extreme rainfall events and climate change
TRANSCRIPT
T. R. Ramachandran
23 January 2016
Extreme Rainfall
Presented during “Chennai’s Legacy: A conversation on governance, environment and society following the 2015 floods”
“Freak Weather”
“Perfect Storm”
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The highest daily rainfall in a century. Freak weather conditions on one day. The hottest-ever Indian Ocean. The strongest-ever El Niño. The hottest year on record. The bad news is that a perfect storm of meteorological conditions combined to create Chennai’s worst-ever deluge last week, exacerbated in no small part by civic infrastructure pushed to its limit and systemic dysfunction
A Question
How Many States in the US had Monthly Record-Breaking Rainfall in 2015?
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2015: Record Monthly Rainfall in US # State Town/City Record Broken in Highest In ~
1 North Carolina Charlotte Nov 137 years
2 Texas Dallas/Fort-Worth & others +
State May, Nov, Full Yr 117 years
3 Oklahoma Oklahoma City + State May, Nov 120 years
4 New Jersey Millville Jun 120 years
5 Illinois State Jun 120 years
6 Missouri St. Louis, Springfield + State Jun, Nov, Dec, Full Yr 141 years
7 South Carolina Charleston + other towns Oct 125 years
8 Maryland Baltimore Jun 142 years
9 Minnesota Many towns May 130 years
10 Iowa Sioux City Nov 100 years
11 California Los Angeles, San Diego Jul 138 years
12 Colorado Boulder, Col. Springs + State Feb, May 121 years
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2015: Record Monthly Rainfall in US # State Town/City Record Broken in Highest In ~
13 Nebraska Lincoln May 100 years
14 Arkansas Fort Smith + others May, Dec, Full Yr 133 years
15 Vermont Montpelier, Mt. Mansfield Jun 120 years
16 Ohio Several towns Jun 120 years
17 Hawaii Honolulu August 138 years
18 Massachusetts Boston, Worcester Feb, Winter 142 years
19 Indiana Fort Wayne + State Jun 120 years
20 Oregon Portland Dec 75 years
21 Florida Miami-Dade Dec 83 years
- Contiguous US Entire country May 121 years
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Source: http://www.kanvz.com/trr/canvas/1444143085761
2015: Record Monthly Rainfall in US # State Town/City Record Broken in Highest In ~
1 North Carolina Charlotte Nov 137 years
2 Texas Dallas/Fort-Worth & others +
State May, Nov, Full Yr 117 years
3 Oklahoma Oklahoma City + State May, Nov 120 years
4 New Jersey Millville Jun 120 years
5 Illinois State Jun 120 years
6 Missouri St. Louis, Springfield + State Jun, Nov, Dec, Full Yr 141 years
7 South Carolina Charleston + other towns Oct 125 years
8 Maryland Baltimore Jun 142 years
9 Minnesota Many towns May 130 years
10 Iowa Sioux City Nov 100 years
11 California Los Angeles, San Diego Jul 138 years
12 Colorado Boulder, Col. Springs + State Feb, May 121 years
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Eliminated extreme drought of past 5 years 35T gallons, ~27 yrs drinking water for world
Eliminated extreme drought of past 5 years
Across NJ, 4th wettest Jun after 3rd driest May
Eliminated drought in several parts of state
Wettest months usually Jan-Mar, more rain in 1 day in Jul than all of Jan after worst drought in > a century
Wettest month usually Mar
Wettest months usually Sep-Nov
Wettest month usually Jun
Wettest months usually Aug-Sep
Wettest month usually May
Wettest months usually Jul-Aug
Sixth “1-in-1000 year” event since 2010
Should We Keep Assuming These Are Just “Freak” Events?
A Global Data Set from MunichRe
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Source
Extreme Rainfall Events in the US
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Source
nca2014.globalchange.gov
A Key Factor
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Annual Average Worldwide T
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Source
Averages are Misleading - I
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Increasing Likelihood of Extreme Events
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Averages are Misleading - II
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Worldwide T Anomalies (2015)
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Source
Local T Anomalies
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Averages are Misleading - III
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Here’s What is Happening in the Oceans – That Cover 70% of Earth’s Surface
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Source
The Vast Majority of Warming is Actually Occurring in Our Oceans
Staggering Level of Ocean Warming Has Widespread Consequences
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Source
The Heat Trapped in Our Oceans Since Recorded History Has Doubled Since 1997
How Much Heat?
What is Causing Global Warming?
We’ve Changed Our Atmosphere Radically Since the Industrial Revolution
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Source
But Isn’t El Nino The Cause of Anomalous Warming?
El Nino and La Nina
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Source
El Nino and La Nina
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Source
In Short
Less “Freak”, Less “Perfect Storm”
More “Climate Change”
So, Where is the Excess CO2 Coming From?
What We Need to Do
Takeaways 1. Focus more aggressively on switching from coal, oil,
gas to solar, wind, hydro (and if needed, nuclear) Collective effort required, driven by government
Balance needs of development with needs of survival and livelihoods
2. Make the soil around our homes and buildings strongly water-absorbent – esp. in towns and cities The right soil, the right vegetation, the right trees for the location
Allows water to seep through and get distributed slowly to water respositories
Ideally, do not build near large water bodies or low lying areas
3. Listen to experts when it comes to making and enforcing laws that impact the world around us Tap into wealth of research and learning worldwide
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