Top misconceptions about El Niño and La Niña
Forecasts by the International Research Institute for Climate and Society and other institutions show that a weak El Niño has developed in the equatorial Pacific, and is likely to continue evolving with warmer-than-normal conditions persisting there until early 2010.
Given this,the IRI is trying to use the opportunity to educate people about El Niño and its cooler sister, La Niña. We decided to do this by addressing some common misconceptions that our scientists come across when talking with people about these important climate phenomena. Such “list” stories are quite effective on the web and are favorites for people to spread via sharing and social networks.
I also kicked off a series of brief audio interviews with our top scientists to discuss how El Niño affects food production, health, water availability and other social concerns. By releasing these over a few months, I can keep communicating to journalists, policy makers, etc., that IRI staff has a deep and broad level of knowledge on the topic. Below are the first few paragraphs of the story. Enjoy, and share!
Forecasts by the IRI and other institutions show that a weak El Niño has developed in the equatorial Pacific, and is likely to continue evolving with warmer-than-normal conditions persisting there until early 2010.What exactly is this important climate phenomenon and why should society care about it? Who will be most affected? We address these questions as well as clear up some common misconceptions about El Niño, La Niña, and everything in between!
First, the basics.
El Niño refers to the occasional warming of the eastern and central Pacific Ocean around the equator. The warmer water tends to get only 1 to 3 degrees Celsius above average sea-surface temperatures for that area, although in the very strong El Niño of 1997-98, it reached 5 degrees or more above average in some locations. La Niña is the climatological counterpart to El Niño– a yin to its yang, so to speak. A La Niña is defined by cooler-than-normal sea-surface temperatures across much of the equatorial eastern and central Pacific. El Niño and La Niña episodes each tend to last roughly a year, although occasionally they may last 18 months or longer.
The Pacific is the largest ocean on the planet, so a significant change from its average conditions can have consequences for temperature, rainfall and vegetation in faraway places. In normal years, trade winds push warm water-and its associated heavier rainfall-westward toward Indonesia. But during an El Niño, which occurs on average once every three-to-five years, the winds peter out and can even reverse direction, pushing the rains toward South America instead. This is why we typically associate El Niño with drought in Indonesia and Australia and flooding in Peru. These changing climate conditions, combined with other factors, can have serious impacts on society, such as reduced crop harvests, wildfires, or loss of life and property in floods. There is also evidence that El Niño conditions increase the risk of certain vector-borne diseases, such as malaria, in places where they don’t occur every year and where disease control is limited.
During either an El Niño or a La Niña, we also observe changes in atmospheric pressure, wind and rainfall patterns in different parts of the Pacific, and beyond. An El Niño is associated with high pressure in the western Pacific, whereas a La Niña is associated with high pressure in the eastern Pacific. The ’seesawing’ of high pressure that occurs as conditions move from El Niño to La Niña is known as the Southern Oscillation. The oft-used term El Niño-Southern Oscillation, or ENSO, reminds us that El Niño and La Niña episodes reflect changes not just to the ocean, but to the atmosphere as well.
ENSO is one of the main sources of year-to-year variability in weather and climate on Earth and has significant socioeconomic implications for many regions around the world. The development of a new El Niño episode in recent months offers an opportunity to clear up some common misconceptions about the climate phenomenon:
El Niño periods cause more disasters than normal periods. On a worldwide basis, this isn’t necessarily the case. But ENSO conditions do allow climate scientists to produce more accurate seasonal forecasts and help them better predict extreme drought or rainfall in several regions around the globe. (Read a 2005 paper on the topic here.)
On a regional level, however, we’ve seen that El Niño and La Niña exert fairly consistent influences on the climate of some regions. For example, El Niño conditions typically cause more rain to fall in Peru, and less rain to fall in Indonesia and Southern Africa. These conditions, combined with socioeconomic factors, can make a country or region more vulnerable to impacts.
“On the other hand, because El Niño enhances our ability to predict the climate conditions expected in these same regions, one can take advantage of that improved predictability to help societies improve preparedness, issue early warnings and reduce possible negative impacts,” says Walter Baethgen who runs IRI’s Latin America and the Carribbean regional program.
El Niño and La Niña significantly affect the climate in most regions of the globe. Actually, they significantly affect only about 25% of the world’s land surface during any particular season, and less than 50% of land surface during the entire time that ENSO conditions persist.
Regions that are affected by El Niño and La Niña see impacts during the entire 8 to 12 months that the climate conditions last. No. Most regions will only see impacts during one specific season, which may start months after the ENSO event first develops. For example, the current El Niño may cause the southern U.S. to get wetter-than-normal conditions in the December to March season, but Kenyans may see wetter-than-normal conditions between October and December.
El Niño episodes lead to adverse impacts only. Fires in southeast Asia, droughts in eastern Australia, flooding in Peru often accompany El Niño events. Much of the media coverage on El Niño has focused on the more extreme and negative consequences typically associated with the phenomenon. To be sure, the impacts can wreak havoc in developing and developed countries alike, but El Niño events are also associated with reduced frequency of Atlantic hurricanes, warmer winter temperatures in northern half of U.S., which reduce heating costs, and plentiful spring/summer rainfall in southeastern Brazil, central Argentina and Uruguay, which leads to above-average summer crop yields.
Read the rest of the story and listen to an audio interview with IRI’s Director-General, Steve Zebiak.
Audio slideshow on Index insurance
Index insurance for development and disaster management from IRI Video Pages on Vimeo.
This is our latest audio slideshow, which Jason and I produced in record time for the launch of the Climate and Society publication at the 2009 Global Humanitarian Forum. I’ve written it before, and I’ll write it again: audio slideshows are a fantastic, low budget way to add pop to your stories. And we’ve found they’re much more virulent than traditional web stories. At IRI, we use Vimeo to share our multimedia.
Climate information hot topic in World Disasters Report
The latest World Disasters Report by the International Federation of Red Cross and Red Crescent Societies argues that disaster-relief agencies need to shift focus from expensive response operations to cost-effective prevention measures. An important component of this, the report details, is using climate records, monitoring and forecasts to make planning decisions days, weeks, even months ahead. This, of course, is what the International Research Institute for Climate and Society is all about, and our work is mentioned numerous times throughout the document.
Read the whole story on the IRI home page.
Climate training for health professionals
We kicked off the second annual Summer Institute this week. Twelve public-health professionals and climate scientists from ten countries are visiting the Lamont campus, where the International Research Institute for Climate and Society is based, to learn how to use climate information to make better decisions for planning and disease prevention.
It is essential for the health community to better understand the role climate plays in determining the fundamentals of health – air, water and food – as well as its role as a driver of specific outcomes related to infectious disease, says Madeleine Thomson, who runs both the health and Africa programs at the IRI and is one of the brains behind the two-week training course.
“After all, health is fundamental to the way we understand human well-being, and a key indicator of sustainable development. Here, we like to think of climate as both a challenge and a resource,” she says.
Extreme weather events or prolonged droughts are often associated with negative outcomes, Thomson says, but by understanding climate and its associated impacts and potential predictability, decision makers can start responding proactively to climate challenges. In some situations, they can even get ahead of the game, she says. At IRI, we call it climate risk management.
Read more about the Summer Institute on Climate Information for Public Health here.
AMNH biobulletin on peatland fires
The Science Bulletins crew at the American Museum of Natural History has created brief but excellent feature about the work the International Research Institute for Climate and Society is doing in Central Kalimantan (see an earlier post for a description of that work). The piece really connects the way in which satellite and remotely-sensed data can be used to inform decision making for societally relevant issues. The AMNH became interested after viewing the audio slideshow below, which we put together after our trip to the region last year.
Reducing Indonesia’s Peatland Fires from IRI Video Pages on Vimeo.
Filed under IRI related | Comment (0)IPCC Chief Rajendra Pachauri new IRI Board Chairman
Rajendra K. Pachauri, chairman of the Intergovernmental Panel on Climate Change, which shared the 2007 Nobel Peace Prize with former U.S. Vice President Al Gore, has agreed to serve as the next board chairman of the International Research Institute for Climate and Society.
“I think there’s so much that the IRI can do. Climate change gives us an opportunity to reengage with rest of world and the IRI is uniquely placed to do that,” Pachauri said during IRI’s board meeting last week, the first in which he served as chairman.
Columbia University hosted a small event commemorating Pachauri’s new role in the institution, as well as honoring outgoing chairman and respected climate scientist Michael B. McElroy, from Harvard University.
“We are very appreciative of Mike’s support and counsel, which have helped build the institution from its infancy to where it is today,” said IRI Director-General Stephen E. Zebiak. “And we are both excited and honored to welcome Dr. Pachauri as our board chair. He’s a recognized global leader in climate affairs, and will assist us in engaging the growing international agenda on adaptation and climate risk management.”
The Earth Institute’s Jeffrey Sachs, also an IRI board member, praised the IRI’s mission, which is to enhance society’s ability to understand, anticipate and manage climate risk in order to improve human welfare.
“The IRI was 13 years ahead of its time in seeing the importance of linking climate and society,” he said. “The world is catching up now. Climate-change adaptation is front and center, and no other institution in the world has pioneered this field with such depth and skill.”
Visit the IRI’s Governance pages to learn more about the institution’s board and its role.
Photo: Francesco Fiondella
visual communication + science
I have been asked to give a brownbag seminar on using visuals to communicate science at the International Research Institute for Climate and Society. Should make for an interesting discussion. As I go about researching the talk, I’m sure I’ll find some excellent resources on information graphics, visual communication and design, which I’ll post on my tumblr site Communicating Science.
Please feel to use the comments section here to share any good links you’ve come across.
Posted via email from communicating science
Filed under IRI related | Comment (0)Climate and coconuts – a Sri Lanka story
The full story is available on the International Research Institute for Climate and Society (IRI) web site.
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