Share

Want to Slow Sea Level Rise? Curb 4 Pollutants

Becky Oskin
Published: April 15, 2013

Andrew Kemp, Yale University

Sea level rise is swamping coasts; Rodanthe in the Outer Banks of North Carolina is pictured.

Sharp reductions in short-lived airborne pollutants could significantly slow sea level rise before 2100, a new study finds.

The four pollutants — black carbon, methane, ozone and hydrofluorocarbons — all cycle through the atmosphere more quickly than carbon dioxide, which lasts for centuries in the troposphere, the part of the atmosphere we live in and breathe. Carbon dioxide is the main culprit in Earth's warming temperatures, which impacts sea level rise both by the expansion of water as it warms and by the melting of glacial ice.

Cutting the air pollutants, which all also act to trap heat in the atmosphere and last anywhere from a week to decade, worldwideby 30 to 60 percent over the next several decades would lower predicted sea level rise by 22 to 42 percent by 2100, according to the study, published April 14 in the journal Nature Climate Change.

(MORE: Air Pollution Bigger Killer Than AIDS, U.N. Says)

Sea levels are expected to rise between 7 inches to 6.6 feet this century, according to a 2007 assessment by the Intergovernmental Panel on Climate Change. The higher tides will bring more coastal flooding and bigger storm surges, the IPCC report warned.

Though the four pollutants are known contributors to climate change, policymakers tend to focus on carbon dioxide, the 800-pound-gorilla of global warming, when it comes to reducing emissions. Frustrated at the slow pace of negotiations on cutting carbon dioxide, the research team decided to investigate other ways to slow the planet's warming, according to a statement from the National Center for Atmospheric Research (NCAR) in Boulder, which participated in the research.

"To avoid potentially dangerous sea level rise, we could cut emissions of short-lived pollutants even if we cannot immediately cut carbon dioxide emissions," NCAR's Aixue Hu, lead study author, said in the statement. "This new research shows that society can significantly reduce the threat to coastal cities if it moves quickly on a handful of pollutants."

The study models relied on emissions cuts beginning in 2015. Hu and his colleagues tested the effects of lowering atmospheric levels of the four gases and particles by 30 to 60 percent over the next several decades, the steepest cuts believed possible by economists, the study said.

Even if these cuts are made, though, carbon dioxide is still the main threat, the authors said.

"It must be remembered that carbon dioxide is still the most important factor in sea level rise over the long term," Warren Washington, a study co-author at NCAR, said in the statement. "But we can make a real difference in the next several decades by reducing other emissions."

MORE ON LIVESCIENCE.COM:

MORE: Amazing Rainbow Waterfalls

Glow sticks are used to capture this colorful long-exposure photo, featuring several waterfalls from Northern California. The series is entitled Neon Luminance. (Sean Lenz and Kristoffer Abildgaard)

Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.


Featured Blogs

Tropical Depression Nine Dissipates

By Dr. Jeff Masters
October 23, 2014

Small and weak Tropical Depression Nine dissipated over Mexico's Yucatan Peninsula Wednesday night, shortly after making landfall near 8 pm EDT Wednesday October 22, 2014 on the western shore of the peninsula. By Saturday, some of the spin associated with TD 9 may emerge over the Western Caribbean, and we should carefully watch this area on Sunday and Monday for tropical cyclone development--though none of our reliable models were predicting development in their Thursday morning runs.

September 2014 Global Weather Extremes Summary

By Christopher C. Burt
October 22, 2014

September was globally the warmest such on record according to NASA and NOAA. Deadly flooding affected the Kashmir region of India and Pakistan as well as in southern France, China, and Serbia. Record heat occurred in Jakarta, Indonesia and south-central Canada. It was the driest September on record for the U.K.

Live Blog: Tracking Hurricane Arthur as it Approaches North Carolina Coast

By Shaun Tanner
July 3, 2014

This is a live blog set up to provide the latest coverage on Hurricane Arthur as it threatens the North Carolina Coast. Check back often to see what the latest is with Arthur. The most recent updates are at the top.

Tropical Terminology

By Stu Ostro
June 30, 2014

Here is some basic, fundamental terminology related to tropical cyclones. Rather than a comprehensive and/or technical glossary, this represents the essence of the meaning & importance of some key, frequently used terms.

2013-14 - An Interesting Winter From A to Z

By Tom Niziol
May 15, 2014

It was a very interesting winter across a good part of the nation from the Rockies through the Plains to the Northeast. Let's break down the most significant winter storms on a month by month basis.

What the 5th IPCC Assessment Doesn't Include

By Angela Fritz
September 27, 2013

Melting permafrost has the potential to release an additional 1.5 trillion tons of carbon into the atmosphere, and could increase our global average temperature by 1.5°F in addition to our day-to-day human emissions. However, this effect is not included in the IPCC report issued Friday morning, which means the estimates of how Earth's climate will change are likely on the conservative side.