The Impact of Climate Change on the Predictability of the

Indian Monsoon“ Weird things are happening. Certainly monsoons are hitting

in the wrong places at the wrong times, and officials aren’t ready for it. ”

– Devendra Fadnavis, Indian Legislature

Member from NagpurRuthie King, Jennifer Mayer, Sabilah Eboo, and James

Dawson

Take Away ConceptsFor centuries, the culture of India has depended on the

ability to predict the monsoon. Now, global warming may begin to alter the machinery that makes the

monsoon predictable – which could profoundly impact the social and political fabric of the Indian subcontinent.

1). Understanding the Natural Monsoon Cycle

2). How ENSO Impacts India’s Monsoon

3). How the ENSO/Warming Relationship Damages Predictability

4). How Global Warming Itself Makes the Monsoon Less Predictable

5). Conclusions

6). Problems of Predictability

The Natural Monsoon Process (Healy 2007):

• Specific Heat of Water Higher Than Land

• In Summer, Land Warms Faster than Ocean

• Warm Air Rises, Causing Low Pressure

• Low Pressure Pulls Wind Toward Land

• Wind Carries Warm, Ocean Moisture to LandIn India, this “natural process is intensified” (Hahn and others

1975) because the air is trapped by the Himalayas and forced to rise. As it rises, it cools and, due to the adiabatic lapse rate,

condenses to create more rain. Hahn D, Manabe S. 1975. The Role of Mountains in the South Asian Monsoon Circulation. Journal of the Atmospheric

Sciences 32: 1515-1540.

Healy, Mark. South Asia: Monsoons.  World Regional Geography, Lecture: South Asia [Internet]. Fall 2007 [cited 30 October, 2007]; 5:00.  Available from: http://library.osu.edu/sites/guides/cbegd.php.

Natural Monsoon Cycle

http://images.google.com/imgres?imgurl=http://www.geo.arizona.edu/Antevs/ecol438/monsoon.gif&imgrefurl=http://www.geo.arizona.edu/Antevs/ecol438/

lect03a.html&h=428&w=402&sz=118&hl=en&start=9&um=1&tbnid=52m1400nRohYJM:&tbnh=126&tbnw=118&prev=

Natural ENSO/Monsoon Relationship

ENSO variability impacts temperatures in the Indian Ocean, which impacts rainfall conditions in India. The

Clausius-Clapeyron relation states that warm air can hold more water. Thus, “the natural ENSO/monsoon relationship” (Annamalai and others 2004) is:

El Nino conditions create drought, which weakens the monsoon La Nina conditions create rain, which

further intensifies the monsoonAnnamalai H, Xie SP, McCreary JP. 2004. Impact of Indian Ocean Sea Surface Temperature on

Developing El Nino. International Pacific Research Center at the University of Hawaii Honolulu.

http://images.google.com/imgres?imgurl=http://www.pmel.noaa.gov/tao/elnino/gif/winter.gif&imgrefurl=http://www.pmel.noaa.gov/tao/elnino/impacts.html&h=302&w=533&sz=10&hl=en&start=13&um=1&tbnid=u6mf_pjLNuSLeM:&tbnh=75&tbnw=132&prev=

Global Conditions during El Nino Summers

Global Warming Will Lead to Less Predictability in the ENSO/Global

Warming Relationship

Scientists are divided over how global warming will impact ENSO.

One camp thinks that global warming will lead to near-constant El Nino conditions. They believe that the ocean will warm uniformly, which will create

an ocean-atmosphere coupling to sustain El Nino. If this happens, the monsoon may occur less frequently and with less power.

Another thinks that global warming will lead to near-constant La Nina conditions. They believe the western Pacific will warm most, which will

strengthen the natural Walker Cell and sustain La Nina. If this happens, the monsoon may occur for a longer amount of time with more power. Pant, GB. 2003. Long-Term Climate Variability and Change Over Monsoon Asia. Indian Institute of Tropical

Meteorology 7(3): 125-134.

www.tropmet.res.in/~jsc/IITM-Brochure.pdf

La Nina = Flooding

El Nino = Drought

Conclusions from Part 1:

India relies in part on the natural cycle of ENSO variability in order

to predict the timing and severity of the monsoon. As

global warming changes ENSO, these predictions will become

less accurate.

The ultimate result will be more surprising and damaging

monsoons.

Global Warming and the MonsoonIn 2001, the Japanese Centre for Climate

System Research and the National Institute for Environmental Studies ran a model which

coupled atmosphere-ocean general circulation around India to simulate India's monsoon as closely as possible in order to

project climate change onto it. They projected A1, A2, B1 and B2.

The summed average of the models “suggests an annual mean area-averaged

surface warming over the Indian subcontinent to range between 3.5 and

5.5°C over the region during 2080s." (Murari and others 2001)

http://144.16.79.155/currsci/nov102001/1196.pdf

Climate change will have a greater impact on India's winter, with a "5 to 25% decline in rainfall," thus increasing the extreme anti-

monsoon drought which already occurs during the winter months.  (Murari and others 2001)  

The climate change during summer will increase land temperatures and increase the pressure gradient between the land and ocean. This will intensify the monsoon and increase rainfall "10 - 15%...

over India” (Murari and others 2001)  

The model indicates intensifying seasons, but it also shows an increased volatility and unpredictability of the cycle.  India relies

on knowing when the floods and droughts will occur, but with climate change, "the date of onset monsoons over central India

could become more variable" (Murari and others 2001).

http://144.16.79.155/currsci/nov102001/1196.pdf

Conclusions from Part 2:

India relies on predictable pressure gradients and temperatures to predict when

the monsoon will come and how severe it will be.

As global warming continues, these temperatures and pressures will become less predictable. The monsoon will thus become more volatile and its arrival will

become less foreseeable.

A2: 2071-2100; www.defra.gov.uk/ENVIRONMENT/climatechange/internat/devcountry/pdf/india-climate-2-climate.pdf

On the whole, we have to take long-term monsoon predictions with a grain of salt.

 But, according to Kurzweil’s “Singularity Law of Accelerating Returns” (as explained by Peter Eisenberger), knowledge is like a puzzle; we open new doors with each new

piece.

In this sense, the research that climatologists are currently doing on ENSO /

global warming linkages is promising. Although the exact semantics of the

interaction is unclear, new research will yield new ideas to be researched until, ultimately,

the problem is understood. 

Bibliography:Hahn D, Manabe S. 1975. The Role of Mountains in the South Asian Monsoon Circulation. Journal

of the Atmospheric Sciences 32: 1515-1540.

Healy, Mark. South Asia: Monsoons.  World Regional Geography, Lecture: South Asia [Internet]. Fall 2007 [cited 30 October, 2007]; 5:00.  Available from: http://

library.osu.edu/sites/guides/cbegd.php.

Annamalai H, Xie SP, McCreary JP. 2004. Impact of Indian Ocean Sea Surface Temperature on Developing El Nino. International Pacific Research Center at the University of Hawaii Honolulu.

Pant, GB. 2003. Long-Term Climate Variability and Change Over Monsoon Asia. Indian Institute of Tropical Meteorology 7(3): 125-134.

Battisti D,  Sarachik E. Impacts of El Niño and benefits of El Niño prediction. National Oceanic and Atmospheric Administration [Internet]. 2007 [cited 2007 Nov 8]; 1-4. Available from: http://

www.pmel.noaa.gov/tao/elnino/impacts.html. 

Kumar K, Kumar R, Soman M. Seasonal Forecasting of Indian Summer Monsoon Rainfall: A Review. Indian Institute of Tropical Meteorology [Internet]. 2007 [cited 2007 Nov 8]; 1-8. Available from:  http://www.tropmet.res.in/%7Ekolli/MOL/Forecasting/frameindex.html.

Meise CJ, Johnson DL, Stehlik LL, Manderson J, Shaheen P. 2003. Growth rates of juvenile Winter Flounder under varying environmental conditions. Trans Am Fish Soc 132(2):225-345.

Murari L, Nazawa T, Namori S, Harasawa H, Takahashi K, Kimoto M, Abe-Ouchi A, Nakajima T, Takemura T, Numaguti A. 2001. Future Climate Change: Implications for Indian Summer

Monsoon and its Variability. Current Science 81(9): 1197-1207.