate change is warming different parts of the world at different rates, and models show the eastern Pacific area warming more quickly, Balaguru said.

That extra warming sets things in motion through Rossby waves, according to the study—atmospheric waves that move west to east and are connected to changes in temperature or pressure, like the jet stream or polar vortex events.

“I like to explain it to my students like a rock being dropped in a smooth pond,” said University of Albany atmospheric scientist Kristen Corbosiero, who wasn’t part of the study. “The heating is the rock and Rossby waves are the waves radiating away from the heating which disturbs the atmosphere’s balance.”

The wave ripples trigger a counterclockwise circulation in the Gulf of Mexico, which bring winds blowing from east to west in the eastern Atlantic and south to north in the Gulf of Mexico, Corbosiero and Balaguru said.

It also reduces wind shear—which is the difference in speed and direction of winds at high and low altitudes—the study said. Wind shear often decapitates hurricanes and makes it harder for nascent storms to develop.

Less wind shear means stronger storms, Balaguru said.