Hurricane Katrina damage just a dose of what’s to come

Carnegie Institution

19 years ago

Hurricane Katrina damage just a dose of what’s to come
Ken Caldeira
Carnegie Institution release
September 21, 2005

Warm ocean waters fuel hurricanes, and there was plenty of warm water for Katrina to build up strength once she crossed over Florida and moved into the Gulf of Mexico. This image depicts a 3-day average of actual sea surface temperatures (SSTs) for the Caribbean Sea and the Atlantic Ocean, from August 25-27, 2005. Every area in yellow, orange or red represents 82 degrees Fahrenheit or above. A hurricane needs SSTs at 82 degrees or warmer to strengthen. The data came from the Advanced Microwave Scanning Radiometer (AMSR-E) instrument on NASA’s Aqua satellite. The GOES satellite provided the cloud data for this image.

Image Credit: NASA/SVS

Stanford, CA. The kind of devastation seen on the Gulf Coast from Hurricane Katrina may be a small taste of what is to come if emissions of the greenhouse gas carbon dioxide (CO2 ) are not diminished soon, warns Dr. Ken Caldeira of the Carnegie Institution’s Department of Global Ecology in his opening remarks at the 7th International Carbon Dioxide Conference in Boulder, Colorado, September 26, 2005.

If current trends continue, some 5 trillion tons of carbon is expected to be spewed into the atmosphere over the next three centuries from human fossil-fuel burning. It will have serious consequences by warming the planet on average between 7 and 20 degrees Fahrenheit and turning the oceans acidic.

“These global changes would happen so fast they would overwhelm most natural processes and have devastating effects on plant and animal life on land and in the oceans. What we do this decade and the rest of this century will dramatically affect what happens to our planet for thousands of years to come,” Caldeira cautions. “Although centuries seem like a long time, they aren’t when you look at how long it takes organisms to adapt to new conditions. What if people a few centuries ago had knowingly damaged our long-term climate and ocean chemistry for their short-term gain; what would we think of them?” he poses.

With stronger storms like Hurricane Katrina, the causes and effects of global climate change are gaining more public attention. The National Oceanic and Atmospheric Administration (NOAA) is hosting the 7th International Carbon Dioxide Conference in Boulder, Colorado, beginning September 26. Experts from all over the world convene to evaluate methods used to study the CO2 cycle, describe research results, and discuss effective responses to climate change.

Caldeira’s talk follows the opening address given by the Bush administration’s James Mahoney, director of the U. S. Climate Change Science Program. Caldeira sets the stage for the long-term consequences of continued CO2 emissions based on the physics and chemistry of ecological systems, analysis of Earth’s history, and sophisticated climate modeling. He begins with a brief history of carbon-cycle science: In the 19th century, scientists found that the greenhouse gas CO2 could explain why the Earth is not a frozen planet. The gas produces an insulating blanket, which acts like a greenhouse. Some scientists suspected that CO2 played a role in the waxing and waning of the ice ages. Since that time, researchers have developed a much better understanding of the carbon cycle, but the basic science underlying the importance of CO2 for the Earth has been established for over a century.

What is a Category 5 Hurricane? – 21-September-2005
Hurricane Rita just strengthened to a Category 5 hurricane. A Category 5 hurricane is the strongest and most severe class of hurricane. The scale, known as the Saffir-Simpson Hurricane Scale, classifies hurricanes by the intensity of their sustained winds, storm surge and flooding, developed in 1969 by civil engineer Herbert Saffir and National Hurricane Center director Bob Simpson.

Tampa Bay could be hit by 25-foot storm surge in Category 4 hurricane – 16-September-2005
A Category 4 hurricane could cause a storm surge of as much as 25 feet in Tampa Bay, according to a University of Central Florida researcher who is looking at the risks Florida cities face from tidal surges and flooding.

Number of Category 4 and 5 hurricanes has nearly doubled over past 35 years – 16-September-2005
The number of Category 4 and 5 hurricanes worldwide has nearly doubled over the past 35 years, even though the total number of hurricanes has dropped since the 1990s, according to a study by researchers at the Georgia Institute of Technology and the National Center for Atmospheric Research (NCAR). The shift occurred as global sea surface temperatures have increased over the same period. The research appears in the September 16 issue of Science.

Hurricane could hit Los Angeles, San Diego – 8-September-2005
San Diego has been hit by hurricanes in the past and may be affected by such storms in the future according to data from the National Oceanic and Atmospheric Administration (NOAA). While a hurricane in San Diego would likely produce significantly less damage that Hurricane Katrina in New Orleans, it could still exact a high cost to Southern California especially if the region was caught off guard.

Environmental problems worsened Hurricane Katrina’s impact – 31-August-2005
The loss of coastal marshlands that buffer New Orleans from flooding and storm surges may have worsened the impact of Hurricane Katrina.

Hurricanes getting stronger due to global warming says study – 29-August-2005
Late last month an atmospheric scientist at Massachusetts Institute of Technology released a study in Nature that found hurricanes have grown significantly more powerful and destructive over the past three decades. Kerry Emanuel, the author of the study, warns that since hurricanes depend on warm water to form and build, global climate change might increase the effect of hurricanes still further in coming years.

Caldeira addresses the carbon budget—the amount of carbon released to the atmosphere minus that which is locked-up by terrestrial plants as they use carbon for photosynthesis or is absorbed by the oceans. Some of the ocean carbon is used to make skeletons and shells. It is possible that about half of the predicted emissions could be sequestered this way. According to Caldeira, however, the net result of continuing current trends could yield an atmosphere with about five times more CO2 than would have occurred without human-made emissions.

He states that if the planet were to warm by only 3.6 degrees F per century, as suggested by some models, the snow and ice in latitudes near the poles would melt and higher temperature bands would “march poleward” by more than 30 feet (10 meters) per day, affecting everything in the wake. If CO2 from fossil-fuel resources is ultimately released to the atmosphere, the Antarctic and Arctic ice sheets would be at risk of melting, which would cause a rise in sea level potentially over 230 feet (70 meters) over several thousand years.

In addition to the effects from temperature increases, Caldeira discusses how the chemistry of the oceans would be altered. Carbon dioxide dissolves in water to produce carbonic acid—a corrosive agent that would eat away shells and skeletal materials of marine organisms. This ocean acidity could kill off entire species, including those vital to the bottom of the planet’s food chain.

Caldeira emphasizes that “to find comparable events in Earth history, we need to look back tens of millions of years to rare catastrophic events.” He called on international governments, policy-makers, and industry “to act now to meet our responsibility to reduce emissions so we can avoid scenarios of devastation and be proud of how our civilization responded to this global challenge.”

7th International Carbon Dioxide Conference Web site https://www.icdc7.com/

Carnegie’s department of Global Ecology was founded in 2002 on the campus of Stanford University http://globalecology.stanford.edu/DGE/CIWDGE/CIWDGE.HTML Its staff conducts basic research on the interactions among Earth’s ecosystems, land, atmosphere, and oceans to understand how the interactions shape the behavior of the Earth system, including its response to future change. The Carnegie Institution (www.CarnegieInstitution.org) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

This is a Carnegie Institution press release. The original appeared on Sept. 21 2005 here